New Baleen Whale Species Described in the Gulf of Mexico.

NEW BALEEN WHALE SPECIES DESCRIBED IN THE GULF OF MEXICO.

EMER KEAVENEY | JANUARY 24TH 2021

A new Baleen whale species was described recently by a team of researchers from the National Oceanic and Atmospheric Administration (NOAA) and the National Museum of Nature and Science, Tokyo ( 国立科学博物館). The researchers described a new species of baleen whale from the Gulf of Mexico and named it "Rice's Whale", after cetacean researcher Dale Rice. The Rice whale was considered to be significantly different from the Bryde's whale based on morphology and DNA analysis. Unfortunately, the Rice's whale, endemic to the Gulf of Mexico, has an estimated population size of less than 100 individuals and was immediately listed as critically endangered.

This week NOAA Fisheries announced the publication of a scientific research paper that describes a new species of baleen whale in the Gulf of Mexico. The article in Marine Mammal Science indicated that the whale previously known as the Bryde’s (pronounced “broodus”) whale is actually a new whale species living in the Gulf of Mexico. The new manuscript, authored by NOAA Fisheries scientist Dr. Patricia Rosel, provided the first morphological examination of a complete skull from these whales and identified diagnostic characteristics that distinguished it from the other closely-related baleen whale species. Genetic data were also provided as a second line of evidence which supported the uniqueness of the whales in the Gulf of Mexico.

The journey of the discovery of the now Rice’s whale, began back in 2008, when Dr. Rosel examined the first genetic data obtained from samples collected on NOAA Fisheries vessel surveys in the Gulf of Mexico and found that it was quite different from other whales. However, Rosel and fellow NOAA scientist Dr. Keith Mullin began collaborating on the new species even earlier. Mullin and his colleagues had been studying the whales at sea since the 1990s and believed they were rare and needed protection and further study. These finding led to more in depth studies and more efforts to collect samples to study genetic linkages between whales. Describing a new species is a lengthy process that involves spending a tremendous amount of time conducting research, forming collaborations, and reviewing previously published scientific papers. Once there is sufficient evidence to describe a new species, it then receives a Latin name and a "common name". The Latin name for the Rice's whale is Balaenoptera ricei .

The Smithsonian now holds the specimen of record—known as the "type specimen"—for this species. It came from a male Rice's Whale that stranded in Florida in January 2019 and, through a Herculean effort led by our very own John Ososky, it was transported to the Smithsonian's whale collections and prepared for researchers to study in perpetuity.

The most noticeable morphological difference in the new species as compared to its closest relatives is found in the animal’s skull. Dr. Rosel was examined the skull of a Rice’s whale in 2020 after one stranded in Florida off Everglades National Park in January of 2019. While losses of individuals of a rare species are detrimental to their long-term sustainability, the death and the subsequent efforts by marine mammal stranding network responders to recover and investigate stranded animals provide scientists an opportunity to thoroughly study the animal from top to bottom, inside and out.

Rice’s Whale Facts

• Rice’s whales can weigh up to 30 tons, which is about five times as heavy as an elephant!
• They can grow over 12 meters in length
• Like the closely related Bryde's species, they have three lateral ridges on the top of their rostrum (upper jaw area).
• Not much is known about their life expectancy, but closely related species reach sexual maturity at 9-years-old and can live about 60 years.
• Biggest threats to the species include vessel strikes, ocean noise, energy exploration, development and production, oil spills and responses, entanglement in fishing gear, and ocean debris.
• Found in the Gulf of Mexico in the Southeast United States.

Reference:

Rosel, P.E., Wilcox, L. A., Yamada, T. K., Mullin, K.D., (2021). A new species of baleen whale ( Balaenoptera ) from the Gulf of Mexico, with a review of its geographic distribution. Marine Mammal Science.