Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-25T19:57:02.641Z Has data issue: false hasContentIssue false

Demography of krill in the Elephant Island area during summer 2001 and its significance for stock recruitment

Published online by Cambridge University Press:  27 April 2004

V. Siegel
Affiliation:
Seafisheries Research Institute, Palmaille 9, D-22767 Hamburg, Germany
B. Bergström
Affiliation:
Kristineberg Marine Biological Station, Fiskebäckskil, Sweden
U. Mühlenhardt-Siegel
Affiliation:
German Centre of Marine Biodiversity, Martin-Luther-King Platz 3, D-20146 Hamburg, Germany
M. Thomasson
Affiliation:
Kristineberg Marine Biological Station, Fiskebäckskil, Sweden

Abstract

A net sampling survey was carried out for krill in a standard station grid around Elephant Island during 27 January to 4 February 2001. In comparison with recent years the station grid was extended south, where a large proportion of small size classes, one-year-old juvenile krill was found. Results show a spatial separation of the juvenile krill and the spawning stock, Krill density was significantly higher than during the past years (229 krill 1000 m−3 or 13.0 g m−2). The proportional recruitment index for the entire survey area for the 1999/2000 year class was R1 = 0.573, which is among the highest values recorded during the past 20 years. The maturation index (based on the proportion of gravid stages) was G = 0.99, indicating an early initiation of the spawning season. The results indicate a turning point after a succession of years with poor recruitment success and low stock biomass. This is thought to be the first step for a successful spawning event and a later potential recruitment success of the 2000/01 year-class. The spatial extent of the station grid is discussed in the light of a representative coverage of the stock and the estimated recruitment index.

Type
Life Sciences
Copyright
© Antarctic Science Ltd 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)