GLERL Publications Abstracts: FY 1989

Publications List Key
Capitalized names represent GLERL authors.
* = Not available from GLERL.
** = Available in GLERL Library only.

ASSEL, R.A. Impact of global warming on Great Lakes ice cycles. In The Potential Effects of Global Climate Change on the United States: Appendix A - Water Resources, U.S. EPA Office of Policy, Planning and Evaluation, Washington, DC, 5.1-5.30 (1989). https://www.glerl.noaa.gov/pubs/fulltext/1989/19890008.pdf

No abstract.

Bedford, K.W., C.J. Merry, and D.J. SCHWAB. Real-time Lake Erie current and temperature field forecasting--An integrated modeling and AVHRR methodology. Proceedings, 1989 American Society of Photogrammetry and Remote Sensing, Cleveland, OH, September 17, 1989. (1989).

This presentation is offered in the nature of a concept review. A real-time forecasting system is being developed to predict the three-dimensional distributions of currents and temperature in each of the Great Lakes. Two-dimensional surface distributions of water-level, wind waves and shoreline erosion potential are to be predicted as well. The Lake Erie Forecasting System (LEIFS) is the first of the Great Lakes to be implemented. Temperature calculations proceed with knowledge about the existing temperature state of the Lake and the surface heat transfer rate. AVHRR satellite data and a network of privately and publicly held temperature data are being used to provide these data. This presentation reviews elements of the proposed forecasting concept and its thermal data component.

BEETON, A.M. A vision of the future. Proceedings, The Great Lakes Basin: A Regional Focus on the Environment and Human Health, Chicago, IL, October 16-18, 1988. Great Lakes Coalition of Public Health Associations, 31-35 (1989).

No abstract.

BENNETT, J.R., and J.E. CAMPBELL. Accuracy of a finite-difference method for computing lake currents. Journal of Computational Physics 68(2):262-271 (1987).

A semi-analytic model is used to assess the accuracy of a finite-difference model for computing lake currents. Both models solve the vorticity equation for two-dimensional, time-dependent now to compute currents in a circular lake with a parabolic depth profile. The semi-analytic solution is obtained by using separation of variables to remove the azimuthal dependence and reduce the equations in cylindrical coordinates to a single equation in two variables, time and radius. This equation is then solved by a finite-difference technique for grid sizes small enough that the solution appears to converge. Comparison with the rectangular finite-difference solution shows a strong improvement in accuracy with decreasing grid size. It is found that about 20 grid points across a lake basin are required to adequately resolve wind driven flow.

BOLSENGA, S.J. Certain properties of spectrally integrated and spectral transmittances of freshwater ice from 400-700 nm. Proceedings, POAC '89: 10th International Conference on Port and Ocean Engineering under Arctic Conditions, Lulea, Sweden, June 12-16, 1989. Lulea University of Technology, 188-198 (1989).

Considerable information is available on the transmittance of photosynthetically active radiation (PAR: 400-700 nm) through sea ice, whereas relatively little is known about PAR transmittance through freshwater ice. Transmittances of PAR through some common freshwater ice types (including clear ice, refrozen slush, and snow ice) are reported from studies using instruments which measure both spectral (2-10 nm increments) and spectrally integrated transmittances over this range. Snow causes the greatest attenuation of radiation, often reducing transmittances to 10% or less over the spectrum as a result of even light covers (2-8 cm). Clear ice showed transmittances of 80-95% for the spectrally integrated data and from 65 to nearly 95% for the spectral data. Transmittances of other ice types were bounded by the clear ice/snow-covered-ice transmittance range. Comparisons between the spectral and spectrally integrated data sets show specific applications for each type of measurement.

BOLSENGA, S.J., J.E. Gannon, G. Kennedy, D.C. NORTON, and C.E. Herdendorf. ROV dives under Great Lakes ice. Cold Regions Science and Technology 16:89-93 (1989).

No abstract.

BOLSENGA, S.J., H.A. VANDERPLOEG, M.A. QUIGLEY, and G.L. FAHNENSTIEL. Note--Operations for an under-ice ecology program. Journal of Great Lakes Research 14(3):372-376 (1988). https://www.glerl.noaa.gov/pubs/fulltext/1988/19880009.pdf

A pilot program tested the feasibility of conducting a study on the under-ice ecology of the Great Lakes. The east arm of Grand Traverse Bay, in the lower peninsula of Michigan, was chosen as the test area. The project was conducted in three phases; (1) a pre-ice cruise (open-water), (2) an under-ice phase, and (3) a post-ice cruise (open water). Overall, an under-ice ecology program that could produce sound scientific results was found to be feasible. However, to be successful, detailed planning is essential and careful attention must be given to operational safety, proper winter clothing, and scientific coordination.

CARRICK, H.J., and R.L. Lowe. Benthic algal response to N and P enrichment along a pH gradient. Hydrobiologia 179:119-127 (1989).

Nutrient enrichment and its effect on benthic algal growth, community composition, and average cell size was assessed across two sites of differing pH within a single habitat. Nutrients were added using in situ substrata, which released either N, P, or no additional nutrients (controls) at each site for 21 days. Upon collection, chlorophyll and biovolume standing stocks of the attached algal microflora were measured. Chlorophyll concentration was different among all treatments, accumulating greatest on P, followed by N, and the least on C substrata (P < 0.001) and was highest at site-2 (P < 0.001), while total algal biovolume was highest on P compared to both N and C substrata (P < 0.05) and did not vary between sites. Increased growth on P substrata was due to the enhanced biovolume of filamentous green algae, although the affected taxa varied between sites. Biovolume to cell density ratios (as a measure of average cell size) were highest on P substrata over both N-enriched and control substrata (P < 0.05) and this pattern was similar between sites. Progression towards a community composed of larger cells following P enrichment observed along this pH gradient, seems to be related to the dominance of larger celled filamentous green algae. Thus, nutrients exhibited greater control on benthic algal growth than did changes in hydrogen ion concentration.

CARRICK, H.J., R.L. Lowe, and J.T. Rotenberry. Guilds of benthic algae along nutrient gradients: Relationships to algal community diversity. Journal of North American Benthological Society 7(2):117-128 (1988).

We attempt to define groups of functionally related benthic algal species or guilds to assess if the species richness of such guilds varies across experimentally manipulated nutrient gradients, and to determine the relative contribution of these guilds to total community diversity. Nutrient gradients were established using nutrient-releasing substrata; treatments consisted of Si, N+P, Si+N+P, and controls. Nutrient enrichment significantly altered the biovolume of 27 species (out of a total of 141). Results from one-way ANOVA tests coupled with multiple means range tests categorized these species into four major guilds: three guilds of species which achieved their highest abundance on either Si, N+P, or Si+N+P treatments, and a guild that grew best on controls. This pattern of structuring was corroborated by cluster analysis and principal components analysis. Total community diversity and the relative contribution of guilds to total community diversity was less on N+P and Si+N+P substrata compared with that on Si and the control substrata. This suggests that nutrient enrichment may narrow the conditions amenable to many algal species (nutrient generalists), creating a niche occupied by those taxa sufficiently equipped to benefit under such conditions (nutrient specialists).

CAVALETTO, J.F., H.A. VANDERPLOEG, and W.S. GARDNER. Wax esters in two species of freshwater zooplankton. Limnology and Oceanography 34(4):785-789 (1989). https://www.glerl.noaa.gov/pubs/fulltext/1989/19890007.pdf

Lipid classes were determined in three Lake Michigan hypolimnetic calanoid copepods, Limnocalanus macrurus, Diaptomus sicilis, and Senecelia calanoides. Limnocalanus macrurus and S. calanoides contained large stores of wax esters (57-80% of total lipid). Wax esters in this amount have not previously been reported for freshwater zooplankton. Diaptomus sicilis exhibits a typical freshwater lipid profile and contains triacylglycerols as its lipid reserves. Lipid storage sites are morphologically different in the copepods. Limnocalanus macrurus and S. calanoities store their wax esters in a large sac that surrounds the intestine, whereas D. sicilis maintains lipid droplet morphology typical of freshwater "triacylglycerol-storing" zooplankton. Limnocalanus macrurus and S. calanoides are "glacial relicts," which may explain the origin of their typically marine wax ester lipid class.

