An Experimental Enclosure in Fox Creek – photo by Robin Munshaw
This week my masters work was published in Ecosphere, an open access journal that is a part of the ESA (Ecological Society of America) family of journals. For the study we experimentally manipulated a stream in the Angelo Coast Range Reserve, dramatically reducing inputs of terrestrial prey into the stream from the surrounding forest. Our work further demonstrated the importance of terrestrial invertebrate prey for juvenile steelhead growth and for the effects of predatory fish on the food web. In small, forested tributary streams invertebrates falling in from the bank and forest canopy represent a major portion of juvenile salmon and steelhead diets and our results suggest that these subsidies likely boost stream carrying capacity for juvenile fish significantly. Furthermore, while steelhead have been shown to elicit strong top-down responses in the larger South Fork Eel River, much of the aquatic invertebrate community in Fox Ck – where we carried out our experiment – is comprised of armored or otherwise invulnerable taxa (mostly cased caddis). This is likely a legacy of high fish densities and the fact that steelhead and other predatory fish are supported within the stream food web at levels far exceeding what could be supported by in situ prey alone.
Check out a copy of the manuscript on the ESA website, it’s open access!