GLERL Publication Abstracts: FY 2005

ASSEL, R. A. A Laurentian Great Lakes ice cover climatology. Proceedings of the 61st Annual Meeting of the Eastern Snow Conference, Portland, Maine, June 9-11, 2004. 2 pp. (2004).

Composite ice charts, a blend of observations from different data sources (ship, shore, aircraft, and satellite) that cover the entire area of the Great Lakes for a given date, and which may contain some estimated ice cover data, were produced starting in the 1970s. Recently, a 30-winter (1973-2002) set of composite ice charts was digitized, and a multi-winter statistical analysis of the climatology of the ice cover concentration was completed. The result of this analysis was published as an electronic National Oceanic and Atmospheric Administration Great Lakes Ice Atlas, which is available for browsing on the Internet (Assel 2003a). A series of reports (Assel 2004, Assel 2003b, Assel 2003c, Assel et al. 2003, Assel et a!. 2002, Assel and Norton 2001) document and supplement data and products given in the electronic atlas. However, because the atlas contains approximately 1.4-gigabytes of data, much of which is in compressed files, it is not practical to download the entire atlas from the Internet. Therefore, it is available on CD-ROM and DVD formats. To request a copy of the atlas send an email to

ASSEL, R. A. Computerized National Weather Service Great Lakes ice reports for winter seasons 1899-1970. NOAA Technical Memorandum GLERL-130, NOAA, Great Lakes Environmental Research Laboratory, Ann Arbor, MI, 31 pp. (2004).

Historical National Weather Service Great Lakes ice reports were digitized to provide a data set of ice thickness and ancillary ice information in the coastal zone of the Great Lakes for winter seasons from 1899 to 1970. These data are made available here for the first time in a computer compatible format. Temporal and spatial distribution patterns of ice report observations are discussed briefly.

ASSEL, R. A. Great Lakes weekly ice cover statistics. NOAA Technical Memorandum GLERL-133. NOAA, Great Lakes Environmental Research Laboratory, Ann Arbor, MI, 27 pp. (2005).

Data and methods used to calculate weekly ice cover statistics for a 30-winter (1973-2002) base period are documented. Spatial distribution patterns of the maximum, minimum, first quartile, median, and third quartile ice cover statistics are presented and discussed within the context of lake bathymetry ranges. Mild and severe winters are identified for each Great Lake. These data are available free of charge on CD-ROM, DVD, and are also on the Internet at: Anomaly ice charts and other data given here for the first time are available in this report.

ASSEL, R. A. Conditional probability of December and January ice cover at selected Great Lakes shore sites. NOAA Technical Memorandum GLERL-134. NOAA, Great Lakes Environmental Research Laboratory, Ann Arbor, MI, 31 pp. (2005).

The National Weather Service (NWS) in Cleveland, Ohio requested improved information on ice cover for use in making outlooks of early winter ice cover at eight locations in the shore region of the Great Lakes (Fig. 1) (personal communication, Will Kubina). Bilello (1964) developed an empirical water temperature decline model to simulate the date of initial ice formation on bays and harbors. Greene (1983) applied the Bilello model to several sites along the St. Marys River. Assel and Norton (unpublished) applied the model to several additional Great Lakes shore sites, modified it for operational use, and provided it to the NWS in the mid-to-late 1980s. In this paper, empirical freezing degree-day (FDD) conditional probability and linear regression models of spatial average ice cover are described and discussed. These models are applied to the eight sites of interest to the NWS to estimate early winter (December and January) spatial average ice cover.

ASSEL, R. A. Great Lakes ice cover climatology update: Winters 2003, 2004, and 2005. NOAA Technical Memorandum GLERL-135. NOAA, Great Lakes Environmental Research Laboratory, Ann Arbor, MI, 21 pp. (2005).

A 30-winter ice concentration climatology (Assel 2003a) is updated for winters: 2003, 2004, and 2005. Original ice charts are from the National Ice Center and the Canadian Ice Service. These data are quality controlled for over-water grid cell location and ice concentration codes to be consistent with Assel (2003a). Data are available in the form of ASCII grids and graphic files. The 2003, 2004, and 2005 ice cycles are described and discussed briefly within the context of dates of first (last) ice, ice duration, daily lake-averages, and spatial and temporal distribution patterns of ice cover and anomalies.

Bailey, S. A., K. Nandakumar, I. C. Duggan, C. D. A. Van Overdijk, T. H. JOHENGEN, D. F. REID and H. J. MacIsaac. In situ hatching of invertebrate diapausing eggs from ships' ballast sediment. Diversity and Distributions 11:453-460 (2005).

Ships that enter the Great Lakes laden with cargo carry only residual ballast water and sediment in ballast tanks. These ships are designated 'no ballast on board' (NOBOB) and constitute > 90% of inbound traffic. We conducted in situ experiments using emergence traps to assess the viability and the introduction potential of invertebrate diapausing stages present in ships ballast sediment. All trials commenced while vessels operated on the lower lakes (Erie, Ontario) and were completed 6–11 days later at ports on the upper lakes (Michigan, Lake Superior). Eight trials were conducted on four ships using five different ballast sediments. Hatching was observed on every ship, although not from all sediments on all ships. Overall hatch rates were very low (0.5 individuals per 500 g sediment), typically involving activation of < 0.05% of total eggs present. Five species of rotifers and copepod nauplii were hatched from ballast sediments, although only one or two species typically hatched from any one sediment. Results of this study indicate that hatching of diapausing eggs contained in ballast sediment of NOBOB ships poses a relatively low risk of invasion to the Great Lakes. However, as reproduction may occur in tanks, and non-indigenous species may be involved in numerous introduction events, the risk posed by this vector is small but potentially important. While dormancy is a characteristic enabling enhanced survival during transportation in ballast tanks, it becomes a hindrance for introduction.

BEETON, A. M. Book Review: The Lakes Handbook, Volume 2: Lake Restoration and Rehabilitation. The Quarterly Review of Biology 80(3):371 (2005).

This volume contains 22 articles grouped into five parts: General Issues; Regional Studies; Human Impact on Specific Lake Types; Lake and Catchment Models; and Legal Frameworks. Information on more than 350 lakes (natural and reservoirs) in 40 countries in included. Specific information is presented for 51 lakes. Only one lake in China is included and none for Japan.

Crane, J. L., C. Richards, D. Breneman, S. J. LOZANO and J. A. Schuldt. Evaluating methods for assessing sediment quality in a Great Lakes embayment. Aquatic Ecosystem Health & Management 8(3):323-349 (2005).

A probability-based, sediment quality assessment was conducted during 1995 in the lower St. Louis River Area of Concern, located in western Lake Superior. A regional application of the intensified sampling grid developed for the United States Environmental Protection Agency's Environmental Monitoring and Assessment Program was used to randomly select 90 sites for measuring the following sediment quality indicators: sediment chemistry, physical parameters, sediment toxicity, and benthic macroinvertebrate community structure. Screening methods were used to assess sediment chemistry and sediment toxicity at all sites, whereas more conventional metrics were used at a subset of sites. In addition, sediment quality data were collected from 20 a priori training sites, 10 in low impact areas and 10 in high impact areas. Mean probable effect concentration quotients were calculated for sediment chemistry variables at each site. As the range of mean probable effect concentration quotients values increased, the incidence of sediment toxicity increased. Benthic data from the training sites were used to establish standard criteria for developing two benthic integrity indices based on multimetric analysis and discriminant function analysis. Based on the training site results, the discriminant function analysis categorized the macroinvertebrate community at all random sites as 45 percent low impact and 55 percent high impact. A multimetric approach categorized 55 percent of the random sites as low impact and 36 percent as high impact. Due to the overlap of 95 percent confidence intervals, the multimetric approach also placed 9 percent of the random sites into an indeterminate category. The incidence of high impact sites appears to be primarily due to physical habitat characteristics. This finding was supported by the sediment quality triad assessment of 52 random sites that indicated alteration of the benthic community at 71 percent of sites was probably not due to chemical contamination.

CROLEY, T. E. II, C. He and D. H. LEE. Distributed-parameter large basin runoff model. II: Application. Journal of Hydrologic Engineering 10(3):182-191 (2005).

Following the derivation of a distributed-parameter large basin runoff model from a lumped-parameter version for the Great Lakes in the companion paper, we here apply it to the Kalamazoo River watershed in southwest Michigan. First we review relevant similar efforts and then describe the digitization of the watershed into a network of cells through which watershed internal flows are routed. We present the technology used on the Kalamazoo River to create grids of topography, soils, land use, and vegetation data. We describe the calibration of both lumped-parameter and distributed-parameter runoff models on the Kalamazoo River and use observed spatial data variations in our parameter determinations. We investigate alternative evapotranspiration schemes, spatial parameter patterns, solar insolation interpretations, and temporal scaling and compare model results. We suggest model extensions for future work.

CROLEY, T. E. II. and C. He. Distributed-parameter large basin runoff model. I: Model Development. Journal of Hydrologic Engineering 10(3):173-181 (2005).

We present a case study of modifying an existing macroscale rainfall-runoff model, the large basin runoff model (LBRM), developed at NOAA�s Great Lakes Environmental Research Laboratory, to the microscale in a two-dimensional representation. First, we review the LBRM and then describe changes in several process submodels, which were originally designed specifically for large areas. We also change the model structure so that we may use the LBRM on an individual cell at the microscale within a watershed. We then discuss spatial scaling of model parameters to enable an initial application to the microscale with parameters available from the macroscale. We then organize watershed cells and flow routing and conclude with notes on computer implementation. In the accompanying companion paper, we present details of the model calibration, application, and experimentation on the Kalamazoo River watershed.

CROLEY, T. E. II. Recent Great Lakes evaporation model estimates. Proceedings of the 2005 World Water and Environmental Resources Congress: Impacts of Global Change, Anchorage, AK, May 15-19, 2005. American Society of Civil Engineers, 12 pp. (2005).

NOAA's lumped-parameter Great Lakes continuous evaporation model solves for each day's over-water and over-ice surface fluxes (which in turn are functions of heat storage and ice and water surface temperatures). They include incident short-wave radiation, reflection, evaporative heat transfer (both latent and advected), sensible heat transfer, precipitation heat advection, long-wave radiation exchange, and surface flow advection. The model simultaneously finds daily heat storage and surface temperature with a heat balance, a model of linear temperature rise (or loss) with volume beneath the water surface, an empirical wind mixing model, and a one-dimensional (vertical) superposition of past aged heat additions or losses. The model couples ice formation and loss to lake thermodynamics and heat storage by utilizing both heat and mass balances for the ice pack and boundary conditions of ice-water existence. It simultaneously finds ice temperatures, pack size, and heat transferred between ice pack and both the atmosphere and the water. Since measured whole-lake evaporation is unavailable, the model is calibrated to existing daily water surface temperatures and ice cover, and compared with measured temperature-depth profiles and independently estimated or measured water surface thermodynamic fluxes. Two calibrations are used to apply the model; the first minimizes error with observed water surface temperatures to determine parameters for superposition heat storage, wind mixing, and radiation exchange. The second minimizes error with observed ice cover to determine ice cover parameters. The calibrations alternate until changes in all parameters are insignificant. Presented calibrated parameters result in 1.1–1.6�C root mean square error with water surface temperatures and verify well over a time period independent of the calibration. Example results of the evaporation model include estimated temperature-depth profiles over a year on Lake Michigan, and both a year's worth of daily evaporation and five years' worth of monthly evaporation on Lake Superior. Deep water evaporation characteristics are readily seen and described. Turnovers occur as a fundamental behavior of the model. Hysteresis between heat in storage and surface temperature, observed during the heating and cooling cycles on the lakes, is preserved. The model also correctly depicts lake-wide seasonal heating and cooling cycles, vertical temperature distributions, and other mixed-layer developments.