CLITES, A.H. Observations of concurrent drifting buoy and current meter measurements in Lake Michigan. Journal of Great Lakes Research 15(2):197-204 (1989). https://www.glerl.noaa.gov/pubs/fulltext/1989/19890001.pdf

Data generated by satellite-tracked drifting buoys released in the Great Lakes are being used to study lake circulation and test trajectory prediction models. Before data from drifters can be used with confidence, the water-tracking accuracy of the drifters must be known. During the winter of 1983, drogued drifters were released in Lake Michigan in the vicinity of an array of vector-averaging current meters. Several times during the next 3 months, the drifters moved within a few kilometers of one of the current meters and remained in the vicinity for up to 30 hours. The average wind effect that best aligns the currents measured by the moored current meters and the currents from drifter paths is 0.76% of the wind speed. This value is the weighted average of the wind effects calculated for seven separate cases, which ranged from 0.06% to 2.09% of the wind speed. The average value is in good agreement with theoretical estimates and field test results. The horizontal coherence of the currents within 5 km was fairly high as revealed by comparisons between drifter trajectories and current meter progressive vectors. The separation distance between the vectors was generally under 1 km while drifter path length ranged from 4 to 9 km. Results indicate that during these encounters, about 25% of the variability between current trajectories estimated by drifting buoys and current meter measurements is explained by a simple wind correction. The remaining discrepancy is attributed to wave action (Stokes drift) and data limitations such as a lack of overlake wind conditions.

CROLEY, T.E.II. Lumped modeling of Laurentian Great Lakes evaporation, heat storage, and energy fluxes for forecasting and simulation. NOAA Technical Memorandum ERL GLERL-70, Great Lakes Environmental Research Laboratory, Ann Arbor, MI (PB89-185540/XAB) 48 pp. (1989). https://www.glerl.noaa.gov/pubs/tech_reports/glerl-070/

Lake evaporation for the Laurentian Great Lakes is of the same order of magnitude as precipitation and runoff to the lakes and its estimation is important for simulations and forecasts of lake levels. Water or energy balance estimates of Great Lakes evaporation require storage-change data, not available in simulations or forecasts, and errors in the components of the balances are summed in the residual, giving large estimation errors for evaporation. Evaporation models, which use the aerodynamic equation with mass transfer coefficients developed originally in the Lake Hefner studies, were further developed for Lake Ontario during the International Field Year for the Great Lakes and adapted for other Great Lakes. Neither these models nor the balance models can be verified since independent estimates of evaporation are not available with sufficient accuracy. However, surface temperatures are available and can be used as verification data. The mass transfer coefficient research (where water surface temperatures must be known) is combined here with lumped model concepts of classical energy conservation and superposition heat storage to provide continuous simulation capability of both water surface temperatures and lake evaporation for use in outlooks and forecasts of lake levels. A new function is presented that uses a simple relation between surface temperature and heat stored in a lake based on current understandings of the thermal structure of large lakes. Calibration of the resulting model matches the water surface temperatures for those Great Lakes and small Lake St. Clair with satellite observations of water surface temperatures over the past 20 years. Evaporation and heat budgets over the annual cycle are presented for four of the Great Lakes and Lake St. Clair, and comparisons with long-term water balances are made.

CROLEY, T.E.II. Verifiable evaporation modeling on the Laurentian Great Lakes. Water Resources Research 25(5):781-792 (1989).

Water or energy balance estimates of Great Lakes evaporation require storage change data, not available in simulations or forecasts, and errors in the components of the balances are summed in the residual, giving large estimation errors. Neither these balance estimates nor evaporation models, which use the aerodynamic equation with mass transfer coefficients developed originally in the Lake Hefner studies, can be verified, since independent estimates of evaporation are not available with sufficient accuracy. However, water surface temperatures can be used to verify energy budgets. The mass transfer coefficient research is combined here with lumped concepts of classical energy conservation and a new superposition heat storage model to provide continuous simulation capability of both water surface temperatures and lake evaporation for use in outlooks and forecasts of lake levels. Calibration matches remotely sensed water surface temperatures for those Great Lakes with observations over the past 20 years. Model sensitivities are analyzed and heat and water budgets are compared.

CROLEY, T.E., II, and H.C. HARTMANN. Climate change effects on Great Lakes levels. Reprinted from Hydraulic Engineering Proceedings '89, National Conference, New Orleans, LA, August 14-18, 1989. Hydraulic Division/American Society of Civil Engineers, New York, NY, 653-658 (1989).

The Great Lakes Environmental Research Laboratory has developed conceptual models for simulating moisture storages in and runoff from the 121 watersheds draining into the Laurentian Great Lakes, overlake precipitation into each lake, the heat storages in and evaporation from each lake, connecting channel flows and lake levels, and regulation of flows at control points. We determine net water supplies and levels for each lake to consider climate change scenarios developed from atmospheric general circulation models through linkages on air temperature, precipitation, humidity, wind speed, and cloud cover. Scenarios of a doubling of atmospheric C02 are considered by abstracting changes in linkages, making these changes in historical data, observing the impact of the changed data in model outputs, and comparing it to model results obtained from. unchanged data. The implications of the climate change effects modeled herein suggest that new paradigms in water management will be required.

Eisenreich, S.J., P.D. Capel, J.A. ROBBINS, and R. Bourbonniere. Accumulation and diagenesis of chlorinated hydrocarbons in lacustrine sediments. Environmental Science and Technology 23(9):1116-1126 (1989).

Two sediment cores were taken from the Rochester Basin of eastern Lake Ontario and analyzed for the radionuclides 210Pb and 137Cs and several high molecular weight chlorinated hydrocarbons (CHs). The two sites are geographically proximate but differ in sedimentation rate, permitting sedimentation-dependent processes to be factored out. The 210Pb chronology showed a mixed depth of 3-5 cm and an intrinsic time resolution of 11-14 years. Vertically integrated numbers of deposit-feeding oligochaete worms and burrowing organisms are insufficient to homogenize the sediment on the time scale of CH inputs, which are non steady state. U.S. production and sales of polychlorinated biphenyls (PCBs), DDT, Mirex, and hexachlorobenzene (HCB), as determinants of the shape of the input function, adequately predict the overall shape and, in many cases, details in the sedimentary profile. Sediment focusing factors (FF) inferred from 137Cs and 210Pb inventories averaged 1.17 and 1.74 for cores E-30 and G-32, respectively. This permitted CH accumulation rates to be corrected for focusing. Apparent molecular diffusion coefficients modeled for many of the CHs were about (1-3) x 10-9 cm2/s.

Evans, M.S., and P.F. LANDRUM. Toxicokinetics of DDE, Benzo(a)pyrene, and 2,4,5,2',4',5',-Hexachlorobiphenyl in Pontoporeia hoyi and Mysis relicta. Journal of Great Lakes Research 15(4):589-600 (1989). https://www.glerl.noaa.gov/pubs/fulltext/1989/19890004.pdf

The toxicokinetics of DDE, benzo(a)pyrene (BaP), and 2,4,5,2',4',5'-hexachlorobiphenyl (HB) were followed for the amphipod, Pontoporeia hoyi, and the mysid, Mysis relicta. Pontoporeia and Mysis had similar uptake clearances (Ku) for DDE (mean = 79.2 mL/g/h and 46.0 mL/g/h and 57.5 mL/g/hr, respectively) compounds with log octanol-water partition coefficients (Kow's) ranging from 5.7 to 6.7. Amphipods and mysids were most efficient at eliminating BaP (mean Kd = -0.0017/h and -0.0047/h, respectively) and least efficient at eliminating HB (mean = -0.0008/h and -0.0001/h respectively). Amphipods were more efficient than mysids in eliminating DDE (mean = -0.0010/h and -0.0005/h, respectively) and HB while mysids were more efficient at eliminating BaP. Because Kd's for DDE, BaP, and HB were substantially different between P. hoyi and M. relicta, there were substantial differences in the calculated bioconcentration factors (BCFs). Amphipods tended toward larger BCFs than mysids for BaP (mean = 48,582 and 8,496, respectively) but lower BCFs for DDE (mean = 95,629 and 138,760, respectively) and HB (mean = 101,663 and 442,231, respectively) than mysids.

