Summary Report EEGLE/KITES All-Hands Meeting October 27-30, 1999 Minneapolis, MN

• Overall EEGLE/KITES Summary Report
  • Workshop Objectives
  • Meeting Format
  • Next Year's Meeting
• EEGLE Components
  • Comparison of 1998 and 1999 events
  • Cruise and Web Stats
  • Special Sessions
• Summary of EEGLE Overview Presentation
  • Program Goal
  • Hypothesis 1 and Corresponding Posters
  • Hypothesis 2 and Corresponding Posters
  • Hypothesis 3 and Corresponding Posters
• EEGLE Individual Session Reports
  • Phisical Measurements & Modeling
  • Modeling
  • Ecological Processes
    • Tentative Cruise Plan for FY2000
  • Sediment Processes

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The third annual "all-hands" EEGLE/KITES meeting was held at the Radisson Hotel and the Coffman Union on the University of Minnesota's Minneapolis campus. The workshop objectives were:

1. Communication within and between the programs
2. Communication to NOAA & NSF
3. Summarizing findings to date
4. Establishing sampling strategy(s) for the next field year: planned experiments, cruise details, etc
5. Review by NSF/CoOP Steering Committee

Approximately 100 participants attended the workshop, including many students. Over 50 posters and a series of project "overviews" were delivered. Cruise plans for the 2000 field season were developed, and several working groups met to refine their plans for 2000 and beyond.

The format of the meeting was as follows:

Day 1 (October 28)

EEGLE: Group meetings: discussed progress, status, issues, strategy for coming field year, and plans for modeling-measurement exercises. Physical measurements and modeling (chaired by Dave Schwab) Ecological processes and modeling (chaired by Wayne Gardner) Sediment processes and modeling (chaired by Val Klump) Prepare synthesis presentation for Plenary Plenary with Group Presentations

KITES: OS meeting Ship planning Spatial coverage Discuss Saturday activities Informal Science Exchange Science exchange Small groups: Stratification changes: upwelling/downwelling/thermal bar (chaired by Elise Ralph and Jim Churchill) Food web/Particle dynamics (chaired by Noel Urban)

Day 2 (October 29)

All-Hands Overview
Speakers:
    Mike Roman
    Larry Clark
    John Wickham
    Sarah Green
    Brian Eadie

3 Poster Sessions containing 53 posters

Day 3 (October 30)

EEGLE: Group meetings: discussed sampling strategies/options, draft cruise schedules, improve modeling and measurement integration Modeling Group Cruise Planning Group Sediment Sampling Strategy Group EEGLE Plenary Discuss issues raised in morning sessions

KITES: Group Meetings Data-model integration Ship planning: sampling in last field year, What critical data is missing, Does everyone have access to what they need?

Next year's all-hands meeting will again include both EEGLE and KITES participants. The proposed format for that meeting is 2 or 3 half-hour overview presentations from EEGLE and KITES and 4 to 6 hours of posters from the PIs. The meeting will most likely last 3-4 days to allow for more interactions within and between the 2 major projects. It was suggested that next year's workshop convene at the Homestead Conference Center near Sleeping Bear Dunes in Michigan.

The remainder of this report will concentrate on the EEGLE components of the all-hands meeting.

The EEGLE program is designed to examine the impacts of massive storm events in late winter-early spring on sediment resuspension and transport of particles and associated materials and on subsequent spring ecology. While it appears that the winter-spring storms occur annually, there is a large range in scale. As illustrated in figure 1, the 1999 event was much smaller than the very large 1998 event. The two images of AVHRR reflectance (channel 1 - channel 2) illustrate the approximate maximum of each year's event. A longer-term estimate of the scale of the event is illustrated by the yearly maximum of the 10-day running mean of winter-spring turbidity from the St Joseph, MI Water Treatment Plant. The last bar represents 1999 and shows it to be somewhat below the average. The 1998 bar is similar to 1973 and they are the largest events for this 39-year period. Other water intake (and wind/wave) data are being accumulated for similar long-term evaluations.

The relatively small 1999 event allows for an interesting contrast to the large 1998 event. During 1999, we've had successful survey cruises before, during and after the event, along with a number of process cruises. Water sample and Plankton Survey System (PSS) tows will continue on a monthly basis throughout the year. The table shows program activities in calendar years; the 3rd column is a snapshot of where we are now. There is one more field year, which should be similar to 1999.

