In order to manage the commercial harvesting of Antarctic marine living resources in accordance with the ‘ecosystem approach’ that is embodied in Article II of the CAMLR Convention, the effects of fishing on harvested species (target species) as well dependent species and associated species need to be taken into account. Dependent species are those species that feed on the target species or are impacted by the removal of the targets species from the food web. Associated species are typically those that are impacted directly by the action of fishing e.g. through by-catch or incidental mortality. In order to provide information of the effects of fishing on dependent species, CCAMLR set up the CCAMLR Ecosystem Monitoring Program (CEMP). The two aims of CEMP are to:

1. detect and record significant changes in critical components of the marine ecosystem within the Convention Area, to serve as a basis for the conservation of Antarctic marine living resources
2. distinguish between changes due to harvesting of commercial species and changes due to environmental variability, both physical and biological.

CEMP's major function is to monitor the key life-history parameters of selected dependent species to detect changes in the abundance of harvested species. ‘Dependent species’ are marine predators for which species targeted by commercial fisheries are a major component of their diet. In the case of ‘krill-dependent species’ used in CEMP they include land-based species such as seals and penguins.

Suitable ‘indicator species’ should show measurable responses to changes in the availability of the harvested species, for example in changes in population size, breeding success, body mass and foraging behaviour. The spatial and temporal scales over which different CEMP parameters reflect changes in the status of the ecosystem may be over a few days within a relatively small distance from the breeding site (e.g. foraging trip duration and offspring growth rates) to months (e.g. breeding success) whereas indices of population size reflect a combination of multi-year factors including adult survival/condition and juvenile recruitment.

The indicator-species used in the CEMP program are Adélie (Pygoscelis adeliae), chinstrap (P. antarctica), gentoo (P. papua) and macaroni penguin (Eudyptes chrysolophus), black-browed albatross (Thallasarche melanophrys), Antarctic petrel (Thalassoica antarctica), Cape petrel (Daption capense) and Antarctic fur seal (Arctocephalus gazella). Some krill-dependent species, such as crabeater seal (Lobodon carcinophagus), while considered likely to respond to changes in krill availability, have not been used in monitoring because they live in the pack-ice and so are not amenable to repeated/annual monitoring.

In order to ensure comparability between sites and over time, CCAMLR has agreed a set of CCAMLR Ecosystem Monitoring Program Standard Methods (1.06 MB) that include details of how data should be collected, formats for submission of the data to the CCAMLR Secretariat and procedures for data analysis.

FURTHER READING

Agnew, D.J. 1997. The CCAMLR Ecosystem Monitoring Programme. Antarctic Science, 9 (3): 235–242.

Constable, A.J., W.K. de la Mare, D.J. Agnew, I. Everson and D. Miller. 2000. Managing fisheries to conserve the Antarctic marine ecosystem: practical implementation of the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR). ICES Journal of Marine Science, 57: 778–791.

Reid, K., J.P. Croxall, D.R. Briggs, and E.J. Murphy. 2005. Antarctic ecosystem monitoring: quantifying the response of ecosystem indicators to variability in Antarctic krill. ICES Journal of Marine Science, 62:366–373.