FAHNENSTIEL, G.L., and H.J. CARRICK. Primary production in Lakes Huron and Michigan: In vitro and in situ comparisons. Journal of Plankton Research 10(6):1273-1283 (1988). https://www.glerl.noaa.gov/pubs/fulltext/1988/19880018.pdf

Oxygen- and carbon-14-based primary production estimates from 9-16 h in vitro incubations were compared in Lakes Huron and Michigan. For surface mixing layer comparisons, gross O2/14C photosynthetic quotients (gross PQ) averaged 2.2, and net O2/14C photosynthetic quotients (net PQ) averaged 1.4. The mean gross PQ is consistent with a theoretical PQ based on the CO2 and NO3 assimilation ratio. However, within the deep chlorophyll layer, gross PQ and net PQ averaged 4.9 and 2.8 respectively. These higher values were likely due to excess NO3 reduction at the expense of CO2 uptake . Thus, during short experiments under low light conditions, oxygen evolution and CO2 uptake may not be tightly coupled. In vitro and in situ O2-based production estimates were compared in four diurnal (dawn to dusk) experiments in Lake Huron. In situ production estimates were determined by measuring water-mass oxygen changes and oxygen transfer across the air-water interface. In situ production estimates were approximately twice in vitro production estimates for both surface mixing layer and deep chlorophyll layer comparisons. The difference between estimates was attributable to containment effects manifest in 13-16 h bottle incubations. Short-term (1-2 h) in vitro production was also compared to diurnal in vitro production. Rates of short-term production were ~1.6 times higher than rates of diurnal production, suggesting that short-term in vitro production experiments may provide reasonable estimates of in situ primary production.

FAHNENSTIEL, G.L., J.F. CHANDLER, H.J. CARRICK, and D. SCAVIA. Photosynthetic characteristics of phytoplankton communities in Lakes Huron and Michigan: P-I parameters and end-products. Journal of Great Lakes Research 15(3):394-407 (1989). https://www.glerl.noaa.gov/pubs/fulltext/1989/19890002.pdf

Photosynthetic-irradiance (P-I) curves and partitioning of photosynthate into major end-products (protein, lipids, polysaccharides, and low molecular weight [LMW] metabolites) were examined for phytoplankton communities from Lakes Huron and Michigan. The mean and variance of P-I parameters and photosynthetic end-products were similar in both lakes. Mean PBM (maximum light saturated rate) and a (initial linear slope) values were 2.3 mg C mg Chl-1 h-1 and 5.5 mg C mg Chl-1 Einst-1 m2 for Lake Huron communities, and 2.4 mg C mg Chl-1lh-1 and 7.0 mg C mg Chl-1 Einst-1 m2 for Lake Michigan communities. The mean percent incorporation of 14CO2 into proteins, lipids, polysaccharides, and LMW metabolites from short-term experiments (2-4 h) were 32.4, 21.3, 28.0, and 18.9, respectively, for Lake Huron communities and 34.8, 24.7, 24.5, and 15.8, respectively, for Lake Michigan communities. Over longer incubations the activity in each end-product increased linearly during the day; during the night the activity in the LMW and polysaccharide fractions decreased and the activity in the protein fraction increased. There were significant seasonal variation in P-I parameters and the photosynthetic end-products. In both lakes, phytoplankton communities from the late winter-spring isothermal period were characterized by lower PBM values, higher a values, significant susceptibility to photoinhibition, and less incorporation into protein, as compared to communities from periods when the lakes were thermally stratified.

Fox, M.G., and A.M. BEETON. Phosphorus concentration trends in the Saline River watershed, USA. Verhandlungen-Internationale Vereinigung Fuer Theoretische und Angewandte Limnologie 23:1119-1124 (1988).

No abstract.

GARDNER, W.S., J.F. CHANDLER, and G.A. LAIRD. Organic nitrogen mineralization and substrate limitation of bacteria in Lake Michigan. Limnology and Oceanography 34(2):478-485 (1989).

https://www.glerl.noaa.gov/pubs/fulltext/1989/19890006.pdf

Labile organic nitrogen mineralization and the apparent degree of bacterial substrate limitation were examined to consider seasonal relationships between substrate availability and bacterial activity in Lake Michigan. Accumulation rates of ammonium nitrogen in amino acid fortified and unfortified samples of epilimnetic Lake Michigan water, incubated in the dark, provided reasonable estimates of potential and actual rates of organic nitrogen mineralization. The labile organic nitrogen demand (LOND), defined as the difference between these respective rates, provided an index of heterotrophic potential. LOND ranged from ~1-3 ng-atoms N liter h-1 (during May-June and November) to 3-9 ng-atoms N liter h-1 (during July-October) as compared to actual organic nitrogen mineralization rates of < 1 ng-atom N liter h-1 in some unfortified samples. The high LOND, relative to actual turnover, observed in late summer is consistent with the hypothesis that growth rates of epilimnetic Lake Michigan bacteria are strongly limited by organic substrate during late stratification.

GARDNER, W.S., B.J. EADIE, J.F. CHANDLER, C.C. PARRISH, and J.M. MALCZYK. Mass flux and nutritional composition of settling epilimnetic particles in Lake Michigan. Canadian Journal of Fisheries and Aquatic Sciences 46(7):1118-1124 (1989).

A series of sediment-trap samples, collected at a 30-m depth in southeastern Lake Michigan, was analyzed to evaluate the seasonal flux and nutritional value of settling epilimnetic particles as potential food for benthic organisms. Flux was highest in the spring (due in part to resuspension), lowest in the summer during stratification, and intermediate during autumn months. Organic content of the particles ranged from 10% ash free dry weight (AFDW) in March through May samples to 17-19% in July-August samples. During the summer, microbial degradation of organic materials occurred in the trap bottles without added preservative, as evidenced by less AFDW in nonpreserved trap bottles than in similar chloroform-preserved bottles. The percentage of AFDW occurring as lipid ranged from 3.5% in April-May up to 14% during May through August. Dominant lipid classes were hydrocarbons, polar lipids including phospholipids and chlorophyll a, and free fatty acids. The ratio of n-alkane C-17 (algal indicator) to n-alkane C-29 (terrestrial or resuspension indicator) and the ratio of biogenic silica to AFDW in preserved samples both reached a maximum in May, shortly before lipid content peaked in the benthic amphipod, Pontoporeia hoyi. This observation agrees with the hypothesis that P. hoyi receives much of its nutrition from the spring algal bloom.

GAUVIN, J.M., W.S. GARDNER, and M.A. QUIGLEY. Effects of food removal on nutrient release rates and lipid cotent of Lake MichiganPontoporeia hoyi. Canadian Journal of Fisheries and Aquatic Sciences 46(7):1125-1130 (1989). https://www.glerl.noaa.gov/pubs/fulltext/1989/19890009.pdf

Pontoporeia hoyi, the dominant benthic invertebrate in the upper Great Lakes, appears to be well adapted to environments with seasonal inputs of high-quality food such as those supplied by the spring diatom bloom. Ammonium and phosphate excretion rates and lipid content were examined in P. hoyi under the following conditions: (1) field animals sampled seasonally, (2) food-deprived animals in filtered lake water, and (3) control animals held in native sediments without new food inputs. Nutrient excretion rates for P. hoyi (0.5 to 2 nmole NH4 (milligrams dry weight)-1 x h-1 and 0 to 0.15 nmole PO4 (milligrams dry weight)-1 x h-1) were low relative to rates previously reported for other benthic and pelagic invertebrates and varied little among the three treatment groups. In contrast to the animals held in the laboratory without new food inputs, field-collected P. hoyi accumulated increased levels of lipids following the spring diatom bloom. However, after lipid levels in field animals peaked in May, they decreased during the rest of the season at rates similar to those of starved and control animals. P. hoyi's low nutrient-excretion rates, and its ability to accumulate and store energy as lipids, for periods when food is not abundant, appear to be important factors allowing this animal to thrive in temperate lakes with spring diatom blooms.

