Frequently Asked Questions—Rice’s Whales

What is the current status of the Rice’s whale in the Gulf of Mexico?

NOAA Fisheries listed the Rice’s whale, previously known as the Gulf of Mexico Bryde’s whale, as an endangered species under the Endangered Species Act in 2019. Rice’s whales are also protected under the Marine Mammal Protection Act and considered depleted. There are likely fewer than 100 Rice’s whales in the Gulf of Mexico, which is the only location where the species is believed to occur. The most recent abundance estimate from 2017–2018 surveys in the northeastern Gulf of Mexico is approximately 50 individuals.

Are Rice’s whales truly a unique species?

Yes, Rice’s whales are a unique species. The existence of these whales in the Gulf of Mexico has been known for many decades. They were previously considered to be a subpopulation of Bryde’s whale (Balaenoptera edeni), a similar-looking species found in other parts of the world. In 2021, a team of scientists demonstrated that Rice’s whales are genetically and physically distinct from Bryde’s whales. For comparison, the degree of genetic differentiation between Rice’s whales and Bryde’s whales is the same as between fin and blue whales. It's two to three times greater than the genetic difference between species of right whales. Physically, Rice’s whales have a unique skull morphology that distinguishes them from other subspecies of Bryde’s whales. They also have unique vocalizations that are clearly distinguishable from the calls of other whales. 

The species was named Rice’s whale (Balaenoptera ricei) in honor of Dale W. Rice, the first scientist to write about these whales in 1965. Read more on how the Gulf of Mexico Bryde’s whale became the Rice’s whale.

Do Rice’s whales only occur in the Gulf of Mexico?  

Rice's whales are only known to reside in the Gulf of Mexico, where they live year round. Most sightings of Rice’s whales have been concentrated in 100-400 meter water depths in the northeastern Gulf off the west coast of Florida and south of Alabama. They have also been seen and heard offshore of Louisiana and Texas, and their calls were recently confirmed in the southern Gulf, off of Mexico. Rice's whales have stranded along the U.S. Atlantic Coast from Florida to Virginia. But it is unclear if Rice's whales normally inhabit the Atlantic Ocean waters, or if these standings were sick, injured, or vagrant individuals. No sightings or calls of Rice's whales have been confirmed in Atlantic Ocean waters to date. 

What are the major threats to Rice’s whales?

Low genetic diversity, small population size, and a restricted range makes the loss of any whales particularly significant. 

Threats to Rice’s whales from human activities include:  

• Vessel strikes
• Noise from vessels and energy exploration
• Oil spills and other pollutants, including lingering effects of the Deepwater Horizon oil spill
• Ingestion of and entanglement in marine debris
• Climate change and its effect on prey
• Entanglement in fishing gear 

As new human activities occur in the Gulf of Mexico, we’re working with multiple partners to design conservation measures to minimize the potential impact of those activities on whales. Learn more about what we’re doing to minimize and mitigate potential impacts of offshore wind development on protected species and their habitats. 

What are the causes of known deaths and serious injuries to Rice’s whales?

In 2009, an adult female Rice’s whale was struck and killed by a ship. Her body was carried into Tampa Bay, draped across the ship’s bow. Researchers determined that she was lactating at the time of her death. If she was nursing a calf, her calf probably died during or after the strike. In 2019, NOAA scientists photographed a free-swimming Rice’s whale with a severely deformed spine that was likely caused by a vessel strike. In that same year, an adult male Rice’s whale died after ingesting marine debris and washed ashore in southwest Florida. These three observed deaths represent only a fraction of actual mortalities. 

The species was also likely heavily impacted by the Deepwater Horizon oil spill. Scientists estimate that 48 percent of their habitat in the eastern Gulf was exposed to oil from the spill. As a result, the population may have declined by up to 22 percent, and there are likely lingering effects on reproduction and population growth. It is difficult to effectively monitor deaths because the species occurs far from shore and we do not regularly conduct surveys in their known habitat. 

What makes Rice’s whales vulnerable to vessel strikes? 

