Monday, May 12

Dear Reader,

A while back, Dot got a letter from a reader curious about the impact of krill supplements on penguins, which rely on krill for much of their diet. It was the first I’d thought about how our growing appetite for fish and krill oil might, literally, be taking food from animals. I reached out to some experts, as I typically do to answer reader questions, and learned that: 1) the word “krill” means “whale food” in Norwegian; 2) they are plankton (though not all plankton are krill) and can grow to about the length of the space bar on your computer keyboard; and 3) they live in swarms for up to five years and make up almost the entirety of a blue whale’s diet. I also learned that, while humans do indeed have a growing appetite for krill, including in supplements, the vast majority of harvested krill ends up as aquaculture feed and bait, as well as livestock and pet food. However, I assured my reader then (and am, subsequently assuring you now) that various groups are encouraging alternatives to krill for these purposes. 

But that’s not the end of the krill story. Inside Climate News tells the story of a Scandinavian research crew in Antarctica exploring the impact of krill fishing vessels on whales. Krill oil has become so popular (for the reasons I noted above) that it’s sometimes called “red gold.” Consequently, a remote channel in the Antarctic has become a hotspot for boats whose crew harvest krill. The researchers were there to monitor the impact of krill harvesting on the year-round presence of baleen whales in the strait. “There are 15 species of baleen whales,” Inside Climate News tells us, “including the humpback, fin and the Antarctic minke whale, that use comb-like plates of baleen instead of teeth to filter tiny prey out of the water. Some can eat more than 3,000 pounds of krill in a day.” Penguin populations in the region are suffering and pregnancy in humpbacks seems to be declining — both issues that experts connect to decreasing krill populations, though they lay the blame for that on warming waters due to climate change. 

At this point, researchers are collecting what they call “baseline” data. If they discover that the whale’s presence doesn’t overlap with the harvesting, then that would be good news.

It’s an incredible story of the lengths (depths!) to which researchers go to help us better understand our world and our impact on it, and how we might best mitigate the negative parts of our impact. What’s more, krill isn’t just a food source, it’s an important component of carbon sequestration, “transferring excess carbon dioxide from the atmosphere to the deep ocean,” the article explains. “When [marine animals] eat phytoplankton, which absorb carbon from the atmosphere through photosynthesis, they absorb this into their bodily tissue. When they shed their exoskeletons or poop, this matter sinks to the deep ocean where the carbon is then stored for up to 100 years.”

Antarctically,

Dot