Brett Peters

Project Title: ”Implementing and evaluating effective management strategies for controlling invasive aquatic animals“

External Partnership: The Ottawa National Forest

Concern about biodiversity loss is increasing worldwide. There is evidence that biodiversity is currently decreasing at alarming, unprecedented rates. The effect of invasive species is one of the leading causes of biodiversity loss in aquatic systems.  Unlike invasive aquatic plants and terrestrial invasive species, there are few examples of effective control of invasive aquatic animals.  Brett's research focused on implementing and evaluating effective management strategies for controlling invasive aquatic animals. The majority of his research explored the management efforts for controlling rusty crayfish (Orconectes rusticus) in northern Wisconsin and in the upper peninsula of Michigan. 

 One control method is the introduction of smallmouth bass. Smallmouth bass (Micropterous dolomieui) are very effective crayfish predators and are a favorite target of many northwoods anglers.  The University of Notre Dame, in collaboration with the U.S. Forest Service and the Michigan DNR, has initiated a management experiment to decrease the abundance of rusty crayfish in Lake Ottawa (Iron Co. MI).  Collaborators took two actions to achieve the goal of reducing crayfish abundance: (1) fish manipulation and (2) trapping crayfish.  In June 2005, the Michigan DNR instituted catch-and-release regulations for smallmouth bass (Micropterous dolomieui) and largemouth bass (Micropterous salmoides) in Lake Ottawa (Iron Co. MI).  These catch-and-release regulations have made smallmouth bass larger and more numerous.  Altering the fish community in this way has had a drastically reduced the population of invasive crayfish.  The presence of larger, fecund bass has also helped to recruit smallmouth bass, which has further enhanced reductions in crayfish predation on bass nests.

To guide future management efforts, it is important to evaluate thoroughly the effectiveness of management strategies like the one being carried out in Lake Ottawa.  To do this Brett and his collaborators have collected baseline data on many environmental variables in Lake Ottawa and a set of control lakes.  This data was analyzed using a BACI design to determine the long term effect of these management actions.  In addition, an evaluation of the short term effectiveness of a month-long mechanical removal effort was conducted in the summer of 2006.  The results of this management experiment have helped guide future fisheries management in lakes with rusty crayfish populations.

Distinctive Outcomes: Brett recently presented his research to the national TNC meeting. He has also submitted a research proposal to NSF.