GOTTLIEB, E.S., J.H. SAYLOR, and G.S. MILLER. Currents and temperatures observed in Lake Michigan from June 1982 to July 1983. NOAA Technical Memorandum ERL GLERL-71, Great Lakes Environmental Research Laboratory, Ann Arbor, MI (PB90-131921/XAB) 47 pp. (1989). https://www.glerl.noaa.gov/pubs/tech_reports/glerl-071/

An array of 15 moorings, supporting current meters at 15 and 50 m depth, was in place in Lake Michigan from June 1982 to July 1983. Six moorings surrounded the southern basin on about the 75 m isobath, six closely spaced moorings transected the mid-lake ridge and adjacent valley, and three moorings occupied the centers of the southern and northern basins. In the southern basin, monthly-averaged currents are weakly anticyclonic during June and July, cyclonic during the rest of the year, and most intense during march. Temperatures and bidaily-averaged currents both show the effects of the gravest (4-day period) vortex-mode oscillation. Also, it is shown that the seasonal thermocline became well established much earlier in 1983 (early June) than in 1982 (middle August).

GOTTLIEB, E.S., J.H. SAYLOR, and G.S. MILLER. Currents, temperatures, and divergences observed in eastern central Lake Michigan during May-October 1984. NOAA Technical Memorandum ERL GLERL-72, (PB90-131194/XAB) 48 pp. (1989). https://www.glerl.noaa.gov/pubs/tech_reports/glerl-072/

An array of four instrumented moorings covering an area of 150 km2 was in place approximately 40 km offshore in eastern central Lake Michigan during May-October 1984. Each mooring supported current meters at the depth levels 5, 10, 20, 30, 50, and 100 m, and a thermistor chain between 6 and 46 m depth. The current velocity data were used to compute the divergence and curl across the array area at each depth level. Two or three events of large southeastward currents, north-south alternating wind bursts, upwelled thermocline, and increased positive divergence and negative curl were observed from mid-August to early September.

GREAT LAKES ENVIRONMENTAL RESEARCH LABORATORY. Annual Report for the Great Lakes Environmental Research Laboratory, FY 86-87. Great Lakes Environmental Research Laboratory, Ann Arbor, MI, 61 pp. (1989).

No abstract.

HARTMANN, H.C. Historical basis for limits on Lake Superior water level regulations. Journal of Great Lakes Research 14(3):316-324 (1988). https://www.glerl.noaa.gov/pubs/fulltext/1988/19880007.pdf

The 1979 International Joint Commission (IJC) Supplementary Orders of Approval for the regulation of Lake Superior outflows call for maintaining Lake Superior water levels below an elevation of 183.49 m (IGLD55) in 1985, the IJC ordered discharges in excess of the operational regulation plan outflows. Continued pressure to reduce high water levels on the lower Great Lakes by storing water in Lake Superior calls into question the sanctity of the 183.49 m (IGLD55) limit. Based on IJC hearings and historical water level records, the present limit appears to be equivalent to the upper limit specified in the original 1914 Orders of Approval, when the latter is adjusted for differential isostatic rebound. However, testimony reveals that the IJC of 1914 expected levels to exceed the limit by about 0.15 m during water supply conditions similar to those of 1869 and 1876, which were matched in 1985. Although the expected exceedance of the 1914 limit appears to be based on an inaccurate maximum water level record, other historical records substantiate that Lake Superior should be expected to rise above 183.49 m (IGLD55) during times of high water supplies, such as 1985.

Holland, R.E., A.M. BEETON, and T.H. JOHENGEN. Saline Valley rural clean water project interim report on monitoring during 1988. Contract Report, Michigan Department of Agriculture, Washtenaw County Board of Commissioners, the Monroe County Board of Commissions, the Washtenaw County Soil Conservation District, and the Monroe County Soil and Water Conservation District, 85 pp. (1989).

No abstract.

JOHENGEN, T.H., A.M. BEETON, and D.W. Rice. Evaluating the effectiveness of best management practices to reduce agricultural nonpoint source pollution. Lake and Reservoir Management 5(1):63-70 (1989).

The Saline Valley project is one of 20 national projects sponsored by the U.S. Department of Agriculture (USDA) under the Rural Clean Water Program (RCWP) to evaluate methods of controlling agricultural non-point source pollution. The goals of this project were (1) to evaluate whether a voluntary approach using cost-share incentives would produce adequate participation by local farmers and (2) to reduce phosphorus loads from the area by 40 percent. Water quality has been monitored since 1981 using weekly grab samples and flow measurements. Trends in empirical relationships between concentration and discharge at three sampling stations were used to examine the effectiveness of best management practices (BMP). These relationships were highly variable among the sub-basins and years, and did not appear to correlate with areal estimates of BMP implementation. Overall, low participation within the project area hindered the ability to quantify changes in water quality resulting from BMP implementation and prevented the project from meeting its phosphorus reduction goals.

KEILTY, T.J. Note--A new biological marker layer in the sediments of the Great Lakes: Bythotrephes cederstroemi (Schodler) Spines. Journal of Great Lakes Research 14(3):369-371 (1988). https://www.glerl.noaa.gov/pubs/fulltext/1988/19880008.pdf

The European cladoceran, Bythotrephes cederstroemi (Schodler), recently invaded the Laurentain Great Lakes. Based on recent zooplankton records, it most likely appeared first in 1984 in Lakes Ontario, Erie, and Huron, and in 1985 in Lake Michigan. It has yet to be reported from Lake Superior. This species is a relatively large-bodied predatory form that possesses a long, caudal, laterally barbed spine. B. cederstroemi spines and spine fragments were found in the upper fractions (predominantly 0-4 cm) of 35 sediment cores collected from seven areas of deposition in the eastern basin of Lake Erie. All remains were well preserved an easy to identify. Very few to 0 spines were found in core depths greater than 4 cm suggesting that the invasion of this species has resulted in a new, readily distinguishable time horizon marker.

KEILTY, T.J., and G.R. STEHLY. Preliminary investigation of protein utilization by an aquatic earthworm in response to sublethal stress. Bulletin of Environmental Contamination and Toxicology 43:350-354 (1989).

Previous studies have illustrated the potential usefulness of monitoring biomolecule levels (total protein, DNA, and RNA) in juvenile fish and invertebrates exposed to sublethal doses of environmental toxicants. Ninety-six hr exposures of five contaminants (benzophenone, ethyl acetate, hexavalent chromium, hydrogen cyanide, and p-cresol) to larval fathead minnows yielded measurable alterations in total protein, DNA, and RNA that closely paralleled results from concomitant 28-32 d growth assays (Barron and Adelman 1984). Daphnia magna exposed to toxicants in various assays also exhibited changes in protein, RNA, and DNA levels, with the most sensitive responses usually occurring during the rapid growth life stage (McKee and Knowles 1986a, b; Knowles and McKee 1987). These results suggest that the use of biomolecule analyses as indicators of reduced growth in chemically stressed aquatic organisms holds promise. Over the past several years, we have conducted both acute and sub-acute sediment bioassays using endrin-contaminated Great Lakes sediments and the aquatic earthworm Stylodrilus heringianus (Keilty et al. 1988a, b, c). Because growth, or the lack of it (measured as the change in dry worm body weight over an experiment), has proved to be a reliable indicator of sublethal stress, the relationship of total protein to dry body weight was investigated in this preliminary study. Total protein was chosen because it is relatively easy to measure (a spectrophotometer and commercially available protein reagent packages are all that is needed), is a major component of dry weight and is less susceptible to breakdown or interferences during analysis (Barron and Adelman 1984).

KEILTY, T.J., D.S. White, and P.F. LANDRUM. Sublethal responses to endrin in sediment by Limnodrilus hoffmeisteri (Tubificidae), and in mixed-culture with Stylordilus heringianus (Lumbriculidae). Aquatic Toxicology 13:227-250 (1988).