CROLEY, T. E. II, and C. He. Great Lakes spatially distributed watershed model of water and materials runoff. Proceedings, International Conference on Poyang Lake Wetland Ecological Environment. Advanced Workshop on Watershed Modeling and Water Resources Management, Jiangxi Normal University, Nanchang, Jiangxi, P.R. China, June 27, 2005. 12 pp. (2005).

Prediction of various ecological system variables or consequences (such as beach closings), as well as effective management of pollution at the watershed scale, require estimation of both point and non-point source material transport through a watershed by hydrological processes.  The Great Lakes Environmental Research Laboratory and Western Michigan University are developing an integrated, spatially distributed, physically-based water quality model to evaluate both agricultural non-point source loadings from soil erosion, animal manure, and pesticides, and point source loadings at the watershed level. We are augmenting an existing physically based integrated surface/subsurface hydrology model. It is a two-dimensional, spatially-distributed accounting of moisture in several layers (zones) for every cell (1 square kilometer) of a watershed.  We modified the model to allow flow routing between adjacent cells surface zones, upper soil zones, lower soil zones, and groundwater zones.  We are expanding it, by adding material transport capabilities to it, to include movement of other materials besides water. We will gather information on pollutants in Saginaw Bay watersheds and apply the model to simulate the movement of various materials into the bay, producing estimates useful to ecological system forecasters.

Dermott, R., M. Munawar, R. Bonnell, S. Caron, H. Niblock, T. F. NALEPA and G. Messick. Preliminary investigations for causes of the disappearance of Diporeia spp. from Lake Ontario. In Proceedings of a Workshop on the Dynamics of Lake Whitefish (Coregonus clupeaformis) and the amphipod Diporeia spp. in the Great Lakes. L. C. Mohr and T.F. Nalepa (eds.). Great Lakes Fishery Commission, Technical Report 66, Ann Arbor, MI, 203-232 (2005).

The amphipod Diporeia spp. comprised 60-80% of the benthos in offshore Lake Ontario and was an important food for fish. In eastern Lake Ontario, Diporeia spp. began disappearing in 1993 just after the arrival of dreissenid mussels. We compared survival of Diporeia spp. and Hyalella azteca in sediments from areas where Diporeia spp. populations had vanished with survival in sediments still inhabited. Survival was also examined in the presence of zebra mussel (Dreissena polymorpha) pseudofeces, filtered water from mussel cultures, and added bacteria. The Microtox� test indicated that sediment pore water was not toxic. Sediments from sites with large Dreissena spp. populations (Lake Erie and western Lake Ontario) lowered Diporeia spp. survival. Diporeia spp. and H. azteca responded differently to test sediments and zebra mussel pseudofeces. Pseudofeces added to Lake Superior sediment greatly reduced H. azteca survival but had less effect on Diporeia spp. survival. Added bacteria had little effect on the survival of either species. Sediments exposed to dying Diporeia spp. caused significant mortality suggesting the presence of a pathogen. Diporeia spp. remained common in two inland lakes containing dreissenids indicating that the amphipod can co-exist with the mussels.

Dobiesz, N. E., D. A. McLeish, R. L. Eschenroder, J. R. Bence, L. C. Mohr, M. P. Ebener, T. F. NALEPA, A. P. Woldt, J. E. Johnson, R. L. Argyle and J. C. Makarewicz. Ecology of the Lake Huron fish community, 1970-1999. Canadian Journal of Fisheries and Aquatic Sciences 62:1432-1451 (2005).

We review the status of the Lake Huron fish community between 1970 and 1999 and explore the effects of key stressors. Offshore waters changed little in terms of nutrient enrichment, while phosphorus levels declined in inner Saginaw Bay. Introduced mussels (Dreissena spp.) proliferated and may have caused a decline in Diporeia spp. This introduction could have caused a decline in lake whitefish (Coregonus clupeaformis) growth and condition, with serious repercussions for commercial fisheries. Bythotrephes, an exotic predatory cladoceran, and other new exotics may be influencing the fish community. Sea lampreys (Petromyzon marinus) remained prevalent, but intensive control efforts on the St. Mary�s River may reduce their predation on salmonines. Overfishing was less of a problem than in the past, although fishing continued to reduce the amount of lake trout (Salvelinus namaycush) spawning biomass resulting from hatchery-reared fish planted to rehabilitate this species. Massive stocking programs have increased the abundance of top predators, but lake trout were rehabilitated in only one area. Successful lake trout rehabilitation may require lower densities of introduced pelagic prey fish than were seen in the 1990s, along with continued stocking of hatchery-reared lake trout and control of sea lamprey. Such reductions in prey fish could limit Pacific salmon (Oncorhynchus spp.) fisheries.

EADIE, B. J. and J. A. ROBBINS. Composition and accumulation of recent sediments in Lake Michigan. In State of Lake Michigan (SOLM) - Ecology, Health, and Management. T. Edsall and M. Munawar (eds.). Ecovision World Monograph Series, Aquatic Ecosystem Health and Management Society, 89-111 (2005).

No abstract.

GOSSIAUX, D. C. and P. F. LANDRUM. Toxicokinetics and tissue distributions of non-polar contaminants from aqueous and dietary exposures for the crayfish Pacifastacus leniusculus. NOAA, Great Lakes Environmental Research Laboratory, Ann Arbor, MI, 23 pp. (2005).

The crayfish, Pacifastacus leniusculus, was exposed to dissolved polycyclic aromatic hydrocarbon (PAH) and polychlorinated biphenyls (PCB) congeners in short-term static and flow-thru water-only exposures. The uptake and elimination rate constants were determined for the total body mass and internal organ tissues. The uptake rate coefficient (ku) for whole crayfish (1–2 g) from static water-only exposures ranged from 23.8 to 33.1 ml g-1 h-1 and was negatively correlated with log Kow. Uptake rates varied between tissues and compounds. For example, the ku from static aqueous exposures for the gill tissue ranged from 37.7 to 63.8 ml g-1 h-1 and generally increased with increasing log Kow, while ku from static aqueous exposures for the hepatopancreas ranged from 357.1 to 37.8 ml g-1 h-1 and decreased with increasing log Kow. The elimination rate constant (ke) for whole crayfish ranged from 0.001 to 0.013 h-1 and decreased with increasing log Kow. Similarly, the ke values for other individual tissues decreased with increasing log Kow. In addition to the aqueous exposures, crayfish were exposed via ingestion to zebra mussel, Dreissena polymorpha, tissue pre-exposed to radiolabeled contaminants. The percent absorption efficiency (%AE) ranged from 91.2 to 96.5%, and the % AE increased with increasing log Kow.

Green, S. A. and B. J. EADIE. Introduction to special section: Transport and transformation of biogeochemically important materials in coastal waters. Journal of Geophysical Research 109(C10S01):2 pp. (2004).

Two projects in the Laurentian Great Lakes were funded under the Coastal Ocean Processes Program. In Lake Superior the Keweenaw Interdisciplinary Transport Experiment in Superior (KITES) focused on a region dominated by a strong coastal jet, and a sister project in Lake Michigan, Episodic Events—Great Lakes Experiment (EEGLE), concentrated on the biogeochemical effects of a major plume of resuspended sediment that occurs annually in the southern portion of the lake.

Greenberg, M. S., G. A. Burton Jr., P. F. LANDRUM, M. T. Leppanen and J. V. K. Kukkonen. Desorption kinetics of fluoranthene and trifluralin from Lake Huron and Lake Erie, USA, sediments. Environmental Toxicology and Chemistry 24(1):31-39 (2005).

Desorption kinetics were determined for fluoranthetie (FLU) and trifluralin (TF) spiked onto Lake Erie and Lake Huron, USA, sediments at three concentrations (10, 40, 100 mg/kg dry wt). Following four months of equilibration, desorption was measured by extraction with Tenax� and the data were fit to a first-order three-compartment kinetic model. The rate constants of the rapidly (krap), slowly (kslow and very slowly (kvs) desorbing fractions were on the order of lO-1/h, 10-2-3/h, and 10-4/h, respectively. The t99.9 (time required for 99.9% of the FLU and TF to desorb from each pool value) for each compartment indicated that FLU and TF desorption from rapid, slow, and very slow compartments were on the order of hours, days, and years, respectively. Higher rates of desorption were observed for FLU and TF from the Lake Huron sediments and this was not apparently related to the total organic carbon (TOC), particle size distribution, or polarity (carbon-to-nitrogen ratio) of the sediments. In general, the total fraction of the initial contaminant amounts that desorbed over the time course was directly related to concentration, which we hypothesized was due to the combined effects of saturation of high-energy (slow and very slow) binding sites in the organic carbon matrix and hysteresis. In extrapolations to field conditions, FLU and TF were predicted to persist in the sediments for years due to the very slow desorption of an estimated 31 to 53% of the bulk concentrations. Based on the rapidly desorbing fractions, the bioavailable amounts of the contaminants were predicted to be between 31 to 55% of bulk sediment concentrations.

He, C. and T. E. CROLEY II. Development of a 2-D large basin operational hydrologic model. Proceedings of the Workshop on Modeling and Control for Participatory Planning and Managing Water Systems, Venice, Italy, September 29 - October 1, 2004. International Federation for Automatic Control, 12 pp. (2004).

This paper reviews recent developments in hydrologic modeling, and through development of a 2-D large basin runoff model (2-D LBRM), discusses five essential components in the development of operational hydrologic models: model input, model structure, spatial variability, model calibration, and GIS-model interface. Operational hydrologic models should utilize multiple biophysical databases to develop model input parameters over multiple temporal and spatial scales. They should be based on mass continuity equations and include land surface, soil zones, and groundwater components. Spatial heterogeneity of watersheds needs to be taken into consideration using either a hydrological response unit or grid network approach. Simulation results should be calibrated with respect to multiple-objectives for better assessment of model and data errors. GIS-model interfaces need to be developed to facilitate model implementation and applicability.

He, C. and T. E. CROLEY II. Estimating nonpoint source pollution loadings in the Great Lakes watersheds. Proceedings of the International Conference on Poyang Lake Wetland Ecological Environment, Jiangxi Normal University, Nanchang, Jiangxi, P.R. China, June 27, 2005. 12 pp. (2005).

Nonpoint source pollution (NPS) from contaminated sediments, urban runoff, storm sewers, and agriculture impairs Great Lakes shoreline waters; accurate NPS accounting is essential to effective water quality and ecosystem management. We are developing a physically based, spatially-distributed hydrology model to simulate spatial and temporal NPS distributions in the Saginaw Bay watersheds. Multiple databases of meteorology, land use, satellite imagery, topography, hydrography, soils, and agricultural statistics are used to estimate nonpoint source loading potential in the study watershed. Soil erosion and sediment yield by both wind and water are estimated based on the universal soil loss equation and vegetation indices derived from the satellite imagery. Animal manure production is computed from tabulations of animals by zip code area. Relative chemical loadings for agricultural land use are calculated from county fertilizer and pesticide estimates by crop. These estimates will be used as the input to the water quality model for simulating pollutant transport through surface and subsurface processes to the Great Lakes waters. After verification with Saginaw Bay water quality data, these simulations will help researchers better understand the dynamics of Great Lakes aquatic systems and enable agencies to target critical areas for management.

Holcombe, T. L., L. A. Taylor, J. S. Warren, P. A. VINCENT, D. F. REID and C. E. Herdendorf. Lake floor geomorphology of Lake Erie. World Data Center A for Marine Geology and Geophysica Research Publication RP-3. NOAA NESDIS National Geophysical Data Center, Boulder, CO, 26 pp. (2005).

