February 14, 2024 — The following was released by NOAA Fisheries:
For the past 25 years, Rice’s whales have been consistently observed in the northeastern Gulf of Mexico. They have been seen along the continental shelf break in waters roughly between 100 and 400 meters deep. In 2017, a single Rice’s whale sighting was confirmed in the western Gulf of Mexico off the coast of Texas, suggesting that their distribution may extend further west. New science led by NOAA Fisheries provides more evidence that these whales may be more prevalent in the western Gulf of Mexico than previously thought.
Listening for Rice’s Whales
Melissa Soldevilla, Ph.D., of the NOAA Fisheries Southeast Fisheries Science Center led an international team of researchers that used passive acoustic recorders called High-frequency Acoustic Recording Packages to listen for Rice’s whales in the western Gulf of Mexico. The recorders were moored to the seafloor for up to 2 years and captured ocean sound from a variety of sources, including whale sounds. The team used specialized software to analyze the recordings for Rice’s whale calls, which were then validated manually by an experienced acoustic analyst.
The team deployed these long-term passive acoustic recorders offshore of Louisiana and Texas for 356 days, and in Mexican waters for 680 days. They detected Rice’s whale calls on 25 percent of days recorded offshore of Texas, and 33 percent of days recorded off Louisiana. These findings provide additional support for Rice’s whales’ persistent occurrence in the western Gulf, including new information demonstrating their regular occurrence in waters offshore of Texas.
Even more striking was the detection of Rice’s whale calls on 15 percent of days recorded offshore of Mexico, at sporadic intervals throughout the year. This provides the first evidence that Rice’s whales occur in Mexican waters.
The paper, Rice’s whale occurrence in the western Gulf of Mexico from passive acoustic recordings, was published in the journal of Marine Mammal Science on February 13, 2024.
What This Means for Rice’s Whales
This discovery has many implications for the management and conservation of Rice’s whales. The results of this research will be used to inform management decisions for this endangered species.
These findings also highlight the importance of continuing surveys into these waters to refine future population estimates and track the Rice’s whale population status. NOAA Fisheries continues to conduct research on these whales to better understand them and plan for recovery of their population. Ongoing research on Rice’s whales includes:
- Studying their trophic interactions and habitat requirements
- Conducting stock assessments
- Observing whales on vessel-based visual surveys
- Leading acoustic studies to better understand Rice’s whale distribution, movement, and behavior
Rice’s whales face threats that contribute to their risk of extinction such as:
- 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
Rice’s whales are listed as an endangered species under the Endangered Species Act, and is protected under the Marine Mammal Protection Act. They are also a part of NOAA Fisheries’ Species in the Spotlight initiative, which brings greater attention and leverages partnerships and resources to save this highly at-risk species.
Partnerships
This work involved many researchers from these partner institutions:
- Scripps Institution of Oceanography
- University of Miami
- Universidad Veracruzana
- Universidad Nacional Autonoma de Mexico
Help Keep Whales Safe
NOAA Fisheries encourages boaters, anglers and others to report all suspected sightings of Rice’s whales by calling (877) WHALE-HELP (877-942-5343). This information is invaluable for helping us learn more about this endangered species.
The Endangered Species Act and Marine Mammal Protection Act prohibit harassing, harming, pursuing, wounding, killing, capturing, or collecting protected marine mammals. Observe marine animals from a safe distance of at least 100 yards—the length of a football field. Never approach or touch them. Please read our marine life viewing guidelines for more information.