New species of whale identified in the Gulf of Mexico

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New species of whale identified in the Gulf of Mexico
Photo Credit Mark Carwardine, Bryde's whale

A critically endangered species of whale has been identified in the Gulf of Mexico by researchers with the National Oceanic and Atmospheric Administration (NOAA). 

It is thought there are less than 100 of these baleen whales, who were originally thought to be a subspecies of the Bryde’s whale.

In the 1990s scientists first discovered a small whale population living year round, in the north eastern Gulf of Mexico. It was originally thought these were Bryde’s whales, a species that can be found in every ocean of the world but favour tropical and subtropical waters. Bryde’s whales are a large species growing to lengths of 15.5m long. They have a large slender body and distinctive parallel ridges on the top of the head, which is a key identification feature. When surfacing, they rarely show more than the top of their head and can often be confused with sei whales due to their size and shape.

The journey to discovering the Rice’s whale started for Dr Patricia Rosel, a research geneticist with NOAA, in 2008 when she and her colleague, examined the first genetic data obtained from samples collected on a NOAA Fisheries vessel survey in the Gulf of Mexico. They noticed the data was quite different from samples collected from other whales. When these whales were first identified in the Gulf of Mexico in the 1990s it was noticed that this group of animals was rare and needed protection. This prompted the genetic samples to be studied to see how closely the whales were related to others in our ocean.

The genetic data suggested this was a new species, but morphological data was needed to confirm this. In January 2019 a whale stranded in Florida off the Everglades National Park in the southern tip of the state. Strandings of individual animals can be destructive to small and rare populations, however this discovery provided scientists with the unique opportunity to study the animal.

The skull of the stranded whale was examined and the most noticeable difference that was found was a group of bones at the top of its skull distinguishing the Rice’s whale from any other species.  Body measurements were also taken to compare this animal with previous stranded whales.

After the original examination and a necropsy by NOAA, the whale remains were buried and a few months later were recovered by the Smithsonian National Museum of Natural History, cleaned, and then transported to their warehouse outside of Washington D.C. This gave Rosel and her colleagues the opportunity to take a closer look and identify the differences between this and other species of baleen whales. Their findings were enough to distinguish this whale as a new species.

Formally describing a new species can take a huge amount of time, as well as research collaborations and reviews by a number of scientists. For example, NOAA staff and collaborating scientists have worked since the 1990s to collect data and biopsy samples so that genetic analyses of the group of whales could take place. Once sufficient evidence has been collected to describe the new species, they then receive a scientific name and a ‘common name’.

This new species has been given the ‘common name’ of Rice’s whale. It has been named for Dale Rice, an American biologist who had a 60-year career in marine mammal science. He was the first researcher to recognise this group of whales in the Gulf of Mexico.

There are around 90 species of cetacean worldwide, but this number fluctuates as new species, such as the Rice’s whale, are discovered and sadly some others are becoming extinct, for example the vaquita porpoise which is highly endangered with about 10 individuals left.

The Rice’s whale will remain protected under the Endangered Species Act, as it was previously listed as an endangered subspecies of the Bryde’s whale, and it is also protected under the Marine Mammal Protection Act.  It is thought there are fewer that 100 of these whales, which makes them critically endangered.

The next stages are for the name, Rice’s whale, to be formally accepted by the Society for Marine Mammalogy Committee on Taxonomy; NOAA Fisheries will then go through the process to update the name in the endangered species list.

This discovery is not only very exciting, but will give NOAA scientists a better understating of this rare species in order to protect them.

Key facts about the Rice’s whale

  • They can weigh up to 60,000 pounds (30 tons)
  • They can grow up to 42 feet long (around 12 meters)
  • Similar to the Bryde’s whale, they have three parallel ridges on the top of their head
  • Not much is known about their life expectancy, but similar to related species, they are thought to live till around 60 years’ old
  • They are found in the Gulf of Mexico in the South East United States
  • Biggest threats include ship strike, noise pollution and entanglement in fishing gear

NOAA fisheries have published a research paper that describes the new species of baleen whale in Marine Mammal Science.