Sediment reworking by Limnodrilus hoffmeisteri (Tubificidae) alone, and with Stylodrilus heringianus (Lumbriculidae) were measured in sediments dosed with endrin by monitoring the burial of a 137cesium marker layer. Endrin concentrations ranged from 16.1 to 81 400 ng/g dry sediment weight. Alterations in reworking rates were observed at sediment concentrations two to five orders of magnitude below LC50 values. In single species experiments with L. hoffmeisteri at low endrin concentrations, marker layer burial rate data did not suggest stimulation of reworking, as had previously been found for S. heringianus. At higher concentrations, reworking rates were equal to or slower than control rates early in experiments, followed by dramatic decreases thereafter. Reworking rates with mixed species (1:1 species ratio) suggested that the presence of S. heringianus enhanced the reworking response of L. hoffmeisteri. Post-experimental worm dry weights were inversely related to high sediment concentrations for both species. Reductions in post-experimental L. hoffmeisteri mortalities and increases in L. hoffmeisteri dry weights in mixed species tests at high endrin concentrations implied that L. hoffmeisteri benefits from the presence of S. heringianus, although the reverse was not observed. High final sediment endrin concentrations in the upper three cm implied worm mediated upward contaminant transport. Bioaccumulation factors for S. heringianus ranged from 9.7 to 43.8 and were consistently three to four times greater than bioaccumulation factors for L. hoffmeisteri (1.7 to 13.6).

KEILTY, T.J., D.S. White, and P.F. LANDRUM. Sublethal responses to endrin in sediment by Stylodrilus heringianus (Lumbriculidae) as measured by a 137-cesium marker layer technique. Aquatic Toxicology 13:251-270 (1988).

Sediment reworking by Limnodrilus hoffmeisteri (Tubificidae) alone, and with Stylodrilus heringianus (Lumbriculidae) were measured in sediments dosed with endrin by monitoring the burial of a 137cesium marker layer. Endrin concentrations ranged from 16.1 to 81 400 ng/g dry sediment weight. Alterations in reworking rates were observed at sediment concentrations two to five orders of magnitude below LC50 values. In single species experiments with L. hoffmeisteri at low endrin concentrations, marker layer burial rate data did not suggest stimulation of reworking, as had previously been found for S. heringianus. At higher concentrations, reworking rates were equal to or slower than control rates early in experiments, followed by dramatic decreases thereafter. Reworking rates with mixed species (1:1 species ratio) suggested that the presence of S. heringianus enhanced the reworking response of L. hoffmeisteri. Post-experimental worm dry weights were inversely related to high sediment concentrations for both species. Reductions in post-experimental L. hoffmeisteri mortalities and increases in L. hoffmeisteri dry weights in mixed species tests at high endrin concentrations implied that L. hoffmeisteri benefits from the presence of S. heringianus, although the reverse was not observed. High final sediment endrin concentrations in the upper three cm implied worm mediated upward contaminant transport. Bioaccumulation factors for S. heringianus ranged from 9.7 to 43.8 and were consistently three to four times greater than bioaccumulation factors for L. hoffmeisteri (1.7 to 13.6)

LANDRUM, P.F. Bioavailability and toxicokinetics of polycyclic aromatic hydrocarbons sorbed to sediments for the amphipodPontoporeia hoyi. Environmental Science and Technology 23(5):588-595 (1989).

The accumulation kinetics, by the benthic amphipod, Pontoporeia hoyi, were measured for sediment-associated, selected polycyclic aromatic hydrocarbons (PAHs) and 2,4,5,2',4',5'-hexachlorobiphenyl (HCB). The kinetics data suggest that uptake occurs largely via the sediment interstitial water and is kinetically controlled by desorption from sediment particles and dissolved organic matter. Assimilation from ingested material may be significant for the more strongly sorbed compounds such as benzo[a]pyrene and HCB. The desorption rate of contaminants from the sediment matrix appears to determine whether the major sediment contaminant source is interstitial water or ingested particles. The log of the contaminant uptake clearance is inversely proportional to the log octanol-water partition coefficient for PAHs. Bioavailability of sediment-sorbed contaminants declined as the contact time between the sediment and contaminant increased. Chemical extractability remained high even though bioavailability was reduced. A conceptual model to describe accumulation or organic contaminants from sediments is described.

LANDRUM, P.F., W.R. FAUST, and B.J. EADIE. Bioavailability and toxicity of a mixture of sediment-associated chlorinated hydrocarbons to the amphipod Pontoporeia hoyi. In Aquatic Toxicology and Hazard Assessment: 12th Volume, ASTM STP 1027, U.M. Cowgill and L.R. Williams (eds.). American Society for Testing and Materials, Philadelphia, 315-329 (1989).

The toxicity and bioavailability of a mixture of 13 sediment-associated chlorinated hydrocarbons were determined for the amphipod Pontoporeia hoyi. The processes were traced with two radiolabeled compounds, 14C-2,2',4,4'-tetrachlorobiphenyl (2244TCB) and 3H-benzo(a)pyrene (BaP). The toxicity of the chlorinated hydrocarbon mixture resulted primarily from the lindane and dieldrin components. The 72-h LC50 was 14.5 nmol g-1 as the sum of the added chlorinated hydrocarbons and 4.7 nmol g-1 as the sum of the lindane and dieldrin. At 144 h the LC50s had dropped to 1.51 and 0.53 nmol g-1, respectively. At the lowest dose, 2.4 nmol g-1 sediment, the time to yield 50% mortality (LT50) was 119 h. The toxicokinetics for the radiolabeled compounds yielded sediment uptake clearance constants of 0.0018 and 0.018 g dry sediment g-1 animal h-1 for BaP and 2244TCB in the absence of added chlorinated hydrocarbons. At the lowest chlorinated hydrocarbons dose, the clearance constants of both BaP and 2244TCB were approximately doubled. The clearance constants were not proportional to the freely dissolved concentration of the radiolabeled compounds in the interstitial water but were presumed to be proportional to the compound desorption rates. For the chlorinated hydrocarbons, the uptake clearances were inversely proportional to the log of the octanol-water partition coefficient. The bioaccumulation factor (BAF, concentration in the organism divided by the concentration in the sediment) appeared to peak at about a log octanol-water partition coefficient of 6. However, the BAF ranged from less than 1 to greater than 30 for compounds with a log Kow near 6.

LANDRUM, P.F., and R. POORE. Toxicokinetics of selected xenobiotics in Hexagenia limbata. Journal of Great Lakes Research 14(4):427-437 (1988). https://www.glerl.noaa.gov/pubs/fulltext/1988/19880012.pdf

Understanding the role of benthos in the fate and transport of contaminants requires understanding the toxicokinetics of those organisms for both waterborne and sediment-associated compounds. This effort focused on the toxicokinetics of Hexagenia limbata as an important component of the benthic community of the upper Great Lakes connecting channels. The accumulation and elimination of two polycyclic aromatic hydrocarbon congeners and a hexachlorobiphenyl isomer were followed over the course of a season in H. limbata collected from Lake St. Clair. Both the water uptake clearance and elimination rate constants increased with increasing temperature through the spring and summer. The elimination constants were relatively large. The uptake constant for sediment-associated compounds was essentially constant the two times it was measured and was large compared to sediment accumulation by Pontoporeia hoyi. Steady state model calculations indicate that the amount of compound in H. limbata should decline as temperature increases. The BCF values on a lipid content normalized basis remain relatively constant for both PAHs and show some change with season for hexachlorobiphenyl. Based on the best estimates of environmental concentration of the contaminants studied in both sediment and water, the model suggests that H. limbata should obtain greater than 90% of its contaminant body burden from the sediment-associated pollutants.

LANG, G.A., J.A. MORTON, and T.D. FONTAINE. Total phosphorus budget for Lake St. Clair: 1975-80. Journal of Great Lakes Research 14(3):257-266 (1988). https://www.glerl.noaa.gov/pubs/fulltext/1988/19880006.pdf

As part of the U.S.-Canadian Upper Great Lakes Connecting Channels Study a total phosphorus budget was developed for Lake St. Clair. An unbiased ratio estimator technique was used to estimate annual loads and variances from monitored hydrologic areas. During the 1975-80 period, Lake Huron was the major sources of phosphorus to Lake St. Clair, accounting for approximately 52% of the total annual load. Hydrologic area loads, which include diffuse and indirect point sources, contributed approximately 43% of the total annual load. The remaining 5% came from the atmosphere, shoreline erosion, and direct point sources. Of the hydrologic area loads, 85% could be attributed to diffuse sources. The Thames area contributed 58% of the total hydrologic area load, followed by the Sydenham (17%), the Clinton (9%), the Ruscom (7%), the Black (6%), the St. Clair (3%), and the Rouge (0.4%). Over the entire 6-year period examined, the lake's total input and output of phosphorus were nearly equal. It was concluded that there was no significant net source or sink of phosphorus in Lake St. Clair during the 1975-80 period.

