Giant mammals  play a crucial role in recycling nitrogen, which promotes bigger  fisheries, researchers find

NOVA SCOTIA, CANADA – This real whale research isn’t good news for whalers (unlike Japanese ‘research,’ no whales were slaughtered, either). Read how giant mammals, such as whales, play a crucial role in recycling nitrogen, which is to say, help sustain the planet we share. It’s whales’ enormous volume of waste we have to thank, which feeds the marine ecosystem, and therefore, our interconnected lives. – Global Animal


Ocean researchers probing nitrogen supplies in the Bay of Fundy off the coast of Nova Scotia and adjacent parts of the Gulf of Maine have discovered an unexpected linchpin in the marine ecosystem: whale poop.

After collecting and studying whale waste described as a “very liquidy, flocculent plume,” two U.S. researchers have found that the huge mammals play a crucial role in lifting nutrients from the ocean depths to the upper layers of North Atlantic sea water.

There, they argue, nitrogen liberated by whales during their deepwater dives enriches the food web for a host of fish species and countless other sea creatures.

The nitrogen input from whale waste in the Gulf of Maine is “more than the input of all rivers combined” — an estimated 23,000 tonnes per year, write study co-authors Joe Roman, a University of Vermont conservation biologist, and Harvard University zoologist James McCarthy.

Their research appears in the latest edition of PLoS ONE — a journal published by the U.S.-based Public Library of Science — under the title The Whale Pump: Marine Mammals Enhance Primary Productivity in a Coastal Basin.

“We think whales form a really important direct influence on the production of plants at the base of this food web,” McCarthy states in a summary of the study.

Roman added that whale waste encourages the growth of phytoplankton, which then “pushes up the secondary productivity” as animals that feed on plankton take advantage of the poop-fuelled bounty.

Such nitrogen recycling promotes “bigger fisheries and higher abundances throughout regions where whales occur in high densities,” Roman added.

The Bay of Fundy, the northeast arm of the Gulf of Maine, is known to be a key habitat for species such as the endangered North Atlantic right whale.

In recent years, the Canadian government has implemented protective measures such as ship speed limits and changes to lobster-fishing equipment to reduce the risk of right whales being injured or killed in the Bay of Fundy and surrounding waters.

In their study, Roman and McCarthy note that the Bay of Fundy in particular, is one of the key areas in the Gulf of Maine where the year-round “diving and surfacing” habits of whales “can markedly increase surface nitrogen levels.”

That said, the researchers note that the steep decline in whale populations in the 20th century has not only deprived the oceans of many of these majestic creatures, but has also drastically reduced the nitrogen-recycling benefits of their presence for other species.

“In the Bay of Fundy, humans have reduced the biomass of the upper trophic level of vertebrates by at least an order of magnitude,” the authors state. “One unanticipated consequence of this depletion of deep-diving mammals is a likely decline in the carrying capacity for higher trophic levels in coastal ecosystems.”

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