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

• Published in: Polar Biology
• Main Author: Brierley, Andrew S.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Springer-Verlag 1999
• Subjects: Antarctic; The Antarctic; Deception Island; Antarc*; Euphausia superba; Polar Biology
• Online Access: http://nora.nerc.ac.uk/id/eprint/503042/; http://link.springer.com/content/pdf/10.1007%2Fs003000050397.pdf; https://doi.org/10.1007/s003000050397

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.