Download AEBR 348 Non-target fish and invertebrate catch and discards in New Zealand southern blue whiting trawl fishery from 2006–07 to 2022–23

Anderson, O.F.; Edwards, C.T.T.; Finucci, B. (2024). Non-target fish and invertebrate catch and discards in New Zealand southern blue whiting trawl fishery from 2006–07 to 2022–23. New Zealand Aquatic Environment and Biodiversity Report No. 348. 75 p.

This report provides estimates of non-target catch and discards in the southern blue whiting fishery between 2006–07 and 2022–23 (comprising 12 195 trawls from 30 vessels).

Southern blue whiting (SBW) accounted for over 99% of the total estimated catch from all observed tows; with no other species contributing more than 0.2% of this catch. The remainder of the observed catch included ling (534 t), hoki (382 t), hake (275 t), porbeagle (178 t), silver warehou (106 t), silverside (51 t), plus a range of other species caught in small amounts, such as rattails, morid cods, and chondrichthyans.

Total estimated annual non-target catch ranged from about 57 t to 341 t, similar to levels for earlier periods from the previous assessment and without any clear indication of increasing or decreasing levels over time.

Southern blue whiting made up most of the discards due to gear breakage, malfunction, or net damage. Estimated annual discards of southern blue whiting ranged from 19 t to 272 t and showed a slight decline over time.