The Aquatic Animal Community in a Chagrin River Tributary at Case Western Reserve University’s Squire Valleevue Farm

Since 1937 Case Western Reserve University has been managing Squire Valleevue Farm as a natural resource for education, research, and recreation. One of the most notable natural features of the property is a small headwater tributary of the Chagrin River that runs from west to east across the Farm’s property. Even though the stream is a valuable educational resource, and its location at the Farm affords it a degree of environmental protection, the aquatic animal community inhabiting the stream remains undocumented. Therefore, the stream’s fish, amphibian, and macroinvertebrate species were surveyed to determine which species are present. In addition, the typical ecological characteristics of each fish species were analyzed and compared to their geographical distributions within the stream in order to determine their path of immigration into the stream. Stream-adapted species (Western Blacknose Dace, Rhinichthys obtusus; Creek Chub, Semotilus atromaculatus) were found at downstream sites close to the Chagrin River, suggesting that these species had naturally colonized upstream from the River. Several pond-adapted species (Bluegill, Lepomis macrochirus, Largemouth Bass, Micropterus salmoides, Yellow Bullhead, Ameiurus natalis) were found at upstream sites that would be difficult to reach through natural colonization due to the presence of large waterfalls. The geographical distribution of these species within the stream indicates that at most two of them may have immigrated from artificial ponds located on Farm property, but at least two of the three species immigrated from a source located upstream of Farm property. The pond-adapted fishes are relatively large, predatory species, and their effects on the amphibian and macroinvertebrate communities remain to be determined.