How poop could counter calls to resume commercial whaling

This post was first published by Scientific American in August. As such, it refers in the future tense to a meeting that took place back in September. You will find an update — and some good news — at the end of the story.

Before whales dive into the darkness of the deep ocean they often come to the surface and release a huge plume of faecal matter—which can be the colour 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 non-profit 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.

Fertilising the ocean

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 fertilises 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 faeces. 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 that the iron defecated each year by the 12,000 resident sperm whales feeds phytoplankton that store in the deep ocean 240,000 more metric tons of carbon  than the whales exhale. This means that, on balance, whales help lock carbon away.

But today’s benefits are a fraction of what these animals provided prior to the era of commercial whaling, which devastated whale populations during the 19th and 20th centuries. In 2016, ecologist Chris Doughty of the University of Oxford and his colleagues estimated ocean animals’ capacity to move nutrients around has decreased to just 5 percent of historic values. The IWC—the global body with greatest say over the fate of these animals—is beginning to take note.

Paradigm shift

The IWC was set up in 1946 not to conserve whales but rather to ensure populations remained healthy enough for continued economic exploitation of their blubber and meat. It ultimately presided over decades of overexploitation, which saw the world’s whale numbers fall by 85 percent over the second half of the 20th century. In 1986, an IWC moratorium on commercial whaling entered into force, allowing many species to begin to recover.

For the next 30 years, the IWC focused on whether there were enough whales to sustain resumed hunting. But in 2016 it passed a paradigm-shifting resolution that recognized for the first time the central role whales and dolphins play in ocean ecosystems, specifically because their poop boosts productivity and could help limit climate change.

As a result, the IWC Scientific Committee is now tasked with considering the broader environmental effects of allowing whales to continue to recover. It is planning an expert workshop to review knowledge of the ecological functions whales and dolphins serve, and to develop a list of research priorities.

“The 2016 resolution put the IWC at the centre of an opportunity to reconsider whales; not just for their economic or social value—to be consumed or watched—but their global ecological contributions,” Fisher says. “In the future, when policy makers can factor in the value of the ecological services of the whales affected, they will be able to make a much more informed and holistic decision.”

Clash of ideals

The subject will be on the agenda again when the IWC meets in September in Brazil*. Representatives of the 88 member nations will consider adopting a new resolution, proposed by Chile, that would encourage governments to integrate the ecological value of whales and dolphins into local, regional and global decision-making on the environment—including climate change and conservation policies. Under another draft resolution, submitted by Brazil, the IWC would agree its mandate includes a responsibility to ensure whale numbers increase to precommercial hunting levels so that they may “fulfil their ecological and nutrient cycling roles.”

But Japan, which has led the push to resume commercial whaling, opposes these resolutions. Hideki Moronuki, a senior negotiator with Japan’s fisheries agency, says Chile’s proposal “is outside the competence of the IWC” and Brazil’s “is inconsistent with the objectives of the International Convention for the Regulation of Whaling,” the multilateral agreement under which the IWC was created.

The resolutions will face votes at the September meeting and will pass if a majority of IWC members agree. But some countries have not yet paid their annual membership dues and will lose the right to vote if the fees remain unpaid. With nearly half of the IWC members siding with Japan in recent years, the votes could be tight. The U.S. has not yet decided whether to support either resolution but “will seek to advance key conservation initiatives” and will “continue to support the moratorium on commercial whaling and will continue to oppose lethal research whaling,” says Scott Smullen, a spokesperson for the National Oceanic and Atmospheric Administration.

Some conservationists are excited that the resolutions are even being considered. “Seeing this move forward at the IWC is heartening,” says Astrid Fuchs, who heads the program to end whale hunting at Whale and Dolphin Conservation, a U.K.-based nongovernmental organisation. “The fact that whales play a significant role to maintain healthy oceans as ‘the oceans’ gardeners—as they sustain fish stocks and help combat climate change—is a powerful argument for their strict protection.” For Roman’s part, he says he is “thrilled” that the IWC is giving weight to his and others’ findings. “I hope,” he says, “this work will lead to better, more informed conservation efforts.”

*This post was first published (here) by Scientific American in August. When the IWC met in Brazil in September, a majority of its member nations voted to adopt the resolutions proposed by Chile and Brazil, and voted against a proposal by Japan that would allow a resumption of commerical whaling. Patrick Ramage, of the International Fund for Animal Welfare, called it “a big win for whales and a clear signal of intent.” He said: “The IWC has evolved from an old whalers’ club to a forward thinking conservation body.”

Photo credit: Humpback whale – Whit Welles / Wikimedia Commons

References:

Doughty, C.E. et al. 2016. Global nutrient transport in a world of giants. PNAS 113: 868-87 [Read online]

Lavery, T.J. et al. 2010. Iron defecation by sperm whales stimulates carbon export in the Southern Ocean. Proceedings of the Royal Society B. Biological Sciences 277: 3527-3531 [Read online]

Roman, J. et al. 2016. Endangered Right Whales Enhance Primary Productivity in the Bay of Fundy. PLoS ONE 11(6): e0156553. [Read online]

Roman, J. et al. 2014. Whales as marine ecosystem engineers. Frontiers in Ecology and the Environment 12: 377-385 [Read online]

International Whaling Commission. 2016. Resolution 2016-3. Resolution on Cetaceans and Their Contributions to Ecosystem Functioning. [Read online]

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