Please select your home edition
Edition
Raymarine AUS Element HV LEADERBOARD

Learning more about a big fish: Atlantic Halibut Team goes "Under the Hood"

by NOAA Fisheries 7 Dec 2019 14:56 UTC
An adult Atlantic halibut is one of the largest fish in the Gulf of Maine. © NOAA Fisheries

For nearly three centuries Atlantic halibut off New England and Atlantic Canada were taken for food and sometimes discarded as a nuisance. Their fate depended on the market and just how numerous they were.

It proved to be a cyclical fishery. Several years of massive landings and discards were followed by many years of fallow seas before the fish would reappear in substantial numbers.

As these cycles played out, the fish also got smaller. By the late 19th century, the 6- to 7-foot specimens routinely encountered in the early days became the stuff of legend. Today the stock is a remnant of its former numbers.

In U.S. waters, a fishery focused on halibut is a thing of the past, but small catches are allowed in commercial and recreational fisheries from Maine to Connecticut. Canada has a commercial fishery for Atlantic halibut that fishes on the southern Grand Banks and Scotian Shelf. It extends to Canadian waters on the northern edge of Georges Bank and in the Gulf of Maine.

In recent years, fishermen have seen more halibut. Researchers have started to look more closely at the life history, age, growth and reproduction of these fish. They're looking for signs that rebuilding efforts are having an effect.

A three-part study is under way now to better understand basic life history, stock structure, and where the fish go. The Northeast Fisheries Science Center is helping with the life history component, especially reproductive biology.

The study is focused on three questions: When and where do halibut spawn? Is there one overall population in the region, or are there several populations? And when do they mature? These are key questions for stock assessment scientists.

Not enough samples for a study

"We would catch maybe six to 12 halibut a year in our scientific surveys during the last decade," said Rich McBride, head of the Northeast Fisheries Science Center's Population Biology Branch, who is part of the study. "That was not nearly enough for a study about the animal's life history. We needed more samples than what we were catching."

It took two years and special permission from the New England Fishery Management Council, but researchers now have enough samples from U.S. fish to learn more. The council agreed to let study participants take up to six halibut per trip, exceeding the current trip limit of one.

The study needed 450 to 500 more samples from about 250 fish. Alliance members hit that target this year. They have provided about half the samples available for the study.

Fishermen fill the sample gap

The Cape Cod Fishermen's Alliance in Chatham, Massachusetts worked with researchers to provide training. They taught fishermen how to collect biological data from halibut needed for the study.

Fishermen learned how to gather the most important samples for a basic biology study: heart, spleen, gonad (reproductive organ), earbones (for aging), and a fin clip. They also got familiar with the data sheet they would use to record fishing location, the time, and the length and weight of the fish. Researchers could then match that information back to the sample.

"When fishermen caught halibut in the course of a fishing trip, they would collect the samples," explained George Maynard, research and policy coordinator for the Alliance. "Back on shore, I would collect the samples from the fishermen and bring them back to the lab for preservation and archiving. The tissue samples were all preserved and shipped to our collaborators in Canada for genetic analysis."

Looking "Under the Hood" of a Halibut Egg

Maynard prepared gonad samples and brought them to McBride for processing. McBride, Maynard, and Emilee Tholke, another fisheries biologist, are studying cross-sections. They want to get an idea of each halibut's maturity status.

"To get at those answers, we're looking at developing eggs 'under the hood,' at the cellular level," said McBride. "Having some sense of their current life history would be helpful as we move forward."

"The next steps will be to combine these data with the length/weight and time of capture data from the fishermen, and aging data from the Massachusetts Division of Marine Fisheries," said Maynard. "That will allow us to build a clearer picture of the size and age at which halibut reach maturity, and what time of year they spawn."

The three-part study is funded by a Saltonstall-Kennedy grant developed by Chris McGuire at The Nature Conservancy. The other two parts include a stock structure study using genetic samples led by the Bedford Institute of Oceanography in Halifax, Nova Scotia. The University of Massachusetts-Dartmouth's School for Marine Science and Technology is leading a satellite-tagging effort to understand halibut habitat use and distribution.

For more information, please contact Shelley Dawicki .

Related Articles

Progress of habitat restoration projects
Check in on the progress of projects in North Carolina, South Carolina & Alaska The projects were funded through the National Fish Habitat Partnership. They demonstrate our commitment to engage anglers in habitat restoration efforts, and support access to sustainable saltwater recreational fishing opportunities. Posted on 21 Jun
Large whale entanglements report confirmed in US
More than 100 large whale entanglements were confirmed nationally in 2018 Many large whale populations are increasing in the United States, but entanglements in fishing gear or marine debris are a growing threat to the continued welfare and recovery of these species. Posted on 20 Jun
Economic effects of oyster reef restoration
Restored oyster reefs could boost the blue crab population - and the economy Oysters play critical roles in the Chesapeake Bay ecosystem—by filtering water as they feed and by providing habitat and forage for other Bay species. Posted on 16 Jun
Atlantic highly migratory species by the numbers
Facts about recreational Atlantic highly migratory species fishing that may surprise you Anglers fish for highly migratory species from the rocky shores of New England to the warm waters of the Gulf of Mexico and Caribbean Sea. HMS fishing is important to the cultural, social, and economic life of Atlantic coastal communities. Posted on 15 Jun
National Fishing and Boating Week 2020
We celebrate one of nation's most cherished pastimes: saltwater recreational fishing National Fishing and Boating Week took place June 6-13, 2020 and highlights the importance of recreational boating and fishing in our nation. National Fishing and Boating Week occurs each year during the first full week of June. Posted on 14 Jun
Autonomous vehicles help scientists estimate fish
An innovative scientific approach to survey Alaska pollock this year Scientists are capitalizing on existing technological capabilities and partnerships to collect fisheries data. This will help fill the information gap resulting from the cancellation of FY20 ship-based surveys due to the COVID-19 pandemic. Posted on 5 Jun
Leading the Fight Against IUU Fishing
June 5 marks International Day for the fight against IUU Fishing Every day, the United States and our partners across the world work together to crack down on Illegal, Unreported and Unregulated (IUU) Fishing and Seafood Fraud. Posted on 5 Jun
President signs order promoting American seafood
Calls for the expansion of sustainable U.S. seafood production The President signed a new Executive Order promoting American seafood competitiveness and economic growth to propel the United States forward. It calls for the expansion of sustainable U.S. seafood production. Posted on 9 May
New state of the ecosystem reports
Human uses affect ecosystem productivity but also fishing communities and regional economies Two newly issued reports provide a snapshot of the Northeast U.S. Shelf Ecosystem. They look at everything from phytoplankton production at the bottom of the food web to the fishery harvests at the top. Posted on 13 Apr
West Coast salmon fishing and southern residents
Chinook salmon fishing is a mainstay of the West Coast economy Southern Resident killer whales have long pursued the biggest and most nourishing Chinook salmon from coastal Pacific waters. Chinook salmon fishing is also a mainstay of the West Coast economy, generating nearly $72 million in income last year. Posted on 12 Apr
Marina Exchange FOOTER 1Raymarine AUS Element HV FOOTER