This report summarises bycatch and discards in hoki, hake, ling, silver warehou, and white warehou trawl fisheries for 1990–91 to 2016–17, based on analysis of fisheries observer and commercial catch effort data. Javelinfish, other rattails, and spiny dogfish were the main bycatch species recorded by observers. Total annual bycatch for the period ranged from 17 500 t to 49 000 t; total annual discards (for 2002–03 to 2016–17) were 5000 t to 25 000 t and decreased significantly after 2002–03.

This document provides consistent and clear guidance for the benthic monitoring and management of salmon farms in the Marlborough Sounds (NZ). The protocol for conducting seabed surveys, as well as the compliance framework are contained within, and are based around an agreed set of environmental quality standards (EQS). This is a living document that is reviewed, updated and amended as required. It was initially released in 2015, and the 1.1 version reflects revisions resulting from its first review in 2018.

An understanding of marine animals’ movements is paramount for their effective management and conservation, especially with a changing climate. This project’s aim was to produce south Pacific Ocean carbon and nitrogen isotopic maps, referred to as “isoscapes”, to improve our understanding of species foraging habits and movements in marine ecosystems. The geographical variation in these isoscapes, over varying spatial scales, can contribute to many future BRAG/MPI projects.

New Zealand Aquatic Environment and Biodiversity Report No. 217. 62 p.

This study provides an indicative assessment of vessel traffic and seismic survey related noise. Vessel AIS data for the year of July 2014 to June 2015 was used to determine density and speed grids by vessel category. JASCO’s cumulative vessel noise model was used to model the sound from 15 vessel categories and two marine seismic surveys during representative summer and winter months in 1-minute time steps. Results are presented as maps, animations and plots of sound levels at static locations.

New Zealand Aquatic Environment and Biodiversity Report No. 216.

An individual-based population model was fitted to genetic capture-recapture data collected during 2001-16 from Māui dolphins (Cephalorhyncus hectori maui), to estimate population size and trends. The population is estimated to be declining despite declining mortality rates. Forward projections under various scenarios imply that a further reduction of anthropogenic mortality of at least 50% is required to arrest population decline and avert extinction, regardless of the main source of the mortality, which is suspected to be fisheries bycatch and/or disease.

New Zealand Aquatic Environment and Biodiversity Report No. 215. 18 p.

A Bayesian Māui dolphin population model was developed integrating information from genetic “mark-recapture” and population size estimates. Model runs incorporated estimates of historical annual deaths from commercial fisheries and toxoplasmosis obtained from a separate spatial risk assessment. These models were then used to simulate the effects of estimated threat-specific mortality rates on future population growth.

New Zealand Aquatic Environment and Biodiversity Report No. 214. 168 p.
(Manuscript 3334)

A spatial risk assessment of threats was undertaken for Hector’s and Māui dolphins, to inform a revised Threat Management Plan (TMP) for the species. A Bayesian risk model was developed using the spatially-explicit fisheries risk assessment (SEFRA) approach, incorporating revised estimates of Hector’s and Māui dolphin spatial density and intrinsic population growth rate. The risk model was used to estimate spatial overlap, annual deaths and risk for commercial fisheries and lethal non-fishery threats, including toxoplasmosis. Spatial overlap was estimated for other threats.

Francis, M.P.; Hoyle, S.D. (2019). Estimation of fishing effort in the Southern Hemisphere.

New Zealand Aquatic Environment and Biodiversity Report No. 213. 24 p.

This report estimates the high seas fishing effort expended in the Southern Hemisphere by the main methods likely to impact seabirds (surface and bottom longline, and trawl). Data were sourced from 10 Regional Fisheries Management Organisations. Effort totals are biased low (sometimes substantially) in some regions and times, although the degree of under-estimation has probably declined through time. These estimates will be used in a subsequent quantitative risk assessment of seabirds.

978-1-98-859461-3

(Manuscript 3308)

Alestra, T.; Gerrity, S.; Dunmore, R.A.; Marsden, I.; Pirker, J.; Schiel, D.R. (2019). Rocky reef impacts of the Kaikōura earthquake: quantification and monitoring of nearshore habitats and communities.
New Zealand Aquatic Environment and Biodiversity Report No. 212. 120 p.


Surveys along 130 km of coastline in the first sixteen months following the Kaikōura earthquake showed significant damage to intertidal benthic communities at all sites. Subtidal communities were impacted only at sites with uplift greater than 2 m. Taonga species such as paua and bull kelp were still present at most sites and showing signs of post-earthquake recruitment. This information provides a key baseline for management decisions and new research into long-term trajectories of recovery.

Manuscript 3269

This assessment presents bycatch estimates of seabirds in commercial trawl and longline fisheries in New Zealand’s Exclusive Economic Zone. The estimation relied on statistical models that used fishing effort and observer data up to the 2015–16 fishing year. Estimates for the latter fishing year included a total of 4517 (95% credible interval: 3760–5825) seabird captures in trawl and longline fisheries in New Zealand waters.

This report summaries annual estimates of bycatch levels of individual fish and invertebrate species in the trawl fisheries for arrow squid, hoki/hake/ling, southern blue whiting, jack mackerel, orange roughy, oreo, scampi, and the longline fishery for ling from 1990–91 to 2016–17. Total annual bycatch was estimated using a statistical model method, replacing a ratio estimator-based method used in previous iterations of this work.

A reassessment of population size and trends of Hutton’s shearwater following the 2016 Kaikōura earthquake and outlook for the species’ management.

McMillan, P.J.; Francis, M.P.; James, G.D.; Paul, L.J.; Marriott, P.; Mackay, E.; Wood, B.A.; Stevens, D.W.; Griggs, L.H.; Baird, S.J.; Roberts, C.D.; Stewart, A.L.; Struthers, C.D.; Robbins, J.E. (2019). New Zealand fishes. A field guide to common species caught by bottom, midwater, and surface fishing. New Zealand Aquatic Environment and Biodiversity Report No. 208.

Manuscript 3258

This single-volume guide describes over 400 of the more common marine fishes caught by bottom, midwater, and surface fishing methods in New Zealand seas. This revised and updated guide replaces the three-volume set of guides published in 2011 (McMillan et al. 2011a-c) and includes an additional 54 species.

D’Archino, R.; Neill, K.F.; Nelson, W.A.; Fachon, E.; Peat, C. (2019). New Zealand Macroalgae: Distribution and Potential as National Scale Ecological Indicators.

New Zealand Aquatic Environment and Biodiversity Report No.207. 217 p.

Canopy-forming macroalgae are internationally recognised as critical components of coastal ecosystems as primary producers, coastal buffers and provision of habitat. This report evaluates the use of large brown macroalgae as indicators of ecosystem health by: summarising the international and national literature; testing the responses of key species to stressors in culture; investigating a range of approaches to mapping and monitoring, including the use of drones and machine learning to analyse underwater videos.

Tuck, I.D.; Hewitt, J.E.; Bulmer, R.H. (2019). Monitoring Recovery of Benthic Fauna in Spirits Bay.

New Zealand Aquatic Environment and Biodiversity Report No. 206. 74 p.

This report describes changes in the benthic communities of Spirits Bay related to fishing pressure and environmental factors. Survey data were analysed from 2006, 2010 and 2017. Epifaunal and infaunal communities consistently identified year, habitat, depth and fishing effects. Weaker fishing effects were detected from recent surveys, where fishing effort was lower. Species identified as sensitive to fishing were previously identified as sensitive on the basis of life history and morphology.

A data driven bioregionalisation to underpin shellfish fisheries restoration, Nelson Bays, New Zealand