EEGLE Statistics from the web data base - October, 1999

	1997	1998	Oct 24, 1999	2000
Cruises	8	34	33	Similar to '99
Total Days	22	104	147	Similar to '99
Water Samples	12	133	219	Similar to '99
PSS Tows	-	22	49	Similar to '99
Traps samples	12	205	178	391
ROV Dives	-	120	253	Similar to '99
Current meters	-	11	27	28
Drifter days	-	40	350	Similar to '99
Papers & reports	2	1	8	?
Presentations - Public	11	20	9	?
Presentations - Professional	2	6	24	Spec Session at AGU-OSM
Visits to EEGLE web	-	17,730	22,425	?

Special Sessions at:

• ASLO-99 Sante Fe, NM
• IAGLR-99 Cleveland, OH

Program Goal: to create an integrated observational and numerical modeling program for the winter-spring resuspension event(s) and to assess their impact on the transport and transformation of BIMS and on lake ecology. Three fundamental hypotheses focus this program:

Hypothesis 1: The plume is a result of the first winter-spring storm after ice-out and represents the resuspension of particulate materials (and associated constituents) that have been stored in the lake as surface sediment "floc" for a distribution of times, during which they have undergone differential diagenesis

What have we learned so far?

• Don't need ice
• There are spring and fall events and there may be several per season
• Interannual events can range over an order of magnitude
• Constituents resuspended from sediment inventory > annual external input
• Particle transport into sediment depositional basins is complex, but radionuclide tracers look promising

Results

• Large, basin-scale spatial variation tau res
• Mesoscale spatial variation (coring)
• Traps clearly illustrate basin-scale impacts
• BBL tripod providing regional ss:tsm relations

Future Plans

• Less spatial coverage
• More time series to hone tau res
• Tightly designed sediment-water coupling efforts
• Develop coupled box models and eventually couple with hydrodynamic modeling

Eight posters were presented on this topic:

Bedford, K.W., and P. Chu. DEVELOPMENT OF LAKE MICHIGAN NOWCAST/FORECAST MODELING SYSTEM AND THE PROGRESS ON A SEDIMENT TRANSPORT MODEL

Bogdon, J.J., K. Hornbuckle, and J.W.Budd. INCREASED ATMOSPHERIC DEPOSITION OF SOCs DUE TO LARGE-SCALE SEDIMENT RESUSPENSION IN SOUTHERN LAKE MICHIGAN.

Chye, J.D., J. W. Budd, V. Ransibrahmanakul, D.Ullmann, P Cornillon, and A. Mariano. REMOTE SENSING OF THERMAL FRONTS AND PARTICLE DISTRIBUTIONS IN LAKE SUPERIOR AND SOUTHERN LAKE MICHIGAN

Eadie, B.J., M.B. Lansing, A. Winkelman, C.Riley, and B. Giroux. BASIN-SCALE PARTICLE FLUX RESPONSES ASSOCIATED WITH EPISODIC EVENTS.

Lesht, B. IN SITU OBSERVATIONS OF SEDIMENT RESUSPENSION IN DEPOSITIONAL AND NON-DEPOSITIONAL REGIONS OF SOUTHERN LAKE MICHIGAN.

Robbins, J.A., D.N. Edgington, B.J. Eadie, N.R. Morehead, and R.W. Rood. ACCUMULATION OF PARTICLE-ASSOCIATED RADIONUCLIDES AT THE HIGH-DEPOSITION AREA IN SOUTHERN LAKE MICHIGAN.

Waples, J., J.V.Klump, D.N. Edgington, K. Orlandini. TH-234 STUDIES OF SUSPENDED PARTICLE RESIDENCE TIMES IN NEARSHORE REGIONS OF SOUTHERN LAKE MICHIGAN.

Warrington, D.S., J.W. Budd, and R.P. Stumpf. ESTIMATING AREAL EXTENT AND SUSPENDED SEDIMENT CONCENTRATIONS OF COASTAL PLUMES: APPLICATIONS OF SEAWIFS ALGORITHMS TO GREAT LAKES WATERS.

Hypothesis 2: The forced, two-gyre vorticity wave response of the lake to episodic wind events, occasionally modified by stratification, is a major mechanism for nearshore-offshore transport of particulate matter and associated constituents in the Great Lakes.

