This project developed five food-web models of the Hauraki Gulf describing how energy flows from primary producers, through lower and middle trophic levels to fish, benthic invertebrates, seabirds and marine mammals. The models represent 5 historical periods: the present day; 50 years ago (just before industrial-scale fishing); 220 years ago (before European whaling and sealing); 500 ago (pre-European Māori phase); and 1000 years ago (before humans arrived in New Zealand).

This review has highlighted the range of approaches that have been adopted worldwide for understanding the potential impacts of aquaculture developments in terms of the nitrogen loadings in the receiving marine environment. Four international sites with comparable physical settings and levels of aquaculture development to four key New Zealand aquaculture areas were reviewed.

This report provides estimates of annual levels of individual fish and invertebrate species bycatch in eight fisheries across nine New Zealand Tier-1 deepwater species, for 1990–91 to 2012–13. Commercial catch-effort data were used to scale up rates calculated from the observed fishery. Summary tables detail the annual bycatch and bycatch trend for each species or species group.

New Zealand adopted a revised National Plan of Action for the Conservation and Management of Sharks (NPOA-Sharks 2013) in January 2014. The NPOA-Sharks established a risk-based approach to prioritising management actions. This report details outcomes from a qualitative (level 1) risk assessment (RA), generated by an expert panel (and data informed where possible), which assessed the risk to all New Zealand chondrichthyes taxa from commercial fishing.

This report documents the collation, summarising and plotting on maps of distributional information on commercial catches, fishing effort, and catch-per-unit effort for all of New Zealand’s shark, ray and chimaera species. The five-year period October 2008 to September 2013 was used to plot the distribution of recent commercial catches, and a longer term perspective was provided by trawl catches made during the fishing years 1989−90 to 2007−08.

Vulnerable marine ecosystems are deep-sea ecosystems that are highly vulnerable to fishing activity. There is a need to develop spatial management options for the protection of VMEs in the South Pacific Ocean region. Habitat suitability models for VME indicator taxa, historical fishing data, and the Zonation conservation planning software tool were used to illustrate how options for spatial management can be developed.

Commercial fisheries often catch species that are not targeted by the fishing operation (bycatch). Since this bycatch is not fully recorded it is necessary to estimate the absolute quantity using observer data. In this study we compare estimates from a ratio-based approach with a model-based estimator using data from the ling longline fishery, and scampi and squid trawl fisheries. It is argued that a model-based estimator should be the preferred approach for future work of this kind.

In Jan-Mar 2006, RV Tangaroa conducted a geophysical survey of the Ross Sea outer shelf and eastern slope. Secondary objectives of the voyage included an opportunistic biological sampling programme which increased knowledge about the distribution and abundance of a wide variety of surface, water column and benthic fauna on the scale of the Ross Sea.

This report attempts to assess fisheries risks to the population viability of Gibson’s wandering albatross (Diomedea gibsoni). Three data sets were analysed: mark-recapture, nest-based, and counts of breeders.
Three conclusions are possible: most fisheries mortality is caused by surface longlines; mortality from fishing is now probably lower than it was; and there is no indication that the drops in demographic rates were caused primarily by fishing.

A set of indicators are proposed for reporting on the state of the New Zealand marine environment. The recommended indicators are intended to form part of New Zealand’s Atmospheric and Ocean Climate Change Tier 1 Statistic, and are relevant to “State of the Environment” reporting. This project focusses on physical changes to the ocean-climate environment and does not include biodiversity indicators, which were recommended separately (project ZBD2015/01).

The limited capacity of elasmobranch populations to compensate for increased mortality, both in adult and juvenile stages, is widely recognized, and the management of these species should include protecting juvenile populations including the maintenance of healthy nursery areas, where they exist. The objective of this study was to identify threats to these nursery ground areas and recommend mitigation measures.

Vulnerable marine ecosystems (VMEs) are ecosystems that are vulnerable to damage from bottom-contact fishing. Preliminary habitat suitability models have been developed to predict the occurrence of VME indicator taxa in the area managed by the South Pacific Regional Fisheries Management Organisation. A survey of seamounts along the Louisville Seamount Chain in the area was carried out to validate the preliminary large-scale models and collect data to develop new seamount-specific models for VMEs.

Systematic literature review addressing methods of reducing shark catch rates on longline fishing gear. Gear technology as well as operational and environmental variables were evaluated as potential elasmobranch bycatch reduction methods for use in New Zealand commercial longline fisheries. Methods of mitigating shark bycatch that ranked highest in this assessment were nylon leaders, large hooks and squid bait. Circle hooks appeared to increase shark retention but may complement nylon leaders by improving the odds of survival for animals that bite off the leader.

In October 2012, the New Zealand Government signed off on the development of a “Marine Biodiversity” Statistic to report on the wellbeing and knowledge state of marine biodiversity in New Zealand waters. This project evaluated potential metrics for New Zealand marine biodiversity including: 1) species richness per square km; 2) state of knowledge index; 3) proportion of endemic species; and 4) number of threatened species.

New Zealand long-line fishery data were fitted with Boosted Regression Tree models to examine the extent to which biological and physical environmental forces might predict the distribution of highly migratory species.
Models fitted to presence/absence generally performed better than those predicting the number caught. Smaller datasets, or those with limited spatial distributions had poorer predictive ability.
Sea surface temperature, latitude and subarea were most influential in Binomial models

This report presents an authoritative data set of documented captures of New Zealand sea lion (Phocarctos hookeri) in New Zealand’s commercial trawl fisheries. Data were sourced from the Ministry for Primary Industries observer programme, fisher-reported captures, necropsy records, and Deepwater Group records. Data was collated into a single database and linked to rectify duplicate or conflicting records.