A comparison of Antarctic euphausiids sampled by net and from geothermally heated waters: insights into sampling bias

The Antarctic euphausiids Euphausia superba and E. crystallorophias were sampled using an 8 m2 rectangular midwater trawl inside the caldera of Deception Island. Specimens of the same species were collected on the same day from the strandline and sublittoral fringe within the caldera at a bay where these euphausiids had been incapacitated by high temperature geothermally heated waters. Differences between length frequency distributions of samples obtained by both methods were investigated once net-caught specimens had been subject to the simulated effects of geothermally heated waters. Differences between maturity stage/sex ratios for E. superba samples were also assessed. No significant differences between sizes of net-caught or beach-sampled E. crystallorophias were detected, but significant differences were found between both the sizes and sex/maturity stages for E. superba samples. Possible explanations for these differences are discussed.

Details

Publication status:
Published
Author(s):
Authors: Brierley, Andrew S.

Date:
1 January, 1999
Journal/Source:
Polar Biology / 22
Page(s):
109-114
Digital Object Identifier (DOI):
https://doi.org/10.1007/s003000050397