From 20 to 31 October, the International Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) will meet in Hobart, Australia. A central topic will be the future regulation of krill fishing. Prior to this, an international research team led by Prof. Dr. Bettina Meyer, who is a professor at the University of Oldenburg and conducts research at the Alfred Wegener Institute in Bremerhaven, presented a new concept for sustainable management. The aim is to involve the krill industry more closely in research and thereby secure the stocks for the future. A corresponding study has been published in the journal “PNAS.”
Swarms of krill in the Southern Ocean form the second tier of the Antarctic food pyramid, following plant plankton. If stocks were to shrink due to over-intensive fishing, this would incur direct consequences for many animal species that feed almost exclusively on krill. Weighing in at an estimated 300 to 500 million tonnes of biomass in the Southern Ocean, Antarctic krill ranks as one of the most abundant multicellular wild animal species in the world.
In the Antarctic food web, it forms the central link between primary marine production and many higher animals, such as seals, fish, penguins and baleen whales, whose populations are directly reliant on krill stocks. And humans have also joined the ranks of consumers in recent years. Large quantities of Antarctic krill are fished by humans and processed into feed pellets for aquaculture (salmon farms, shrimp farming) and food supplements (omega-3 fatty acid oil) and also find use in cosmetic products, toothpaste and animal feed.
Fishing industry as a partner
Our monitoring concept provides a pragmatic approach to the actual realities.“
Prof. Dr. Bettina Meyer; study author
The CCAMLR regulates and controls the krill fishery in the Southern Ocean (also known as the Antarctic Ocean). The annual general meeting of this international commission will commence on 20 October in Hobart, Australia. "We published a sustainable management concept in advance, which links fishing activities with closely-meshed scientific monitoring," says Meyer. „Current management is based on historical fisheries data and only one large-scale survey of krill biomass from the year 2000. In order to utilise krill stocks in a sustainable manner whilst also ensuring the survival of penguins, seals and whales, it is imperative that we adapt our approach to the challenges of the 21st century and strengthen the scientific basis of our decisions.”
In line with their new concept, Meyer and her team of authors are therefore focussing on closely integrating and involving the fishing industry – regarding the latter less as an opponent and more as a partner. "Since 2020, every fishing vessel must have a scientific observer on board who collects biological data on the krill that have been caught - such as length, sex and degree of maturity," says the expert. "This data, however, is not included in current krill monitoring."
Fishing vessels as data suppliers
In view of this situation, the researchers propose that fishing vessels should be used more as research platforms to collect essential data for the development of sustainable krill fishery management. Acoustic data from echo sounders that detect swarms of krill, recorded sightings of krill predators such as seals and whales, in addition to data collection on the composition of krill catches in terms of length, sex and maturity of the shrimp iwould provide a comprehensive picture of krill populations that individual research vessels would not be able to generate. This study presents data collection methods that could be implemented on krill fishing vessels in order to develop sustainable fishery management for the species. This approach ensures that commercial interests are aligned with the long-term protection of the Southern Ocean ecosystem, which is also in the interests of fisheries.
The integration of this concept into a new management strategy is to be discussed and implemented at CCAMLR this year - if all members can agree, as proposals are only implemented by consensus. Current catch quotas document just how important this is: Although Antarctic krill are distributed throughout the Southern Ocean, krill fishing is concentrated almost exclusively in the Atlantic sector of the Southern Ocean (CCAMLR Area 48), which is home to around 63 million tonnes of krill biomass. Fishing activities are focused on three main fishing areas close to the coast: the Antarctic Peninsula, the South Orkney Islands and South Georgia. Since 1991, a maximum catch quota of 0.62 million tonnes has applied to the entire area. As from 2009, the quota has been divided into four smaller sub-areas (48.1 to 48.4) to prevent fishing from becoming too concentrated in one area. For instance, the total allowable catch of krill in sub-area 48.1, which encompasses the Antarctic Peninsula, was limited to 0.155 million tonnes.
" Despite extensive consultations, CCAMLR members were unable to reach a consensus on the continuation of this regulation last year," as Meyer explains. „Due to the absence of regional restrictions, the amount of krill fished in sub-area 48.1 more than doubled to almost 0.4 million tonnes by July of this year and the maximum permitted catch in the entire fishing area 48 was reached for the first time.” It is unclear what impact this will have on the stocks and krill-dependent predators in this ecologically sensitive marine region in the vicinity of the Antarctic Peninsula.
"Our monitoring concept provides a pragmatic approach to the actual realities. It is evident that eliminating fishing in the Antarctic would be a highly preferable scenario," Bettina Meyer states. "However, given the economic interests of individual CCAMLR states, this is not a viable option." Close cooperation with the fishing industry can multiply the available scientific data and yield a much better picture of the population dynamics of Antarctic krill. On this foundation, sensitive regions such as spawning grounds and hotspots for krill-eating animals can be specifically identified and effectively protected. By carefully planning catch quotas, fishing areas and fishing seasons, the permitted amount can be utilised efficiently, while minimising the impact on the krill population and the entire ecosystem.
The involvement of the industry in this area can deliver significant benefits: On the one hand, regular, seasonal data collection on krill biomass and population composition – as is already being conducted in some cases – can provide valuable information for fishery management. Conversely, the provision of direct financial support for research projects with the objective of enhancing the management of fisheries can assist in the long-term security and expansion of international research programmes.
The text is based on a press release from the Alfred-Wegener-Institute (AWI).