What have we learned so far?

• The longshore convergence associated with the forced, two-gyre vorticity wave is apparent in the first set of current meter and drifter measurements from 1997-98
• Preliminary hydrodynamic model results indicate qualitative agreement with observed currents and sediment deposition patterns
• Offshore flow and resulting sediment resuspension and transport are sensitive to local meteorology

• HF Radar Measurements
• Remote Sensing
• HOC fluxes
• Meteorological modeling
• OSU products and sediment modeling
• GLERL hydrodynamic modeling and sediment transport

Beletsky, D. and D. Schwab. HYDRODYNAMIC AND SEDIMENT TRANSPORT MODELING OF MARCH 1998 RESUSPENSION EVENT.

Ji, R., C. Chen, D. Schwab, D. Beletsky, J. W. Budd, T. H. Johengen, and G. L. Fahnenstiel. MODELING STUDIES OF THE ECOSYSTEM OF LAKE MICHIGAN: 1-D AND 3-D NUMERICAL EXPERIMENTS

Lang, G.A. and D. J. Schwab. EEGLE DATABASE MANAGEMENT

McCormick, M.J, R. Murthy, J. Saylor, and G, Miller. OFFSHORE AND LONGSHORE TRANSPORT MEASUREMENTS IN EEGLE.

McCormick., M.J., G, Miller, C.R. Murthy, and J. Saylor. COASTAL FLOW STATISTICS FOR WINTER 1997-98 IN SOUTHEASTERN LAKE MICHIGAN"

Neibauer, J. SOME RESULTS FROM MODELING THE COASTAL CROSS AND ALONG-SHORE FLUX IN LAKES SUPERIOR AND MICHIGAN.

Roebber. P. SOME METEOROLOGICAL MODELING RESULTS FOR LAKE MICHIGAN AND LAKE SUPERIOR.

Vesecky, J.F., L.A. Meadows, C.C.Teague, and Y. Fernandez. HF RADAR MEASUREMENTS OF NEAR-SURFACE CURRENTS DURING 1999 EPISODIC EVENTS.

Yerubandi, R.C.R. and Raj Murthy. NEARSHORE PHYSICAL MEASURMENTS

Hypothesis 3: Physical processes, (e.g. resuspension, turbulence) associated with the plume event are important in determining the nutrient and light climate, and in structuring the biological communities throughout the spring isothermal period, and in setting the conditions for the critical `spring bloom' period.

What have we learned so far?

• Primary production is reduced within the plume - low light
• Heterotrophic production is high in the plume - sediment supplied substrate
• Events don't seem critical in supplying "seed" populations of diatoms
• Although substantial P is resuspended, plume algae are P starved

• Event and monthly surveys of nutrients and PSS
• Detailed optical characterization of plume and adjacent waters
• Species specific primary production measurements
• Microzooplankton-distinct communities in plume region- important grazers of small PP
• Feeding studies of calanoids on PP & MZP
• Size shift and change in ZP composition between 1998 and 1999 -> smaller & cyclopoids replaced calanoids

• More spatial coverage
• Extend process cruises into spring bloom
• Expand ZP feeding studies
• Enhance integration of field experiments & modeling

Agy, M., H. A. Vanderploeg, and T Johengen. NEARSHORE-OFFSHORE DIFFERENCES IN MESOZOOPLANKTON COMMUNITY STRUCTURE DURINGTHE RECURRENT COASTAL PLUME IN SOUTHERN LAKE MICHIGAN

Biddanda, B. and J. Cotner. PLANKTON RESPIRATION AND CARBON FLUX THROUGH BACTERIOPLANKTON IN SOUTHERN LAKE MICHIGAN.

Budd, J.W., V. Ransibrahmanakul, D.S. Warrington, and W.C. Kerfoot. EPISODIC EVENTS AND TROPHIC PULSES: ESTIMATING SURFACE CHLOROPHYLL CONCENTRATIONS USING REMOTELY SENSED IMAGERY.

Bundy M.H., H. A. Vanderploeg, and P. Lavrentyev. MESOZOOPLANKTON GRAZING RELATIVE TO THE LAKE MICHIGAN RECURRENT COASTAL PLUME: THE ROLE OF PHYTOPLANKTON VS. MICROZOOPLANKTON PREY.