Lake floor physiographic features of Lake Erie, many seen in detail for the first time, are described with the aid of new bathymetry.  Geomorphology of these features is discussed utilizing the bathymetry, existing data, and previous interpretations.  The nearshore zone surrounding the main basins of Lake Erie deepens to 5-15 m within the first 1-3 km of the shore, exposing bedrock, glacial drift, and glaciolacustrine clay.  Glacial erosion interacting with bedrock of varying resistance to erosion has accounted, directly or indirectly, for certain Lake Erie escarpments and other features, such as those occurring within the islands area and in the eastern Basin.  Long Point Escarpment is apparently the surface expression of a bedrock escarpment formed on the edges of erosion-resistant southward-dipping strata.  Clear Creek Ridge resembles an offshore bar built from accumulations of sand moving along the former shore at lower lake levels, though it may have a morainic foundation.  The Pelee-Lorain, Long Point-Erie, and Point Pelee Ridges, are interpreted as morainic ridges on which sands were later concentrated by longshore transport at lower than present lake levels.  Conneaut Bank, Fairport Ridge, and Point Pelee Fan are interpreted as deltas formed at lower lake levels.  Pennsylvania Ridge flanks Pennsylvania Channel and resembles a natural levee extending westward from the southern end of the Long-Point Erie Ridge.  Strong westward currents at depth through Pennsylvania Channel have apparently kept the channel open.

HONDORP, D. W., S. A. POTHOVEN and S. B. BRANDT. Influence of Diporeia density on diet composition, relative abundance, and energy density of planktivorous fishes in southeast Lake Michigan. Transactions of the American Fisheries Society 134:588-601 (2005).

The benthic amphipod Diporeia spp. is an important prey for many fish in offshore areas of the Great Lakes, but its abundance has been rapidly decreasing. To assess the influence of Diporeia availability on the food habits, relative abundance, and energetics of planktivorous fish, the diet composition, catch per unit effort (CPUE), and energy density of planktivorous fish in southeast Lake Michigan during 2000-2001 were compared among locations with different Diporeia densities. Diporeia densities at St. Joseph, Michigan, were near 0/m2 over much of the bottom but averaged more than 3,800/m2 at Muskegon and Little Sable Point, Michigan. Consistent with these differences in Diporeia density, fish diet composition, CPUE, and energy density varied spatially. For example, alternative prey types comprised a larger fraction of the diets of bloater Coregonus hoyi, large (>100 mm total length) alewife Alosa pseudoharengus, and slimy sculpin Cottus cognatus at St. Joseph than at Muskegon and Little Sable Point. This pattern was seasonally dependent for alewives and bloaters because Diporeia were eaten mainly in June. Food biomass per stomach was not lower at St. Joseph than elsewhere, suggesting that the spatial variation in diet composition was due to greater consumption of alternative prey by fish at St. Joseph. Although slimy sculpin and bloaters were able to feed on alternative prey, the CPUE of these species at certain depths was considerably lower at St. Joseph than at Muskegon or Little Sable Point, indicating that Diporeia availability may also influence fish abundance and distribution. Finally, a link between Diporeia density and fish energetics was suggested by the comparatively low energy density of deepwater sculpin Myoxocephalus thompsonii and large alewives at St. Joseph, a result that may reflect the low energy content of other prey relative to Diporeia.

Hook, T. O., E. S. Rutherford, S. J. Brines, C. A. Geddes, D. M. MASON, D. J. SCHWAB and G. W. Fleischer. Landscape scale measures of steelhead (Oncorhynchus mykiss) bioenergetic growth rate potential in Lake Michigan and comparison with angler catch rates. Journal of Great  Lakes Research 30(4):545-556 (2004).

The relative quality of a habitat can influence fish consumption, growth, mortality, and production. In order to quantify habitat quality, several authors have combined bioenergetic and foraging models to generate spatially explicit estimates of fish growth rate potential (GRP). However, the capacity of GRP to reflect the spatial distributions of fishes over large areas has not been fully evaluated. We generated landscape scale estimates of steelhead (Oncorhynchus mykiss) GRP throughout Lake Michigan for 1994-1996, and used these estimates to test the hypotheses that GRP is a good predictor of spatial patterns of steelhead catch rates. We used surface temperatures (measured with AVHRR satellite imagery) and acoustically measured steelhead prey densities (alewife, Alosa pseudoharengus) as inputs for the GRP model. Our analyses demonstrate that potential steelhead growth rates in Lake Michigan are highly variable in both space and time. Steelhead GRP tended to increase with latitude, and mean GRP was much higher during September 1995, compared to 1994 and 1996. In addition, our study suggests that landscape scale measures of GRP are not good predictors of steelhead catch rates throughout Lake Michigan, but may provide an index of interannual variation in system-wide habitat quality.

Janssen, J. J., M. B. Berg and S. J. LOZANO. Submerged terra incognita: Lake Michigan's abundant but unknown rocky zones. In State of Lake Michigan (SOLM) - Ecology, Health, and Management. T. Edsall and M. Munawar (eds.). Ecovision World Monograph Series, Aquatic Ecosystem Health and Management Society, 113-139 (2005).

No abstract.

Johnson, T. B., M. H. Hoff, A. S. Trebitz, C. R. Bronte, W. P. Brown, T. D. Corry, J. F. Kitchell, S. T. LOZANO, D. M. MASON, J. V. Scharold, S. T. Schram and D. R. Schreiner. Spatial patterns in assemblage structures of pelagic forage fish and zooplankton in western Lake Superior. Journal of Great Lakes Research 30(Supplement 1):395-406 (2004).

We assessed abundance, size, and species composition of forage fish and zooplankton communities of western Lake Superior during August 1996 and July 1997. Data were analyzed for three ecoregions (Duluth-Superior, Apostle Islands, and the open lake) differing in bathymetry and limnological and biological patterns. Zooplankton abundance was three times higher in the Duluth-Superior and Apostle Islands regions than in the open lake due to the large numbers of rotifers. Copepods were far more abundant than Cladocera in all ecoregions. Mean zooplankton size was larger in the open lake due to dominance by large calanoid copepods although size of individual taxa was similar among ecoregions. Forage fish abundance and biomass was highest in the Apostle Islands region and lowest in the open lake ecoregion. Lake herring (Coregonus artedi), rainbow smelt (Osmerus mordax) and deepwater ciscoes (Coregonus spp.) comprised over 90% of the abundance and biomass of fishes caught in midwater trawls and recorded with hydroacoustics. Growth and condition of fish was good, suggesting they were not resource limited. Fish and zooplankton assemblages differed among the three ecoregions of western Lake Superior, due to a combination of physical and limnological factors related to bathymetry and landscape position.

Kerfoot, W. C., S. L. Harting, J. Jeong, J. A. ROBBINS and R. Rossmann. Local, regional, and global implications of elemental mercury in metal (copper, silver, gold, and zinc) ores: insights from Lake Superior sediments. Journal of Great Lakes Research 30(Supplement 1):162-184 (2004).

Anthropogenic inventories for copper (229 � 89 ug/cm2, N = 30), and mercury (470 � 307 ng/cm2, N = 25) in Lake Superior sediments are much greater than inventories in remote lakes (Cu 50 � 31 ug/cm2, Hg 64 � 34 ng/cm2, N = 16) that receive inputs largely from long-distance atmospheric sources. Whereas the absolute concentration of mercury in Lake Superior sediments is not high (80–110 ng/g), enrichment ratios along coastal margins indicate industrial sources. An example of previously unreported mining-related inputs comes from native copper mining on the Keweenaw Peninsula. Around the peninsula, sediment inventories for mercury, silver, and copper are highly correlated and can be traced back to shoreline tailing piles, smelters, and parent ores. Elemental mercury occurs as a natural amalgam or solid solution substitution in native metal (copper, silver, gold) deposits and associated gangue minerals (e.g., sphalerite, ZnS) at �g/g or higher concentrations. Native copper stamp mills discharged more than 364 million metric tons of �stamp sand� tailings, whereas copper smelters refined five million metric tons of copper, liberating together at least 42 metric tons of mercury. Release of trace mercury from Lake Superior mining deserves regional attention as preliminary estimates resemble EPA Region #9 patterns and could help explain the 4–7 fold sediment inventory discrepancies. We show that the Keweenaw situation is not unique geographically, as mineral-bound trace mercury is commonplace in U.S. and Canadian Greenstone Belts and of worldwide occurrence in precious (gold, silver) and massive base metal (copper, zinc) ore deposits.

Kracker, L. M., L. Zhou, J. M. Jech, J. K. Horne, J. A. Tyler and S. B. BRANDT. Spatial and temporal variance in fish distributions: A Lake Ontario case study. In State of Lake Ontario (SOLO) - Past, Present, and Future. M. Munawar (ed.). Aquatic Ecosystem Health and Management Society, 385-406 (2003).

Aquatic environments are a heterogeneous patchwork of physical and biological features, much like terrestrial landscapes. In  aquatic landscapes, "structure" can be defined as the collective arrangement and configuration of these features (Kracker, 1998). We suggest that heterogeneity in the aquatic landscape, quantified by partitioning spatial and temporal variance in fish distributions, reveals a structure indicative of the underlying ecological processes. Lake Ontario is a three-dimensional, heterogeneous environment exhibiting a structure comprised of temperature gradients, geomorphological elements, and temporally and spatially diverse biota and habitats (Olson et al., 1988; Goyke and Brandt, 1993). Studies of the Laurentian Great Lakes have evolved from whole-lake, homogeneous approaches (e.g., Kitchell et al., 1977; Rand et al., 1995) to partitioning the ecosystem, thereby increasing spatial resolution (Sklar and Costanza, 1991; Brandt and Kirsh, 1993; Mason et al., 1995). This trend reflects the greater emphasis that has been placed on the importance of scale, pattern, and variation of biological quantities in ecological processes (Petitgas, 1993; Horne and Schneider, 1995; Syrjala, 1996; Kracker, 1997). Environmental heterogeneity plays an important role in ecosystem function by influencing the flow of energy within and among trophic levels (Turner and Gardner, 1991). Spatial and temporal heterogeneity of aquatic resources is driven by processes such as solar energy input, diel migrations by aquatic organisms, aggregative behavior of fish, and water movement.

KRUEGER, D. M. and T. R. Hrabik. Food web alterations that promote native species: The recovery of cisco (Coregonus artedi) populations through management of native piscivores. Canadian Journal of Fisheries and Aquatic Sciences 62:2177-2188 (2005).

We evaluated the effects of fisheries management on food webs in three northern Wisconsin lakes with exotic rainbow smelt (Osmerus mordax). In two of the lakes, restrictions on fishing reduced mortality rates on adult walleye (Sander vitreus) during the study period. In these lakes, walleye populations increased concurrently with a decline in rainbow smelt populations. As rainbow smelt populations declined in both lakes, native cisco (Coregonus artedi) populations increased. Our analysis of walleye diets illustrated that walleye fed selectively on rainbow smelt but did not feed on cisco during the summer months. When entered into bioenergetics simulations, this information demonstrates that walleye predation alone was enough to cause the observed rainbow smelt declines in our study lakes. Our results indicate that increased walleye density allows for a parallel increase in cisco density. Based on our results, fishery regulations to restore walleye to high densities in lakes invaded by rainbow smelt may restore native planktivores that have co-evolved traits.

Kukkonen, J. V. K., S. Mitra, P. F. LANDRUM, D. C. GOSSIAUX, J. Gunnarsson and D. Weston. The contrasting roles of sedimentary plant-derived carbon and black carbon on sediment-spiked hydrophobic organic contaminant bioavailability to Diporeia spp. and Lumbriculus variegatus. Environmental Toxicology and Chemistry 24(4):877-885 (2005).

