Please select your home edition
Raymarine AUS Element HV LEADERBOARD

Saildrone set to track Alaska red king crab

by NOAA Fisheries 16 Jun 2019 14:10 UTC
NOAA Fisheries scientist Leah Zacher tests a trial tag on a female red king crab. © NOAA Fisheries

Fishing industry and researchers team up to track red king crab seasonal movements to provide data vital to keeping the Bristol Bay fishery sustainable in a changing climate.

Alaska red king crab and the perils that fishermen face to catch them have gained worldwide fame. But fishermen are also working hard, together with NOAA Fisheries, to keep red king crab populations healthy and sustainable.

Reasons for declines in Bristol Bay red king crab stocks over the last decade are not well understood. Very little is known about how recent environmental variability drives crab seasonal movements, habitat use, and interactions with groundfish trawl fisheries.

NOAA Fisheries is partnering with the fishermen-supported nonprofit Bering Sea Fisheries Research Foundation to find answers to these unknowns. We are launching research to track the movements of adult male red king crabs in Bristol Bay using an unmanned surface drone (Saildrone, Inc.). Their findings will provide information crucial to keeping red king crab sustainable in a changing climate.

"So little is known about where crabs are and how they move. We have only snapshots from summer surveys. This research will fill in the life history gaps to better inform the management of red king crab as both target and bycatch," said Scott Goodman of Bering Sea Fisheries Research Foundation.

"Managers need to understand where crabs go in different seasons, and what habitats are essential, to set effective rules for fishing," said NOAA Fisheries scientist Leah Zacher, who is leading the project. "Everyone benefits from increasing our knowledge of crab distributions."

Tag and Seek: Tracking Seasonal Movements of Crabs
Scientists will be working with fishermen in June to tag crabs with acoustic devices that transmit an ID number and the bottom temperature. Tagging is timed right after the NOAA Fisheries summer survey so researchers will be able to target where crabs are most abundant.

The team will deploy the saildrone, equipped with an acoustic receiver, in October 2019 and again in April 2020 to relocate the tagged crabs.

"We know where crabs are in the summer from annual NOAA Fisheries surveys, but there is little information for the rest of the year. We will relocate the crabs in the fall to understand how crabs move onto the fishing grounds, and in the spring to determine their locations when they are vulnerable to being caught as bycatch in trawl fisheries," Zacher said.

The saildrone, contracted and funded by Bering Sea Fisheries Research Foundation, provides invaluable capabilities to make the search, and the research, possible.

"We have a huge area to search for moving targets in an ever-changing environment. Traditional tag and recover methods require an enormous investment of time. You are dependent on the crabs being caught in a fishery and the tags returnedyou never know if or when the tags will come back. Tracking crabs acoustically from a manned vessel would be unfeasibly expensive," Zacher explained. "With a saildrone we can cover huge areas cost-effectively, at the times when we need data."

"This technology will collect many data points for each crab released. It is a new paradigm for tag release and recovery studies," Goodman said.

Essential Habitat in a Changing Climate
An important outcome of the research will be finding out what habitats are essential for Bristol Bay red king crab in different seasons, and whether current protected areas are effective.

Temperature information transmitted by each tagged crab will help determine how temperature influences crab movement among key areas. The team will also compare crab locations with sediment maps to identify the characteristics of essential habitat.

The study will also show whether protected areas are in fact protecting crabs.

"The Red King Crab Savings Area is closed to trawling to provide a protected habitat. But the area was initially set based on limited information, and since then the climate has changed, the environment is changing. Managers need to know if and when red king crabs are moving through and using those areas to know if they are effective," Zacher said.

Understanding how crab movements are affected by climate is a longer-range goal of the study. Warm conditions are projected for the Bering Sea in 2019, so the team will document habitat use and movement under a warm regime. This can be compared to future tracking efforts in cooler conditions.

Additional Resources:

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
Raymarine AUS Element HV FOOTERMarina Exchange FOOTER 1