The effects of temperature, latitudinal origin, and dam escapement on management of muskellunge

Wolter, Max

The effects of temperature, latitudinal origin, and dam escapement on management of muskellunge

Wolter, Max

Permalink

https://hdl.handle.net/2142/31170

Description

Title

The effects of temperature, latitudinal origin, and dam escapement on management of muskellunge

Author(s)

Wolter, Max

Issue Date

2012-05-22T00:33:19Z

Director of Research (if dissertation) or Advisor (if thesis)

Wahl, David H.

Department of Study

Natural Res & Env Sci

Discipline

Natural Res & Env Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

Fisheries management
muskellunge
bioenergetics
dam escapement

Abstract

Muskellunge Esox masquinongy are commonly stocked to either maintain or supplement populations across the Midwestern United States. The objectives of most fish stockings are to maximize survival and growth. Many potential factors influencing stocking success of muskellunge have been identified including temperature, predation, handling stress, competition, prey availability, habitat, dam escapement, and genetic or latitudinal origin. Much work remains to be done exploring the significance and interaction between several of these variables. My thesis focuses on temperature, source latitude of populations, and dam escapement as factors influencing growth and survival of muskellunge. Three different genetic groupings of muskellunge have been identified as the Upper Mississippi, Ohio, and St. Lawrence River drainage stocks. Different populations occurring across a range of latitudes and climates exist within each of these stocks. A recent and increasingly popular strategy in muskellunge management is to identify and utilize populations with perceived growth advantages for stocking. However, there is little understanding of how stocks, and populations within stocks, may vary in their physiological tolerance to thermal stress and the implications when relocating fish. In the first study I examined thermal tolerance among populations representing several stocks of muskellunge from varying latitudes using lethal chronic thermal maxima and sub-lethal physiological stress response experiments. Contrary to expectations, I found few indications that muskellunge populations included in this study differed in their capacity to withstand heat challenges. Other sources of mortality should be examined to explain survival differences among these populations that may be observed in the field. I also expected physiological differences at the population level to influence growth rates of muskellunge. In the second study I attempted to understand thermal adaptation of growth among latitudinally separated muskellunge populations using bioenergetics modeling to explore whether approaches refined to the population level would improve accuracy and usefulness of future modeling efforts. Bioenergetics modeling simulations indicated that growth rates of muskellunge populations may be adapted to native thermal environments. In addition to many other known factors, survival of muskellunge stocked into reservoirs may also be influenced by dam escapement. Escapement from reservoirs has been identified as one of the unknown factors in muskellunge management, thought to have the potential to greatly reduce abundance and structure populations. Laboratory studies of a simulated spillway and field evaluations utilizing a PIT tag interrogating antennae found dam escapement of muskellunge to be more prevalent during the day. Field evaluations of escapement also found 20% of a reservoir population to escape in one year, with adults escaping more than juveniles. Results of my thesis demonstrate that interactions between latitudinal origin and temperature may have influences on growth more so than survival of stocked muskellunge, and that dam escapement is an important factor influencing management of reservoir populations.

Graduation Semester