Andrew is an undergraduate student in his 4th year of an environmental science, with concentration in ecology, degree at Carleton University. He is currently working on his honours project with Dr. Steven Cooke. The duration of his work extents from January 2006 to May 2007. Details of his proposal can be reviewed below.
Thesis Proposal
Evaluating the interactive effects of air exposure duration and water temperature on angled fish using lethal and sublethal indicators
Background and Rationale:
The goal of catch-and-release fishing is to release fish in a condition such that they will survive and experience no long-term sublethal effects. A significant amount of research has evaluated the factors that can impede the ability of catch-and-release to be a viable conservation and management activity. Some of the factors identified as playing a role in stress and mortality include hooking location, duration of the angling event, water temperature, and air exposure duration. Of these factors, air exposure and water temperature are perhaps best understood with respect to their effects on fish. However, more research is necessary to quantify the compound stress that some of these variables provide, and how they alter mortality and sub-lethal effects. The purpose for this research will be to evaluate how air exposure duration and water temperature (°C) interact to affect mortality and loss of equilibrium (sub-lethal stress) when catch-and-release fishing.
Proposed Approach:
For this study, we opted to use bluegill as a model because they are readily available and can be captured across a broad range of water temperatures. Furthermore, bluegill are small enough that we can standardize angling duration so that it was not a co-factor. The research will occur at Queen’s Biology Station on Lake Opinicon, located in southeastern Ontario. Treatment fish will be captured using conventional angling gear and landed within 20 seconds. Once landed, fish will be exposed to air for periods ranging from 1 to 300 seconds (randomized). Afterwards, fish will be individually marked using binary fin clips and placed in a cooler filled with lake water to assess their post-treatment behaviour. Fish will be observed for a period of five minutes noting sub-lethal behavioral characteristics (i.e., floating upside down, floating on side, and resting on substrate) at time intervals of 0, 15, 30, 60, 90, 180 and 300 seconds, before they will be placed in a larger holding pen. Fish will be revaluated in the holding pen 48 hrs later to observe delayed mortality. The holding pen is to be located in the same body of water where the fish were caught. This experiment will be repeated on at least three different days providing a range of temperatures between about 14 and 26ºC. In addition to the treatments described above, there will also be two control groups; Control 1, Fish angled but not exposed to air, and Control 2, Fish captured by seine net and not exposed to air.
Significance:
At present, both high water temperature and lengthy air exposure are regarded as some of the more stressful aspects of catch-and-release. The proposed research will enable a more precise understanding of how water temperature and air exposure play a compounding roll in catch-and-release fishing. Using bluegill as a model, we will be able to place these findings in a general context such that they will enhance the conservation of our fisheries resources. |
