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Warming oceans affect the growth, reproduction and location of fish species. Using a bioeconomic framework, we estimate the relationship between sea surface temperature (SST) and the catch of de facto open‐access commercial fisheries of flatfish, trevally and jack mackerel in New Zealand. Assuming either a logarithmic or quadratic relationship between the SST and the carrying capacity of the fish stock, we consider three fishing methods (bottom trawl, set net and midwater trawl) and two measures of effort (count and duration). We show that ocean warming results in an increase in catch for all species if we assume a logarithmic relationship, with the highest marginal product of SST (MPSST) for jack mackerel caught using midwater trawl. The highest marginal revenue product (computed by the MPSST, current price and fished area) is found for flatfish caught by set net. However, when assuming a quadratic relationship, there is a threshold above which catch starts to decrease, with the maximum catch of species ranging between 10 and 12.2°C. These results also vary spatially, with higher values of MPSST observed in areas closer to the South Pole. Our findings are relevant for any review of fisheries management systems in response to ocean warming. [ABSTRACT FROM AUTHOR]

This paper explores the ways in which the affective and material dimensions of the commons come together to produce commoner subjectivities. Threats of enclosure can draw attention to the ways in which subjectivity reproduction is dependent on an environment which enables embodied acts of care. Using the example of the East Otago Taiāpure and Waikouaiti Mātaitai, a form of customary fisheries management in New Zealand, this paper illustrates the limitations of the institutionalised commons in its capacity to create an effective caring and protective space. Historical colonial transformation of the landscape and contemporary industrial activities have resulted in an "ecological enclosure" of the area, threatening the health of the ecosystem and its ability to encourage Māori subjectivities, specifically, kaitiakitanga, a relational responsibility to care for the physical and social environment. [ABSTRACT FROM AUTHOR]

Composition and length-frequency are important attributes considered in the management of fish communities and can be affected by both exploitation and environmental forces. Vulnerability to these effects varies among species depending on environmental tolerance, ecological traits, and life-history strategies. In the present study, data from scientific bottom trawl surveys conducted between 1991 and 2018 were analysed to identify long-term changes in community structure and length-frequency of demersal fish species of the east coast of the South Island, New Zealand. Analysis of variance, hierarchical clustering analysis and multidimensional scaling relationships demonstrated that community composition has changed significantly over the last three decades, with a tendency towards greater spatial overlap among species in the most recent periods. Changes in depth distribution were identified but were mainly correlated with shifts in relative biomass. Total catch rate (kg km−2) of the whole community has increased significantly over time, while the average trophic level decreased, primarily explained by an increase in relative biomass of intermediate trophic level species. Fishing activity was significantly related to the variation in length-frequency of species at intermediate trophic levels, confirming that the impacts of fisheries are heterogeneous throughout the community, providing vital information to support multi-species management of fishery resources. [ABSTRACT FROM AUTHOR]

Although being some of the most valuable and heavily exploited wild organisms, few fisheries species have been studied at the wholegenome level. This is especially the case in New Zealand, where genomics resources are urgently needed to assist fisheries management. Here, we generated 55 Gb of short Illumina reads (92× coverage) and 73 Gb of long Nanopore reads (122×) to produce the first genome assembly of the marine teleost tarakihi [Nemadactylus macropterus (Forster, 1801)], a highly valuable fisheries species in New Zealand. An additional 300 Mb of Iso-Seq reads were obtained to assist in gene annotation. The final genome assembly was 568 Mb long with an N50 of 3.37 Mb. The genome completeness was high, with 97.8% of complete Actinopterygii Benchmarking Universal Single-Copy Orthologs. Heterozygosity values estimated through k-mer counting (1.00%) and bi-allelic SNPs (0.64%) were high compared with the same values reported for other fishes. Iso-Seq analysis recovered 91,313 unique transcripts from 15,515 genes (mean ratio of 5.89 transcripts per gene), and the most common alternative splicing event was intron retention. This highly contiguous genome assembly and the isoform-resolved transcriptome will provide a useful resource to assist the study of population genomics and comparative eco-evolutionary studies in teleosts and related organisms. [ABSTRACT FROM AUTHOR]

