Habitat Mapping and Predator-Prey Dynamics in Ohio Resevoirs

Mechanisms associated with habitat choice in fish are often unknown, and require exploration of many different abiotic and biotic habitat features. The importance of finding these drivers lies in helping to explain population variation. Saugeye Sander vitreum ¿ X S. canadense ¿ are stocked with varying success in Ohio reservoirs. As a step toward understanding what might be limiting saugeye in some reservoirs, we used spatially explicit information about temperature, prey availability, depth, slope, and substrate to predict saugeye habitat use. Using telemetry we mapped saugeye locations to assess factors that influence saugeye habitat use. Saugeye were tagged with a radio tag for location. Hydroacoustics were used to map prey densities and biomass, and to map substrate type. Akaike's Information Criterion (AIC) was used to determine which habitat variables are the most important for explaining the presence or absence of saugeye. In general, saugeye favored steeper slopes in nearshore areas with sand, gravel, and rock, and shallower depths during April -October, and over a 24-h period. Saugeye habitat suitability maps were created from AIC parameters. To determine how prey availability influences saugeye habitat choice, we created a spatially explicit growth rate potential (GRP) model. Using a saugeye bioenergetics model, we combined spatially referenced prey biomass and water temperature to determine potential growth of saugeye during the months of April - October. Overall, we found that GRP was low in the spring, before their main prey item, gizzard shad Dorosoma cepedianum, spawn, and saugeye GRP peaked, post-spawn, in August. When comparing GRP in 3-5m to 10-12m we found that the shallower depths have a bioenergetic advantage over the deeper waters. This information can be used to influence stocking rates of saugeye by considering both the temporal availability of gizzard shad and the amount of suitable habitat in a reservoir.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Evolution, Ecology and Organismal Biology

Grantor dc:publisher

The Ohio State University

Year dc:date

2008

Author dc:creator

• May, Cassandra J.

Contributors dc:contributor

• Marschall, Elizabeth

• Ecology
• Organismal Biology

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=osu1364461349

OAI identifier oai:identifier

oai:etd.ohiolink.edu:osu1364461349