Antarctica and the Southern Ocean Conservation: Part 3
Achieving Sustainable Fisheries: The Case of Antarctic Krill Fishery Governance
Kitty Cheng
Krill is a keystone species that is crucial for providing nutrients for species across the food web, including humans. Although there are numerous krill populations spread across the world, the Southern Ocean have the largest stock of krill population, the Antarctic krill (Euphausia superba). In her final blog in this Antarctic series, Kitty Cheng examines the management approach of krill fisheries by the Conservation of Antarctic Marine Living Resources (CCAMLR), and future challenges.
Seafood is being used in multiple levels within the food supply chain: direct consumption, fishmeal and fish oil. Only 76% of seafood is directly consumed by humans, 10% is used to feed other animals and 12% is being discarded or spoiled. It is estimated that 80% of fish discards comes from industrial fishing, as mass fishing techniques often have a higher percentage of bycatch, causing species to be damaged. In particular, 95% of shrimps from ocean floor trawling is discarded. In Antartica, krill must be processed within 3 days of catch in order to be preserved as krill paste. This is an energy intensive process with high levels of spoilage. Thus, it is recommended that small-scale fisheries should be promoted as a more sustainable fishing method, as it only targets certain species, produces minimum wastage and has a lower carbon footprint.
Krill. Photo: Øystein Paulsen.
By feeding on phytoplankton and algae, krill helps to remove greenhouse gases on the water surface, hence depletion of krill will lead to a positive feedback in climate change. Moreover, krill is a keystone indicator species and krill dynamics in the Southern Ocean is correlated with the reduction of sea ice. Acting as primary consumers in Southern Ocean nutrient cycling, krill fishing has direct impacts on seals, penguins and krill-dependent whale populations. For example, Adélie and chinstrap penguins have declined by 50% in the last 30 years, as changes in ice sheets and a lack of access to krill threatens penguin populations. CCAMLR predicted that with the current krill biomass trend, this will cause penguin populations to drop by 30%.
Chinstrap penguins (above), and Adeilé penguins (left). Photos: Pixabay.
Shortly after the beginning of krill fishery industry in 1976, the krill market collapsed in less than a decade due to unregulated pelagic fishing. After this, the immediate ban on fishing marine resources, and sustainable fisheries management, allowed both krill stocks and other marine resources to return to the optimally productive level. After 5 years of negotiation, a new MPA in the Antarctica Ross sea was established in 2017, where 72% of the MPA is set as ‘no-take’ zone, and the convention area covers 10% of the total ocean surface area. Within the regulatory framework, management strategies are being evaluated annually, where catch limits of krill will be adjusted according to stock changes.
Similar to other open capture fisheries, the Southern Ocean has suffered from overexploitation in history. However, its geographical location allows it to be least affected by human activities including building infrastructures, urbanization and direct pollution. This provides the objectives of policy making to be purely focused on sustainable fishing practices, which will be a challenge when applied to other marine systems. Moreover, the specific board members in the CCAMLR committee have brought in a legal and political dimension in krill fishery governance. For example, in the Southern Ocean, krill fishing appears to be an exclusive industry conducted by a handful of developed nations. While management strategies of CCAMLR claim that mechanisms are made to accommodate new entrants, only 5 member states had fished krill in 2014, where nearly 60% of the catch is taken by Norway.
The Antarctic - a krill-dependent ecosystem. Photo: Pixabay.
When applying management approaches to marine resources, attention should be focusing on human behaviours, and ensuring that solutions should address consumption at both current and long-term scales. As overfishing affects organisms that we know little about, research regarding specific species will have to take an ecosystem approach: considering the biology of interrelated species, habitat changes, as well as local livelihoods dependent on fisheries. The future of krill fisheries can be uncertain, due to human activities and climate change. Effects of climate change including ozone depletion, changes in atmospheric circulation and decreases in sea ice will create significant changes to the Southern Ocean marine system. Krill populations will be affected as they are sensitive to large oscillations in temperature beyond their tolerance. This will causes chain reactions along the food web, and changes in Antarctic marine ecosystems dynamics. Thus, to conserve krill populations, external policies that work towards the two degrees climate change goal is urgently needed.
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