Fahnenstiel, G.F., et al. SINGLE CELL MEASUREMENTS OF IMPORTANT PROCESSES IN EEGLE

Johengen, T. and A. Winkelman. TEMPORAL TRENDS IN THE NEARSHORE-OFFSHORE DISTRIBUTION OF PARTICULATE MATTER AND NUTRIENTS IN SOUTHERN LAKE MICHIGAN IN RESPONSE TO THE RECURRENT COASTAL SEDIMENT PLUME.

Julius, M. and Goad, L. INITIAL INVESTIGATION OF THE RELATIONSHIP BETWEEN PERIODIC RESUSPENSION EVENTS AND DIATOM BLOOMS IN LAKE MICHIGAN.

Kelly, K, S. Lohrenz, and G. Fahnenstiel. MICROPHOTOMETRIC ANALYSIS OF LIGHT ABSORPTION CHARACTERISTICS OF PHYTOPLANKTON ASSOCIATED WITH A RECURRENT COASTAL PLUME IN SUTHEASTERN LAKE MICHIGAN

Kerfoot, W.C., C.S. Lorence, D. Enderson, and X. Ma. RESURRECTION ECOLOGY: THE ROLE OF EPISODIC EVENTS IN MAINTAINING GENETIC DIVERSITY IN SPECIES COMPOSITION OF ZOOPLANKTON COMMUNITIES.

Lavrentyev, P. MICROZOOPLANKTON COMPOSITION AND DISTRIBUTION DURING A MAJOR EPISODIC EVENT IN LAKE MICHIGAN

Lohrenz, S. E., G. Fahnenstiel, O.Schofield et al. DISTRIBUTIONS OF INHERENT OPTICAL PROPERTIES IN A RECURRENT COASTAL TURBIDITY PLUME IN SOUTHEASTEN LAKE MICHIGAN

Vanderploeg, H., S. Ruberg, G. Lang, T. Johengen, M. Agy, and J. Liebig. SPATIAL AND TEMPORAL PATTERNS OF PLANKTON SEEN BY THE PLANKTON SURVEY SYSTEM: DOES THE RECURRENT COASTAL PLUME HAVE AN EFFECT?

PHYSICAL MEASUREMENTS & MODELING

Participated: D. Beletsky, J. Budd, P. Chu, P. Healy, K. Hornebuckle, L. Meadows, K. Miners, M. Muny, P. Roebber, J. Saylor, D. Schwab, J. Vesecky, R.C.R Yerubandi. Chair : D. Schwab

1. Physical measurements.

Current and meteorological measurements (GLERL and CCIW)
Pilot year measurements captured episodes of significant offshore flow during resuspension events. Full mooring array deployed in 1998-99 included SACM measurements in shallow water (6 out of 8 returned data in summer 1998, 3 out of 7 in fall 98- spring 99, currently 5 SACMs are deployed), VACM measurements in deep water (24 VACM s on 12 moorings), and ADCPs in the St. Joseph area (5 in deep water and 1 in shallow water). VACMs were not deployed until fall to minimize biofouling. The convergence zone tends to occur in northern part of array, therefore additional transect will be added in 1999-2000 deployment. Coastal meteorological stations deployed at Muskegon, St. Joseph, Michigan City, Kenosha, and Milwaukee. Coastal meteorological buoy (UM) operated during spring 1999. About 30-40 drifter tracks were collected in April 1998.

HF Radar measurements (University of Michigan)
The HF Radar measurements demonstrated feasibility for high resolution surface current mapping over freshwater with successful 45 day deployment of dual Doppler system at St. Joseph in March-April, 1999.

Remote sensing (Michigan Technological University)
Time-series of AVHRR reflectance, SeaWIFS reflectance and chlorophyll images from 1998- 99 show significant differences between surface reflectance and chlorophyll patterns.Chlorophyll shows both an offshore and mid-lake minimum.

PCB Fluxes (University of Iowa)
Analyses of organic pollutants from 6 cruises and over 400 air, water, and sediment samples from 1998-99 indicate that the southern Lake Michigan resuspension event results in significant net input of atmospheric pollutants in Lake Michigan by scouring dissolved organics from the water column and disrupting air/water equilibrium concentration balance.

