KRILLBASE

KRILLBASE is a data rescue and compilation project which aims to improve the availability of information on two of the Southern Ocean’s most important zooplankton taxa: Antarctic krill (Euphausia superba) and salps (Family Salpidae).

In 2016, the project released a database of information from 12,880 scientific net samples, collected between 1926 and 2016 by scientists from ten countries. These data, on the density (number under 1m² of sea surface) of Antarctic krill and salps, with associated environmental data and sampling information provide a resource for analysing the distribution and abundance of these taxa throughout the Southern Ocean.

Why Antarctic krill?

The shrimp-like crustacean Antarctic krill (Euphausia superba) if often described a key species in the Southern Ocean, because of its abundance (estimated at around 780 trillion (7.8 * 10¹⁴) individuals, excluding eggs and larvae), its wide distribution (it is found at all latitudes of the Southern Ocean and at all depths) and its importance as prey to a wide range of predators (from brittle stars on the seabed to great whales). The role of Antarctic krill as a major prey species and a grazer of phytoplankton mean that it has a profound influence on foodwebs and biogeochemical cycles. It is also caught by a fishery, which must be managed to prevent disruption of the ecosystem. Information about Antarctic krill distribution and dynamics is important for the development of sustainable fishery management and conservation policy (e.g., identifying suitable Marine Protected Areas and assessing the dynamics of fished stocks).

Why salps?

Although a similar size to Antarctic krill, salps look very different. They are jelly-like filter feeders and have alternating generations of solitary individuals followed by long chains of connected individuals. They can form dense “blooms” in some years and are important members of the Southern Ocean ecosystem. Some scientists have suggested that salps thrive in conditions which are detrimental for Antarctic krill and may become more abundant as a result of climate change. Thus, information on salps provides a more complete picture of the changes that affect Antarctic krill.

A brief history of KRILLBASE

In the 1990s several countries began monitoring programmes in selected parts of the Southern Ocean, sampling the same area every year to assess changes in the ecosystem. In the same decade, the founders of KRILLBASE recognised that combining these data, and adding historical data that pre-dated the monitoring programmes, would provide more information than any individual programme could. They identified masses of data on Antarctic krill and salps. However these data were mainly confined to dusty archives, faded logbooks, old disks or databases.

Compiling the data is a mammoth task which is progressing with the cooperation of scientists from  the US, UK, Germany, Ukraine,  Australia, South Africa, Japan, Poland, Spain, Norway and Chile. Indeed, new data are collected every year, and participants in the project intend to produce new updates in the future.

Along the way the project has produced a series of papers that have updated our understanding of Antarctic krill, and the ecosystem that depends on them.

In 2016, with the support of WWF, the project released the first publicly accessible compilation of circumpolar data on krill and salp density. See the “Data” tab for access to these data and information on their use.