In bioavailability studies, the biota sediment accumulation factor (BSAF) is invoked to describe the thermodynamic partitioning of a hydrophobic organic contaminant (HOC) between the organism lipid and the organic carbon fraction of the sedimentary matrix and accounts for differences in bioavailability among sediments. Bioaccumulation experiments were performed with Lumbriculus variegatus and Diporeia species exposed in seven sediments dosed with 2,4,5,2',4',5'-hexachlorobiphenyl (HCBP) and benzo[a]pyrene (BaP) or pyrene (PY) and 3,4,3',4'-tetrachlorobiphenyl (TCBP). The BSAF values for the nonplanar HCBP were consistent with equilibrium partitioning theory (EQP) and averaged 2.87 for L. variegatus and 1.45 for Diporeia, while the BSAF values for the planar compounds (BaP, PY, TCBP) were generally lower than estimated from EQP (<1). Correcting the BSAF values of the planar compounds for enhanced sorption due to black carbon improved the BSAF values for L. variegatus, generally resulting in values consistent with EQP, but substantial variation remained for Diporeia. The BSAF values for the planar compounds showed significant positive correlations with plant-derived carbon in sediments (lignin and pigments) but were more consistent for L. variegatus than for Diporeia. These correlations imply that compounds sorbed to plant-derived carbon are more bioavailable since this material is more likely ingested providing a second exposure route.

LANDRUM, P. F., J. A. Steevens, M. McELROY, D. C. GOSSIAUX, J. S. Lewis and S. D. ROBINSON. Time-dependent toxicity of Dichlorodiphenyldichloroethylene (DDE) to Hyalella azteca. Environmental Toxicology and Chemistry 24(1):211-218 (2005).

Temporal effects on body residues of dichlorodiphenyldichloroethylene (DDE) associated with mortality in the freshwater amphipod Hyalella azteca were evaluated. Toxicokinetics and body residues were determined from water-only exposures that varied from 4 to 28 d, and DDE concentrations ranging from 0.0013 to 0.045 umol L-1. Uptake and elimination parameters were not affected significantly by the various temporal and concentration treatments. Uptake rate coefficients ranged from 134.3 to 586.7 ml g-1 h-1, and elimination rate coefficients ranged from 0.0011 to 0.0249 h-1. Toxicity metric values included body residue for 50% mortality at a fixed sample time (LR5O) and mean lethal residue to produce 50% mortality from individual exposure concentrations (MLR5O) for live organisms and dead organisms. A twofold increase occurred in the MLR5O values calculated using live organisms compared to MLR5O values using dead organisms. Toxicity and kinetic data were fit to a damage assessment model that allows for the time course for toxicokinetics and damage repair, demonstrating the time-dependence of body residues to toxicity. The DDE appeared to act through a nonpolar narcosis mode of action for both acute and chronic mortality in H. azteca. Furthermore, the temporal trend in the toxic response using body residue as the dose metric is steep and found to be similar to another chlorinated hydrocarbon, pentachlorobenzene, but was more potent than that found for polycyclic aromatic hydrocarbons (PAH5).

Lee, J.-S. and J.-H. LEE. Influence of acid volatile sulfides and simultaneously extracted metals on the bioavailability and toxicity of a mixture of sediment-associated Cd, Ni, and Zn to polychaetes Neanthes arenaceodentata. Science of the Total Environment 338:229-241 (2005).

Laboratory microcosm experiments were conducted to investigate the influence of acid volatile sulfides (AVS) and simultaneously extracted metals (SEM) in sediments on the bioavailability and toxicity of Cd, Ni, and Zn in sediments to polychaete worms Neanthes arenaceodentata. Cohorts of juvenile N. arenaceodentata were exposed to sediments spiked with metal mixtures containing Cd, Ni, and Zn (0.5-15 mmol g-1 of total SEM) with Low- (~1 mmol . g-1), Medium- (~5 mmol . g-1), and High-AVS concentrations (~10 mmol . g-1) for 20 days to determine mortality, growth rate, and metal bioaccumulation. Tissue Cd and Zn concentrations at the end of the exposure were significantly higher in sediments with the low-AVS concentration at a given SEM concentration due to the increased dissolved metal concentrations in overlying water (OW). However, tissue Ni concentrations were not related to dissolved Ni in the OW. AVS concentrations also influenced the toxicity of metals to the worms. Significant mortality was observed only at the highest SEM treatments at Low-AVS series. Most individuals survived at the highest SEM treatments at Medium- and High-AVS series. Similarly, the growth rates of worms were reduced in treatments having higher molar differences between SEM and AVS ([SEM-AVS]). Overall, the bioavailability and toxicity of metals in sediments was not well predicted by sediment metal concentrations only, but considering the influence of geochemical factors (AVS) on the metal bioavailability improved the prediction of toxicity. Also, the relationship between tissue metal concentration and toxicity was used to determine which contaminant was most responsible for the observed toxicity of the metal mixture.

Lee, C.-H., D. J. SCHWAB and N. HAWLEY. Sensitivity analysis of sediment resuspension parameters in coastal area of southern Lake Michigan. Journal of Geophysical Research 110(C03004):16 (2005).

[1] Model sensitivity analysis was performed to identify and compare quantitatively the important resuspension parameters in the coastal area of southern Lake Michigan. A one-dimensional resuspension and bed model capable of dealing with the type of mixed sediments (fine-grained+sand) common in the coastal area was developed and utilized to compare with measured suspended sediment concentrations. The results show that the most sensitive parameters in the model are the fraction of fine-grained materials and sediment availability. Other resuspension parameters such as settling velocity, critical shear stress, and erosion rate constant are also found to be important and may cause up to a 40% difference in suspended sediment concentration. Among those, the absolute magnitude of settling velocity is most crucial in controlling the first order prediction.

Lin, E.-B. and P. C. LIU. A discrete wavelet analysis of freak waves in the ocean. Journal of Applied Mathematics 2004:5:379-394 (2004).

A freak wave is a wave of very considerable height, ahead of which there is a deep trough. A case study examines some basic properties developed by performing wavelet analysis on a freak wave. We demonstrate several applications of wavelets and discrete and continuous wavelet transforms on the study of a freak wave. A modeling setting for freak waves will also be mentioned.

LIU, P. C. and B. V. Babanin. Using wavelet spectrum analysis to resolve breaking events in the wind wave time series. Annales Geophysicae 22:3335-3345 (2004).

This paper presents the development of a new approach, based on wavelet spectrum analysis, for the detection of breaking waves in a time series of surface wave fluctuations. The approach is shown to be capable of producing equivalent wave breaking statistics as field measurements based on detection of whitecaps at a fixed point of observation. This wavelet-based approach is applicable to both deep water and finite depth environments. Based on applications of this approach to the analysis of available field data, a novel classification of wave breaking processes that consists of incipient, developing, and subsiding phases is proposed.

LOFGREN, B. M. A model for simulation of the climate and hydrology of the Great Lakes basin. Journal of Geophysical Research 109(D18108):20 pp. (2004).

The Coupled Hydrosphere-Atmosphere Research Model (CHARM) was developed by coupling the Regional Atmospheric Modeling System (RAMS) to models of the land hydrology of the Great Lakes basin and of the evaporation and thermodynamics of the Great Lakes. It is intended for running coupled atmosphere-surface climate scenarios for the Great Lakes basin, to gain a perspective that has been missed by running hydrologic models in off-line mode, driven by the output of global general circulation models. This paper presents validation of this model using historical atmospheric data to drive the regional embedded CHARM model. The current version of CHARM simulates the near-surface air temperature in the region quite well, with some positive bias during the winter and negative bias during the summer. Biases in the temperature averaged over 1 month and over the portion of the domain that is not directly forced by observations are less than or approximately 2 K. The annual precipitation has a positive bias of 6.6% and does well at placing the lake-effect precipitation areas, but may have too strong a west-east gradient. Simulation of annually averaged runoff meets well with expectations, but additional empirical fitting may be required to replicate the seasonal cycle. Aspects of the model that remain troublesome are the tendency for unrealistically low pressure at mean sea level and for persistent heavy low stratus clouds.

LOFGREN, B. M. Development of the second-generation Hydrosphere-Atmosphere Research Model (CHARM) for the Laurentian Great Lakes region. Proceedings, 19th Conference on Hydrology, 85th Annual Meeting of the American Meteorological Society, San Diego, CA, January 9-13, 2005. American Meteorological Society, 3 pp. (2005).

The question of what effect global warming might have on the amount of water available within the Laurentian Great Lakes basin has gained some controversy. Even the author of this extended abstract has gone on record with predictions in various directions. Several studies during the 1990s used the results of general circulation models (GCMs) to derive a suite of meteorological variables as drivers for offline hydrologic models designed specifically for the Great Lakes basin. That is, the GCMs drove the hydrologic models, but the GCM simulations were already complete, so the GCMs were not aware of what was happening in these hydrologic models. Notably, most of the GCMs altogether ignored the presence of the Great Lakes in their simulations. These simulations consistently show that, while GCMs generally show increased precipitation over the basin, increased evapotranspiration from the basins, associated with increased temperature and available energy at the surface took the upper hand, leading to decreased net basin water supply and lowered lake levels.

LOFGREN, B. M. CLIP: Climate-Land Interaction Project - Investigating human-climate interactions in East Africa. Proceedings, 16th Conference on Climate Variability and Change, 85th Annual Meeting of the American Meteorological Society, San Diego, CA, January 9-13, 2005. 3 pp. (2005).

East Africa is a region with an economy that is rapidly developing in a variety of sectors, an expanding population, and a distinct climatic challenge. Conflict sometimes occurs both between and within tribal groups over conversion of land from pastoral to agrarian use, but the trend is toward the cultivation of crops, both for subsistence and for cash (Campbell et al. 2000). Much marginal land that previously supported a pastoral economy has been irrigated for crops. Large-scale land use change has been shown to have significant effects on climate in other parts of Africa, leading to feedback between vegetation and climate (e.g. Xue 1997). However, land use change in East Africa may be more fragmented and less drastic (typical transformation from savanna to cropland rather than from grassland to desert), and crops will introduce a seasonal character with sharp anthropogenic discontinuities corresponding to tillage and harvest. The Climate-Land Interaction Project (CLIP) was conceived to investigate the interactions and feedback between climate and land use in East Africa. It will specifically consider land use transformations that are mediated by humans, in addition to the more commonly investigated land use/land cover changes that occur in response to climate perturbations through natural processes.

Lohrenz, S. E., G. L. FAHNENSTIEL, D. F. Millie, O. M. E. Schofield, T. H. JOHENGEN and T. Bergman. Spring phytoplankton photosynthesis, growth, and primary production and relationships to a recurrent coastal sediment plume and river inputs in southeastern Lake Michigan. Journal of Geophysical Research 109(C10S14):13 pp. (2004).

A recurrent coastal sediment plume (RCP) is an episodic event in the southern basin of Lake Michigan that typically coincides with the spring diatom bloom. Strong winter storm activity during El Nino conditions in 1998 resulted in a large and intense RCP event. Consistently higher values of the light-saturated rate of photosynthesis, PBmax , were observed in spring 1998 compared to 1999 and 2000. Higher values of PBmax in 1998 appeared to be related to increased availability of phosphorus, as evidenced by significant correlations of PBmax with soluble reactive phosphorus (SRP). Light-saturated growth rates were also significantly correlated with SRP concentrations. These findings were consistent the view that the RCP was a source of enrichment. However, incubation experiments involving lake water enriched with sediments showed relatively small increases in growth and photosynthetic parameters, while enrichments with river water exhibited elevated rates. This result, along with increased levels of river discharge in 1998 and high levels of dissolved phosphorus in river water, supported the view that riverine inputs rather than the RCP were responsible for the higher photosynthetic parameters and growth seen for coastal margin assemblages. Despite the higher levels of PBmax  in 1998, model analyses revealed that reduced light availability resulting from the intense RCP event constrained phytoplankton growth rates and primary production during this season and apparently suppressed the development of a typical spring bloom. These findings indicate a potential for reduced ecosystem productivity in response to extreme storm events, the frequency of which may increase with projected long-term climate changes.