Whales are mammals and must regularly surface to breathe. Limited tagging and foraging studies indicate that the whales dive deep during the day to feed on fish. Tag data suggest the whales spend most of their time near the surface at night when it is difficult to see them. The whales’ proximity to the surface during this time of limited visibility increases the chances for them to encounter moving vessels. 

What is NOAA Fisheries doing to minimize threats to and recover Rice’s whales?

NOAA Fisheries develops and implements recovery plans for the conservation and survival of species listed under the Endangered Species Act. We have developed a recovery outline to serve as an interim guidance document to direct recovery efforts and planning for the Rice’s whale until we develop and approve a full recovery plan. Recovery planning will allow us to holistically consider and prioritize future actions. The process allows the agency to evaluate the species’ needs, set goals for recovery, and outline the path and tasks required to restore and secure a self-sustaining wild population. 

Additionally, we have worked with our partner agency, the Bureau of Ocean and Energy Management as part of a comprehensive consultation in 2020 on their oil and gas program to  minimize threats from oil and gas vessel traffic to Rice’s whale (formerly called Gulf of Mexico Bryde’s whale). Specifically, BOEM is implementing a 10 knot or less daytime speed restriction and nighttime closure area in the eastern Gulf of Mexico for all oil and gas program-related vessels. BOEM also requires oil and gas vessels to maintain a distance of at least 500 meters from Rice’s whales and requires observers to monitor those distances. We continue to work with BOEM on a case-by-case basis to consult on activities that may affect Rice’s whales to determine appropriate protective measures. 

We are undertaking additional conservation and recovery actions, including:

• Finalizing the critical habitat designation for Rice’s whales
• Implementing Deepwater Horizon restoration projects
• Conducting additional vessel risk assessments. 

We also continue to analyze effects of oil and gas activities in the Gulf of Mexico as part of the ESA section 7 consultation process with other federal agencies.

What is critical habitat and has any been designated for Rice’s whales?

Broadly speaking, critical habitat is the habitat needed to support the conservation and recovery of species listed under the Endangered Species Act. NOAA Fisheries is required to designate critical habitat for listed species based on the best available science, and after considering economic, national security, and other relevant impacts, as well as public input. 

Critical habitat does not create new restrictions, such as speed limits, closed areas, marine protected areas or refuges. Rather, critical habitat adds to an existing requirement that federal agencies consult with NOAA Fisheries when undertaking, funding, or permitting activities, in order to ensure that their actions do not jeopardize the continued existence of the listed species. Once critical habitat is designated, federal agencies also need to ensure they do not destroy or adversely modify that habitat. 

NOAA Fisheries proposed critical habitat for Rice’s whales in July 2023. The comment period for the proposed designation closed on October 6, 2023. Virtual public hearings on the proposed critical habitat were held on August 24, 2023, and September 28, 2023. We anticipate completing a final rule by summer 2024. 

Is NOAA Fisheries proposing vessel speed regulations in the Gulf of Mexico for Rice’s Whales?

No. NOAA Fisheries is not proposing vessel speed restrictions or other vessel-related measures to protect Rice’s whales in the Gulf of Mexico at this time. 

NOAA Fisheries received a petition from environmental groups on May 11, 2021 to consider vessel speed regulations to protect Rice’s whales. We notified the public about this petition on April 7, 2023, and solicited public comment on the petition through July 6, 2023. We evaluated the approximately 75,500 comments and information submitted and decided to deny the petition. Fundamental conservation tasks should be undertaken before we consider vessel regulations. These include:

• Finalizing a critical habitat designation
• Conducting a quantitative vessel risk assessment
• Drafting a species recovery plan

We are prioritizing developing a recovery plan for the species, consistent with Section 4(f) of the Endangered Species Act. Recovery planning—informed by the best available science—will allow us to holistically consider and prioritize future conservation actions.

Our response to the petition is separate and distinct from the proposed rule to designate critical habitat. None of the restrictions suggested by the petition will be included in any final rule to designate critical habitat for Rice’s whale.

How do I report sightings of Rice’s whales?

Boaters, anglers, and others should report all suspected sightings of Rice’s whales by calling (877) WHALE-HELP (877-942-5343). This information is valuable for helping us learn more about this endangered species.