Northern Pike condition and habitat quality within the St. Lawrence River (Cornwall) AOC

Session: Poster session

Dominique Lapointe, St. Lawrence River Institute of Environmental Sciences, [email protected]
Alexandre Poulain, University of Ottawa, [email protected]
Juan Montiel, Universite de Montreal, [email protected]
Sung Vo Duy, Universite de Montreal, [email protected]
Sébastien Sauvé, Universite de Montreal, [email protected]

Abstract

The Northern Pike Esox Lucius is of great economic and ecological importance within the upper St. Lawrence River (USLR) as it is a popular sportfish, a top predator, and an indicator species of water-level changes. Northern Pike abundance has been declining in the USLR since the early 2000s and levels are currently at the lowest since the 1980s. Loss and degradation of habitat, changes in water levels, diseases, and pollution have been identified as potential causes of their demise. Tributaries of the USLR provide spawning grounds and nursery habitat for Northern Pike. Considering the intensity of agricultural activities in the watershed of tributaries located within the St. Lawrence River (Cornwall) Area of Concern (AOC), we assessed habitat quality and fish condition in two tributaries within the AOC as well as one embayment of the river where land-use differ. We measured water quality (temperature, dissolved oxygen, pH, conductivity, total suspended materials, turbidity, nitrate, pesticides), habitat characteristics (substrate, land use, flow, vegetation), and performed fish surveys. Northern pike were collected for condition and health assessments. Tissues were also collected for mercury analysis. Results showed that Northern Pike early-life stages were exposed to elevated levels of agricultural pesticides in these tributaries.

1. Keyword
fish

2. Keyword
pesticides

3. Keyword
mercury