Impacts of Hydrological Conditions on Fish Diversity and Populations in a Small Urban Stream

Abstract

Record ID: 280

Program Affiliation: NA

Presentation Type: Poster

Abstract: The characteristics of urban streams create stressors for fish that cause dramatic shifts in population dynamics. These characteristics include, a flashy hydrograph, increased nutrient input, loss of biodiversity, and channelization. Hydrology is a major factor that impacts fish compositions because it determines habitat availability in streams. Hydrology is especially important in urban streams, as urban fish communities already face habitat degradation compared to natural streams. Urban streams are populated by fewer species that are more tolerant to changes caused by urbanization, but these species are still affected by changing hydrology. Using a five-year dataset collected in four sites within Cooper Creek, an urban headwater stream in Cincinnati, OH, we analyze variations in fish population and community structure in response to habitat availability in wet and dry years in an urban stream. The two focuses of this study are understanding (1)  how fish community composition and (2) population characteristics (e.g., size distribution, body condition) change in wet versus dry years. Cooper Creek is inhabited by tolerant pioneer species like Creek Chub, Western Black nose Dace, Central Stoneroller, and a few more species present in the lower reaches of the creek. In this study we hypothesize that there is a correlation between fish community composition/population characteristics and the amount of rainfall in a year. We predict that in wetter years with more rainfall there will be greater habitat availability. This will result in better population numbers, larger fish, and more well rounded size distributions.