TV ads, pharmacy shelves, it’s hard to miss bottles of Omega 3 capsules, derived from krill, promising relief or protection from cardiovascular and other diseases.
There are two serious problems with this. One is the impact this will have on krill populations, and the other is the validity of the evidence of the benefits.
First the source. The main source is Antarctic Krill, Euphausia superba. It grows to 5cm long, and lives in huge schools in the the near-ice regions around Antarctica. Much of its food comes from the algae growing on the under side of the ice. Its predators? Pretty well every marine vertebrate living or hunting in the Southern Ocean: baleen whales, seabirds (penguins), most of the seals, many fish species, and now humans.
In our illustrious past as hunters in the Southern Ocean, we eliminated the Antarctic fur seals by 1900, most of the great whales by the 1930s, pelagic fish by the 1970s, and bottom finfish by the 1980s. That has left krill.
Krill trawling began in the 1970s, and didn’t look promising: the animals had to be processed within hours of capture to avoid rapid enzymatic breakdown releasing toxic flourides. Now, however, ships process the krill quickly, rapidly removing the oil, and freezing or drying the meat.
We don’t actually eat krill meat – that goes into fish meal for chickens – but during the past decade the oil has become an increasingly popular source of Omega 3 as a human dietary supplement.
The current level of krill fishing in the Southern Ocean may appear to be sustainable, but the signs of ecosystem stress are everywhere. Apart from Southern Humpbacks, the great whales have not recovered; Adelie and chin-strap penguin populations are in decline; in warmer water areas of the West Antarctic Peninsula non-nutritious gelatinous salps are outcompeting krill; and in areas where sea ice is shrinking, less under-ice algae exists for krill to feed on.
The Southern Ocean ecosystem depends on krill, but even without our krill fishing, something is clearly very wrong. The deepest, newest threat to the krill is our desire for Omega 3, for we are too numerous, too obsessed by our health, and too susceptible to sophisticated marketing. We are insatiable.
Now, to complicate things, and just published in The Annals of Internal Medicine, comes a meta-study of 72 studies of the dietary use of Omega-3 fatty acids in treating coronary disease, altogether involving 600,000 participants from 18 countries. Its conclusion? No support actually exists for cardiovascular guidelines that promote high consumption of Omega 3.
We are extracting oil from Antarctic Krill for medical benefits for ourselves that are dubious at best, to supplement fish meal which is ecologically short-sighted, and to supplement what we feed our pets. None of this is necessary, and appears in fact have no true value for any of us: chickens, cats, dogs or humans.
This isn’t a hard situation to resolve: we can stop krilling. At stake is the viability of an immense, critical and threatened ecosystem.