Impacts of Land Use and Sedimentation on Brown Trout (Salmo trutta) Populations in a High Quality (Class A) Fishery

Brody, Eden

Impacts of Land Use and Sedimentation on Brown Trout (Salmo trutta) Populations in a High Quality (Class A) Fishery

Persistent URL

https://hdl.handle.net/10456/57677

Author(s)

Brody, Eden

Date Issued

April 30, 2024

Abstract

In recent decades, anthropogenic land alteration has intensified worldwide, with land alteration increasing erosion processes, causing increased waterbody sedimentation. Increased fine sediment deposition has been linked to declines in the abundance of many Salmonid fishes (trout and salmon). However, the mechanisms linking increased sediment to declines in salmonid abundance are idiosyncratic and dependent upon the species, stream habitat, and watershed landscape. Caldwell Creek is a Class A Brown Trout (Salmo trutta) fishery in Northwest Pennsylvania that is reported to have a decline in trout abundance. This decline is hypothesized to be associated with increased fine sediment inputs within the watershed. To evaluate the extent and potential causes of this decline in trout abundance, data on physical habitat, water quality, sedimentation levels, macroinvertebrate communities, and trout populations were collected from 10 sample sites in the Caldwell and Pine Creek watersheds. Analysis was conducted to determine the differences in historic and current trout population metrics and the connections between abiotic stream inputs and trout populations. Results indicated a significant decline in the intactness of the macroinvertebrate communities (p = 0.0151) and the abundance of Brown Trout (p = 0.0407) in the West Branch of Caldwell Lower site, as well as a significant decline in the biomass of brown trout (p = 0.0496) in the West Branch of Caldwell Upper site. A principal component analysis on abiotic inputs revealed that water temperature, stream-sediment loads, habitat quality, and watershed area were the primary factors influencing trout abundance in Caldwell Creek. This indicates that changes in thermal regimes due to climatic trends and increases in sediment loads from land use changes are likely responsible for the decline in trout abundance. The Caldwell Creek watershed should be a prioritization for both restoration and mitigation to restore the sustainability of the Caldwell Creek Brown Trout Fishery.

Major

Biology

Honors

Biology, 2024

First Reader(s)

Bradshaw-Wilson, Casey R.