This document describes the development of standardised catch per unit effort (CPUE) index series for CRA 2 using data collected by the mandatory Catch Effort Landing Return (CELR) forms and data collected voluntarily by commercial fishers in a logbook (LB) programme and an electronic fine scale / harvest pot programme. These three data sets index different parts of the population, but all generally agree with each other.

Submissions received during consultation on East Coast tarakihi

This work reassesses the potential impact of historical setnet fishing on Māui dolphin, replicating previous analyses in combination with updated catch rate estimates. Catch rates for Hector’s dolphin around Banks Peninsula have been applied to Māui dolphin, and aerial surveys conducted in 2012/13 resulted in Hector’s dolphin abundance estimates that were greater than those from boat-based surveys conducted in 1998–2000. As such, catch rates may be much lower than estimated previously.

Benthic invertebrate communities on the Graveyard Knolls have been monitored over a period of 20 years, with photographic surveys of six features with a mixture of fishing histories. Multivariate analyses indicate little change in overall community patterns on five of the six features. However, on ‘Morgue’ which was heavily fished until its closure in 2001, there are indications that community structure might be changing and that branching stony corals are either regrowing or recolonising.

This report documents updated information for Underwater Topographic Features (UTFs: seamounts, knolls, hills) in the New Zealand region, and the development of a new Postgres database to serve this information. There are 42 fields for each UTF covering generic descriptors, with physical, oceanographic, geological, biological, and fisheries information. Data are given for 2964 UTFs distributed within the Territorial Sea (89), Exclusive Economic Zone (EEZ) (1907), and outside the EEZ (968).

An updated risk assessment was conducted for 54 New Zealand marine mammals using a multi-species spatially explicit risk assessment. Goodness-of-fit assessments indicated reasonable performance to predict total number of captures for pinniped and delphinid species with >5 captures, but poor performance to predict the spatial location of those captures. Poor performance may be due to inappropriate structural model assumptions or to biological inputs. Results should be interpreted with caution.

The fisheries taking trevally (TRE) in Quota Management Area TRE 2 are described from 1989–90 to 2016–17. Most of the TRE 2 catch is taken by the mixed-species bottom trawl fishery within Hawke Bay and Poverty Bay. Since the last analysis (with data to 2009–10) CPUE indices have been relatively stable, with an increasing trend from 2008–09 to 2016–17. This increase is corroborated by a tow-based series using data collected on Trawl Catch Effort Returns from 1 October 2007.

An analysis of juvenile red rock lobster growth around New Zealand, based on existing length and mark-recapture based growth information, is reported here. The time lag from puerulus settlement to recruitment in stock assessment models is highly likely to be 2–3 years, when this occurs at 30–35 mm tail width (TW). Annual growth increment at 30 mm TW is about 9 mm based on Stewart Island growth information, about 12 mm at Gisborne, and potentially faster along the north coast North Island.