Lindner, G., W. Pfeiffer, J.A. ROBBINS, and E. Recknagel. Long-lived Chernobyl radionuclides in Lake Constance: Speciation, sedimentation, and biological transfer. Proceedings, XV Conference of the International Radiation Protection Association. The Radio Ecology of Natural and Artificial Radionuclides Progress in Radiation Protection Series, FS-89048T, W. Feld (ed.), Visby, Sweden, September, 1989. Verlag, TUV Rheinland GMBH, Koln, 295-300 (1989).

No abstract.

Lindner, G., W. Pfeiffer, U. Wahl, J. Kleiner, H.H. Stabel, P. Frenzel, J.A. ROBBINS, F. Giovanoli, A. Lenhard, and E. Recknagel. Sedimentation of long-lived radionuclides in Lake Constance. Proceedings, Heavy Metals in the Environment, Vol. 1, J-P. Vernet (ed.), Geneva, Switzerland, September 14, 1989. CEP Consultants Ltd, Edinburgh, UK, 449-452 (1989).

No abstract.

LIU, P.C. On the slope of equilibrium range in the frequency spectrum of wind waves. Journal of Geophysical Research 94(C4):5017-5023 (1989).

An effort to empirically assess the slope of the equilibrium range in a wind wave frequency spectrum with a large number of data recorded in the Great Lakes did not serve to clarify the uncertainty between a -4 or a -5 frequency exponent representation. The uncertainty is further compounded by indications that the slope is not necessarily unique, but tends to vary with wave momentum. For sufficiently well developed wind waves the exponent appears to cluster between -3 and -4. For practical applications the f-4 equilibrium range is perhaps an effective approximation. What the correct slope is for the equilibrium range, or even whether or not a unique slope exists, remains elusive and has yet to be satisfactorily substantiated.

LIU, P.C. What is the slope of equilibrium range in the frequency spectrum of wind waves? Proceedings, 21st Coastal Engineering Conference CERC/ASCE, Costa del Sol-Malaga, Spain, June 21, 1988. 1045-1057 (1988).

An effort to empirically assess the slope of the equilibrium range in a wind-wave frequency spectrum with a large number of data recorded in the Great Lakes did not serve to clarify the uncertainty between a -4 or a -5 frequency exponent representation. The uncertainty is further compounded by indications that the slope is not necessarily unique, it tends to vary with wave momentum. For sufficiently well-developed wind waves the exponent appears to cluster between -3 and -4. For practical applications the f-4 equilibrium range is perhaps an effective approximation. What the correct slope is for the equilibrium range, or even whether or not a unique slope exists, remains elusive and has yet to be satisfactorily substantiated.

McCORMICK, M.J. Potential climate changes to the Lake Michigan thermal structure. In The Potential Effects of Global Climate Change on the United States: Appendix A - Water Resources, EPA DW13932957-01-0, U.S. EPA, Office of Policy, Planning and Evaluation, Washington, DC, 6.1-6.26 (1989).

No abstract.

MILLER, G.S., R.W. MUZZI, J.E. DUNGAN, and J.H. SAYLOR. Technical Note. Adding LORAN-C position recording to a satellite-tracked drifter buoy. MTS Journal 23(3):36-38 (1989).

A LORAN-C receiver-recording system was designed and embodied in a satellite-tracked drifter buoy. The purpose of the system is to obtain more accurate, uniformly-spaced times series of Lagrangian current measurements. LORAN-C positions, clock counter, receiver status, and other ancillary data are recorded on a data storage module on board the buoy. Depending on battery capacity, minimum deployments of twelve to forty-four days can be expected for sampling rates of ten to sixty minutes.

MUZZI, R.W., and G.S. MILLER. Improving satellite tracked drifter buoy resolution by using LORAN-C. Proceedings, Oceans '89, Seattle, WA, September 18-21, 1989. Marine Technology Society and the Oceanic Engineering Society of the Institute of Electrical and Electronics Engineers, 856-859 (1989).

A LORAN-C receiver-recording system was designed and embodied in a satellite-tracked drifter buoy. The purpose of the system is to obtain more accurate, uniformly-spaced times series of Lagrangian current measurements. LORAN-C positions, clock counter, receiver status, and other ancillary data are recorded on a data storage module on board the buoy. Depending on batter capacity, minimum deployments of twelve to forty-four days can be expected for sampling rates of ten to sixty minutes.

NALEPA, T.F. Estimates of macroinvertebrate biomass in Lake Michigan. Journal of Great Lakes Research 15(3):437-443 (1989). https://www.glerl.noaa.gov/pubs/fulltext/1989/19890003.pdf

To obtain updated, more accurate estimates of macroinvertebrate standing stocks in Lake Michigan, benthic biomass (ash-free dry weight) was determined at 40 stations in the southern end of the lake in 1980 and 1981. Biomass generally increased as sampling depth increased from 16 to 30 m, peaked at depths of 30-40 m, and then declined at depths greater than 40 m. Mean total biomass at the 16-30 m, 31-50 m, 51-90 m, and > 90 m depth intervals was 4.9, 7.8, 4.2, and 1.9 g m-2, respectively. Oligochaetes (46%) and Pontoporeia hoyi (44%) accounted for most of the biomass at depths shallower than 30 m, but P. hoyi was the dominant form (65%) at depths greater than 30 m. Differences in total biomass between years and seasons (spring, summer, fall) were not significant, but year X season interaction was significant at depths greater than 30 m. Mean biomass in the profundal of southern Lake Michigan (> 90 m) was over twice that found in the profundal of either Lakes Superior, Huron, or Ontario.

NALEPA, T.F., and J.M. GAUVIN. Distribution, abundance, and biomass of freshwater mussels (Bivalvia:Unionidae) in Lake St. Clair. Journal of Great Lakes Research 14(4):411-419 (1988). https://www.glerl.noaa.gov/pubs/fulltext/1988/19880011.pdf

A mussel population survey was conducted in Lake St. Clair with divers using SCUBA to sample at 29 stations throughout the lake. Mean abundance was 2 m-2 and mean biomass was 4.4 g dry wt m-2. Of the 18 species collected, Lampsilis radiata siliquoidea was by far the most abundant, accounting for 45% of all individuals. The age-frequency distribution of L. r. siliquoidea was dominated by individuals between 9 and 12 years old. In contrast, the second most abundant species, Leptodea fragilis, showed yearly variation in recruitment with no apparent trends in year class strength. Annual production of L. r. siliquoidea was 0.20 g m-2 y-1 and the turnover ratio was 0.13. The diversity and composition of mussels in Lake St. Clair appear little changed since the turn of the century, but there are indications that population numbers may be declining in the future.

QUIGLEY, M.A., and G.A. LANG. Measurement of amphipod body length using a digitizer. Hydrobiologia 171:255-259 (1989).

A digitizer/camera lucida method was developed to measure total body length and gut contents of an amphipod Pontoporeia hoyi. The method was more accurate and precise than two conventional methods (the forceps/ocular micrometer method, and the map wheel/camera lucida method). The digitizer/camera lucida method also provided rapid and direct transfer of body and gut length values to a computer file for subsequent analysis.

QUINN, F.H. Detroit River flow reversals. Journal of Great Lakes Research 14(4):383-387 (1988). https://www.glerl.noaa.gov/pubs/fulltext/1988/19880010.pdf

Detroit River flow reversals were investigated using a water surface gradient analysis in conjunction with Detroit River unsteady flow models. Three cases and five highly probable cases were simulated to occur between 1900 and 1986; the most recent episode occurred in April 1984. Flow reversals are likely only during St. Clair River ice jams, when the water supply to Lake St. Clair is severely restricted. The reversals appear to be of limited duration, less than 12 hours, with maximum flows less than 4,200 m3s-1. Flow reversals were most common during the first 40 years of this century and 46 years separate the last two occurrences. The decreased frequency probably results from the 7.6 m and 8.2 m navigation dredging projects on the St. Clair river. The use of the Gibraltar water level gage to represent the mouth of the river was found to be critical for the analysis.

QUINN, F.H. Fluctuations of Great Lakes water levels. In Great Lakes water levels: Shoreline dilemmas, Water Science and Technology Board Colloquim Series, National Academy Press, Washington, DC, 13-24 (1989).

