MARAM_Tristan_2020_JAN_01.pdf (1.02 MB)

Tristan Group Biomass Survey (Leg 1) results including data from the 2019 season

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posted on 29.01.2021, 11:32 by Susan Holloway

This paper reports the updated biomass indices (to include the 2019[1] season) obtained from the annual (Leg 1) biomass survey at each island. The index values have declined notably since the 2018 season at the outer islands of Inaccessible, Nightingale and Gough but increased marginally at Tristan. There have been some changes over time in the size distributions, the most marked of which have been steady increases at Inaccessible and Tristan in the mean length of the survey catch. However, the mean length of the catch from Gough continues to decline. The percentage of females in the catch at Gough (around 25-35%) is much higher that at the other three islands (around 5-15%).

[1] The split season is denoted by the first year, i.e. 2019 refers to the 2019/2020 season.



Department of Mathematics and Applied Mathematics, University of Cape Town