To make coherent and just choices about introduced species management in postcolonial contexts such as Aotearoa, a nuanced understanding of human relationships to introduced species is needed. Inspired by relational values thinking, we interviewed 13 knowledge holders to explore diverse meanings and experiences with introduced trout and their management. Trout have impacted ecosystems and communities in profoundly different ways, ranging from ecological enhancement and cultural empowerment for some communities to devastation and loss for others. Some people consider trout potentially compatible with a 'healthy' ecosystem, while others consider them incompatible. Despite the existence of deep and legitimate reasons for differences in perspectives on trout, we found convergence among interviewees on three principles that could provide a foundation for future trout management: shared decision-making within a Treaty framework, management of the negative impacts of trout, and coordination across government agencies to set and achieve holistic fish management objectives. [ABSTRACT FROM AUTHOR]

The emergence of high resolution population genetic techniques, such as genotyping-by-sequencing (GBS), in combination with recent advances in particle modelling of larval dispersal in marine organisms, can deliver powerful new insights to support fisheries conservation and management. In this study, we used this combination to investigate the population connectivity of a commercial deep sea lobster species, the New Zealand scampi, Metanephrops challengeri, which ranges across a vast area of seafloor around New Zealand. This species has limited dispersal capabilities, including larvae with weak swimming abilities and short pelagic duration, while the reptant juvenile/adult stages of the lifecycle are obligate burrow dwellers with limited home ranges. Ninety-one individuals, collected from five scampi fishery management areas around New Zealand, were genotyped using GBS. Using 983 haplotypic genomic loci, three genetically distinct groups were identified: eastern, southern and western. These groups showed significant genetic differentiation with clear source-sink dynamics. The direction of gene flow inferred from the genomic data largely reflected the hydrodynamic particle modelling of ocean current flow around New Zealand. The modelled dispersal during pelagic larval phase highlights the strong connectivity among eastern sampling locations and explains the low genetic differentiation detected among these sampled areas. Our results highlight the value of using a transdisciplinary approach in the inference of connectivity among populations for informing conservation and fishery management. [ABSTRACT FROM AUTHOR]

Galaxiid post-larvae constitute five of the six species in New Zealand's iconic whitebait fishery. Distinguishing the five species needs to occur at a younger age than is convenient for easy identification. Traditional identification uses subjective characteristics such as colouration of fresh specimens and fin position, but supervised classification methods could be more accurate and less labour-intensive. We compared the accuracy of six methods (multinomial logistic regression, linear discriminant analysis, quadratic discriminant analysis, naive Bayes, decision tree, and random forest) using total length, wet weight, body depth, and date, latitude and longitude of capture as predictive variables. Four of the galaxiid species were represented in 17,546 observations, but the other species was too rare to analyse. The best method, determined using 10-fold cross-validation classification accuracy (95.2% overall), was random forest across all species. The most difficult species to classify correctly (giant kōkopu) was the rarest species included in data with 66.1% accuracy at best. In addition to examining overall accuracy, we show how use of a cost function can improve classification performance with respect to rare species. This research could improve the efficiency of monitoring the composition of the whitebait fishery, and thus management of this occasionally overfished group of fish. [ABSTRACT FROM AUTHOR]

Tarakihi (Nemadactylus macropterus) is a demersal fish that supports valuable commercial, recreational, and customary fisheries in New Zealand. However, little is known about its stock structure. The population genetic structure, genetic diversity, and demographic history of N. macropterus were investigated using the hypervariable region one of the mitochondrial control region. 370 samples from 14 locations around New Zealand were collected. While weak genetic breaks were detected between Hawke's Bay and East Northland and between the west and east coasts of South Island, no clear genetic structure was detected for the overall New Zealand area (ФST = 0.002, P = 0.18), indicative of a panmictic genetic structure. N. macropterus display a high level of genetic diversity and appear to have a historically large and stable population with a long evolutionary history. Bayesian skyline analysis indicates that the historic population has gone through two expansions, likely caused by repeated glacial cycles during the second half of the Pleistocene. The addition of 15 king tarakihi samples (Nemadactylus n.sp.) collected from the Three Kings Islands showed a clear genetic differentiation between the two morphotypes. These findings can inform the future management of N. macropterus and N. n.sp. to ensure a sustainable harvest. [ABSTRACT FROM AUTHOR]

