Three surveys of acoustic data from around South Georgia, collected using a four frequency echosounder (38, 70, 120 and 200 kHz), were used to characterise Antarctic krill. Identification of krill targets was carried out using different permutations of two and three-frequency windows. Density was estimated, from identified krill targets, using the 120 kHz data and an acoustic scattering model. A Bland-Altman analysis with a pre-set nominal cut-off of ≤5 gm-2 bias between methods identified that only the 120-70 kHz (Sv120-70) identification window was comparable with the regularly used 120-38 kHz (Sv120-38) window, and only the 200-120 kHz and 120-70 kHz (Sv120-70 & Sv200-120) identification window was comparable with the regularly used 120-38 and 200-120 kHz (Sv120-38 & Sv200-120) three-frequency window.
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Abstract:
The proposed boundaries of the Weddell Sea MPA (WSMPA) include the significant area of 1.3 million km². It is shown that the WSMPA boundaries should be revised in compliance with sea-ice conditions for vessel navigation being a fundamental factor for the successful completion of assigned research tasks in designated areas.
Abstract:
It is shown that the proposals for the establishment of an MPA in the Weddell Sea should be complemented by information on the commercial potential and future rational use for dominant fish species and krill in Subareas 48.5 and 48.6.
There is no description / abstract available for this document.
There is no description / abstract available for this document.
There is no description / abstract available for this document.
There is no description / abstract available for this document.