Is Krill Fishing in the Antarctic Sustainable?

You may know that overfishing is a massive threat facing the ocean as stocks of cod and tuna, amongst many others, plummet. Yet have you heard of the rapidly growing industry of krill fishing? This sector has seen a massive growth in the last decade and is not only targeting the food source at the base of our food chain but is also taking place in one of the most fragile areas of ocean in the world. Let’s take a closer look at krill fishing and what it means for our blue planet. 

Krill are certainly less well known than many of our marine species and are tiny crustaceans around the size of a paperclip. Yet despite what they lack in size and fame, they make up for in number as they are thought to be the most abundant species on Earth! Krill can be found in all the world’s oceans but the Antarctic krill is the focus of the fishing industry. 400 million tonnes of tiny krill are thought to live in Antarctic waters and they fuel some of our most iconic animals such as penguins and seals whilst not forgetting our whale species which stock up on krill to fuel their epic migrations to warmer waters each year. Incredibly, these tiny forgotten creatures provide 96% of calories to seabirds and mammals living in the Antarctic Peninsula.

Not only is krill essential for many species but it is also helps keep the ocean environment in a healthy condition. Krill feed on microscopic plants called phytoplankton which store carbon and release oxygen. As a result of this, krill excrete carbon and nutrient rich pellets which sink down towards the seafloor and the deep ocean. This takes the carbon which was floating on the surface of the ocean and stores it in the deep ocean where it is much less likely to be released into the atmosphere where it can contribute to climate change. In fact, one recent study believes Antarctic krill store the equivalent amount of carbon produced by 35 million cars each year, making the Southern Ocean one of the largest carbon sinks in the world! These nutrient rich pellets are also fantastic at fertilising the surrounding seawater, helping phytoplankton grow and therefore providing a large supply of food for other marine species.

Krill has been harvested in the past, mostly to fatten up fish in aquaculture farms but now the increasing demand for dietary supplements is another reason krill are being sought after by fishermen. Expeditions to the Antarctic are costly, time consuming and incredibly dangerous as crews face icebergs, treacherous weather and giant waves reaching up to 40 feet. Yet it seems some companies now believe this is a risk worth taking to be a part of the billion-dollar health supplement industry as they set sail from Ushuaia in Argentina across the notorious Drake’s Passage to the Antarctic Peninsula. Krill is a modern alternative to traditional fish oil pills which they boast to be more effective at delivering omega-3 fatty acids into our bloodstream which improves heart and brain health. They are also marketed as being more sustainable than traditional supplements but is that really the case?

The rapid rise in demand in the health industry has seen fishing quotas met earlier and earlier in the season each year. With companies keen to extract as much as possible as quickly as possible before the quota is met, countries such as Norway, China, Russia and South Korea are investing in bigger vessels and larger fleets. Whilst there may only be just over a dozen boats operating in the area currently, their size makes up for their lack in number. Many of the ships are now the size of a football pitch and referred to as ‘floating factories’ which can hoover up an incredible 1,000 tonnes of krill a day. Some boats can even process the krill straight away on board. 

For the meantime, quotas are being adhered to and the krill industry does seem to be operating in a more transparent and regulated way than traditional fishing, however one conservationist pointed out that it is not just how much we extract but also where and when. There are several regions in which krill fishing is allowed to take place and each has a different set quota depending on the wildlife that lives there. However, most vessels all operate in the same small patch of ocean where the most krill are congregated and this is also where the most marine species tend to live to make the most of abundant food supplies. This means that these huge vessels are not only coming into close contact with but also directly taking the food supply of migrating whales, hunting seals and breeding penguins. In fact, 95% of the catch in one particular fishing zone came from only 5.6% of the area as fishing vessels flocked to a productive and biodiverse area of ocean. This could be incredibly harmful to the animal populations which live in these areas as they suddenly have a new competitor for food and already studies have shown that some penguin populations are struggling since fishing vessels have moved closer to their coastal breeding grounds. Whilst krill fishing may not be harming the Antarctic on a large scale, it certainly seems possible that damage is being done in more localised areas.

Each year, the quota limits are met in the Antarctic and this means that there is no room for error, no buffer to protect our ecosystems if another problem hits the area, such as climate change. It is thought that the krill population will fall by 30% by 2100 due to climate change, with the Antarctic being one of the most rapidly warming regions. If we have miscalculated our catch limits, what will happen to this crucial base of the food chain? How big will the knock on effects be throughout the ecosystem? 

Whilst krill fishing may not be causing a significant problem yet, it seems that we must learn from history and take a precautious approach before we start upheaving the delicate balance of one of our last unexploited environments. Whilst the industry is fairly well regulated at the moment, the lack of data and understanding we have about Antarctic environments means we cannot be sure of the impact our activities are having. 

So far, vessels have agreed to avoid certain areas during winter when penguins are breeding and rely more heavily on coastal abundant krill stocks. Many countries are also pushing for an increase in marine protected areas in the Southern Ocean but no protective zones can be established until all countries agree on the plans, something yet to happen. Meanwhile, some scientists question the use of marine protected areas in this case as krill are a migratory species and may often drift outside the set boundaries of a no fishing zone, leaving them open to exploitation. Yet it seems that everyone agrees we must collect more information on the size of the krill population and the range of threats facing them to fully understand the impact we may be having in this remote area. The data regarding krill population size which has been used to make the basis of many of our decisions on this issue is 20 years old. With this species being incredibly sensitive to changes in the surrounding environment, it seems the very base of our ideas is likely outdated.

We have managed to devastate many of our oceans with careless overfishing but this could be the one industry where we still have time to fix our actions and make them more sustainable before it is too late. 

By Neve McCracken-Heywood