The aim of stock assessment is to provide managers with an understanding of the biomass and age-/size-composition of a stock, stock status (ideally relative to target and reference points), and to support management decision making, often through projections and application of harvest control rules. Stock assessments are increasingly being used to form the basis for the operating models used to evaluate the ability of management strategies to achieve the goals of fisheries management. Stock assessments for rock lobsters were among the first to adopt size-structured population models as the basis for stock assessment, and population model-based stock assessments have been used extensively to evaluate management strategies for rock lobster stocks in the USA, Australia, New Zealand and South Africa. This paper identifies how closely population model-based stock assessments for rock lobsters satisfy the guidelines identified for best practices for conducting stock assessments during meetings of, for example, the Center for the Advancement of Population Assessment Methodology and papers identifying best practice guidelines for stock assessment. The paper highlights some key directions for stock assessment science for rock lobsters, including considerations related to environmental variation and climate change. [ABSTRACT FROM AUTHOR]

Today, in Central Otago, New Zealand, with competing claims for water beyond irrigation, farmers and water conservation interests are at loggerheads, and freshwater management has become a site of intense debate, competition and political action. We comment on the polarised politics of water governance in Central Otago, writing from the perspective of fish and gamebird management. Our commentary is allied to an interpretation of freshwater allocation for irrigation in New Zealand, which emphasises the emergence and dominance of a singular 'more water' discourse in rural development in the 2000s. [ABSTRACT FROM AUTHOR]

Loss of access to cultural keystone species is a familiar story across the Pacific. Serial depletion of pāua (abalone, Haliotis iris), a cultural keystone for Māori in Aotearoa New Zealand, threatens Indigenous practices and values. Kāti Huirapa Rūnaka ki Puketeraki, a hapū (subtribe) of Ngāi Tahu, have struggled for over 30 years to address loss of local pāua populations. Regulations introduced by the East Otago Taiāpure, a customary fishery management area established in 1999, recognise Indigenous rights to access and manage marine resources. Despite concerted efforts to rebuild pāua populations while allowing fishing, pāua have continued to decline and the fishery was closed in 2019. A wealth of mātauranga (Māori knowledge) surrounds enhancement practices for pāua. Here, mātauranga relating to translocation was collated through interviews and applied, in conjunction with additional knowledge bases, to translocate pāua from reefs threatened by sand inundation to more accessible but historically overexploited bays. In total, 420 pāua, translocated across 21 sites, were monitored for a 2-week period, after which aggregations returned to pretranslocation densities. Total mortality reached 8.8% over this time, attributed primarily to predation by the sea star Astrostole scabra. Results suggest that translocation may not be suitable for creating artificial aggregations using the methods applied; however, it could address other management concerns, hence suggestions are made for methodological improvements. The interaction between pāua and A. scabra demonstrates the need for continued transformation in management to allow for the application of a multispecies integrated approach in the restoration of pāua. Translocation as a management tool for Haliotis iris was trialled within a customary fishery management area in Aotearoa New Zealand, demonstrating the possibility, within an appropriate legal framework, for conservation biology to be transformed from institutionally led science to research guided by community managers, applying Indigenous principles to address local issues. [ABSTRACT FROM AUTHOR]

Spatially discrete stocks that vary in life history traits on a reef‐to‐reef scale present a challenge for fisheries managers. Nationally or regionally applied one‐size‐fits‐all approaches to management fail to account for this variability, and when coupled with fishing pressure this can result in serial depletion and localized extinction.Where mechanisms for local management exist, as they do in New Zealand via customary protection areas (Taiāpure Local Fisheries, Mātaitai Reserves), managers have the opportunity to trial tools on scales relevant to the stocks managed. This study assesses the effect of bag limits and a rāhui (temporary closure) in managing the spatially discrete, and culturally important, blackfoot abalone (Haliotis iris, pāua) in the East Otago Taiāpure, in southern New Zealand.Using surveys spanning 8 years and 26 sites, the rāhui was found to have had mixed results: halting the decline in pāua density at 0 m but not 0.5 m depths. The rāhui did, however, result in an increase in the percentage of individuals above the minimum legal size at both depths.Where bag limits alone had been applied, pāua densities and the percentage of legal‐sized individuals continued to decline over the 8‐year period, with the loss of large individuals, translating into a decline in estimated egg production.Growth estimates from mark–recapture and surveys of juvenile abundance at sites inside and outside the rāhui highlight the fine‐scale variability in pāua life history even within this local area. This suggests there may be biological impediments to pāua management using bag limits alone.Though pāua restoration efforts have had mixed results to date, this study highlights the potential for legally empowered local managers and communities to respond to fisheries declines in their own local area in an action‐driven, adaptable, and timely way. [ABSTRACT FROM AUTHOR]

