A subspecies of Bryde's whale in the Gulf of Mexico is close to extinction. Photo by Morningdew/Wikimedia Commons
Feb. 7 (UPI) -- Baleen whales are under increasing pressure as a result of microplastic pollution. And at least one group of baleen whales is inching dangerously close to extinction.
As Nature recently reported, the new listing of the Gulf of Mexico whale, a subspecies of Balaenoptera edeni, as "critically endangered" by the International Union of Concerned Scientists has garnered little public response.
The baleen whale could be the first whale to go extinct since the Atlantic grey whale died out some 300 years ago.
The Gulf of Mexico whale is part of a group known as the Bryde's whale complex, the taxonomy of which is poorly characterized. The newly listed subspecies is closely related but genetically distinct from the Bryde's and Eden's whale. The population is confined entirely to the Gulf of Mexico.
Like other baleen whales, the subspecies is being harmed by increasing levels of microplastic pollution. Baleen whales, like humpbacks, grey whales and blue whales, are filter feeders. They don't have teeth. They use long hair-like filters in their mouths to trap and eat krill and other tiny organisms.
New research, published in the journal Trends in Ecology and Evolution, suggests microplastics are increasingly becoming caught in their baleen filters.
"Despite the growing research on microplastics in the marine environment, there are only a few studies that examine the effects on large filter feeders," Elitza Germanov, a researcher at the Marine Megafauna Foundation, told The Guardian. "We are still trying to understand the magnitude of the issue. It has become clear, though, that microplastic contamination has the potential to further reduce the population numbers of these species, many of which are long-lived and have few offspring throughout their lives."
While a number of threats are harming baleen whale numbers, including oil spills, overfishing and illegal whale hunting, microplastics are cause for concern.
"Exposure to these plastic-associated toxins pose a major threat to the health of these animals since it can alter the hormones," Maria Cristina Fossi, a professor at the University of Siena, said in a news release.
Scientists say more needs to be done to inform the public of the dangers plastic pollution poses to vulnerable species.