Olympic swimmers burn 12,000 calories a day during training. Dolphins burn nearly three times as many: 33,000, according to a new research study of common bottlenose dolphins in Sarasota Bay, Florida.

That’s equivalent to 60 portions of salmon a day, or 10 to 25kg (22 to 55 lbs) of fish, just to survive.

Why does it matter? With climate change, discarded plastic and industrial pollution affecting the world’s oceans at an alarming — and growing — rate, researchers say it’s important to study the metabolic rates of whales and dolphins if we’re to learn exactly what’s going on in our oceans, and why. The blue planet depends on knowledge — actual scientific knowledge, not opinion or guesswork — if it is to survive.

This wasn’t some fly-by-night survey, either, but a proper scientific, peer-reviewed study sanctioned by the Woods Hole Oceanographic Institution, Oceanographic Foundation in Spain and published in the journal Royal Society Open Science.

http://rsos.royalsocietypublishing.org/content/5/1/171280

Calculating the nutritional health of an active sea mammal like a bottlenose dolphins is a complex mathematical equation that involves sea temperature, lung function and the number of calories a dolphin burns while diving, swimming, resting and sleeping during a 24-hour period.

Determining the exact diet and energy requirements of whales and dolphins is critical to conservation efforts, researchers such as Andreas Fahlman argue, in part because the future of the world’s oceans will depend on effective fisheries management.

The study’s results have already had an impact. Knowledge is power — the power to actually do something if, as a society, we have the will to do it.

“We can use this as a health check of various populations, and therefor the environment,” Fahlman said, as reported Wednesday by BBC News.

“If the dolphins are sick, there may be problems with the environment.”

First Nations coastal people and scientists who work the West Coast of Canada have been saying this for years about B.C.’s resident population of killer whales. Autopsies of marine mammals have showed increasing levels of toxins in their blood, leading scientists to conclude that coastal pollution is having a long-term and in many cases deadly effect on marine life, even — perhaps especially — apex predators at the top of the food chain.