August 29, 2018 — Before whales dive into the darkness of the deep ocean they often come to the surface and release a huge plume of fecal matter—which can be the color of over-steeped green tea or a bright orange sunset. When Joe Roman, a conservation biologist at the University of Vermont, saw one of these spectacular dumps in the mid-1990s, he got to wondering: “Is it ecologically important? Or is it a fart in a hurricane?”

Roman and other researchers have since shown whale excrement provides key nutrients that fuel the marine food chain, and that it also contributes to the ocean carbon cycle. These important roles are now influencing scientific and economic arguments for protecting whales, at a time when calls for a resumption of whaling are growing. “The scientific community is coming to understand a new value of whales: their role in maintaining healthy and productive oceans,” says Sue Fisher, a marine wildlife consultant at the nonprofit Animal Welfare Institute. “We are beginning to see governments use this rationale to justify measures to protect whales.” But as the International Whaling Commission (IWC) prepares for its biennial meeting next month, the ecological services whales provide are set to split the gathered countries—with an unknown outcome for the whales.

Whale poop’s importance is nothing to sniff at. In a 2010 study Roman’s team found whale defecation brings 23,000 metric tons of nitrogen to the surface each year in the Gulf of Maine—more than all the rivers that empty into the gulf combined. This nitrogen fertilizes the sea by sustaining microscopic plants that feed animal plankton, which in turn feeds fish and other animals including the whales themselves. Studies have found similar effects elsewhere, and with other nutrients found in whale feces. And when they migrate, whales also redistribute nutrients around the globe. By moving them from higher latitudes, Roman says, the giant mammals could be increasing productivity in some tropical waters by 15 percent.

By stimulating the growth of microscopic plants called phytoplankton, whale scat may also help limit climate change. These tiny aquatic plants remove carbon from the atmosphere and carry it deep into the ocean when they die. Research in the Southern Ocean showed the iron defecated each year by some 12,000 resident sperm whales feeds phytoplankton that store 240,000 more metric tons of carbon in the deep ocean than the whales exhale. This means that, on balance, whales help lock carbon away.

Read the full story at the Scientific American