2. Modeling.

Meteorological modeling (University of Wisconsin-Milwaukee)
Accomplishments include operation of realtime forecast system and data archival since November 1998 and modeling of meteorology associated with March 1998 resuspension event. Plans include ongoing evaluation of model simulations during resuspension events, incorporating MM5 meteorological forecasts into GLFS hydrodynamic forecasts, and construction of meteorological climatology of resuspension events.

Great Lakes Forecasting System and sediment transport modeling (Ohio State University)
Nowcast-forecast system for Lake Michigan is now operational which is beneficial to all EEGLE participants. In addition, a coupled circulation-sediment transport model CH3D-SEDwas applied to Lake Michigan. The model was tested with 2 sediment classes. Currently, themodel does not account for sediment resuspension caused by waves. It will be later coupledwith state-of-the-art wave model WAM.

Hydrodynamic and sediment transport modeling (GLERL)
Developed linked circulation/wave/sediment transport modeling system. The system wasapplied to the March 1998 sediment resuspension event in Lake Michigan on a 2 km rectangular bathymetric grid. Circulation and wave model results were compared withavailable observation data. Results indicate qualitative agreement with observed currents and sediment deposition patterns. Sensitivity studies were conducted with various objectively analyzed winds (based on both nearest neighbor and natural neighbor techniques) and mesoscale meteorological model (MM5) winds.

MODELING

Participants: D.Beletsky, C.Chen, P.Chu, J.Niebauer, L.Meadows, P.Roebber, J.Rubao, J.Saylor, R.C.R.Yerubandi. Chair: D.Beletsky

Brief overview of accomplishments in 1998-99:

GLERL: Created a system of linked circulation, wave, and sediment transport models named GLMS - Great Lakes Modeling System. Circulation model is a Great Lakes version of the Princeton Ocean Model (POMGL). Wave model (WMGL) is 2D parametric model developed at GLERL. Sediment model (STMGL) is a quasi-3D model developed by Jing Lou (former NRC postdoc at GLERL). Ice transport model will be built later as extension of the existing POMGL code. The system was applied to the March 1998 sediment resuspension event in Lake Michigan on a 2-km rectangular bathymetric grid. The hydrodynamic model employs 20 sigma levels. Circulation and wave model results were compared with available observation data. Sensitivity studies were conducted with various objectively analyzed winds (based on both nearest neighbor and natural neighbor techniques) and mesoscale meteorological model (MM5) winds.

OSU: Nowcast-forecast system for Lake Michigan is now operational which is beneficial to all EEGLE participants. In addition a coupled circulation-sediment transport model CH3D-SED was applied to Lake Michigan. CH3D-SED has an advantage over STMGL because it can include several classes of sediments (along with some other refinements). The model was tested with 2 sediment classes. Currently, the model does not account for sediment resuspension caused by waves. It was confirmed that a graduate student at OSU will begin working on data assimilation problem before 2000.

UGA: Biological model was built as an extension of POMGL. It includes 8 components (Si, P, small and large phytoplankton and zooplankton, bacteria and detritus). The model was tested in a 1D version for 1994-95. No loading from sediment resuspension was included. Observations at 100 m depth station off Muskegon, MI were used to evaluate model performance. The model was also run for March 1998 episode in a 3D mode. Sediment concentration was derived from satellite images of surface reflectance calibrated with observed sediment concentration. This approach proved to be acceptable in early spring when the lake is well mixed and vertical variation of sediment concentration is small.

UWM: The MM5 system is operational. Model output has been archived since fall 1998. Model output (on a 6 km grid) was used in sensitivity studies conducted with POMGL. Particular attention was paid to two cases of significant offshore transport in March 1998: the passage of a cold front and mesoscale atmospheric vortex. A coupled 2D physical-biological model was developed for a transect Racine, WI-Saugatuck, MI by J.Niebauer. The model employs 1.5-km grid, vertical resolution is 5m. The model is being used primarily for studies of short-term physical-biological interactions during upwelling-downwelling events.

Plans for 1999-2000:

Having a multi-year simulation as a goal, we will carry out March-April 1998 and March- April 1999 simulations using GLMS first. This will allow us to study interannual variability of resuspension events in southern Lake Michigan. Hydrodynamic and biological models will include river discharges information to study the importance of nutrient load from major rivers. Physical/biological simulations will be performed with objectively analyzed winds and with MM5 winds. Sediment concentration will be derived from satellite data. We expect CH3D-SED to be coupled with a state-of-the-art wave model (WAM) by summer 2000. That will allow us to use modeled sediment concentration in multi-year (1998-99) physical/biological model runs. Initially, modeled sediment concentration can be saved at OSU and transferred to UGA to be used as the biological model input. Eventually, the solution to this problem should be either to refine STMGL or to develop a work-station based version of SED (from CH3D-SED) to link it to other GLMS models. We are planning a physical- biological workshop at GLERL in summer 2000 to discuss this and other issues.

