Potential predation between fishes of recreational interest has incited many bitter conflicts between angler groups. Large predators, such as esocids, are often at the center of these conflicts because of their capacity to alter fish populations. Such a conflict certainly exists between the Muskellunge Esox masquinongy and Smallmouth Bass Micropterus dolomieu fisheries of the New River, Virginia. Following the institution of a 42-in minimum-length limit (MLL) on Muskellunge, bass anglers feared that increased Muskellunge abundance might be negatively affecting Smallmouth Bass via increased predation. In order to ascertain the impacts of the 42-in MLL, I estimated the demographics, abundance, and food habits of Muskellunge combined with bioenergetics modeling to assess changes (i) in the quality of the Muskellunge fishery and (ii) in Muskellunge predation on Smallmouth Bass. Additionally, given the likelihood of future regulations to incite similar concerns from bass anglers, I modeled alternative length-limit regulations (iii) to assess their potential to improve fishery quality, thereby laying the groundwork for managers to address angler concerns before they arise. I found substantial increases in population size structure and in average adult density of Muskellunge since the institution of the 42-in MLL, but bioenergetics modeling did not indicate a notable increase in the consumption of Smallmouth Bass. I also found that high MLLs (e.g., 48-in) were likely to promote the largest increases in trophy production of Muskellunge compared to low MLLs or protected-slot limits (PSLs). This study suggests that the current Muskellunge population likely plays a small role in shaping Smallmouth Bass population dynamics and production in the New River; and lays the groundwork for predicting how the impact of Muskellunge on Smallmouth Bass might change under alternative regulations. / Master of Science / Management of fish for recreation can be challenging when multiple species are of interest, particularly when potential exists for one species to negatively influence another and stimulates conflict between users. Large predators are often at the center of these conflicts because of their ability to change fish populations via predation. This type of conflict certainly exists between the Muskellunge <i>Esox masquinongy</i> and Smallmouth Bass <i>Micropterus dolomieu</i> fisheries of the New River, Virginia. The perceived influence of increased Muskellunge predation on Smallmouth Bass and the bass fishery following the institution of a 42-in minimum-length limit (MLL), has created tension between users. In order to ascertain the impacts of the 42-in MLL, I estimated Muskellunge population structure, abundance, and food habits and combined them with diet modeling to assess changes (i) in the number and size of Muskellunge and (ii) in Muskellunge predation on Smallmouth Bass. Additionally, given the likelihood of future regulations to incite similar concerns from bass anglers, I also used regulation modeling to assess (iii) the potential of other regulations to change the number and size of Muskellunge. I found that the size structure (i.e., the proportion of large Muskellunge in the population) and the number of Muskellunge increased after the 42-in MLL, but I did not find a notable increase in the amount of Smallmouth Bass eaten by Muskellunge. I also found that more-restrictive regulations (i.e., a 48-in MLL) could further increase the size structure and number of Muskellunge. My results suggest that the current Muskellunge population probably plays a small role in shaping the Smallmouth Bass population of the New River, and I lay the groundwork for predicting how that role might change under other regulations.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/77440 |
| Date | 21 April 2017 |
| Creators | Doss, Sasha Stevely |
| Contributors | Fisheries and Wildlife Sciences, Castello, Leandro, Murphy, Brian R., Orth, Donald J., Copeland, John R. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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