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Fishing for plankton is ridiculous.

Posted by Willie Mackenzie - 1st June 2016

In the ocean, plankton is food.

There are two types of plankton – tiny plants (phytoplankton) and tiny animals (zooplankton).

Zooplankton includes some eggs and larvae of things like fish and crabs, as well as some minute animals that feed on phytoplankton. That makes them the first link in any food chain, and the basis for all of the ocean’s food webs. In layperson’s terms, it’s like the bottom layer of a massive pyramid of tin cans in a supermarket or Ferrero Rocher at an ambassador’s reception.

Marine animals either eat plankton directly, eat something that eats plankton, or eat something that eats something that eats plankton… so for small things, they’re a pretty big deal.

To support all of the hungry life in the ocean, there is a heckofalot of plankton: incomprehensibly-large numbers of unbelievably-small organisms. The most common family of planktonic animals are called Copepods. They are prehistoric-looking nano-shrimps, with long antennae and one central eye. In popular culture they’re known for two things: starring as a the megalomaniac ‘Plankton’ in Spongebob Squarepants, and being made into fish food.

Yes, copepods are clearly fish food: they’re marketed as such for people’s aquariums, and most importantly – they are it in the ocean. As well as gentle giants like bowhead whales relying on massive messy mouthfuls of countless copepods for food, lots of everyday fish that humans like to eat do too. Mackerel, whiting, herring, Alaskan pollock and many other fish eat copepods.

So if you want healthy fish stocks, you need healthy oceans full of plentiful plankton. They are the basis of fragile foodwebs that support all of the amazing life in the oceans, from whales, to polar bears, and birds to sharks (some birds and sharks are direct plankton eaters too!).

So it would be reckless to even consider fishing away these foundations, right? Ridiculous to suggest we target the primary support for valuable commercial fish stocks, and amazing whale species?

You’d think.

But in a world where fish stocks are depleted, many big fish have gone, the phenomenon of ‘fishing down the marine food web’ is a very real thing. We fish farther away, closer to the poles, deeper into the ocean, and right down into the very foundations of ocean life.

Krill (another tiny shrimp, but giant by copepod standards, and also a predator of copepods itself) is already being fished in the Southern Ocean. Elsewhere small fish are caught in their millions to be ground into meal to feed to prawn and salmon farms.

Next up – copepods. You might have missed it (in fact you might think you were meant to) but the UK’s Food Standards Agency have just held a “consultation” on using oil from Arctic copepods as a ‘novel food source’.

It’s already caught to make into fish food (oh Hai Nemo!) but this is a big step-change – creating a market and demand by legitimising it as a food or supplement source for humans in a world where populations are increasing, food security is an issue, and our oceans are already being overexploited, overpolluted, and under-protected. And we know that nowadays even poor plankton are even eating our plastic trash.

Fishing plankton is utter nonsense. It’s not a fabulous unexploited food source for humans, it’s the vital foundation of all the marine life we are supposed to value. That’s even more true when you consider how much we don’t know about the effects of global climate change and ocean acidification on these oceanic drifters (clue: it’s not looking good).

Contemplating copepods as human food, in whatever form, really shows how we are failing to think of the impacts on the wider food web when we decide what to do. And it’s another example of ‘because we can’ rather than ‘because we should’.

We’ve succinctly told the FSA what we think.
Wonder if anyone sought to consult the krill, the whales or the mackerel?

Article Tagged as: Featured, Oceans, arctic