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As of 2004, this project is no longer current. Please see the Research Programs page for a list of current research projects.
Modification of Lake Michigan Benthic Habitats by Zebra Mussels
Colonization by dreissenid mussels, Dreissena
polymorpha (Zebra) and Dreissena bugensis
(Quagga), is one of the more ecologically important events to
occur in the Great Lakes during the last decade. Since their
introduction into Lake Michigan, dreissenids have colonized both
soft and hard substrates to depths of 80 m and reached average
densities of 40,000 m-2 in the littoral zone. Because of high
densities, widespread distribution, and high filtering rates,
Dreissena populations can filter large volumes of water
and have the capacity to decrease algal biomass. Therefore this
diversion of algal production into dreissenid tissue and
biodeposits may deprive Diporeia and other deepwater
macroinvertebrates of food settling from the water column.
Further, the lake bottom in the Great Lakes coastal zone is
undergoing dramatic changes as a consequence of the invasion and
spread of Dreissena polymorpha and D.
bugensis. Dreissenid mussels have modified habitats for
benthos and fishes and fostered growth and proliferation of
nonindigenous species, such as the round goby and a Black Sea
amphipod, Echinogammarus.
currently there is no active research on this project
2002 Plans
In this study, we will use acoustic remote sensing technology (sidescan sonar and acoustic bottom classification) as tools to extend and extrapolate information on dreissenid distributions from spatially limited observations. ROV-based operations and orange-peel sampling will be used to calibrate and test the interpretations made of the acoustic data. The acoustic observations will consist of: a) Sidescan images of acoustic backscatter; b) Echosounding for acoustic bottom classification. The data will be loaded into a GIS and models will be constructed to describe the areal distribution of substrate type and dreissenids. From these data, we will create a model that will be used to:
- Study the link between dreissenid distribution and substrate type, morphology and depth;
- Identify lake floor with a high probability of being/becoming infested with dreissenids;
- Predict the ultimate composition of a future dreissenid population.
Our summer cruises will include areas on both the east and west sides of Lake Michigan.
Accomplishments
Scientists at GLERL and at collaborating universities and agencies have completed the first phase to classify Lake Michigan bottom habitat. Using sonar and video technology, we gathered information on zebra mussel populations and their effect on lake resources. The first phase of the project, completed July 2nd, 2001, involved the collection of acoustic data. Working off of the R/V Noodin, a University of Minnesota vessel, scientists utilized multibeam/sidescan sonar to plot mussel distributions on the lakebed. Sidescan sonar operates by transmitting sound waves to surrounding water (and lake bottom) and then analyzing characteristics of returning sound waves reflected from objects in the water or on the bottom. Preliminary results suggest that zebra mussel populations on the lake bottom reflect sound in a unique way and produce a distinct "signature" that will allow researchers to distinguish such populations from other bottom types. Seabed classification sonar (Quester Tangent Corp.) was also used to create a map of the sea bed. These data were combined with video from a camera simultaneously filming the lakebed. This "bentho-cam " was suspended along the side of the R/V Cyclops, a small boat run by GLERL, at a depth of three meters and captured nearly all of the area covered by the sonar. Preliminary results show four unique seabed types that were matched with video clips. In August, 2001, SCUBA divers from the USGS Great Lakes Science Center were used to confirm preliminary results. Sediment samples were also collected for grain size analysis.
Upon their return, scientists plotted their data and are currently creating data overlays. They will overlay the basic plot from the sonar technology with video and other information. The final product will be an interactive map with a feature that will provide depth readings, graphics, latitudinal and longitudinal coordinates, sediment type, and zebra mussel densities for any point on the map.
Multibeam sonar image of sediments near Milwaukee, WI, Lake Michigan
- Vertical exaggeration X25
- Ridges in "central" area
- Bedrock ridges
- Localized high spots (rocks or reefs)
- Sand
Collaborators
NOAA/GLERL:
Steve Lozano, Tom Nalepa
USGS Great Lakes
Science Center:
Greg Kennedy, Marc Blouin
Illinois Natural
History Survey:
John Dettmers
University of Minnesota:
Nigel Wattrus
University of
Wisconsin-Milwaukee:
John Janssen
University of
Michigan:
Dave Jude
Publications
John J. Janssen, Martin B. Berg, and Stephen J. Lozano. In press. Submerged terra incognita: The abundant but unknown rocky zones. In The Lake Michigan Ecosystem: Ecology, Health and Management, edited by T. Edsall and M. Munawar. AEHMS, Burlington, ON.
Presentations
J. Janssen, S. Lozano, M. Berg, D. Jude, and J. Dettmers. Lake Michigan Rocky Habitat, always important, seldom studied In the Nearshore Fisheries Habitat Workshop, in Muskegon, Michigan. April 1-2, 2003.
Stephen Lozano and Marc A. Blouin. 2002. Characterization of coastal Great Lakes benthic habitat. In Symposium on Effects of Fishing Activities on Benthic Habitats: Linking Geology, Biology, Socioeconomics, and Management. November 12-14, 2002. Tampa-St. Petersburg, FL.
Last updated 2004-04-22 mbl