No abstract.

QUINN, F.H. Great Lakes water levels, past, present, and future. Proceedings, The Great Lakes: Living with North America's Inland Waters, Milwaukee, WI, November 6, 1988. American Water Resources Association, 83-92 (1988).

The Great Lakes are one of our nation's greatest water resources containing 95 percent of the nation's and 20 percent of the world's fresh surface water. At the present time, all of the Great Lakes except for Lake Ontario, are receding from record high lake levels for this century. The high lake levels have had a severe impact upon the riparian interests around the lakes. Storms superimposed on the high lake levels have resulted in extensive flooding, houses destroyed, extreme erosion and bluff damage, marina problems, and loss of habitat for various forms of wildlife. This presentation examines Great Lakes water level fluctuations, past, present, and future. Special emphasis is given to the conditions resulting in the recent lake level decline. The types of natural lake level fluctuations and their causes are examined and compared with anthropogenic lake level changes resulting from diversions, connecting channel dredging, regulation, and consumptive use. A longer term climatic perspective and possible future scenarios are discussed.

QUINN, F.H., and S.A. Changnon. Climate scenarios for the Great Lakes Basin. Preprints, Sixth Conference on Applied Climatology, Charleston, SC, March 7-10, 1989. American Meteorological Society, Boston, MA, 27-30 (1989).

No abstract.

ROBBINS, J.A. The role of radiotracers in studies of aquatic contamination. Proceedings, Heavy Metals in the Environment, Vol. 1, J-P. Vernet (ed.), Geneva, Switzerland, September 14, 1989. CEP Consultants Ltd, Edinburgh, UK, 449-452 (1989).

Natural and man-made radionuclides, particularly 210Pb and 137Cs, have been widely used to chronicle the history of heavy metal contamination of lakes and reservoirs as recorded in sediments. Although this application is perhaps best known, there and other tracers have also been used in the Laurentain Great Lakes and other systems to calibrate lake contamination response models, determine epilimnetic residence times, establish sediment mixing scale lengths and rates, tag resuspended sediment components, and estimate the extent and rate of sediment focusing. Some of these applications are illustrated by the case of 137Cs in Lake Erie.

ROBBINS, J.A., T.J. KEILTY, D.S. White, and D.N. Edgington. Relationships between tubificid abundances, sediment composition, and accumulation rates in Lake Erie. Canadian Journal of Fisheries and Aquatic Sciences 46(2):223-231 (1989).

Sediment cores taken at 15 sites within the three main depositional basins of Lake Erie from 1976 to 1982 were sectioned in 1-cm intervals and analyzed for the abundance and vertical distribution of benthic organisms, 137Cs, and 210Pb (in some cores) and for surficial (upper 2 cm) organic and inorganic carbon. Zoobenthos populations were dominated (>85%) by tubificids (Limnodrilus hoffmeisteri, Quistradrilus multietosus, and Tubifex tubifex) and varied in abundance from 6600 to 55 300 individuals m-2. The depth above which 90% of the individuals occurred correlated significantly with their abundance and with radiometrically determined mixed depths. Rates of sediment reworking by tubificids exceeded sedimentation rates by 5-80 times, indicating that worms alone can produce the observed zone of constant tracer activity at the sediment-water interface. Tubificid abundance was not significantly related to organic carbon but instead correlated strongly with the sediment accumulation rate and organic carbon flux. In Lake Erie the abundance of tubificids may be limited by the rate of supply of nutrients as measured roughly in terms of the organic carbon flux.

SCAVIA, D. On the role of bacteria in secondary production. Limnology and Oceanography 33(5):1220-1224 (1988). https://www.glerl.noaa.gov/pubs/fulltext/1988/19880015.pdf

No abstract.

Schelske, C.L., J.A. ROBBINS, W.S. GARDNER, D.J. Conley, and R.A. Bourbonniere. Sediment record of biogeochemical responses to anthropogenic perturbations of nutrient cycles in Lake Ontario. Canadian Journal of Fisheries and Aquatic Sciences 45:1291-1301 (1988). https://www.glerl.noaa.gov/pubs/fulltext/1988/19880024.pdf

Two sediment cores collected from the Rochester basin of Lake Ontario were dated with 210Pb and stratigraphic correlation and analyzed to determine whether nutrient accumulation with time was consistent with previous computer-simulated total phosphorus (TP) loadings. Relative increases in TP and nonapatite inorganic phosphorus (NAIP) accumulation were less than the fivefold increased in TP loading from 1800 to 1950 predicted independently from Chapra's simulation model. In addition, increases in TP accumulation occurred mainly after 1940 and the proportion of NAIP relative to TP increased in one core and decreased in the other. Of the nutrients studied, only increases in organic carbon (OC) paralleled the increases in modelled TP loadings. The relative increase in inorganic carbon (IC) was greatest, with accumulation increasing an order of magnitude after 1940 in one core. This large increase in IC, amounting to 20% calcite in recent sediments, was attributed to biologically induced calcite precipitation, a secondary consequence of increased planktonic photosynthetic removal of carbon dioxide that resulted from accelerated eutrophication after 1940 when modelled TP concentrations increased rapidly. Biogenic silica (Bsi) accumulation, an indicator of increased diatom production, peaked between 1850 and 1870 when increases in TP and NAIP fluxes were minimal. Results provide evidence that historic biogeochemical responses inferred from OC, IC, and Bsi accumulation in the sediment record provide stronger signals of phosphorus enrichment effects than can be inferred directly from changes in accumulation of different forms of phosphorus in the sediment record.

SCHWAB, D.J. A numerical wave prediction model for personal computers. Proceedings, 21st Coastal Engineering Conference CERC/ASCE, Costa del Sol-Malaga, Spain, June 21, 1988. 2991-2997 (1988).

A two-dimensional wave prediction model suitable for use on personal computers is described. The model requires the two-dimensional time-dependent wind field as input. Output consists of wave height, wave period, and wave direction estimates at all grid points on a computational grid representing an enclosed or semi-closed basin. Model predictions compare favorably with observations from a wave research tower in Lake Erie. A formula is provided to estimate how long a model simulation would take on a personal computer given the surface area of the computational domain, the grid size, and the computer clock speed.

SCHWAB, D.J. The use of analyzed wind fields from the Great Lakes Marine Observation Network in wave and storm surge forecast models. Preprints, 2nd International Workshop on Wave Hindcasting and Forecasting, Vancouver, BC, April 25-29, 1989. Environment Canada, Atmospheric Environment Service, Downsview, Ontario, 257-266 (1989).

No abstract.

SCHWAB, D.J., A.H. CLITES, C.R. Murthy, J.E. SANDALL, L.A. Meadows, and G.A. Meadows. The effect of wind on transport and circulation in Lake St. Clair. Journal of Geophysical Research 94(C4):4947-4958 (1989).

A numerical circulation and transport model is used to simulate currents and trajectories in Lake St. Clair. Results from the model are compared to three different types of measurements, namely, 910 mean currents from an array of fixed current meters, (2) currents measured from a ship during seven synoptic surveys of the lake, and (3) trajectories of satellite-tracked drifting buoys during four different experiments. The model is then used to predict the effects of storms on the residence time of water entering the lake from eight tributaries and the probable horizontal distribution in the lake of water from a particular tributary. Results show that although the average residence time of the lake is about 9 days, actual residence times range from less than 2 days to over 30 days depending on wind conditions. The calculated distribution patterns of water from various tributaries coincide closely with observed distributions of some water quality parameters and biota.

STEHLY, G.R., and W.L. Hayton. Disposition of pentachlorophenol in rainbow trout (Salmo gairdneri): effect of inhibition of metabolism. Aquatic Toxicology 14:131-148 (1989).

