The Striped Bass Returns to the St. Lawrence River

In the late 1960s, sustained fishing, poaching and significant changes in certain habitats led to the complete disappearance of striped bass from the estuary. Subsequent to a reintroduction program and intensive monitoring, this species is now being reported in areas throughout the St. Lawrence. A success for biodiversity in the St. Lawrence.

Striped bass, a fish typically found in estuaries up and down the eastern coast of North America, is globally classified as widespread and abundant. Beginning in the 19th century, the St. Lawrence Estuary population of striped bass was subjected to intensive fishing pressure. A highly combative fish, striped bass became a prized catch among recreational fishermen in addition to its important role in the commercial fishery. By the late 1960s, however, this fishing pressure, poaching and significant changes in certain habitats led to the complete disappearance of the estuary population.

In 2004, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assessed this population and designated it as extirpated. With the government of Quebec and various other stakeholders, Fisheries and Oceans Canada responded by forming a joint recovery team that set objectives and proposed approaches in this regard. In September 2011, Fisheries and Oceans Canada published the Recovery Strategy for the Striped Bass (Morone saxatilis), St. Lawrence Estuary Population, in Canada. This document outlined what needed to be done over the years to come to re establish this population.

Reintroduction and observation

A reintroduction program, including fish breeding in hatcheries, was developed using striped bass captured in the Miramichi River in New Brunswick. Between 2002 and 2015, the Quebec government stocked more than 19,600 juvenile and adult striped bass and 34 million larvae. A new striped bass population developed in the St. Lawrence Estuary.

Numerous cooperative data collection projects were undertaken to monitor the pace of striped bass recovery and identify habitats used by the species. By establishing a broad telemetry network for tracking the movements of mature individuals, it was possible to identify winter aggregation areas as well as holding areas during the spawning period, learn more about summer activity and confirm other important holding areas unidentified to date. Along with the results of field work, this information has helped us to understand how the fish specifically uses certain areas. The various networks for tracking young-of-the-year have also provided us valuable information.

Breeding confirmed!

Among other information, these studies have enabled identification of areas frequented by broodstock fish during the spawning period. In 2008, the reintroduced population was observed to be reproducing naturally in the river, and in 2011, an initiative to track the movements of broodstock striped bass confirmed the presence of the first spawning area at the mouth of Rivière du Sud at Montmagny. Other important breeding areas, including Beauport Bay and Rivière Ouelle, have since been confirmed.

Current efforts will assist in delimiting and identifying the roles of these habitats. In addition to breeding areas, we have added significantly to knowledge about the use of habitats in the St. Lawrence by various developmental stages of the striped bass over the last few years. This knowledge will be used to protect critical habitats for various life stages of the striped bass, St. Lawrence Estuary population.

Regaining its place over time

In 2012, COSEWIC reviewed the situation of this population and acknowledged a steady increase in its abundance and distribution. In light of the recent nature of this situation and the resulting uncertainty, it was designated an endangered species and renamed the “St. Lawrence River population.”

Numerous striped bass observations have been reported recently by the public in all parts of the St. Lawrence River. The return to the river of the striped bass is consequently a confirmed success for biodiversity in the St. Lawrence. Hopes are high for the future!

Marthe Bérubé
Ecosystems Management