A new study suggests that big mammals’ poop replenishes our planet’s nutrient reserves because the tremendous quantities of feces coming from whales and now-extinct gigantic animals are transported from the sea to the most remote areas on Earth.
The new study, which was published early this week in the journal Proceedings of the National Academy of Sciences, shows that as sea mammals eat and die the nutrients from their feces and decaying carcasses are transported from the depths of the ocean to the land and from there even to the world’s highest mountaintops.
University of Vermont’s Joe Roman, co-author of the recent research, argued that our planet once had twice as many seabirds, 10 times more whales and gigantic land mammals such as mastodons and mammoths, and 20 times more salmon-like fish, which are born in rivers and spend their adulthood in the ocean.
Scientists concluded that the loss in poop affected nutrient cycling and recycling around the globe. Past research showed that large animals indeed helped move large quantities of nutrients worldwide.
The study suggests that the ability of large animals to move nutrients from ‘concentration patches’ is now 8 percent lower for land mammals and 5 percent lower for sea mammals. Scientists explained that giant mammals’ extinction affects our planet’s ecology in ways we aren’t even aware of.
For instance, as gomphotheres and huge herds of bison steadily vanished, the levels of critical nutrients coming from their feces including phosphorous decreased in the process. Researchers believe that the way big mammals transport these nutrients across the globe is very similar to a ‘planetary pump.’
But as the pump got slower, the amount of nutrients transported also decreased to about 6 percent of the amount recorded when mammoths and giant sloths roamed the Earth. This decline happened very fast as more than 150 different species of mega-fauna mammals disappeared.
Researchers believe that phosphorus, which is essential to plants, once was a major element in the nutrient cycle. But in recent years, the ability of sea mammals to transport it from the sea to land plunged 75 percent since whale populations have decreased by 90 percent in the past three centuries. And human poachers had a lot to do with it.
Unlike fish, whales and other marine mammals feed underwater but they surface to relieve themselves. From there, their feces are eaten by phytoplankton which grows in numbers and helps whales increase their numbers, as well.
Roman explained that phosphorus is non-renewable, and humans usually extract it from mines. But if we manage to preserve whales, seabirds and wild animals the Earth’s phosphorus reserves may be replenished easier.
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