Blue whales have a larger body than any dinosaur that has ever existed on Earth, the body of an adult blue whale can reach more than 30 meters in length and weigh up to 190 tons. Combined with humpback and gray whales, the baleen whales, blue whales, and giant brothers are among the greatest creatures science has ever known.
Looking at their size, it can be said that whales are gluttonous. However, new research makes us clear: we have underestimated the whale’s ability to consume bait. The new figures show that the amount of food consumed by baleen whales is more than any previous estimate, at least 3 times more than what has been reported in studies that have been done.
This means they… defecate more. According to a report published in the journal Nature not long ago, this is good news for the ecosystem.
The Atlantic black whale is one of the whale species on the verge of extinction.
The daily diet of baleen whales contains large amounts of small fish or crustaceans, which include krill. Digestion by-products continue to become an essential source of nutrients for ocean ecosystems.
However, because we are not familiar with the eating habits of whales, and it is difficult to estimate their diets when the whale’s body size is too large, science cannot give an exact amount of whale food. baleen consumption. This is also a major obstacle in whale conservation.
“If we want to protect whales and ensure they thrive in modern ocean environments, knowing how much food whales need to survive and reproduce is paramount.,” Matthew Savoca, the author of the new study, told Inverse news site.
Previous estimates have been inaccurate. Errors arise when researchers make calculations based on metabolic models of smaller creatures (such as dolphins), or parameters that come from whales living in captivity, or analyze human body parts. Food left in the whale’s intestines washed ashore.
In contrast, new research that directly tracks populations of baleen whales in the Atlantic, Pacific and Southern Oceans provides a more accurate figure of how much whale molluscs are consumed, in addition to the amount of dung they consume. giant biological machines of production.
Using individual locators and acoustic meters, the researchers collected actual data from 300 whales, belonging to seven species in the baleen order. From here, science gets the amount of marine life whales consume each day, in addition to the amount of nutrients that return to the sea in the form of feces.
The baleen whale is so named because of the structure of their upper jaw.
Previous studies have shown that baleen whales consume less than 5% of their body weight per day. But according to new research, Mr. Savoca’s team shows that the daily food intake of baleen whales is more than three times previously estimated; they take in prey weighing 5 to 30% of their body weight.
“In short, if whales eat more than estimated, they recycle more nutrition [cho đại dương] – ie excreting more feces than we think“, said Mr. Savoca. Looking at the whale’s huge excrement, scientists can track how nature balances the marine ecosystem.
Every time whales defecate, a large amount of nutrients return to the open sea. The plankton absorb these nutrients and keep the oceans in good shape.
Researcher Savoca explains: “It’s not like these whales put extra iron – or any other nutrients into the system, they just transform the nutrients in the prey’s body, and then put the nutrients into the seabed, theoretically, the amount of nutrients in the body. This nutrient will nourish phytoplankton – the basic unit of all food webs in the open oceans“.
Phytoplankton (English name: Phytoplankton).
New studies suggest that the worst-case scenario could be as whale populations decline. Between 1910 and 1970, baleen whale hunting resulted in a drastic decrease in whale numbers. As a result: the amount of food consumed by whales plummeted, the marine ecosystem lost its huge efficient nutrient-producing machines. It is estimated that before the 21st century (1900 and earlier), baleen whales in the Southern Ocean consumed 430 million tons of krill – twice as many krill in existence today.
“Balk whales maintain the amount of krill they consume‘, said Victor Smetacek, another whale expert. “Everything falls apart when the whale disappears from the equation“.
New research provides unprecedented insights into baleen whales, and highlights the role these giants play in ocean ecosystems.
Humpback whale.
At the present time, the number of individuals of some baleen whale species, such as the humpback whale, has increased significantly. However, its brothers were not so lucky. One study found that baleen whale populations in the North Atlantic fell 8% throughout 2020, to the lowest level in two decades. The absence of baleen whales means that the oceans receive less nutrition.
Researcher Savoca hopes his and his colleagues’ new research will highlight the vital role whales play in marine ecosystems, thereby accelerating efforts to conserve giants. He stressed that conservation action can come from simple efforts, such as getting boats out of the way of whales.
“We’re trying to use this new information to try to protect the whales, and help them recover‘, Mr. Savoca concluded.
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