LOZAN0, S. J. and D. H. MERKEY. Chapter 7: Restoration monitoring of soft bottom habitats. In Science-Based Restoration Monitoring of Coastal Habitats. Volume II: Tools for Monitoring Coastal Habitats. G. W. Thayer, T.A. McTigue, R. Salz, D.H. Merkey, F.M. Burrows, and P. Gayaldo (eds.). NOAA National Centers for Coastal Ocean Science, Silver Spring, MD, 7.1-7.18 (2005).

Soft bottom habitats within coastal environments are characterized by loose, unconsolidated sediment types (Cowardin et al. 1979). The sediments are fine to coarse-grained with at least 25% of the particles smaller than 2 cm and have a vegetative cover less than 30%. Soft bottom habitats are restricted to subtidal, permanently flooded water regimes, characterized by the general lack of areas for plant and animal attachment and by lower energy levels than rocky substrate habitats. The composition of plants and animals present is determined by temperature, salinity, light penetration, and the substrate type that is, in turn, structured by the exposure to wave and current action. Managing the ecological health of soft bottom habitats is integral to managing the health of aquatic systems as a whole. Many organisms live in and on sediments and use sedimentary particles as food. Crustaceans, polychaetes, and gastropods dominate these habitats and are the primary sources of food for many of the larger estuarine organisms such as fish (Boesch et al. 1994).

LOZANO, S. J. and J. V. Scharold. The status of Diporeia spp. in Lake Ontario, 1994-1997. In Proceedings of a Workshop on the Dynamics of Lake Whitefish (Coregonus clupeaformis) and the amphipod Diporeia spp. in the Great Lakes. L. C. Mohr, and Nalepa, T.F (eds.). Great Lakes Fishery Commission, Technical Report 66, Ann Arbor, MI, 233-246 (2005).

Surveys of benthic macroinvertebrates conducted in Lake Ontario between 1994 and 1997 revealed a recent decline in Diporeia spp. (Amphipoda) abundance. The lowest population densities and summer biomass are in the eastern basin of the lake at all depths. Densities and biomass declined in the shallowest (10-50 m) depth zone between 1994 and 1997. Mean Diporeia spp. densities declined from 1412 m-2 to 1 m-2, and the total mean biomass declined from 0.66-g DW m-2 to 0.001 g-DW m-2. The latter represents an overall loss of about 5100 mt of biomass in the shallowest depth zone. In contrast, biomass at the deepest zone (>90 m) did not change from 1994 to 1997 and has actually increased over twofold since 1972. This shift of total biomass from shallow to deeper sediments will have a profound effect on organisms that depend upon Diporeia spp. for food. Because of the importance of benthic macroinvertebrates, and particularly Diporeia spp. in fish diets, changes in the status of Diporeia spp. could have dramatic effects on fish production in Lake Ontario.

LUDSIN, S. A., B. J. Fryer, Z. Yang, S. Melancon and J. L. Markham. Exploration of the existence of natural reproduction in Lake Erie lake trout using otolith microchemistry. 2004 Project Completion Report. Great Lakes Fishery Commission, Ann Arbor, MI, 45 pp. (2004).

Lake Erie fishery management agencies have been attempting to reestablish lake trout (Salvelinus namaycush) as a self-sustaining predator in eastern Lake Erie, primarily through stocking. Although this program has led to the recolonization of eastern Lake Erie by mature adults, and natural egg production has been documented, an understanding of whether these naturally produced eggs successfully recruit to older life stages is lacking. To assess the likelihood of successful recruitment of wild fish, we used laser-ablation inductively coupled plasma-mass spectrometry to develop characteristic otolith elemental �signatures� for the hatchery (from cores) and Lake Erie (from edges) using hatchery-reared lake trout that were recaptured in Lake Erie during 1984-2003. In turn, discriminant functions were developed to determine whether 28 lake trout of unknown origin were produced in the hatchery or wild. Large differences in elemental composition existed between otolith cores (hatchery phase) and edges (Lake Erie phase) of recaptured individuals. Using additional lake trout that spent their entire life in the hatchery or in Keuka Lake (NY), we found that two elements (Zn, Mn) likely differed between core and edge only because of physiology; hence, these elements were not included in our final classification model. The remaining elements (Li, Mg, Rb, Sr, Sn, Ba, and Pb), however, varied more likely as a function of water chemistry, and allowed us to discriminate between environments with 95% accuracy (based on an independent, crossvalidation set consisting of known-origin fish). Barium was the most important discriminator, followed by Sr, Mg, and Li. Ultimately, using these four elements, we classified 24 of 28 unknown individuals as hatchery-reared, whereas the other four fish were classified as wild. Our results strongly suggest that the resident Lake Erie lake trout population no longer consists solely of hatchery-reared Lake trout, and that successful recruitment of naturally produced fish has occurred

Madenjian, C. P., T. O. Hook, E. S. Rutherford, D. M. MASON, T. E. CROLEY II, E. B. Szalai and J. R. Bence. Recruitment variability of alewives in Lake Michigan. Transactions of the American Fisheries Society 134:218-230 (2005).

We used a long-term series of observations on alewife Alosa pseudoharengus abundance that was based on fall bottom-trawl catches to assess the importance of various abiotic and biotic factors on alewife recruitment in Lake Michigan during 1962–2002. We first fit a basic Ricker spawner–recruit model to the lakewide biomass estimates of age-3 recruits and the corresponding spawning stock size; we then fit models for all possible combinations of the following four external variables added to the basic model: an index of salmonine predation on an alewife year-class, an index for the spring–summer water temperatures experienced by alewives during their first year in the lake, an index of the severity of the first winter experienced by alewives in the lake, and an index of lake productivity during an alewife year-classs second year in the lake. Based on an information criterion, the best model for alewife recruitment included indices of salmonine predation and spring–summer water temperatures as external variables. Our analysis corroborated the contention that a decline in alewife abundance during the 1970s and early 1980s in Lake Michigan was driven by salmonine predation. Furthermore, our findings indicated that the extraordinarily warm water temperatures during the spring and summer of 1998 probably led to a moderately high recruitment of age-3 alewives in 2001, despite abundant salmonines.

Madenjian, C. P., S. A. POTHOVEN, P. J. Schneeberger, D. V. O'Connor and S. B. BRANDT. Preliminary evaluation of a Lake Whitefish (Coregonus clupeaformis) bioenergetics model. In Proceedings of a Workshop on the Dynamics of Lake Whitefish (Coregonus clupeaformis) and the amphipod Diporeia spp. in the Great Lakes. L. C. Mohr and T.F. Nalepa (eds.). Great Lakes Fishery Commission, Technical Report 66, Ann Arbor, MI, 189-202 (2005).

We conducted a preliminary evaluation of a lake whitefish (Coregonus clupeaformis) bioenergetics model by applying the model to size-at-age data for lake whitefish from northern Lake Michigan. We then compared estimates of gross growth efficiency (GGE) from our bioenergetics model with previously published estimates of GGE for bloater (C. hoyi) in Lake Michigan and for lake Quebec. According to our model, the GGE of Lake Michigan lake whitefish decreased from 0.075 to 0.02 as age increased from 2 to 5 years. In contrast, the GGE of lake whitefish in Quebec inland waters decreased from 0.12 to 0.05 for the same ages. When our swimming-speed submodel was replaced with a submodel that had been used for lake trout (Salvelinus namaycush) in Lake Michigan and an observed predator energy density for Lake Michigan lake whitefish was employed, our model predicted that the GGE of Lake Michigan lake whitefish decreased from 0.12 to 0.04 as age increased from 2 to 5 years.

Madenjian, C. P., D. W. HONDORP, T. J. Desorcie and J. D. Holuszko. Sculpin community dynamics in Lake Michigan. Journal of Great Lakes Research 31:267-276 (2005).

Two hypotheses have been proposed to explain the dynamics of sympatric populations of deepwater sculpin (Myoxocephalus thompsonii) and slimy sculpin (Cottus cognatus). The first hypothesis is that slimy sculpins negatively affect survival of deepwater sculpins, and therefore deepwater sculpins coexist with slimy sculpins only when a keystone predator, lake trout (Salvelinus namaycush), is abundant. According to the second hypothesis, changes in the abundances of the sculpins are driven by interactions with fishes other than sculpins. To evaluate both hypotheses, we applied regression analyses to long-term observations on abundances of both sculpin populations in Lake Michigan during 1973–2002. For slimy sculpin abundance, we considered the predation effect by lake trout and the effect of deepwater sculpins on slimy sculpins. For deepwater sculpin abundance, we considered the effect of alewife (Alosa pseudoharengus) on deepwater sculpins, the predation effect by burbot (Lota lota), and the effect of slimy sculpins on deepwater sculpins. An information criterion was used to select the best regression model explaining the temporal trends. The best model to explain trends in slimy sculpin abundance was the model that included the lake trout predation term only. The best model to explain trends in deepwater sculpin abundance was a model including the alewife and burbot predation terms. Thus, a negative effect of slimy sculpins on deepwater sculpins was not essential in capturing the sculpin community dynamics. Therefore, our results supported the second hypothesis. Further, our results supported the contention that control of the alewife population was a prerequisite for restoration of deepwater sculpin populations.

Melancon, S., B.J. Fryer, SA. LUDSIN, J.E. Gagnon, and Z. Yang. Effects of crystal structure on the uptake of metals by lake trout (Salvelinus namaycush) otoliths. Canadian Journal of Fisheries and Aquatic Sciences 62:2609-2619 (2005).

This is the first study to report spectroscopic and elemental analysis of aragonite and vaterite growing simultaneously and separately in both the core and the edges of the same otolith. Our investigations focused on understanding differential trace metal uptake, including the influence of the metal itself (i.e., ionic radii), the crystalline structure, and the development state of the fish. Chemistry and crystal structure of sagittal otoliths from lake trout (Salvelinus namaycush) were studied using laser ablation combined with inductively coupled plasma mass spectrometry (LA-ICPMS) and Raman spectroscopy, respectively. Analyses of the composition of vaterite and aragonite growing in the same growth ring show that smaller cations like Mg (0.86 Å) (1 Å = 0.1 nm) and Mn (0.81 Å) were more abundant in the vaterite hexagonal crystal structure, whereas larger cations such as Sr (1.32 Å) and Ba (1.49 Å) were preferentially incorporated in aragonite (orthorhombic). Similarly, the coprecipitation of aragonite and vaterite in cores and edges allowed us to demonstrate that the uptake rates (as determined by element-specific partition coefficients) for Sr and Ba were greater in aragonite than vaterite, whereas those of Mg and Mn were higher in vaterite than in aragonite.

MERKEY, D. H. Chapter 2: Restoration monitoring of the water column. In Science-Based Restoration Monitoring of Coastal Habitats. Volume II: Tools for Monitoring Coastal Habitats. G. W. Thayer, T.A. McTigue, R. Salz, D.H. Merkey, F.M. Burrows, and P. Gayaldo (eds.). NOAA National Centers for Coastal Ocean Science, Silver Spring, MD, 2.1-2.26 (2005).

The water column, defined as a volume of water that extends from the water surface down to (but not including) the substrate, is a very dynamic habitat subject to waves, currents, tides, and river flow. It is also the only habitat in this guidance document that is associated with all the other habitat types described in the rest of Volume Two.  The water column is responsible for transporting materials, nutrients, sediments, and toxins from upland sources into estuarine environments and from one aquatic habitat to another. As such, the water column has direct effects on all other associated habitats (e.g. SAV, coral reefs, riverine forests etc.), and, therefore, must be taken into consideration for any restoration monitoring program.

MERKEY, D. H., F. M. Burrows and G. W. Thayer. Chapter 9: Restoration monitoring of submerged aquatic vegetation (SAV). In Science-Based Restoration Monitoring of Coastal Habitats. Volume II: Tools for Monitoring Coastal Habitats. G. W. Thayer, T.A. McTigue, R. Salz, D.H. Merkey, F.M. Burrows, and P. Gayaldo (eds.). NOAA National Centers for Coastal Ocean Science, Silver Spring, MD, 9.1-9.56 (2005).

