Whales are fascinating beings. After living on the land for a while, their ancestors chose to go back to the sea; they have their own, complicated cultures; they help us and our planet by sequestering carbon dioxide; and they seem to have forgiven us for the many horrific crimes that we’ve committed against them.
But for some time now, there’s been something additionally intriguing about a group of Bryde’s whales living in the Gulf of Mexico. While it had been known that these endangered and rarely studied mammals ranged across the Atlantic, Indian and Pacific Oceans, the ones in the Gulf seemed to be homebodies, preferring to stay put in the waters between Florida and Louisiana. And instead of snagging fish near the surface like other Bryde’s whales do, the ones in the Gulf appeared to dine deep.
Now, a new study led by the National Oceanic and Atmospheric Administration (NOAA) confirms what many scientists had suspected: the Gulf of Mexico’s Bryde’s whales aren’t Bryde’s whales at all. They’re a unique species found only in the Gulf; and they’ve been renamed Rice’s whales (Balaenoptera ricei), honoring Dale Rice, the biologist who first distinguished them from Bryde’s whales almost 60 years ago.
Unfortunately, however, there aren’t many Rice’s whales—and the ones that do exist are in deep trouble.
Proof of a new species
According to the most recent NOAA estimate, there are fewer than 100 Rice’s whales alive today. These critically endangered cetaceans prefer the deep, dark waters of DeSoto Canyon—one of the busiest commercial areas in the Gulf of Mexico—where cargo ships and oil drilling are a constant threat.
If compared side by side, a Rice’s whale and a Bryde’s whale would look almost identical. A Bryde’s whale can be a bit larger, however, growing up to 55 feet long and weighing 45 tons, contrasted with a Rice’s whale’s average length of 42 feet and 30 tons. But both whales are part of a group that NOAA calls the “great whales,” which also includes blue and humpback whales. Rice’s and Bryde’s whales are both filter-feeding, baleen whales that use a range of techniques to catch prey, including lunging and using “bubble nets” to corral krill, small fish and other little animals.
But years of sightings, genetic samples, skeletal remains and beach stranding reports caused NOAA scientists to suspect that the Gulf’s whales were evolutionarily divergent. They didn’t mix with other Bryde’s whales; and while Bryde’s go after anchovies and sardines near the surface, Rice’s whales dive deep. For what, no one really knows.
Whales can be hard to study, however. You only get to see them for seconds at a time, generally when they come up to breathe. And it’s especially difficult to assess those that don’t migrate and that spend most of their time far from coastlines, such as Rice’s whales.
But starting in 2000, researchers managed to begin to collect tissue samples from 36 individuals in the Gulf. Comparing their genes with those of other Bryde’s whales, they got some unexpected results. Then, in January 2019, one of the whales stranded off Florida’s Everglades National Park, and a skull became available. When it was examined, scientists found a noticeable morphological difference: there was a distinct group of bones at the top of this skull, providing proof of a new species.
Evidence of endangerment
In April 2019, Bryde’s whales were granted protection under the Endangered Species Act (ESA). At that time, the ESA listing noted that a distinct population of Bryde’s whales were living in the Gulf of Mexico, but they were characterized as a subspecies. In its final report requesting ESA status for Bryde’s whales, NOAA listed many threats to their survival, including entanglement in fishing gear, increasing noise in the Gulf, ocean trash, oil and gas exploration, oil spills and spill responses, and vessel strikes. As Bryde’s whales, the Gulf whales were already considered one of the most endangered species in the world. But now, as Rice’s whales, they are even more at risk. Because the newly named species has such a small population, the loss of even a single individual is significant.
Unfortunately in 2010, BP’s Deepwater Horizon oil disaster killed about 17 percent of the Gulf of Mexico’s Bryde’s whales and likely caused widespread health problems, including the failure of about a quarter of all pregnancies, according to an assessment by NOAA and other federal and state agencies. This devastation happened, even though the spill occurred outside the whales’ core habitat.
Another problem for the whales is our revolving energy policies. On January 19, 2021, the National Marine Fisheries Service (NMFS) published a regulation allowing deep-penetration, seismic blasts to search for gas and oil deposits on the Gulf of Mexico’s floor. Use of seismic air gun survey technology can disorient, injure or kill marine mammals. According to the nonprofit environmental organization Earthjustice, the NMFS rule would allow the oil industry to “harm marine mammals in the Gulf of Mexico more than 8 million times over five years.” Conservation groups are now suing the NMFS to reverse the order.
Happily, though, the Rice’s whale will retain its protected status under the ESA (a standing held when the mammal was considered a subspecies of Bryde’s whale) and will also receive protection under the Marine Mammal Protection Act. And limiting oil drilling, halting seismic surveys and slowing vessel traffic could all have a profound, positive impact on the survival chances of the Rice’s whale.
Validation of hope
Ongoing research aims to solve a host of mysteries about Rice’s whales, such as how they communicate, what they eat and which human activities pose the greatest risks to their population.
For now, though, when scientists published their paper in January 2021 recognizing the Gulf of Mexico whale as a unique species, they made the Rice’s whale the only species of baleen whale believed to reside entirely off the coast of the United States. The fact that there was an unrecognized species of whale out there gives me hope for the future.
Perhaps somewhere else in the deep, dark ocean, there are even more fascinating forms of life that we have yet to meet.
Here’s to finding your true places and natural habitats,