Diet overlap of Eurasian tench (Tinca tinca) with fishes of the Great Lakes–St. Lawrence River basin

Session: Invasive species (2)

Suncica Avlijas, McGill University, [email protected]
Nicholas Mandrak, Biological Sciences, University of Toronto Scarborough, [email protected]
Anthony Ricciardi, McGill University, [email protected]

Abstract

A globally invasive fish, Eurasian Tench (Tinca tinca), is spreading through the St. Lawrence River and has been detected in Lake Ontario in September 2018. At sites with favourable habitat, such as Lake St. Pierre in the St. Lawrence, Tench abundance is growing exponentially. These recent high rates of dispersal and population expansion raise concerns about the potential ecological consequences of an impending invasion of Tench in the Great Lakes. The Tench is a generalist benthic consumer with largely undocumented ecological impacts in North America, though reports from other invaded regions indicate that it can exert strong competitive pressure for food on other benthic fishes. To assess the potential risk of Tench impacts through competition on co-occurring benthivorous fishes in the Great Lakes region we characterized the diet of Tench and quantified its dietary overlap with co-occurring fishes. Fish stomachs were collected at sites where Tench is currently established in the St. Lawrence River, the Richelieu River and Lake Champlain. Results from our study will inform impact risk assessments for this invader as it spreads into the Great Lakes.

Twitter handle of presenter
@Sunci_A