Submerged aquatic vegetation (SAV - referred to as Aquatic Bed in Cowardin et al. 1979) is a habitat created by vascular4 plants that grow below the surface of the water. The plants are usually completely inundated throughout the growing season. Some SAV habitats may also contain a mix of open water and rooted, floating-leaved, and short-emergent vegetation. The distribution of SAV in a particular area is dependent on water depth, turbidity, and wave energy, the presence of grazers, and characteristics of the sediment. Salinity can also be important in tidal areas. Plant species diversity is greater in freshwater SAV habitats than marine habitats. Approximately 500-700 plant species in 50 genera (Sculthorpe 1967) have been cataloged for freshwater areas compared to just 50 species in 12 genera for marine settings (den Hartog, 1970 cited in Stevenson 1988).

MERKEY, D. H., F. M. Burrows, T. A. McTigue and J. Foret. Chapter 10: Restoration monitoring of coastal marshes. In Science-Based Restoration Monitoring of Coastal Habitats. Volume II: Tools for Monitoring Coastal Habitats. G. W. Thayer, T.A. McTigue, R. Salz, D.H. Merkey, F.M. Burrows, and P. Gayaldo (eds.). NOAA National Centers for Coastal Ocean Science, Silver Spring, MD, 10.1-10.94 (2005).

Coastal marshes are characterized as having erect, rooted, herbaceous plants that extend above the water surface (Figure 1). They are extremely productive systems that provide an abundance of food for wildlife that directly access the marsh and exporting large amounts of organic matter to estuaries and other coastal systems. Coastal marshes also provide a variety of feeding and breeding needs for invertebrates, fish, and other wildlife. The characteristics of the marsh vegetation determines the quality and quantity of habitat available to these animals (Adam 1990; Wilcox 1995). The high stem density typical of marsh vegetation provides excellent cover for invertebrates such as crustaceans, snails, worms, and insect larvae, allowing them to feed on algae and on one another while escaping predation from larger fish and wading birds (Havens et al. 1995; Harrel et al. 2001). If plant stems are too dense, however, even small animals may be restricted. Fish use marshes during high water periods to feed, spawn, and as nursery habitat (Keast et al. 1978; Boesch and Turner 1984; McIvor et al. 1989; Jude and Pappas 1992; Wilcox and Meeker 1992; Yozzo and Diaz 1999). Canada geese and some ducks feed on the tender shoots of emergent vegetation4 (Prince et al. 1992). Wading birds and songbirds migrate along routes through highly productive coastal marshes, using the habitat as temporary feeding areas or as seasonal destinations (Weeber and Vallianatos 2000). The vertical structure provided by emergent plants provides perching areas for birds (Brawley et al. 1998) and allows snails and other animals to escape high water levels (Hamilton 1977). Although many species of mammals such as mink, otter, deer, and raccoons use coastal marshes for feeding and refuge, others such as nutria and muskrats are completely dependent upon them to provide the majority of their habitat needs (Evans 1970; Weller 1981; Wilcox and Meeker 1992).

MERKEY, D. H. Chapter 12: Restoration monitoring of deepwater swamps. In Science-Based Restoration Monitoring of Coastal Habitats. Volume II: Tools for Monitoring Coastal Habitats. G. W. Thayer, T.A. McTigue, R. Salz, D.H. Merkey, F.M. Burrows, and P. Gayaldo (eds.). NOAA National Centers for Coastal Ocean Science, Silver Spring, MD, 12.1-12.20 (2005).

Deepwater swamps are forested wetlands that develop along edges of lakes, on alluvial river floodplains, in slow-flowing strands, and in large, coastal-wetland complexes. Deepwater swamps are commonly referred to as cypress swamps and in Cowardin et al. (1979) these forests are referred to as �estuarine forested wetlands�. They can be found along the coasts of the Atlantic Ocean and Gulf of Mexico and throughout the Mississippi River valley from southern Illinois to Louisiana. Dominant species commonly include: Baldcypress (Taxodium distichum), Water tupelo (Nyssa aquatica), and Swamp tupelo (N. sylvatica var. biflora) (Wharton et al. 1982). The dominant vegetation in deepwater swamps is distinguished from other forested swamps in that it is significantly more tolerant of flooding than other tree species (Figure 1 - Conner and Day 1992b; Allen et al. 1996). Adult baldcypress and tupelo can survive permanent inundation although seedlings require exposed sediments to germinate and become successfully established (Schneider and Sharitz 1988; Keeland et al. 1997; Middleton 2000). The soils of cypress swamps range from mineral to accumulated peat depending on the hydrodynamics and topography of the specific system (Giese et al. 2000; Mitsch and Gosselink 2000).

MERKEY, D. H. and B. D. Keeland. Chapter 13: Restoration monitoring of riverine forests. In Science-Based Restoration Monitoring of Coastal Habitats. Volume II: Tools for Monitoring Coastal Habitats. G. W. Thayer, T.A. McTigue, R. Salz, D.H. Merkey, F.M. Burrows, and P. Gayaldo (eds.). NOAA National Centers for Coastal Ocean Science, Silver Spring, MD, 13.1-13.28 (2005).

A riverine forest is a type of wetland dominated by trees and located along sluggish streams, drainage depressions, and in large alluvial floodplains. Although this habitat occurs throughout the United States, extensive areas of riverine forests are found on the Atlantic and Gulf coasts and throughout the Mississippi river valley from Louisiana to southern Illinois (Figure 1 - Mitsch and Gosselink 2000; Allen et al. 2001). Riverine forests are commonly referred to as bottomland hardwoods, floodplain forests, or riverine swamps. They are referred to as �palustrine forests� by Cowardin et al. (1979).

Mohr, L. C. and T. F. NALEPA. Proceedings of a Workshop on the Dynamics of Lake Whitefish (Coregonus clupeaformis) and the Amphipod Diporeia spp. in the Great Lakes. Technical Report 66. Great Lakes Fishery Commission, Ann Arbor, MI, 310 pp. (2005).

No abstract.

Moore, D. W., R. Baudo, J. M. Conder, P. F. LANDRUM, J. P. McFarland, R. N. Millward, J. P. Shine and J. Q. Word. Bioaccumulation in the assessment of sediment quality: uncertainty and potential application. In Use of Sediment Quality Guidelines and Related Tools for the Assessment of Contaminated Sediments. R.J. Wenning, G.E. Batley, C.G. Ingersoll, and D.W. Moore (eds.). Society of Environmental Toxicology and Chemistry, Pensacola, FL, 429-495 (2005).

The desire for cost-effective screening tools for contaminated sediments has resulted in the development of a variety of numerical sediment quality guidelines (SQGs). Currently developed guideline values can be categorized as either mechanistically based (e.g., equilibrium partitioning [EqP}) or empirically based (threshold effects levels [TELs], probably effects levels [PELs], effects range low [ERLs], effects range median [ERMs], apparent effects thresholds [AETs]) (Chapters 3 and 4). None of the existing approaches in either of these categories were designed or intended to be protective of indirect effects through bioaccumulation Thus, there is a need (and under certain United States [US] regulatory programs, a requirement, e.g., the Marine Protection, Research and Sanctuaries Act [MPRSA] and the Clean Water Act [CWA]) to assess the potential for sediment-associated contaminants to bioaccumulate and to evaluate any potential effects (direct and indirect [i.e., foodchain]) associated with that bioaccumulation. While the technical basis, utility, and accuracy of existing SQG approaches in predicting direct effects to benthic infaunal organisms is discussed in other chapters (e.g., 4, 12, and 13), the intent of this chapter is to provide an overview of the potential for guideline values to predict effects through bioaccumulation.

NALEPA, T. F., D. L. FANSLOW and G. Messick. Characteristics and potential causes of declining Diporeia spp. populations in southern Lake Michigan and Saginaw Bay, Lake Huron. In Proceedings of a Workshop on the Dynamics of Lake Whitefish (Coregonus clupeaformis) and the amphipod Diporeia spp. in the Great Lakes. L. C. Mohr and T.F. Nalepa (eds.). Great Lakes Fishery Commission, Technical Report 66, Ann Arbor, MI, 157-188 (2005).

Populations of the amphipods Diporeia spp. are declining in all of the Great Lakes except Lake Superior. We examine characteristics and potential causes of declines in southern Lake Michigan and outer Saginaw Bay, Lake Huron. Amphipod populations began to decline within 3-4 years after zebra mussels (Dreissena polymorpha) colonized both areas. In Lake Michigan, which was better studied, the decline occurred first in shallow waters (<30 m) and then progressed deeper (51-90 m). Between 1980-1981 (pre-Dreissena) and 1998-1999 (post-Dreissena), densities at sites in these two depth intervals declined 92% and 58%, respectively. At a 45-m site in southeastern Lake Michigan, densities of Diporeia spp. declined to near zero within six months even though mussels were never collected at the site itself. At a nearby 45-m site, densities declined gradually to zero over a six-year period and correlated with increased mussel densities. Although mussels are likely outcompeting Diporeia spp. populations for food, and food limitation is probably a contributing factor to population declines, populations show no physiological signs of starvation; lipid content is at a maximum as densities approach zero. Pathogens, fish predation, contaminants, and low dissolved oxygen do not appear to be the sole causes of population declines. The decline of Diporeia spp. is likely to continue as dreissenid populations expand.

NALEPA, T. F., L. C. Mohr, B. A. Henderson, C. P. Madenjian and P. J. Schneeberger. Lake Whitefish and Diporeia spp. in the Great Lakes: An overview. In Proceedings of a Workshop on the Dynamics of Lake Whitefish (Coregonus clupeaformis) and the amphipod Diporeia spp. in the Great Lakes. L. C. Mohr and T.F. Nalepa (eds.). Great Lakes Fishery Commission, Technical Report 66, Ann Arbor, MI, 3-20 (2005).

Because of growing concern in the Great Lakes over declines in abundance and growth of lake whitefish (Coregonus clupeaformis) and declines in abundance of the benthic amphipod Diporeia spp., a workshop was held to examine past and current trends, to explore trophic links, and to discuss the latest research results and needs. The workshop was divided into sessions on the status of populations in each of the lakes, bioenergetics and trophic dynamics, and exploitation and management. Abundance, growth, and condition of whitefish populations in Lakes Superior and Erie are stable and within the range of historical means, but these variables are declining in Lakes Michigan and Ontario and parts of Lake Huron. The loss of Diporeia spp., a major food item of whitefish, has been a factor in observed declines, particularly in Lake Ontario, but density-dependent factors also likely played a role in Lakes Michigan and Huron. The loss of Diporeia spp. is temporally linked to the introduction and proliferation of dreissenid mussels, but a direct cause for the negative response of Diporeia spp. has not been established. Given changes in whitefish populations, age-structured models need to be re-evaluated. Other whitefish research needs to include a better understanding of what environmental conditions lead to strong year-classes, improved aging techniques, and better information on individual population (stock) structure. Further collaborations between assessment biologists and researchers studying the lower food web would enhance an understanding of links between trophic levels.

NALEPA, T. F., D. L. FANSLOW and A. J. FOLEY III. Spatial patterns in population trends of the amphipod Diporeia spp. and Dreissena mussels in Lake Michigan. Verh. Internat. Verein. Limnol. 29:426-431 (2005).

