Undermining and “over-mining” the Antarctic food pyramid

WILL CROTHERS

antartic-krill

A look at the Antarctic krill, an endangered species critical to the sea

Antarctic Krill (Euphausia superba) is of crucial importance to the marine food chain, as well as an important ingredient to nutritional supplement manufacturers for its Omega-3 content. Krill is also harvested to create meal for fishery farming.

According to the Living Planet Index 2014 report from the London Zoological Society, on a global scale various species’ populations have been cut in half over the last 40 years. The UK’s National Centre for Statistical Ecology agrees that this is an alarming trend, despite not having complete agreement on the percentage the populations have declined.

The Antarctic has remained one of the most untouched ecosystems on the Earth’s surface due to its unfriendly habitat for human survival. Krill had been a thriving species, with some breeding grounds containing approximately 10,000 krill per square meter of water. However, human intervention combined with global warming is kicking out the legs from under the aquatic ecosystem’s foundation.
Krill are small crustaceans, similar to very small shrimp. Though not the lowest link, krill are near the bottom of the food chain. A myriad of fish, aquatic mammals and other species depend on krill, including whales, penguins and seals.

Although we call it a food chain, it is actually more like a pyramid. The lowest layers have to maintain the highest populations in order to maintain the populations of the predators that feed off them. The base determines the stability of the overall pyramid and constrains the populations that can survive above it.

The krill population is subject to a two pronged attack. Melting sea ice in the Antarctic is undermining the available habitat for the phytoplankton, single celled algae and zooplankton that krill feed upon. The declining Antarctic ice shelf then allows more accessibility for commercial fishing. While the fishing of bigger sea life could offset the predation pressure, krill are unfortunately also targeted to be fished commercially.

It should be noted that having less predation because we have harvested predators is not a good thing, nor should it be a justification to allow further fishing of what the predators feed off. Our aquatic diets have changed over the years in a “race to the bottom” of sorts, where we harvest smaller fish than we used to, and eat previously unpopular species. We are now eating the fish we formerly used as bait for bigger fish. A good example of this trend has been the re-branding of Patagonian toothfish as Chilean Sea Bass. The re-branding was done by wholesaler Lee Lantz in 1977. Ever notice how sea bass is almost never cooked or served whole, but rather as a fillet? Look up what whole toothfish looks like and you will see why it needed some creative marketing.

Some commercially fished krill gets diverted to fish farms, which has sustainability problems as human population and therefore demand are outpacing the ability for species to replenish naturally. While the industry is getting more efficient in reducing the amount of wild feed needed to grow farmed fish, everything removed from the natural ecosystem cannot therefore be used in replenishing populations. While global fish stocks are extended through farming, the only important metric for sustainability is the global decline of populations. A farmed fish is simply made of cannibalized other fish, or the waste from fish harvested for other purposes. It’s like saying, “we didn’t have to take this fish out of the ocean, we grew it on a farm by using other fish we took out of the ocean”.

As ultimately unsustainable global fishing is given current demand, the harvesting of krill for nutritional supplements is even more short-sighted. Omega-3 pills (another clever re-branding pivot from fish oil or fish fat pills) use harvested krill when the same nutrients can be derived from seeds (flax, chia, hemp), leafy greens and other vegetables. The popularity (and for the suppliers, profitability) of taking omega-3 through supplements simply encourages further harvesting of krill legally or illegally. As supplies dip, price goes up, making it more attractive for suppliers to sell. The economic cycle then starts encouraging poaching, especially in an environment extremely hard to police. Krill catching is much less prominent than it was in the 1970s and 1980s, partly due to the collapse of the Soviet Union. However, populations are not rebounding. It is estimated that krill stocks are only 1/5th of what they were in the 1970s.

Fish products are commonly categorized as brain food. Instead of ‘food for thought’, how about we have some thought for food?

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