ECOLOGICAL PROCESSES

Participants: Marie Bundy, Jim Cotner, Tom Johengen, Wayne Gardner, Joann Cavaletto, Peter Lavrentyev, Megan Agy, Hank Vanderploeg, K. Kelly, Gary Fahnenstiel, Steve Lohrenz, Bopi Biddanda

Major Needs

• Effects of plume versus rivers
• Measurements of bacterial grazing
• Continue spatial and temporal coverage
• Continue to integrate field, experimental, and modeling efforts
• Emphasize spring transitional period, not just plume

Zooplankton (inclusive of all groups)

Accomplishments:
Feeding studies of Calanoid adults and nauplii on phytoplankton and microzooplankton

Provide evidence for top down or bottom up control of MFW

Microzooplankton Studies

Results:

• Abundance and growth comparable to those in summer
• Closely follows the distribution of chlorophyll and bacterial production
• Distinct nearshore and offshore (more homogenous) communities
• Plume: increased spatial heterogeneity (minimum Racine/Chicago maximum St. Joseph) and the importance of nearshore taxa
• Important food for copepods: size and motility-based selectivity
• Graze phytoplankton from picoplankton to large diatoms

Plans:

• More spatial sampling and time-series
• Experiments: bacterivory (labeling), herbivory (dilution), zooplankton (cyclopoids)

Mesozooplankton Survey and Monitoring

Results:

• PSS transects were run on pre-plume, plume, and post-plume cruises along with sampling for size fractionated Chl, TSS, zooplankton, nutrients, and microzooplankton. There were extreme differences among nearshore portions of transects.
• Monthly PSS transects and associated sampling were done for Muskegon and St. Joseph transects starting in October 1998.
• There was a major size shift and change in zooplankton compositions between 1998 and 1999: species got smaller and cyclopoids replaced calanoids.

Plans:

• Complete second year of monthly sampling of Muskegon and St. Joseph transects to define and explain major shifts in mesozooplankton composition and size structure. Variables sampled: PSS tows, TSS, Size fractionated Chl, zooplankton from nets, microzooplankton, production by egg ratio.
• PSS improvements
• Calibrate PSS fluorometer, zooplankton count, size frequency, and biomass
• Add PAR sensor
• Do egg ratio estimates on transects from survey cruises to correlate with Chl and microzooplankton. What's going on in "biological deserts" near Gary and Chicago?
• Continue examination of all transects at selected times(s). Add New Buffalo transect? ((There were extreme differences in nearshore areas (out to 10 km) on some transects)). Chlorophyll and zooplankton changed along entire transects, and the deep-water station was different from transects.

Nutrients and Bacteria Studies

Results:

• Distinct spatial pattern in plume between years
• Strong riverine influence St. Joseph and Muskegon
• Elevated TSM/Nutrients limited to <40m
• TP correspond well to TSM
• Smaller but measurable increase in SRP/TDP in plume
• No apparent stimulation of Chl in plume over time
• Bacterial % of community respiration varied between 23-70%
• River input stronger influence on bacteria than plume?
• High bacterial biomass and production in plume doe to increase DOC and PO4
• Drawdown in DOC after plume ~~bacterial C demand

Plans:

• March synoptic cruise
• 2 crosslake transects, more nearshore (non-river) transect
• More river samples, better spatial resolution for Chl
• Experiments on uptake/release of DOC and PO4
• Calibrate satellite reflectivity, TSM, bacterial production
• Water Samplers
• Fine scale temporal data
• Look for offshore transport
• Experiments on bacterial production/nutrient cycling by manipulating particle concentrations and/or river inputs
• Calibrating PSS fluorometry

Optical Characterization Studies

Results:

• Scattering is the dominant factor contributing to variability in light attenuation in RCP
• Variability in particulate absorption was the primary source of variations in total absorption
• Limited variation in phytoplankton spectral absorption across gradients.
• Differences in photoacclimation were apparently not occurring at a rate sufficient to produce clear spatial and vertical gradients in the pigment absorption
• Sub-optimal maximum photosynthetic quantum yields may be indicative of constraints on phytoplankton growth.