Until the late 1980s, the benthic amphipod Diporeia spp. was the dominant benthic macroinvertebrate in offshore waters of the Laurentian Great Lakes and was considered a keystone species in the lakes' trophic structure (COOK & JOHNSON 1974). In Lake Michigan, it comprised over 70% of macrobenthic biomass at depths >30m in the 1980s (NALEPA 1989). As a benthic detritivore, Diporeia feeds mainly upon material freshly settled from the water column (i.e. diatoms) and, in turn, is fed upon by many fish species including yellow perch, lake whitefish, bloater, alewife, and sculpin (WELLS 1980, CROWDER et al. 1981, KRAFT & KITCHELL 1986). Declines in Diporeia populations have been documented in the Great Lakes since the zebra mussel (Dreissena polymorpha) and the quagga mussel (Dreissena bugensis) became established in the late 1980s. Large areas of Lakes Michigan, Huron, Erie, and Ontario are now completely devoid of this organism (DERMOT & KEREC 1997, NALEPA et al. 1998, LOZANO et al. 2001). A common hypothesis for the decline is that Diporeia is being outcompeted for available food resources by Dreissena. Diporeia feeds in the upper few cm of sediment, whereas Dreissena occurs at the sediment surface and filters settling material before it becomes available to Diporeia. Spatial and temporal patterns of the Diporeia decline, however, are often inconsistent with this food-limitation hypothesis (NALEPA et al. 2004). In this paper, we examine trends in Diporeia and Dreissena populations in different areas of Lake Michigan. By comparing spatial patterns of population trends in these two organisms, we may better define causes of declines and thus better predict the eventual extent of Diporeia losses.

NALEPA, T. F., D. L. FANSLOW, G. A. LANG and S. A. RUBERG. Recent trends in benthic macroinvertebrate populations in Lake Michigan. In State of Lake Michigan (SOLM) - Ecology, Health, and Management. T. Edsall and M. Munawar (eds.). Ecovision World Monograph Series, Aquatic Ecosystem Health and Management Society, 269-292 (2005).

No abstract.

PEACOR, S. D. and E. E. Werner. How dependent are species-pair interaction strengths on other species in the food web? Ecology 85(10):2754-2763 (2004).

Abstract. In ecological theory species interaction strengths are typically described by constants or functions that depend on the densities of the two interacting species. However, if species� traits (phenotypes) are plastic, then modifications in these traits (induced by the presence of another species) could affect interaction strengths of the focal species with a number of other species in the system. The magnitudes of such higher-order effects on interaction strengths have not been reported and are not straightforward to measure. We present a methodology to quantify changes in consumer–resource interaction coefficients (a metric of interaction strength) due to effects of predators on consumer (i.e., the prey of the predator) phenotype (e.g., nonlethal or trait-mediated effects). Application of this method to studies in diverse systems indicates that predators can strongly reduce consumer–resource interaction coefficients, often in the range of 20–80%. We use analytic and simulation models to show that effects on interaction coefficients of this magnitude can lead to trait-mediated effects that contribute more strongly than density-mediated effects to the net effects of predators on consumers and their resources, and even qualitatively change model predictions. Our results strengthen previous claims that trait-mediated effects strongly influence species interactions and suggest that recent calls to quantify interaction strengths must be broadened to include examination of the variation in interaction strengths due to their dependence on densities of other species (most notably predators) in food webs.

PEACOR, S. D. and E. E. Werner. Context dependence of nonlethal effects of a predator on prey growth. Israel Journal of Zoology 50:139-167 (2004).

Predators can have a large influence on their prey through induced changes in prey phenotype. Such �nonlethal� predator effects have been abundantly demonstrated empirically in both terrestrial and aquatic systems. But the extent to which changes in species traits alter short-term responses such as growth rate or probability of survival is not clear. Here we develop models to examine the nonlethal effects of predators on prey growth. Our analyses illustrate how the nonlethal effects of predators on individual prey growth depend on environmental context; e.g., factors such as focal species density, competitor density, resource dynamics, and the timescale over which the interactions occur. This context dependence arises because of complex interactions of three mechanisms; (1) the direct negative effect of induced reduction in foraging rates, which is opposed by (2) the potential positive effects of reductions in intra- and interspecific competition, and (3) resource responses to reduced foraging. We present new empirical work, and review previous work, on larval-anuran growth that is in general support of model predictions. The framework presented here can serve to facilitate the design and interpretation of experimental results and predict how the nonlethal predator effect on prey growth in natural systems will vary over time and space.

PEACOR, S., K. PANGLE and H. A. VANDERPLOEG. Behavioral response of Lake Michigan Daphnia galeata mendotae to Mysis relicta. Journal of Great Lakes Research 31:144-154 (2005).

We performed laboratory experiments to determine if Mysis relicta induce changes in the behavior of Daphnia mendotae collected from Lake Michigan. Laboratory results indicate that Daphnia perceived Mysis kairomones and responded by changing their vertical position in cylinders. Experiments using different resource levels, and two procedures to examine the potential effects of the chemical cues from Mysis or from particulate matter or bacteria associated with capture and defecation of prey, suggest that Daphnia detect Mysis via a chemical cue. This is the first laboratory study that we are aware of that indicates that a zooplankton species from the Great Lakes responds behaviorally to an invertebrate predator. Our findings support the hypothesis that changes in vertical distribution of zooplankton associated with changes in invertebrate predator density, observed in previous Great Lakes studies, is due to behavioral responses to reduce predation risk. It is important to understand and quantify such responses, because predator-induced changes in prey behavior represent trait-mediated interactions that can potentially strongly affect prey growth rates, and indirectly affect resources, competitors, and predators of the prey.

PICHLOVA, R., A. Weber and B. Gosser. Leptodora kindtii survival in the laboratory. Aquatic Ecology 38:537-546 (2004).

Leptodora kindtii, a pelagic predatory cladoceran, suffers high mortality on transfer to laboratory, which makes the experimental work difficult. We investigated the causes of high mortality, using four variables: water volume, animal density, light intensity, and origin of water for culturing, i.e., water from native or a non-native lake. For the experiments we used Leptodora and water from Lake Loosdrecht and Lake Maarsseveen  The Netherlands . Water was found to be the most important factor; the animals did not necessarily do better in lake water from which they were collected. Water volume and animal density were of limited importance, and light intensity did not affect survival.

Pinho, U. F., P. C. LIU and C. E. P. Ribeiro. Freak waves at Campos Basin, Brazil. Geofizika 21:53-67 (2004).

Freak waves occur abundantly in Campos Basin, located on the northeast coast of Rio de Janeiro, Brazil in the South Atlantic Ocean. This surprising and unexpected discovery was made from a search of the time-series data of wave measurements recorded in the Campos Basin from 1991 to 1995. In a study on the occurrence of freak waves and their relevant properties, we have also found that freak waves are not of rare occurrence as conventionally presumed, and they occur not only during storm conditions but also during fair weather states as well. While the conventional approach of spectrum analysis provides some weak inference of freak wave effects, the basically stationary random process approach is clearly incapable of contending with the localized non-stationary process of freak wave occurrences.

POTHOVEN, S. A. and H. A. VANDERPLOEG. Diet and prey selection of alewives in Lake Michigan: seasonal, depth, and interannual patterns. Transactions of the American Fisheries Society 133:1068-1077 (2004).

To evaluate the current diet of alewives Alosa pseudoharengus and interactions with their prey in light of recent changes in Lake Michigan, we determined the seasonal diet and prey selectivity of large (>100 mm total length) and small (<100 mm) alewives in southeastern Lake Michigan. Selectivity and diet were evaluated on a biomass basis for alewives collected near Muskegon, Michigan, during June, July-August, and October 1999-2001. Fish were sampled from three depth zones: shallow (15-25 m), transitional (35-55 m), and deep (65-90 m). Prey selectivity and diet patterns indicated that alewives had considerable flexibility in adjusting to prey availability, which varied by season, depth zone, and year. Although small copepods were an abundant prey item throughout the year and in all depth zones, they were mainly important in the diet (large and small alewives) in June and at the shallow stations, where many of the other prey types were not available. Despite declining numbers, Diporeia continued to be important for large alewives in spring, particularly at the transitional and deep stations, where their biomass was many times higher than that of other prey. During summer, large alewives selected either Bythotrephes longimanus or Mysis relicta in all depth zones and years. The diet of large alewives consisted mainly of Mysis in July 1999 and August 2001, whereas in August 2000 mainly Bosmina were eaten. During October, Mysis and Bythotrephes, along with large zooplankters (Daphnia spp. and large calanoid copepods), were selected and were most important in the diet of large alewives. In contrast, only the large zooplankton were selected and were important prey for the small alewives in fall. Annual, seasonal, and depth differences in prey biomass as well as differences in alewife size all influenced diet and selectivity patterns.

POTHOVEN, S. A. Changes in Lake Whitefish diet: Lake Michigan. In Proceedings of a Workshop on the Dynamics of Lake Whitefish (Coregonus clupeaformis) and the amphipod Diporeia spp. in the Great Lakes. L. C. Mohr and T.F. Nalepa (eds.). Great Lakes Fishery Commission, Technical Report 66, Ann Arbor, MI, 127-140 (2005).

Lake whitefish (Coregonus clupeaformis) were collected for diet analysis from Michigan�s waters of Lake Michigan during 1998-2001. When the benthic amphipod Diporeia spp. was available, it was an important item in the diets of small (<430 mm) and large (>430 mm) Lake Whitefish. In southern Lake Michigan, the most-common prey consumed in the absence of Diporeia spp. included zebra mussels (Dreissena polymorpha), gastropods, chironomids, and Mysis relicta. In northern regions of the lake, alternative prey included chironomids, isopods, Bythotrephes, and fish. Following the decline of Diporeia spp. in southeastern Lake Michigan between 1998 and 2001, their contribution to the diet of small lake whitefish fell from 57% to 1% (dry weight). The contribution of Diporeia spp. to the diet was similar for small fish captured in nearshore (9-30 m) and offshore (31-46 m) waters. Mysis were more common in the diets of fish collected at offshore stations whereas chironomids and zebra mussels were more common in fish from nearshore stations.

RUBERG, S.A., D.F. Coleman, T.H. JOHENGEN, G.A. Meadows, H.W. VanSumeren, G. A. LANG, and B. A. Biddanda. Groundwater plume mapping in a submerged sinkhole in Lake Huron. Marine Technology Society Journal 39(2):65-69 (2005).

A multidisciplinary exploratory project team from the Institute for Exploration, the Great Lakes Environmental Research Laboratory, Grand Valley State University, and the University of Michigan located and explored a submerged sinkhole in Lake Huron during September 2003. A CTD system and an ultra-short baseline (USBL) acoustic navigational tracking system integrated with an open frame remotely operated vehicle (ROV) provided high-resolution depth, temperature, and conductivity maps of the sinkhole and plume. Samples were also peristaltically pumped to the surface from a depth of 92 meters within and outside of the sinkhole plume. A 1-2 m thick cloudy layer with a strong hydrogen sulfide odor characterized the water mass close to the plume. Relative to ambient lake water, water samples collected within this layer were characterized by slightly higher (4-7.5 oC) temperatures, very high levels of chloride and conductivity (10-fold) as well as extremely high concentrations of organic matter (up to 400 mg C/L), sulfate, and phosphorus. Our observations demonstrated the occurrence of unique biogeochemical conditions at this submerged sinkhole environment.

SANO, L. L., A. M. Krueger and P. F. LANDRUM. Chronic toxicity of glutaraldehyde: differential sensitivity of three freshwater organisms. Aquatic Toxicology 71:283-296 (2005).

The biocide, glutaraldehyde, is a potential environmental contaminant due to its widespread use in medical applications, off-shore oil extraction, and pulp mill processing. It has also been proposed as a candidate for treating the ballast water of vessels, which could result in a substantial increase in environmental release. To assess the potential for environmental impacts associated with glutaraldehyde, three standard chronic toxicity bioassays were performed: 96-h phytoplankton growth bioassays using Pseudokirchneriella subcapitata (formerly, Selenastrum capricornutum), three-brood reproduction bioassays using Ceriodaphnia dubia, and an embryo–larval bioassay using steelhead trout, Oncorhynchus mykiss. For the green alga, P. subcapitata, significant decreases in growth were observed at glutaraldehyde concentrations greater than or equal to 1.0 mg L-1. Embryos of O. mykiss demonstrated a similar sensitivity with exposures of 2.5 mg L-1 resulting in a 97% reduction in hatch rate. In most cases, this failure to hatch was due to the inability of the embryo to leave the chorion and not to early embryo mortality. In contrast, reproduction and mortality rates in C. dubia were not as sensitive to glutaraldehyde: decreased reproduction was detected at 4.9 mg L-1 (the lowest observed effect concentration), and is similar to concentrations causing acute mortality in adults (4.7 mg L-1 for the estimated LC50, or 50% lethal concentration). These data indicate that both algae and fish embryos may be particularly sensitive to long-term glutaraldehyde exposure; however, this is predicated on whether glutaraldehyde concentrations will achieve high enough environmental concentrations and for a sufficient period of time to elicit such effects.

