Potential influences of climate change and tournament angling on lake ecosystems with a focus on largemouth bass

Aquatic ecosystems and their inhabitants face a long list of threats to their well-being, and the effects of current stressors as well as those that may occur in the future must be assessed for their impact on these systems. Tournament angling an anthropogenic stressor that has the potential to negatively influence populations of popular sportfish, as fish are often removed from nesting grounds during the spawning season. While angled individuals often have limited reproductive success, the impact that these tournaments have on population-level recruitment and juvenile size structure is unclear. Using a replicated pond experiment with representative fish communities common in the Midwestern U.S., I gained insights into how competitive angling practices may affect largemouth bass (Micropterus salmoides), a common target of many fishing tournaments. I also examined the potential effects of a warming climate on lake ecosystems of the Midwest. While the causes of global warming are debatable, there is significant evidence that suggests a warmer climate in the immediate future. Using power plant lakes across the central Midwestern U.S. as proxies for lake systems that may result from climate change, I compared a host of biotic and abiotic variables from these treatment lakes and control lakes of similar size and location, but lacking the artificially warm thermal regime. I found several differences between the two types of systems, including zooplankton concentration and community composition, fish growth, and fish spawning times. These differences lead me to conclude that regional lakes may change substantially in food web dynamics and ecosystem function in response to warmer climates. To determine potential impacts of warmer temperatures on fish health and thermal tolerance, I assessed tolerance of warmer temperatures of fish from both types of lakes using multiple methods. I found little difference in temperature tolerance between largemouth bass from the different systems. I conclude that eurythermal species such as largemouth bass are able to tolerate a wide range of temperatures, and that similar species will likely be the most able to adapt and thrive in a changing climate.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Natural Res & Env Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Mulhollem, Joshua

Contributors dc:contributor

• Wahl, David H.

• Largemouth bass
• Climate change
• Bass tournaments
• Heat stress
• Fish physiology

Statement dc:rights

• Copyright 2014 Joshua Mulhollem

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/50598

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/50598