Identification of marine mammals captured in NZ fisheries 2020/21

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INT2020-02: Identification of marine mammals captured in New Zealand fisheries (1 July 2020 to 30 June 2021) (PDF, 1,099 KB)

Summary

This project forms one part of a wider Conservation Services Programme (CSP) research programme which also covers the identification of bycaught turtles and protected fish species and is designed to complement the existing seabird identification project. The accurate determination of the taxon of marine mammals captured in New Zealand (NZ) fisheries is vital for examining the potential threats to population viability posed by incidental fisheries captures. Observers on commercial vessels are not always able to identify marine mammals with high precision, and the assessment of the age class may require expert knowledge. Information gained through this project will link to FNZ databases and will inform ongoing capture estimations, risk assessments, research, and modelling of the effects of fisheries incidental capture (i.e. bycatch) on various marine mammal species.

There were 116 marine mammal bycatch events reported between 1 July 2020 to 30 June 2021. Of these events, 94 (81%) had either photos or videos that could be assessed to confirm taxa identification and other information. The remaining 22 (19%) events had no photos associated with them and were therefore not able to be assessed. There is some discussion of potential reasons for a lack of photos within the report.

Taxa identification by observers was confirmed as correct in all events where reasonable quality photos were available.

Publication information

Johnston O, Childerhouse S (2022). Identification of marine mammals captured in New Zealand fisheries 2020-21. INT2020-02 final report prepared by Cawthron Institute for the Department of Conservation. 18 pp.