Whales: The great poop pumps of the ocean

Whales. Their large majestic bodies, haunting calls and nourishing bodily excretions. That’s right, bodily excretions.

A new study found that whales play an important ecological role in the discharge of their urine and feces, through which they release nitrogen and iron into the ocean ecosystem. These nutrients provide a boost for plankton, which in turn feeds a variety of fish.

“Whales feed in highly productive and high latitude areas and then they migrate to low productivity, low latitude areas. For example, they feed in Alaska and they breed in Hawaii. They’re not feeding when they’re in Hawaii – or at least only rarely – but they are urinating and defecating,” Joe Roman, one of the authors of the study, told TreeHugger. “So they’re bringing tons of nutrients into those systems.”

In a sense, whales are ‘engineering’ the ocean ecosystem, pumping nutrients from the deep ocean, where they feed, to the surface, and moving them from high nutrient areas to low nutrient areas, replenishing the waters thousands of miles away.

But with whaling continuing to damage whale populations, this pump system isn’t as effective as it could be. Every year, more than 2,000 whales of varying species are killed for their blubber and meat. Since the 80’s, more than 30,000 have been killed. These are staggering numbers for creatures so large and so rare, especially since they live long lives and are slow to reproduce. Add it all up, and that’s a lot of nutrients not getting pumped.

Graham Cook/CC BY 2.0

The good news is that in general, whale populations are recovering. Whaling was much worse in previous centuries and decades than it is now. As the populations grow, they will revitalize ocean ecosystems and fish populations should grow too. That’s good news for fishermen, who often fear that whales will deplete their harvest.

“What is important about this study is that while yes, whales eat fish (including baleen whales), whales enhance the production of fish by providing through excretion the nutrients essential for phytoplankton growth at the base of the food web,” said Jim Ruzicka from the Hatfield Marine Science Center at the University of Oregon. “Whales provide a net gain to fish productivity and potential fish harvest.” Mother nature has systems in place that we as humans are unbalancing, so we need to make sure we don’t get in the way.

While the role that living whales play in ocean ecosystems is important, their role in death is also significant, especially in terms of carbon storage. They sink to the ocean floor and provide ecosystems and food supply for about 60 different aquatic species which can only survive on whale carcasses.

“When whales die, they bring all of that carbon and nutrients into the deep sea where it can be stored for centuries and maybe longer,” said Roman. “Whales certainly could offset some of the effects of climate change. They will do their part, but keep in mind, it’s up to us to make those differences.”

Tags: Biodiversity | Ecology | Oceans | Whales

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