Whales are the bees of the ocean.
That’s a conclusion of new research showing that whales undertake the longest journeys to transport nutrients of any mammal or large animal on Earth, much like bees collect and distribute pollen.
Researchers from the University of Vermont, who published their findings in Nature Communications, found that humpback, gray, and right whales transport more than 3,700 tons of nitrogen each year while migrating along what’s been dubbed the “great whale conveyor belt.”
“Humpback whales and gray whales make the longest-distance migrations of any mammal on the planet, thousands of miles every year,” said study author Joe Roman. “So this study is the first one that I'm aware of that tries to quantify that movement.”
Through urine, feces, placentas, carcasses, and sloughing skin, whales bring nitrogen and other nutrients from high-latitude areas like Alaska and Antarctica to low-nutrient tropical grounds like Hawaii and the Caribbean.
“And [the nutrients] can be picked up by phytoplankton, coral reef systems, fish, birds, and have an impact on these distant ecosystems,” Roman said.
The impact on phytoplankton is particularly important, he said, as it takes in carbon dioxide, expels oxygen, and makes up the base of the marine food web.
“Certainly I think for coral reef systems, for many fish species, for bird species, they depend on this movement every year.”
Ocean currents and upwellings also transport nutrients, Roman said, but only at a fraction as much as what whales provide in their natural migratory patterns.
This research informs an argument for stronger whale conservation, Roman said; as whale populations have declined precipitously over the last few centuries, the great whale conveyor belt has weakened. The nutrient transport numbers — by the tons — might have been three times higher before commercial whaling.
“There's a little bit of an, ‘Oh crap’ moment, that, ‘Man, populations used to be a lot higher,’” he said. “Sadly, North Atlantic right whales and North Pacific right whales are two species that are still critically endangered, and their influence on ocean ecosystems is greatly reduced. So there are many reasons to protect right whales, from my view: the inherent value that I think they're really important to have around, but also for their ecological value as well.”