SANO, L. L. and P. F. LANDRUM. Evaluation of different biocides for potential use in treating overseas unballasted vessels entering the Great Lakes. Aquatic Invaders 16(July-September 2005):1-11 (2005).

The North American Great Lakes are arguably one of the world's greatest natural resources. Containing more than 5,500 cubic miles of freshwater and possessing 10,000 miles of coastline, the Great Lakes constitute a unique freshwater habitat that provides water and generates jobs for tens of millions of U.S. and Canadian citizens. Despite the immense size, the Great Lakes are extremely vulnerable to human activities. Over the decades, the ecosystem has succumbed to anthropogenic pressures associated with over-fishing, eutrophication, and urbanization. Perhaps one of the most profound anthropogenic effects, however, has been from the introduction of aquatic nonindigenous species. Although more than a dozen of these species have been introduced intentionally, most often for recreational enhancement and as biological controls for species such as the invading alewife, some of the more problematic ones are due to unintentional introductions. Two of the most notorious unintentional invaders include the sea lamprey, which was first sighted in the upper Great Lakes the early 1900s, and the zebra mussel, which was first discovered in Lake St. Clair in 1988 (Herbert et al. 1989)

Scharold, J. V., S. J. LOZANO and T. D. Corry. Status of the amphipod Diporeia spp. in Lake Superior, 1994-2000. Journal of Great Lakes Research 30(Supplement 1):360-368 (2004).

The amphipod Diporeia spp. is the dominant component of the Great Lakes benthic macroinvertebrate fauna, and plays an important role in the ecosystem. The Great Lakes Water Quality Agreement of 1978 (GLWQA) calls for the use of Diporeia as an indicator of ecological condition, with a goal of 220 to 320/m2 at depths less than 100 m, and 30-160/m2 at greater depths. To ascertain the status of Diporeia in Lake Superior, a probability-based survey of 27 sites representing the U.S. nearshore (10 to 110 m) waters of Lake Superior was conducted in 1994, and again in 2000. During 1995 to 1998, ten nearshore non-depositional sites and five sites in major depositional basins in the western half of the lake were revisited yearly to examine variability of Diporeia abundance. In 1994, nearshore Diporeia abundance ranged from 550 to 5500/m2, and the entire nearshore area met or exceeded the GLWQA ecosystem objective. In 2000, abundance ranged from less than 10 to 2,800/m2, and 11% of the nearshore area did not meet the GLWQA objective. The area that did not meet the GLWQA objective was located in the eastern half of the lake. Examination of yearly abundance data in the western half of Lake Superior did not reveal a significant trend at nearshore or offshore sites. Although Diporeia abundance in the eastern half of the lake was lower in 2000 than 1994, the severe declines in Diporeia populations that have been observed in the lower Great Lakes are not evident in Lake Superior. Abundances of Diporeia observed in the present study are higher than those reported in the 1970s by a factor of seven.

Schuler, L. J., P. F. LANDRUM and M. J. Lydy. Time-dependent toxicity of fluoranthene to freshwater invertebrates and the role of biotransformation on lethal body residues. Environmental Science and Technology 38:6247-6255 (2004).

The time-dependent toxicity of fluoranthene was examined for Hyalella azteca, Chironomus tentans, and Diporeia spp. C. tentans appeared to be the most sensitive species, and Diporeia was the least sensitive. Incipient LC50 values, the concentration at which the LC50 reaches an asymptote and does not change with increasing duration of exposure, for H. azteca and C. tentans were approximately 60 and 40 mgL-1, respectively. Incipient levels were not reached for Diporeia; however, the 28-d LC50 concentration was 95.5 mgL-1. There was a temporal relationship with respect to lethal body residues for each of the test species. For H. azteca, the LR50, the median lethal residue at an identified exposure time required to cause 50% mortality, based on total fluoranthene equivalents (parent+metabolite compounds) decreased from 3.19 mgL-1 at 5 d to 0.80 mgL-1 at 28 d. For C. tentans, the LR50 decreased from 0.43 to 0.17 mgL-1 from 2 to 10 d. The 10-d LR50 for Diporeia was 9.97 mgL-1, and the 28-d value was 3.67 mgL-1. The toxicokinetics are not sufficient to address the temporal changes in LR50 values. Thus, the data were fit to a Damage Assessment Model that also accounts for toxicodynamic processes. This analysis provides estimates of the incipient lethal residues for H. azteca, C. tentans, and Diporeia: 0.84, 0.21, and 3.00 mgL-1, respectively. When comparing the relative sensitivity among species using lethal body residues, special attention should be given to ensure that comparisons are made at a common point in relation to exposure duration (i.e., time to steady state, Tss). When the LR50 (lipid) values among the three species were compared at steady state, C. tentans is more sensitive than H. azteca and Diporeia spp.; however, there are no significant differences between the amphipod species. The greater sensitivity of C. tentans to fluoranthene as compared to the amphipods may be due, in part, to a potential toxic metabolite.

SCHWAB, D. J., T. E. CROLEY IIand W. M. Schertzer. Physical, limnological, and hydrological characteristics of Lake Michigan. In State of Lake Michigan (SOLM) - Ecology, Health, and Management. T. Edsall and M. Munawar (eds.). Ecovision World Monograph Series, Aquatic Ecosystem Health and Management Society, 3-52 (2005).

No abstract.

STURTEVANT, R. Great Lakes Ecological Forecasting Needs Assessment. NOAA Technical Memorandum GLERL-131, NOAA Great Lakes Environmental Research Laboratory, Ann Arbor, MI, 60 pp. (2004).

To maximize the benefits of our ecosystems, to sustain these benefits into the future and to restore the benefits of impaired systems, decision-makers increasingly rely on understanding of long and short-term changes in ecosystem structure and function. Science today is challenged to play an increasing role in providing forecasts of such changes at temporal and spatial scales appropriate to these decision-making processes and sufficient to support proactive ecosystem management. Ecosystems are influenced by physical, chemical, biological and anthropogenic processes causing complex changes in system structure and function. Predicting these changes – and particularly the effect of these changes on human end-users – in a form that makes the predictions useful to decision makers is the heart of the ecological forecasting concept. This preliminary needs assessment is largely the result of a workshop held at the Great Lakes Environmental Research Laboratory in August of 2003. Workshop participants were challenged to think broadly about the needs of the coastal constituencies whom they represent and with whom they interact on a regular basis that could be served by ecological forecasting. Workshop participants engaged in several levels of prioritization exercises leading to a preliminary recommendation as to areas in which Great Lakes research should focus in developing ecological forecasting capacity.

Thayer, G. W., T. A. McTigue, R. J. Salz, D. H. MERKEY, F. M. Burrows and P. F. Gayaldo. Science-Based Restoration Monitoring of Coastal Habitats. Volume Two: Tools for Monitoring Coastal Habitats. NOAA National Centers for Coastal Ocean Science, Silver Spring, MD, 628 pp. plus appendices (2005).

Without effective monitoring, restoration projects are exposed to several risks including:  (1) the inability to obtain early warnings indicating that a restoration project is not developing as expected, (2) the inability to assess whether specific project goals and objectives (both ecological and human dimensions) are being met, (3) the inability to determine what measures might need to be taken to better achieve those goals, (4) increased difficultly in gauging how well a restoration site is functioning both before and after implementation, and (5) decreased project coordination and efficiency. To address these and other issues associated with restoration monitoring, NOAA has provided guidance to the public in two volumes. The first volume, Science-Based Restoration Monitoring of Coastal Habitats, Volume One: A Framework for Monitoring Plans under the Estuaries and Clean Waters Act of 2000 (Public Law 160-457) was released in 2003. It outlines the steps necessary to develop a monitoring plan for any coastal habitat restoration project. Experienced restoration practitioners, biologists, and ecologists as well as those new to coastal habitat restoration and ecology can benefit from the step-by-step approach to designing a monitoring plan outlined in Volume One. Volume Two, Tools for Monitoring Coastal Habitats expands upon the information in Volume One. Volume Two is designed more for practitioners who do not have extensive experience in coastal ecology or social science than is Volume One. Professionals familiar with coastal habitats and their social and ecological aspects, however, may benefit from the annotated bibliographies, literature review, and other tools provided in Volume Two. Volume Two is intended to provide readers with information on and pertinent to monitoring of restoration activities and, in so doing, includes references to ecological and human dimensions characteristics and to restoration efforts. Volume Two is not intended, however, as a treatise on the ecology and social aspects of each of the habitats. Numerous texts and published documents that do this well are already available, particularly for the ecological characteristics. Likewise, detailed discussions of the restoration of the various habitats are also not presented; again, for many of the habitats, scientific publications on individual restoration methods and projects already exist.

Word, J. Q., B. B. Albrecht, M. L. Anghera, B. Baudo, S. M. Bay, D. M. DiToro, J. L. Hyland, C. G. Ingersoll, P. F. LANDRUM, E. R. Long, J. P. Meador, D. W. Moore, T. P. O'Connor and J. P. Shine. Predictive ability of sediment quality guidelines. In Use of Sediment Quality Guidelines and Related Tools for the Assessment of Contaminated Sediments. R.J. Wenning, G.E. Batley, C.G. Ingersoll, and D.W. Moore (eds.). Society of Environmental Toxicology and Chemistry, Pensacola, FL, 121-161 (2005).

The quantitative extent to which sediment quality guidelines (SQGs) are predictive of the presence, or absence, of toxicity of contaminated sediment to sediment-dwelling organisms or to higher trophic-level organisms is a critical concern among scientists and regulators evaluating the application of one or more numeric SQG approaches in assessments of sediment quality. Users of these guidelines should understand how well various SQGs predict the presence or absence and extent of toxicity in sediment samples. The ability of various SQGs to represent the potential for effects or no effects of contaminants on organisms in freshwater, estuarine, and marine environments was examined through a review of the published literature focused on 3 specific questions:

1) How well do SQGs represent the potential for effects or no effects observed in laboratory toxicity tests and in field studies of benthic communities?

2) How well do SQGs represent the potential for effects or no effects in organisms as a result of contaminant uptake and/or trophic transfer?

3) How have SQGs been applied and validated in the field as part of sediment management and risk management decision making?

Zhulidov, A. V., D. A. Zhulidov, D. F. Pavlov, T. F. NALEPA and T. U. Gurtovaya. Expansion of the invasive bivalve mollusk Dreissena bugensis (quagga mussel) in the Don and Volga River basins: revisions based on archived specimens. Ecohydrology and Hydrobiology 5(2):127-133 (2005).

Archived specimens of Dreissena, collected as part of a long-term biomonitoring effort in the lower Don and Volga River systems and dating back to 1979, were reexamined. Originally identified as Dreissena polymorpha or variants thereof, some of the specimens were identified to be Dreissena bugensis. Based on this new evidence, the invasion history of D. bugensis in these two river systems was re-evaluated. The finding of D. bugensis in the lower Volga River in the early 1980s rather than in the late 1980s/early 1990s indicates that its spread was much slower than earlier believed. Apparently, widespread dispersal was greatly facilitated by the completion of the reservoir system in the Volga River in the late 1980s which created conditions that were more conducive to this species. Upstream dispersal in both the Don and Volga Rivers was likely a function of human-mediated transport.



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