Analyzing Cod Populations in the Atlantic

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Atlantic cod have been a mainstay of coastal economies around the North Atlantic for hundreds of years. Across its geographic range, the Atlantic cod occurs in many discrete populations, called stocks. In U.S. Atlantic waters, cod have been managed as two stock units since the 1970s. Characteristics like size, growth rate, and even genetics distinguish each stock. As more research accumulates, periodic review of fish stock structure is warranted.

The United States and Canada have long histories of harvesting and trading these fish. Each country manages cod fisheries within their waters. Some cod stocks stay within a country's waters; others straddle the international boundaries. Understanding the number and boundaries of these cod populations is key to improving how we manage and use these fish sustainably. This information also guides decisions about how to rebuild depleted stocks.

U.S. and Canadian researchers monitor and study cod. These scientists may be working for government, universities, or non-profit organizations. They often collaborate with the fishing industry to include local ecological knowledge. A complete and detailed picture of the cod stocks requires an international and interdisciplinary effort. This effort brings together the existing data, studies, and knowledge about stock components. 

Atlantic Cod Stock Structure Working Group Objectives

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• Determine the most appropriate representation of Atlantic cod stock structure for use in regional stock assessments
• Identify high priority research that would contribute significantly to understanding cod stock structure
• Broadly consider potential management actions to meet management objectives given current understanding of stock boundaries
• Follow a transparent process that includes stakeholders in public meetings and through regular updates

Findings

The Working Group proposes a biological stock structure that includes both an inshore-offshore separation and multiple inshore stocks, including a mixed-stock composition of spring and winter spawners in the western Gulf of Maine. Specifically, they identified five biological stocks in U.S. waters:

1. Georges Bank
2. Southern New England
3. Western Gulf of Maine and Cape Cod winter spawners
4. Western Gulf of Maine spring spawners (overlaps spatially with the Western Gulf of Maine and Cape Cod winter spawner stock)
5. Eastern Gulf of Maine

Next Steps

The Northeast Fisheries Science Center and the New England Fishery Management Council are organizing two new working groups that will convene in 2021. They will consider the implications of these newly proposed biological cod stocks in terms of: 1) the next research-track assessment for Atlantic cod, scheduled for March 2023, and 2) potential management actions.

More on Atlantic cod

• Atlantic cod
• Consumer guide
• U.S. Atlantic cod fishery management

Meetings

A number of engagements with stakeholders, including a peer-review evaluation under the auspices of the New England Fishery Management Council, were key to the working group’s success.

2020 Meetings

• The Alaska Fisheries Science Center Groundfish Seminar Series (October 6)
• The Transboundary Resource Assessment Committee Meeting (July 8) 
• The New England Fishery Management Council (NEFMC) meeting (June 25)
• The NEFMC’s Scientific and Statistical Committee (June 4)
• The NEFMC peer-review of the ACSSWG’s findings (May 18-20)
• The Maine Fishermen’s Forum (March 7)

2019 Meetings

• Symposium, University of New Hampshire (June 6)
  Cod Population Structure: Building a Shared Vision of Atlantic Cod Population Structure and New England Fisheries

2018 Meetings

• Symposium, University of New Hampshire (June 19)
  Cod Population Structure: Furthering our understanding by integrating knowledge gained through science and fishing

Atlantic Cod Stock Structure Working Group Members

Co-Chairs

Rich McBride
NOAA Northeast Fisheries Science Center
Woods Hole, Massachusetts

Kent Smedbol
Department of Fisheries and Oceans, Canada
Dartmouth, Nova Scotia

Members

Ted Ames
Bowdoin College
Maine Center for Coastal Fisheries
Stonington, Maine

Irene Andrushchenk
Department of Fisheries and Oceans, Canada
St. Andrews, New Brunswick

Steve Cadrin
University of Massachusetts Dartmouth
School for Marine Science & Technology
New Bedford, Massachusetts

Jamie Cournane
New England Fishery Management Council
Newburyport, Massachusetts

Micah Dean
Massachusetts Division of Marine Fisheries
Gloucester, Massachusetts

Greg DeCelles
Massachusetts Division of Marine Fisheries
(present: Ørsted North America)
Oak Bluffs, Massachusetts

Lisa Kerr
Gulf of Maine Research Institute
Portland, ME

Adrienne Kovach
University of New Hampshire
Durham, New Hampshire

Nina Overgaard Therkildsen
Cornell University
Ithaca, New York

Greg Puncher
University of New Brunswick
St. John, New Brunswick

Yanjun Wang
Department of Fisheries and Oceans, Canada
St. Andrews, New Brunswick

Doug Zemeckis
Rutgers University
New Brunswick, New Jersey