Salad. It's What’s for Dinner: Mapping Grass Carp Food Resources in Lake Erie

Session: Poster session

Nicole King, University of Toledo, Lake Erie Center, [email protected]
Jenny Hanson, US Geological Survey, [email protected]
Patrick Kocovsky, U.S. Geological Survey, [email protected]
Christine Mayer, University of Toledo, Lake Erie Center, [email protected]
Song Qian, University of Toledo, [email protected]

Abstract

Grass carp (GC) consume large amounts of plant biomass and cause decreases in abundance and diversity of submersed aquatic vegetation (SAV) which can adversely affect native floral and faunal communities and contribute to declines in water quality. First direct evidence of GC spawning in the Great Lakes Basin was documented in 2015 and has since been documented in two Lake Erie tributaries. Consequently, there is a heightened need to understand the potential ecological effects that a reproducing population of GC may have on Great Lakes’ wetlands. We used a 3-tier assessment tool using object-based image analysis, hydroacoustics, and field sampling with a plant rake to identify current distribution and abundance of SAV species. SAV was primarily restricted to protected shoreline areas and highest density was observed around the Lake Erie islands. We aim to establish baseline data to track any changes in SAV communities potentially caused by GC herbivory. Additionally, we identified areas most at risk of herbivory based on GC feeding preferences (inferred from literature) and SAV density. After comparing areas of preferred GC habitat to documented GC captures (nas.er.usgs.gov), it appears some SAV areas may have already experienced negative impacts from GC herbivory.

1. Keyword
biological invasions

2. Keyword
Lake Erie

3. Keyword
submerged plants

4. Additional Keyword
Grass Carp