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Antarctic krill

Ecosystem implications of fishing

A case study prepared by Virginia Gascón and Rodolfo Werner (Antarctic and Southern Ocean Coalition)


Antarctic krill (Euphausia superba) is central in the Antarctic food chain. The different components of the Antarctic marine ecosystem are made up of predators that rely, directly or indirectly, upon the health of the krill populations. Antarctic krill has a circumpolar distribution and is very abundant in the Southern Ocean.


The Antarctic krill fishery has been the largest fishery in the Southern Ocean since the late 1970s (Croxall & Nicol 2004). In most recent years, almost all krill fishing vessels have been operating in coastal areas of the South West Atlantic region, where the catch rate has historically been higher.  This fishery is the largest crustacean fishery in the world and it has prospects for becoming the largest global fishery (Nicol & Endo 1997).  There is potential for a rapid expansion of the fishery in future years, as krill-processing technology develops and demand for krill products increases. This raises concerns about the future of the vulnerable and still little understood Antarctic marine ecosystem.


Perception of massive abundance of krill stocks might trigger greater investments and it is slowing down policy progress to control the fishery. This is particularly important, taking into account the history of over-exploitation of marine species in the Southern Ocean. This pattern has included seals in the 19th century, the great whales in the middle of the 20th century, the marbled rockcod (Notothenia rosii) in the early 1970s and, most recently, some populations of Patagonian toothfish (Dissostichus eleginoides).


The Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR) is the international regime responsible for managing Antarctic krill stocks in the Southern Ocean. CCAMLR was negotiated in the framework of the Antarctic Treaty and the conservation of Antarctic krill stocks was a major factor in its inception. The Convention was pioneer in formulating the need to take into account the ecosystem as a whole in fisheries management.


Although krill catches in the Southern Ocean are currently well below CCAMLR catch limits, there is a risk of localized, excessive fishing effort that might impact on species that depend on krill for food, particularly during the breeding season. Considerable overlapping exists between the krill fishery and breeding areas for penguins and seals in the South Atlantic Ocean (Constable & Nicol 2002). Little is still known of feeding areas and consumption rates of other seals, whales, dolphins, fish, squid, or flying seabirds.


CCAMLR has made significant progress in the formulation and development of the precautionary principle and an ecosystem-based approach to the management of marine resources, but the full implementation of these principles in the Southern Ocean is still at an incipient stage.  This situation is well illustrated by the case of Antarctic krill.  Although the needs of krill-dependent species are taken into account for the setting up of krill fishing quotas for big areas of the Southern Ocean, CCAMLR still needs to subdivide the overall catch limit into smaller units, so as to distribute the effort geographically in a way that takes into account the relationships between krill and its predators, which occurs at a much smaller scales.


CCAMLR also needs to undertake reforms that strengthen the monitoring and controls applicable to the Antarctic krill fishery. In spite of its magnitude and importance, this fishery is still exempted from most monitoring and control measures applicable to other Southern Ocean fisheries.


Chapter overview:


About Antarctic Krill

"Krill" is a term applied to describe over 80 species of open-ocean crustaceans known as Euphausiids, most of which are planktonic...


The role of krill in the Antarctic food web

The Antarctic marine ecosystem is largely dependent on Antarctic krill as the key prey item. Most species in the Antarctic are one or two trophic levels away from krill...


Effects of environmental conditions on Antarctic krill stocks

Antarctic krill has shown low recruitment rates in recent years, which is regarded with concern. In addition, possible long-term changes like global warming or ozone depletion could have significant effects at the individual or population level...


About the Antarctic krill fishery

The krill fishery has been the largest fishery in the Southern Ocean since the late 1970s and has prospects for becoming the largest global fishery...


History of krill fishery

Interest in krill fisheries began in the 1960s, when a total catch of more than 150 million tonnes was projected, representing the so-called “krill surplus” caused by the great reduction in baleen whale stocks...


Management of the Antarctic krill

The Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR), which came into force in 1982 as part of the Antarctic Treaty System, was negotiated by the Antarctic Treaty Consultative Parties...


Ecological concerns

Recent research has shown that demand for krill has begun to exceed supply in some areas of the southwest Atlantic. As a result, it is thought that penguins and albatrosses might be having difficulties in rearing offspring successfully...


Surveillance, control and monitoring

Although krill is recognized as a key resource in the Southern Ocean, the Antarctic krill fishery still constitutes an exception in regards to most of the basic regulatory requirements applicable to other Southern Ocean fisheries...


Market for Antarctic krill products

Recent analysis of the fishery and the market for krill products has detected signals that an expansion of the Antarctic krill fishery might be about to happen. The main driving factor is an expected increase in the demand for krill products...


Prospects of expansion: New developments in the krill fishery

After a period of highly subsidised krill fishing, particularly by the former Soviet Union, when krill catches reached their peak, krill catches dropped due to lack of economic incentives and problems encountered in krill processing...


The authors




update 2015

In his article for the

Journal of Antarctic Affairs

Rodolfo Werner again provides an overview of current challenges in the management of the Antarctic krill fishery so as to maintain krill availability to penguins in key areas:

Penguins and Krill - Life in a changing Ocean

pdf, 275kB

The complete study in pdf format (915kB)



Constable, A.J. and Nicol, S. 2002. Defining smaller-scale management units to further develop the ecosystem approach in managing large-scale pelagic krill fisheries in Antarctica. CCAMLR Science, Vol. 9: 117-131.

Croxall, J.P. and Nicol, S. 2004. Management of Southern Ocean Fisheries: global forces and future sustainability. Antarctic Science 16 (4): 569-584.

Nicol S., Endo, Y. 1997. Krill fisheries of the world. FAO Fish. Techn. Pap. 367, FAO, Rome.