Fall River Food Web Dynamics and Wild Trout

Partners in Conservation

The Fall River Conservancy partners with a variety of organizations to leverage conservation dollars, and ensure the best scientific minds are tackling the issues at hand. One important relationship is with the USDA Western Regional Research Center who has been partnering with the Fall River Conservancy to analyze the food web dynamics on the Fall River.

Fall River Conservancy has been actively involved by providing on-the-river support. FRC founding Board Member Art Teter has been collecting fish gut contents from wild trout on the Fall River for several seasons now. By pumping the gut and preserving the contents, researchers are able to find out what macro-invertebrates, or bugs, the fish have been eating. This information is critically important in understanding what species of macro-invertebrates are being seen on the Fall River still, and their relative abundance. It also helps researchers understand food web dynamics on the Fall River.

Here are the general findings:

The data indicate that fish gut contents at the upstream most site are dominated by Baetid and Ephemerellid mayflies. Samples from the next three sites downstream were dominated by Chironomid (midge) pupae and larvae. Samples from the downstream most two sites were dominated by Baetid and Ephemerellid mayflies as well as endemic snails (Fluminicola seminalis). Data summarized on the map below was collected in Spring 2015.

Fall River Conservancy

Management Implications for the Fall River:

Why is this important? The Fall River Conservancy is interested in assessing the health of the food web dynamics on the Fall River. We have heard from our members and conservation partners that macro-invertebrate diversity and abundance is “not what it used to be”. Our approach to these observations is to engage the scientific community, and fund applied research that will help shape our understanding of these important observations with the goal of creating an adaptive management plan to address these issues.

The Fall River Conservancy is currently putting together a cross-disciplinary team of researchers and applied scientists to begin research on the Fall River to look at aquatic vegetation, sedimentation, macro-invertebrate density and abundance, and water quality to help to answer these questions.

(Art Teter, FRC Board Member and Jeff Cook, Spring Rivers Ecological Sciences surveying the condition of aquatic vegetation in the Fall River. Summer 2015)

Over the coming months, the Fall River Conservancy will develop a comprehensive study plan to:

  • Assess the health and vigor of the aquatic macroinvertebrate populations in Fall River
  • Assess water quality in Fall River from the top to bottom of the reach as well as from the top to bottom of the water column at monitoring locations
  • Establish some water quality monitoring stations at particular points of interest where some of the localized conditions could be most affected by combined factors
  • Assess the condition of rooted macrophytes (aquatic vegetation) in the Fall River

Stay tuned to find out more as these research progresses over the following months.

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