KRILL (EUPHAUSIA-SUPERBA) DENSITY, PROPORTIONAL AND ABSOLUTE RECRUITMENT AND BIOMASS IN THE ELEPHANT-ISLAND REGION (ANTARCTIC PENINSULA) DURING THE PERIOD 1977 TO 1997
V. Siegel et al., KRILL (EUPHAUSIA-SUPERBA) DENSITY, PROPORTIONAL AND ABSOLUTE RECRUITMENT AND BIOMASS IN THE ELEPHANT-ISLAND REGION (ANTARCTIC PENINSULA) DURING THE PERIOD 1977 TO 1997, Polar biology, 19(6), 1998, pp. 393-398
The Elephant Island region (Antarctic Peninsula) was selected as a lon
g-term monitoring site to describe the interannual variability of impo
rtant krill stock parameters. The analysis reviewed and updated krill
density and proportional recruitment indices. Krill absolute recruitme
nt and biomass from net sampling surveys are introduced as additional
indices from this time series. New survey results from the past two se
asons indicate a very successful 1994/1995 year-class and slightly bel
ow average proportional recruitment of the 1995/1996 krill year-class.
Absolute recruitment of the 1995/1996 year-class was high compared to
preceding years, because total stock size was relatively high in 1996
/1997. After a period of low krill density and biomass in the area for
almost a decade, krill density and biomass have increased. Caution is
expressed as to whether this observed increase represents a long-term
recovery of the stock.