The excrement of minke whales plays an important role in fertilizing phytoplankton and thus reducing the carbon footprint of cetaceans. Reported by AFP.
Researchers at the Norwegian Institute for Marine Research studied the nutrient concentration in whale excrement before it was dissolved in seawater. “They may sound disgusting, but they’re worth their weight in gold for the ecosystem,” the authors said. “Just as cows and sheep fertilize the land, their excrement fertilizes the sea.” Biologists have studied the excrement of minke whales harpooned by whalers – Norway is one of the few countries where commercial hunting of these marine mammals is allowed.
About 15,000 whales, which migrate to the Norwegian archipelago of Svalbard in the Arctic each summer, are known to release approximately 600 tons of excrement, approximately 40 kg per animal, to the water surface each day. During the examination of the captured minke whales, it was possible to find out that this is equivalent to 10 tons of phosphorus and 7 tons of nitrogen. These nutrients are essential for the growth of phytoplankton, microscopic algae that take carbon dioxide through photosynthesis and convert it into oxygen.
In total, minke whale excrement accounts for 0.2 to 4 percent of the daily “feeding” of phytoplankton in the Arctic region of Svalbard.
“The actual contribution of whales is probably higher because these estimates do not include urine that is very rich in nitrogen,” said lead researcher Kjell Gundersen. “Each adult minke whale is an animal weighing 40-50 tons, feeding by filtering large volumes of water and therefore producing several hundred liters of urine per day.”
In turn, the increase in phytoplankton mass helps to combat global warming by absorbing the greenhouse effect carbon dioxide.