We used a new dataset of benthic invertebrate occurrence developed from quantitative seabed photographic surveys to build improved predictive models of taxon and community distributions on Chatham Rise. These predictions are the first abundance-based models of benthic distributions in the region and are the best-informed representations of seabed distributions on Chatham Rise to date, providing a resource that will have applications in marine environmental management and ecosystem research.
The present report details the preparation of data for the estimation of protected species captures in New Zealand commercial fisheries, including data from 2002–03 to 2017–18. Protected species captures included seabirds, marine mammals and turtles. The data preparation included the linking of observer records and fisher-reported data and updates, including changes to the fisher-reported purse-seine effort data, resulting in a decrease in the latter compared with the previous data preparation.
This report documents the preparation of data for the estimation of protected species captures in New Zealand commercial fisheries, up to the end of the 2016–17 fishing year. Recorded captures included captures of seabirds, marine mammals and turtles. The report describes the rationale for and impact of changes that were made to the processing of these data, when compared with the processing carried out in previous years.
Coralline red algae play vital roles in coastal ecosystems providing structurally complex, food-rich habitats for small invertebrates, influencing settlement of other algae and invertebrates, and serving as seed banks for algal life stages. They are vulnerable to impacts from human activities, and as calcified organisms, to the complex interactions of global climate processes. New research approaches have revealed very high diversity in New Zealand coralline species, many of which are unnamed.
This report summarises counts of southern Buller’s albatrosses breeding at The Snares during March 2019. The survey of the main North East Island was incomplete due to adverse weather, but the 3557 breeding pairs recorded along the East Coast, North Promontory, and West Coast was similar to the 3387 breeding pairs estimated in the same areas in 2014. While there was an increase in the size of the breeding population over the period 1969–2002, the present study indicates this has not continued.
This document provides consistent and clear guidance for monitoring and managing water column effects of salmon farms in the Marlborough Sounds (NZ). The protocol for conducting water column monitoring, as well as the compliance framework are based around an agreed set of environmental quality standards (EQS). This is a living document that is reviewed, updated and amended as required and represents our proposed ‘best practice’ at the time of conception in June-October 2018.
The deepwater Tier 1 and Tier 2 target fishstock footprint for fishing years 2008–17 was estimated at 180 100 km2. This 10-year footprint contacted 4.4% of the Territorial Sea and EEZ seafloor area and 13% of the seafloor open to fishing, down to 1600 m. Tier 1 fisheries accounted for 87%, with hoki effort contributing 42%. The 2017 footprint covered 48 203 km2, lower than the 10-year median of 49 845 km2. The aggregated swept area from all bottom-contacting trawls for 2017 was 94 500 km2.
This report summarises and synthesises the population estimate, and demographic parameter estimate components of project PRO200601: Data collection of demographic, distributional and trophic information on selected seabird species to allow estimation of effects of fishing on population viability. The project started in 2006-07 and continued until 2010-11 and comprised work on a range of surface and burrow-nesting seabird species at The Snares, Antipodes Island and the Chatham Islands.
This work compiles available benthic invertebrate records for Benthic Protection Areas and Seamount Closure Areas around New Zealand. Several BPAs are well-described, but most require more sampling to improve knowledge of the biodiversity that is protected. Spatial planning software “Zonation” is used with a variety of data sources to illustrate how such an approach could be used to evaluate BPA efficacy, and improve the effectiveness of future protection measures.
The present study provides estimates of seabird captures in commercial trawl and longline fisheries in New Zealand’s Exclusive Economic Zone. Estimates were obtained from statistical models that integrated fishing effort and observer data. The current estimates update previous analyses to the 2016–17 fishing year. In this most recent fishing year, an estimated total of 4210 (95% credible interval: 3508–5296) seabirds were captured in New Zealand’s trawl and longline fisheries.
Data on sea lion dives was used to construct a model that represents the process of sea lion exit from nets via Sea Lion Exclusion Devices. The model produces estimates of total sea lion deaths as a result of interactions with trawls, including any animals that run out of air after exiting the net. Under a range of assumptions, the results suggest scalers of between 1.2 and 1.5 for estimating total deaths from observed deaths.
A SEFRA model was developed for female New Zealand sea lions at the Auckland Islands. Inputs to the model included: the estimated at-sea spatial density of female sea lions, and cryptic mortality priors relating to SLED use. Across the last 3 years assessed, the estimated annual risk ratio across all Auckland Islands fisheries was 0.24 (95% credible interval (CI) = 0.11–0.47); consistent with population recovery to 97.5% of unimpacted status when assuming deaths at the upper 95% CI level.
Population models were developed for New Zealand sea lions at the Auckland Islands, including current demographic data. The base model was used to estimate an annual PST of 26 females. Future fishery deaths at the PST were estimated to result in a mature female population in 2025 that was 3.9% to 5.0% lower than that estimated in the absence of future squid fishery (SQU 6T) deaths; compared with 0.5% to 1.0% lower when future deaths were consistent with deaths estimated for the recent period.
A dynamic Bayesian modelling framework (including user interface) was developed for the assessment of unobservable mortality (e.g. due to carcass loss during net retrieval) of New Zealand sea lions that interact with trawls using sea lion exclusion devices. A base case model suggested that the total fishery-related deaths are underestimated by a factor of 1.15 (95% credible interval: 1.05-1.31) and 1.60 (95% credible interval: 1.20-2.63) for bottom trawls and mid-water trawls, respectively.
This report is a summary of work to develop a coherent dataset of benthic invertebrate distributions on Chatham Rise based on seabed photographic surveys. The dataset spans the full extent of Chatham Rise in depths from 40 m to 1850 m, combining analyses of 358 seabed transects from five surveys. The primary purpose of the dataset is to enable development of improved predictive models of faunal distributions that can be used to inform ecosystem-based management of the region.