**The title, authors, and abstract for this completion
report are provided below. For a copy of the completion report, please
contact the GLFC via e-mail
or via telephone at 734-662-3209**
of Great Lakes Acoustic Ground-Truthing Workshop
Daniel L. Yule2,
Jean V. Adams3, Thomas R. Hrabik4, Lars G. Rudstam5,
David M. Warner3, Brian Weidel6, Randall M. Claramunt7, Patrick M. Kocovsky8, Patrick J.
Sullivan5, Larry D. Wizel9, and Bernard Pientka10
Lakes Science Center, Lake Superior Biological Station, 2800 Lakeshore Drive E., Ashland, WI 54806.
Lakes Science Center, 1451 Green Road, Ann Arbor, MI 48105.
Department, University of Minnesota Duluth, 207 Swenson Science Building, 1035
Kirby Drive, Duluth, MN 55812.
Biological Field Station and Department
of Natural Resources, Cornell University, 900 Shackelton
Point Road, Bridgeport, NY 13030.
Lakes Science Center, Lake Ontario Biological Station, 17 Lake St., Oswego, NY
Department of Natural Resources, Charlevoix Fisheries Research Station, Charlevoix,
Lakes Science Center, Lake Erie Biological Station, 6100 Columbus Avenue Sandusky,
Ministry of Natural Resources, Lake Erie Management Unit, 1 Passmore
Street, Port Dover, ON N0A 1N0.
Department of Fish and Wildlife, 111 West Street, Essex Junction, VT 05452.
Standardization of the Great Lakes Acoustic Ground-Truthing
Workshop was held 27 September – 1 October, 2010, at the Great
Lakes Science Center, Lake Erie Biological Station, Sandusky, OH.
The workshop was funded by an $8,025 grant received from the Great Lakes
Fishery Commission - Science Transfer Fund. A total of 65 people were invited
of which 19 attended including scientists from four universities, and six state, federal and provincial agencies. The objectives of
the workshop were: 1) train attendees in current methods used to apportion
acoustic fish density estimates to species using ground-truth data, and 2)
develop a flexible pelagic fish community simulator to test the performance of current
apportionment methods through sampling artificial lake environments having
known numbers of each species. The overall mission was to identify the most
scientifically valid approach for assigning acoustically estimated numerical
density and biomass density to fish species in the Great Lakes, and to
collectively decide if standardization of apportionment methods is warranted.
We developed three simulated lake fish communities analogous to lakes Superior
(Lake S), Michigan (Lake M) and Ontario (Lake O) and sampled these with mock
acoustic and midwater trawl gears under different
levels of sampling intensity (i.e., the amount of samples that could be
collected in 1, 3 and 5 nights of work with a real ship). Sampling results were
then used to test performance of five apportionment methods currently in use. In
general, we found that the different apportionment methods performed similarly
in lakes S and M. Lake O was populated with fish such that there was minimal
overlap in the vertical distribution of small rainbow smelt and alewife
compared to adults of these species. In this instance, apportionment methods
that utilized depth stratification (Hierarchical averaging method,
Classification tree method, and the Nearest trawl with
depth stratification) outperformed methods that did not (Keep it simple stupid
method, and Nearest trawl method). We conclude there is little need to select a
standard apportionment method for the Great Lakes, provided methods that can
account for the fact that fish community composition in large lakes can vary
substantially by water column depth are used. An exit survey showed attendees
were generally pleased with the workshop. A manuscript describing results of
objective 2 and 3 is being developed for submission to the Canadian Journal of Fisheries
and Aquatic Sciences. A follow-up to our workshop for European large-lake
scientists is to be held at Stockholm,