F-80-R-6, MichiganAmended: 2004-05
Study 230724New Study: 2002-03
Name of Study: The importance of trophic interactions for salmonine fisheries of the Great Lakes.
Current Amendment: This study is being amended in 2004-05 to add Section D, “Expected Results and Benefits.”
Previous Amendment(s): None
The following information is duplicated from the original study proposal, including amendments, with additions and/or modifications shown in italics.
D.Expected Results and Benefits: Important fishery management decisions in the Great Lakes depend upon scientific understanding of trophic interactions. These management decisions include how many predator fish to stock, the effort to exert in sea lamprey control, and whether and to what extent to harvest different fish species. This study will improve information on trophic interactions within the fish community and thus will provide tools for improved fishery management. We expect to complete a decision analysis of stocking policies on Lake Michigan, in collaboration with partners. This analysis will provide managers with information on the likely consequences of alternative stocking approaches. For example this analysis will provide information on the probability of a major mortality event for chinook salmon under a variety of different stocking policies. We expect this to lead to improved management, and an increased understanding regarding uncertainty and the extent to which the fish community dynamics depends upon stocking versus other uncontrollable factors. On Lake Huron previously developed population models for the top predators will be expanded to new areas of the lake and updated. This will provide improved information on the magnitude of prey fish consumption by these predators. This information, relative to prey fish abundance, is a key piece of information that managers need when deciding on predator stocking level and harvest policies. We expect to provide these models to the Lake Huron Technical Committee and provide training on their use. We will add to these predator models for Lake Huron, additional population models for other fishes that serve as important hosts for sea lamprey, even though they are not top predators themselves. This is a useful first step toward evaluating sea lamprey effects at a fish community level. We expect to work with collaborators to improve our estimates of the sea lamprey functional response and integrate this functional response into models for sea lamprey damages. We expect to use these models to assess how numbers of lake trout and other fish species killed by sea lamprey are likely to change depending upon levels of sea lamprey control. We also expect to work with collaborators to establish economic injury levels for sea lamprey in lakes Michigan and Huron. This will provide important information to fishery managers on these two lakes with regard to appropriate investments in sea lamprey control. Our work on chinook salmon energetics and biology will provide important information on the trophic effects of this top predator. As such, this information will lead to improvements in the next generation of decision models of the type this project is developing.
I.Personnel: James R. Bence, Associate Professor, Department of Fisheries and Wildlife, other Michigan Department of Natural Resources personnel as appropriate; Research Administrative personnel, and contract editor.