Phytoplankton Studies

Results:

• Recurrent Coastal Plume RCP) does not initiate or stimulate the development of the spring bloom
• The Recurrent Coastal Plume (RCP) does not supply a seed population to spring bloom (SB).
  1. Dominate SB diatoms are underrepresented in RCP.
• RCP does not stimulate phytoplankton growth
  1. Chlorophyll and phytoplankton biomass in RCP regions is lower than non-impacted regions after plume dissipates
  2. During 1998 (large RCP) the chlorophyll concentrations in SB were unusually low.
  3. Growth rates of similar species are lower in RCP impacted areas than in non-impacted areas.
  4. After the plume dissipates, phytoplankton communities in RCP impacted areas have greater phosphorus deficiency and lower growth rates than phytoplankton in non-impacted regions.

Tentative Cruise Schedule for FY2000:

Dates	Ship	Activities
Feb 18-25	Guardian	Pre-plume survey, Deploy water samplers Deploy HF radar buoy
Mar 1 - Apr 5 (On call for plume event)	Guardian	8-10 days for Plume survey (PSS, TSM, nuts, bacteria, Chl) and Zoop/MFW grazing experiments
Mar 15 - Apr 5 (Fixed dates)	Laurentian	20 days for Phytoplankton/Optics surveys and shore-based experiments
May 15 - 25	Guardian	6-8 days for post-plume/fronts/spring bloom survey
May 25 - Jun 5	Laurentian	5 days for Phyto/Optics in Lake Superior
June	Laurentian	4 days for Plankton/Nutrient Survey 5 days for Phyto/Optics
July	Laurentian	4 days for Plankton/Nutrient Survey 5 days for Phyto/Optics
Aug	Laurentian	4 days for Plankton/Nutrient Survey
Sep	Laurentian	4 days for Plankton/Nutrient Survey 5 days for Phyto/Optics
Oct	Laurentian	4 days for Plankton/Nutrient Survey
Nov	Laurentian	4 days for Plankton/Nutrient Survey
Dec	Laurentian	4 days for Plankton/Nutrient Survey

Modifications to previous sampling strategies for the Ecological Group

Adding new transect off of New Buffalo to give us a resuspension impacted site without riverine influence on the southeastern side. This site corresponds to stations used by the Phyto/optics group.

Drop Racine transect for the sake of cruise times (?)

Add a cross-lake transect, connecting St. Joseph and Chicago or through offshore features, to better characterize gradients, and help ground truth satellite imagery.

Have the Laurentian and Guardian operating within the same waters during the plume to facilitate cross-discipline comparisons and better integrate data for modelers.

Adding shore based "mesocosm" experiments to examine the effects of sediment and river inputs on bio-optics, phytoplankton, bacteria, and nutrients. These experiments will facilitate activities of outside PI's working on fixed schedules and allow time-series measurements of a variety of biological processes related to particle/nutrient inputs.

Inclusion of moored sequential water samplers to capture high frequency (2d) resolution of sediment/nutrient distributions.

Ongoing Issues

Group leader to promote better coordination among the ecological group. Improved integration with modelers, for defining data needs and timeliness of availability.

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SEDIMENT PROCESSES

Participants: Barry Lesht, Margaret Lansing, Brian Eadie, John Robbins, Jim Waples, David Edgington, Kent Orlandini, Miao-Li Chang

Phase I

• Large, basin-scale spatial variation tau res
• Mesoscale spatial variation both with a time dependent component (coring)
• Traps clearly illustrate basin-scale impacts
• Time series of BBL dynamics BBL tripod providing regional ss:tsm relations

Phase II

• Time series (less spatial coverage)
  1. intensive sediment inventories,
  2. water column inventories
• Onshore-Offshore
• Particle aging and diagenesis
• Particle size dependent transport Focus on particle dynamics and sediment water coupling to transport
• Develop coupled box models & eventually with hydrodynamic modeling

Action Items:

• Synthesize TSM & PSS data for December Sediment Group meeting (Eadie)
  
• Deployment of NDBS buoy as early as possible (Schwab)

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Minneapolis (Oct 1999) Workshop
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