Identification of priority contaminants and their potential effects on early-life stages of the endangered copper redhorse

Description

The Copper Redhorse (Moxostoma hubbsi) is an endangered fish that is only found in the St. Lawrence River and its main tributaries in southern Quebec. According to recent estimates, the population consists of about 2,000 mature individuals. Although an artificial breeding program has stocked approximately 3.5 million larvae and 204,000 fingerlings in the Richelieu River since 2004, population recovery has been slow given that Copper Redhorse mature at a late age. Another factor that may be contributing to poor recruitment^{Footnote 1} is exposure to contaminants at various life stages. Agriculture is a major source of contaminants in this area given that the watersheds of the Richelieu River and two of its tributaries (des Hurons and l’Acadie) are mainly devoted to crop and livestock production. Activities related to other industries in the Richelieu watershed—agri-food, metals processing, chemicals, textiles, and plastics—may have also contributed to a general decrease in water quality in the region.

This project will examine the effects of pesticides and emerging contaminants on early life stage fish—an unexplored area of research for this species. Specifically, the study will:

• measure levels of contaminants at spawning sites in the Richelieu River before, during, and after the natural spawning period to identify priority contaminants and understand their variations over time;
• assess whether chemical contaminants at key spawning grounds are harmful to Copper Redhorse at the early life stage (ELS); and
• use Zebrafish as a model organism to better understand the effects of ELS exposure to priority contaminants on the growth, reproduction, and survival of adult fish in the Richelieu River.

The findings of this research will provide valuable data on the types of contaminants in the Richelieu River and increase knowledge about their potential biological effects on an endangered fish species.

Program Name

National Contaminants Advisory Group (NCAG)

Year(s)

2017 - 2020

Ecoregion(s)

St. Lawrence Lowlands (terrestrial eco region 132)

Principal Investigators

Dr. Jessica Head
Assistant Professor, Natural Resource Sciences
McGill University

Dr. Benjamin Barst
Post-doc, Natural Resource Sciences
McGill University