The accumulation kinetics of pentachlorophenol (PCP) were investigated in rainbow trout (Salmo gairdneri) in the absence and presence of 25 mg/1 salicylamide, an inhibitor of PCP metabolism. After exposure of 5 mg/1PCP over 1-96 h, the amount of PCP in the whole fish, its concentration in water and the total amount of metabolites (water, whole fish, and bile) were measured. Equations for these variables, based on a two compartment pharmocokinetic model, were fitted simultaneously to the data using the computer program NONLIN, which uses an iterative nonlinear least squares technique. Salicylamide decreased the metabolic clearance of PCP, which resulted in an increase in the bioconcentration factor (BCF); this increase was partially offset by a salicylamide-induced decrease in the apparent volume of distribution of PCP. A clearance-volume compartment model permitted partitioning of the BCF in terms of the underlying physiologic and biochemical processes (uptake clearance, metabolic clearance and apparent volume of distribution). With this approach the BCF can be categorized as either dependent (e.g., PCP) or independent of uptake and metabolism resulted in a loss of its dependence on uptake and metabolism. The BCF estimated as the apparent volume of distribution may be useful for assessment of the risk associated with exposure and bioaccumulation potential, as elimination is generally quite variable among aquatic species.

STEHLY, G.R., and W.L. Hayton. Metabolism of pentachlorophenol by fish. Xenobiotica 19(1):75-81 (1989).

No abstract.

TARAPCHAK, S.J., and L.R. HERCHE. Orthophosphate concentrations in lake water: Analysis of Rigler's radiobioassay method. Canadian Journal of Fisheries and Aquatic Sciences 45(12):2230-2237 (1988). https://www.glerl.noaa.gov/pubs/fulltext/1988/19880020.pdf

Rigler's radio bioassay method is frequently used to estimate maximum possible orthophosphate (P) concentrations in natural waters. An evaluation of the method, based on simulated P uptake by hypothetical phytoplankton communities, reveals that the Rigler value is not a consistent estimator of true maximum possible P concentration. Analyses show that all members of that family of curves for which the difference between true and assumed (or estimated values of P is below the minimum half-saturation constant of a component species will pass through the plot's origin. A new upper bound, termed R (Rigler), which is the sum of the true ambient P concentration and the lowest half-saturation constant of a component species, is identified as a consistently distinguishable bound on maximum possible P concentrations in lake water. The R curve cannot be distinguished in a lake water experiment because of the complex behavior of uptake curves in the unobservable substrate region. A theoretical procedure, based on comparing uptake parameters for lake water samples and multispecific hypothetical communities, offers potential for calculating upper and lower limits on R in P-limited lake water samples.

TARAPCHAK, S.J., and L.R. HERCHE. Phosphate uptake by microbial assemblages: Model requirements and evaluation of experimental methods. Journal of Environmental Quality 18(1):17-25 (1989).

A "compound" Michaelis-Menten model provides a conceptual framework for analyzing substrate-dependent phosphate (P) uptake by natural microbial assemblages. Phosphate uptake can be separated into three substrate domains: a region near ambient P concentrations, an intermediate region, and a high-substrate region representing substrate saturation of microbial uptake sites. Simulated P uptake for hypothetical microbial communities, ranging from non-phosphorus-limited to multiple-nutrient-limited communities, show that (i) commonly used "high-level" P addition schemes will underestimate community uptake rates near natural ambient P concentrations in phosphorus-stressed systems by at least an order of magnitude, and (ii) deviations from the simple Michaelis-Menten model may be widespread in nature, particularly in highly phosphorus-stressed or multiple-nutrient-limited systems. A P uptake experiment on a natural microbial assemblage from a phosphorus-limited oligotrophic lake illustrates application of the compound model and statistical procedures for analyzing data. An empirical procedure, based on the concept of substrate-dependent continuity in P uptake, is proposed to determine if P addition schemes are adequate to estimate uptake constants near ambient lakewater P concentrations.

VANDERPLOEG, H.A.(among 56 others). Future marine zooplankton research--A perspective: Marine Zooplankton Colloqium 1. Marine Ecology Progress Series 55:197-205 (1989).

Zooplankton research over the past 100 yr has been focused largely on temporal scales of hours to weeks and spatial scales of decameters to kilometers. Research at both greater and lesser scales has been limited mainly by technical intractability. Recent advances in technology are expanding the horizons of enquiry to those scales which have long been difficult to observe. Discussions on future advances in marine zooplankton research and technology from an open meeting of marine zooplanktologists, held at Lake Arrowhead, California, USA in April 1988, led to specific recommendations for future research. Principal issues and areas of future research include: (1) characterization of individual small-scale behaviors leading to a better understanding of the dynamics of aggregation and dispersal; (20 determination of how environmental variability, rather than mean conditions, affects physiology and behavior; (3) relation of birth, death and growth rates to environmental conditions, both concurrent and past; (4) determination of nutritional requirements; (5) long-term observations of population and community dynamics which would permit analysis of interannual variability and its causes; (6) a critical need to maintain expertise in taxonomy; and (7) continued development of mathematical models encompassing biological, chemical, and physical parameters. Concrete steps that could be taken to facilitate these research goals include; (1) further development of in situ instrumentation that provides (a) measurements at high frequencies and resolutions, (b) the capability for long-term unattended measurements and (c) the ability to monitor birth, growth and physiology; (2) establishment of a Center of Marine Plankton Studies with the full spectrum of facilities required for sophisticated culture, maintenance and experimentation with single or multiple species; and (3) establishment of an Ocean Observatory from which continuous measurements could be make at multiple scales. Significant advances in many areas con be accelerated through multidisciplinary activities.

VANDERPLOEG, H.A., G.-A Paffenhofer, and J.R. LIEBIG. Diaptomus vs. net phytoplankton: Effects of algal size and morphology on selectivity of a behaviorally flexible, omnivorous copepod. Bulletin of Marine Science 43(3):377-394 (1988). https://www.glerl.noaa.gov/pubs/fulltext/1988/19880019.pdf

Effects of algal size, colony form, and morphology on selection by Diaptomus sicilis and D. ashlandi were determined for certain net diatoms commonly found in the pelagic regions in lakes. Mechanisms of capture, observed by high-speed microcinematography, were correlated with selectivity results from traditional feeding experiments with mixtures of algae. The attribute of elongation (up to 365 mm) in one dimension possessed by Synedra spp. was not useful for avoiding grazing. In fact, at low concentrations, selectivities for Synedra were much higher than for Chlamydomonas of equal cell volume. This suggests a perceptual bias for capture of elongated algae. Films showed that D. sicilis could even bite off sections of 700-mm-long Melosira colonies. However, long fragments of Synedra and Melosira were often left behind after attacks by Diaptomus. Elongation in tow dimensions, an attribute possessed by the stellate colonies of Asterionella formosa was extremely effective for avoiding grazing once more than six to eight cells per colony was reached. This results may explain the abundance of the eight-cell form in nature. Selectivity of Diaptomus changed with concentration in mixtures of a 12-mm-diameter spherical green alga and a 240-mm-long Synedra. In these same experiments, the proportion of attacked Synedra that were only partially ingested--i.e., the proportion rejected after partial ingestion--increased linearly with attack rate on Synedra, and was not correlated with attack rate on Chlamydomonas or on the sum of both algal species. These and other data demonstrate that this concentration-variable selectivity is not an optimal-foraging strategy. We assert these observations can be properly viewed within the classical ethological framework of motivation and excitability of different motor patterns used to capture, handle, and ingest different kinds of algae.

Williamson, C.E., and H.A. VANDERPLOEG. Predatory suspension-feeding in Diaptomus: Prey defenses and the avoidance of cannibalism. Bulletin of Marine Science 43(3):561-572 (1989).

High-speed (500 frames s-1) 16-mm film analysis was used to examine the predatory suspension-feeding behavior of Diaptums pallidus. Prior high-speed film analysis of Diaptomus feeding on algae revealed a transition from passive to active captures as cell size increased, where the transition from passive to active captures was distinguished by the additional use of the swimming legs and maxillipeds to aid in capture. In the current study we found that when feeding on microzooplankton, Diaptomus may also employ its first antennae and a more vigorous flap of its swimming legs in an actual attack or orientation response to facilitate prey capture. Diaptomus responded to different prey species at distances that varied with prey type. Many of the microzooplankton which are potentially vulnerable to predation by suspension-feeding diaptomids have rheotactic capabilities which permit them to detect the feeding currents of Diaptomus before body contact and avoid predation through a rapid escape response. the most effective rheotactic escape response is exhibited by the nauplii of Diaptomus. Some experiments with CO2-anesthetized nauplii demonstrate that nauplii are highly palatable to the omnivorous adults and that the rheotactic capabilities of the nauplii aid in reducing cannibalism.

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