Marine Mammal Commission

Northern GOM Bryde's Whale

The Northern Gulf of Mexico Bryde’s (pronounced BROO-dus) whale is the only year-round resident baleen whale in the northern Gulf of Mexico. The Gulf of Mexico population is estimated at 33 animals and is genetically distinct from other populations found in the Pacific, Indian, and Atlantic oceans, making it potentially one of the most endangered of the baleen whales. They are found primarily off Florida, in an area known as De Soto Canyon.

Bryde's whale

Bryde's whale. Photo taken under NOAA research permit #779-1633. (NOAA)

Species Status

Bryde’s whales occur in tropical and subtropical waters of the Atlantic, Pacific, and Indian oceans. Bryde’s whales were targeted by commercial whalers in the 1900’s, after many other large whale species became depleted. Between 1911 and 1987, over 30,000 Bryde’s whales were caught worldwide.

Bryde’s whales in U.S. waters have been divided into three stocks: Eastern Tropical Pacific, Hawaiian, and Northern Gulf of Mexico. Although Bryde’s whales are relatively common in some regions, those in the Northern Gulf of Mexico stock are estimated to number only about 33. They occur along the shelf break in waters 100 to 400 meters deep in the De Soto Canyon region of the northeastern Gulf of Mexico, off the Florida Panhandle. Genetic analyses have determined that the Gulf of Mexico stock is distinct from Bryde’s whale stocks in other parts of the world, and it has a very low level of genetic diversity.

Bryde’s whales in the Gulf of Mexico are currently threatened by vessel strikes, acoustic disturbance from seismic airguns and other oil and gas-related activities, military activities, vessel noise, oil spills, and pollution from agricultural runoff. Commercial fishing with longline and trap gear also overlaps to a limited degree with Bryde’s whale habitat.

A petition was submitted to the National Marine Fisheries Service (NMFS) in 2014 to list the Northern Gulf of Mexico stock as endangered under the Endangered Species Act (ESA). NMFS subsequently initiated a status review of Bryde’s whales under the ESA, which was finalized in December 2016. The status review determined that the Gulf of Mexico Bryde’s whale is taxonomically a subspecies of the Bryde’s whale, thus meeting the ESA’s definition of a species. Based on the Gulf of Mexico Bryde’s whale’s small population (likely fewer than 100 individuals), its life history characteristics, its extremely limited distribution, and its vulnerability to existing threats, NMFS has determined that the Gulf of Mexico Bryde’s whale is in danger of extinction throughout all of its range. In April 2019, NMFS listed the Gulf of Mexico Bryde’s whale as endangered throughout its range. The listing was based on the species’ small population size, restricted range, and threats due to energy exploration, development, and production, oil spills and oil spill response, vessel collisions, fishing gear entanglements, and human-caused sound. The immediate next step would be designation of critical habitat under the ESA.

What the Commission Is Doing

The Marine Mammal Commission is working with NMFS and other partners in the Gulf of Mexico to expand research and monitoring efforts for all marine mammals.

In April 2015, the Commission held a meeting to identify high priority, overarching data needs and to identify potential funding sources and opportunities for expanding marine mammal research and monitoring in the Gulf.

Commission staff serve as one of two technical monitors on a RESTORE Act Science Program-funded project to evaluate Trophic Interactions and Habitat Requirements of Gulf of Mexico Bryde’s Whales. The timeframe for the project is June 2017 to May 2020. Field studies will include shipboard surveys, passive acoustic monitoring, tagging, prey characterization using echosounders and net tows, and collection of biological samples. The focus of the field work would be on primary habitat in the eastern Gulf, but the spatial scope could be expanded to other potential habitat areas. Expected outcomes include an improved understanding of population status, identification of habitat features and characteristics (including critical habitat primary constituent elements), and a better understanding of the risk of exposure to human activities in the Gulf.

Commission Reports and Publications

Gulf of Mexico Marine Mammal Research and Monitoring Meeting Summary (Marine Mammal Commission 2015)

Assessing the Long-term Effects of the BP Deepwater Horizon Oil Spill on Marine Mammals in the Gulf of Mexico: A Statement of Research Needs (Marine Mammal Commission 2011)

Commission Letters

Letter Date Letter Description
August 21, 2018

Letter to NMFS regarding application submitted by the Bureau of Ocean Energy Management (BOEM) seeking issuance of regulations for taking of marine mammals incidental to geophysical surveys in the Gulf of Mexico under section 101(a)(5)(A) of the Marine Mammal Protection Act (MMPA)

February 6, 2017

Letter to NMFS regarding a proposed rule for listing the Gulf of Mexico Bryde’s Whale as an endangered species under the Endangered Species Act

December 4, 2015

Letter to Deepwater Horizon Natural Resource Damage Assessment Trustees regarding the draft damage assessment and restoration plan for the Gulf of Mexico

September 28, 2015

Letter to the Gulf Coast Ecosystem Restoration Council re: Draft Funded Priorities List for Gulf of Mexico restoration activities

July 9, 2013

Letter to Bureau of Ocean Energy Management regarding the notice of intent to prepare a programmatic environmental impact statement on geological and geophysical activities in the Gulf of Mexico

July 8, 2013

Letter to Department of Commerce/Gulf Coast Ecosystem Restoration Council regarding the initial draft comprehensive restoration plan for the Gulf of Mexico

December 28, 2012

Letter to NMFS regarding the Deepwater Horizon Natural Resource Damage Assessment Trustee Council’s development of a restoration plan to address injuries from the oil spill

Learn More

Threats

The Northern Gulf of Mexico Bryde’s whale stock is currently threatened by collisions with vessels, acoustic disturbance from seismic airguns and other oil and gas-related activities, military activities, vessel  noise, oil spills, and pollution from agricultural runoff.

Current Conservation Efforts

In September 2014, NMFS received a petition to list the Northern Gulf of Mexico Bryde’s whale stock under the Endangered Species Act (ESA). NMFS subsequently issued a notice announcing its determination that the petition was warranted, which prompted a status review of the stock to determine if the stock should be listed. The status review was finalized in December 2016 and determined that the Gulf of Mexico Bryde’s whale is taxonomically a subspecies of the Bryde’s whale, thus meeting the ESA’s definition of a species. Based on the Gulf of Mexico Bryde’s whale’s small population (likely fewer than 100 individuals), its life history characteristics, its extremely limited distribution, and its vulnerability to existing threats, NMFS has determined that the Gulf of Mexico Bryde’s whale is in danger of extinction throughout all of its range. NMFS  issued a proposed rule to list the Gulf of Mexico Bryde’s whale as endangered and reviewed comments received on the proposed listing, including comments submitted by the Commission. In April 2019, NMFS issued a final rule to list the Gulf of Mexico Bryde’s whale as endangered.

The Future/Next Steps

Now that NMFS has finalized the listing, the immediate next step would be designation of critical habitat under the ESA.

In the interim, additional information regarding abundance, distribution, diet, habitat use, and stock structure and status in relation to other Bryde’s whale stocks would assist in the designation of critical habitat and the development of a recovery plan outlining strategies to conserve and protect this stock from natural and human-caused threats. The number of species/stocks of Bryde’s whales in other parts of the world is still under study.

Additional Resources

NMFS Gulf of Mexico Bryde’s Whale species page

NMFS 2017 Stock Assessment Report for Northern Gulf of Mexico Bryde’s Whale

Status Review of Bryde’s Whales in the Gulf of Mexico under the Endangered Species Act