Rice's Whale (formerly Northern GOM Bryde's Whale)
The Rice’s whale was recently recognized as a new species, evolutionarily distinct species from other Bryde’s whales. Rice’s whale is the only year-round resident baleen whale in the northern Gulf of Mexico. The population is estimated at 51 animals and it is one of the world’s most endangered baleen whales. Rice’s whale is found primarily off the panhandle of Florida, in an area known as De Soto Canyon, but there has also been a confirmed sighting of a Rice’s whale by NMFS scientists in the western Gulf of Mexico.
Rice’s whales were first recognized in the Gulf of Mexico in 1965, and were assumed to be a population of the broadly distributed Bryde’s whale complex. 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.
Although Bryde’s whales are now relatively common in some regions, the population in the northern Gulf of Mexico is estimated to number only about 51 individuals. They occur in the northeastern Gulf of Mexico, along the shelf break in waters 100 to 400 meters deep in the De Soto Canyon region off the Florida Panhandle. Genetic analyses have determined that the Gulf of Mexico population is genetically distinct from other Bryde’s whale populations. Based on genetics analyses and new morphological information, scientists now recognize the Rice’s whale as a new species (Balaenoptera ricei), distinct from Bryde’s whales.
Rice’s whales are threatened by vessel strikes, acoustic disturbance from seismic airguns and other oil and gas-related activities, marine debris, commercial fishing and aquaculture, vessel noise, military activities, oil spills, and pollution from agricultural runoff in the Gulf of Mexico.
A petition was submitted to the National Marine Fisheries Service (NMFS) in 2014 to list the Northern Gulf of Mexico stock of Bryde’s whale 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 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.
NMFS published a final rule establishing the name change from Bryde’s whale (Gulf of Mexico subspecies) to Rice’s whale under the ESA in August 2021. The immediate next steps are the development of a recovery plan and designation of critical habitat under the ESA. In the interim, NMFS has prepared a guidance document to direct recovery efforts for the Rice’s whale.
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.
Commission staff are serving on a NMFS Steering Committee to convene expert workshops to help identify recovery criteria and recovery actions for the Rice’s whale, as part of NMFS’s recovery planning efforts. Those workshops are scheduled for October and November of 2021.
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 was June 2017 to May 2021. Field studies included shipboard surveys, passive acoustic monitoring, tagging, prey characterization using echosounders and net tows, and collection of biological samples. The focus of the field work was on primary habitat in the eastern Gulf, and outcomes will 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. A video presentation summarizing research from the RESTORE Science Program is available here, along with additional information about the project.
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 Reports and Publications
Gulf of Mexico Marine Mammal Research and Monitoring Meeting Summary (Marine Mammal Commission 2015)
|Letter Date||Letter Description|
|October 31, 2018|
|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|
|December 4, 2015|
|September 28, 2015|
|July 9, 2013|
|July 8, 2013|
|December 28, 2012|
Bryde’s/Rice’s whale is currently threatened by collisions with vessels, acoustic disturbance from seismic airguns and other oil and gas-related activities, military activities, entanglement in fishing gear, aquaculture, vessel noise, oil spills, and pollution.
Bryde’s/Rice’s whale sightings are rare, as are strandings. On 29 January 2019, a 38-foot male stranded in the Florida’s Everglades. A necropsy of the whale determined that the whale was underweight and examination of its stomach revealed a piece of hard plastic, approximately 5 cm by 7.5 cm in size. The plastic piece had sliced through part of the whale’s stomach, which likely contributed to its death. That whale’s skeleton is now at the Smithsonian Institution in Washington, D.C., and represents the holotype for the new species.
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. A notice by NMFS to change the name of the whale from Bryde’s whale to Rice’s whale is expected soon.
The Future/Next Steps
NMFS scientists are in the process of analyzing data recently collected on the abundance, distribution, diet, behavior, and habitat use of Bryde’s/Rice’s whale in the Gulf of Mexico. This information will 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.