The snoek, Thyrsites atun, is a pelagic fish of the family Gempylidae that inhabits cold waters of the southern hemisphere. It is an important fishing resource species (e.g. Chile, Namibia, New Zealand) linked mainly to the artisanal fisheries, however, its phylogeographic and population aspects are largely unknown. In this study we provide the first detailed analysis of the phylogeographic patterns and demographic processes of the snoek for the southern hemisphere using mitochondrial data of the Cytochrome c Oxidase subunit I gene. Our results indicate two lineages: (i) Australia-New Zealand, and (ii) Chile-South Africa-Namibia. The Australia-New Zealand clade shows partial isolation between populations associated with distinct biogeographic regions, likely driven by the region's oceanography. The divergence between the lineages happened ∼800,000 years ago. On the other hand, analysis of the fish caught in the South-eastern Pacific (Chile) showed that the genetic diversity among localities (hT = 0.657) was lower than within localities (hS = 0.664), which was consistent with the pairwise comparisons results, suggesting the absence of phylogeographic structure. Based on our estimations, population expansion in T. atun would have occurred ∼7.5 ka (after LGM) under the Bayesian skyline plots approximation. We discuss the scope that this study could have in fisheries management of this important species. [ABSTRACT FROM AUTHOR]

Fisheries harvest has pervasive impacts on wild fish populations, including the truncation of size and age structures, altered population dynamics and density, and modified habitat and assemblage composition. Understanding the degree to which harvest‐induced impacts increase the sensitivity of individuals, populations and ultimately species to environmental change is essential to ensuring sustainable fisheries management in a rapidly changing world. Here we generated multiple long‐term (44–62 years), annually resolved, somatic growth chronologies of four commercially important fishes from New Zealand's coastal and shelf waters. We used these novel data to investigate how regional‐ and basin‐scale environmental variability, in concert with fishing activity, affected individual somatic growth rates and the magnitude of spatial synchrony among stocks. Changes in somatic growth can affect individual fitness and a range of population and fishery metrics such as recruitment success, maturation schedules and stock biomass. Across all species, individual growth benefited from a fishing‐induced release of density controls. For nearshore snapper and tarakihi, regional‐scale wind and temperature also additively affected growth, indicating that future climate change‐induced warming and potentially strengthened winds will initially promote the productivity of more poleward populations. Fishing increased the sensitivity of deep‐water hoki and ling growth to the Interdecadal Pacific Oscillation (IPO). A forecast shift to a positive IPO phase, in concert with current harvest strategies, will likely promote individual hoki and ling growth. At the species level, historical fishing practices and IPO synergized to strengthen spatial synchrony in average growth between stocks separated by 400–600 nm of ocean. Increased spatial synchrony can, however, increase the vulnerability of stocks to deleterious stochastic events. Together, our individual‐ and species‐level results show how fishing and environmental factors can conflate to initially promote individual growth but then possibly heighten the sensitivity of stocks to environmental change. [ABSTRACT FROM AUTHOR]

Sustainable management of wild fisheries requires accurate delineation of reproductively isolated stocks to avoid depletion of a commercially and ecologically important resource. However, there is still a lack of reliable information on stock structure for most fishery species in New Zealand. DNA markers can assist in the delineation of stocks, but they also can provide significant insights into other areas related to the genetic diversity and the response to pressures. In this review, we first provide a detailed summary of the population genetic studies of New Zealand fish species, with a particular focus on hoki, orange roughy, snapper, ling, and blue cod. We find that genetic data is uniformly lacking for most species. We then discuss how the global shift from low resolution markers to genomics in fisheries genetics has far reaching consequences for the sustainable management of our aquatic resources, by allowing us to address multiple important pressures that wild fisheries are currently facing, and we introduce some of these briefly. We conclude by emphasising the need for a more systematic and holistic approach for the use of genomics in New Zealand fisheries management, so that the best evidence is available to inform the decisions of policy makers. [ABSTRACT FROM AUTHOR]

With growing numbers of tourist-angler arrivals globally it is increasingly important to understand how factors such as licence price may impact anglers' destination choice, and how this may differ among different source markets. Little research has focused on the impacts of discriminatory licencing systems where non-resident anglers are charged a higher fee than resident anglers. This study reports on a survey of 749 non-resident anglers in New Zealand, and explores how they have reacted to the recent introduction of a non-resident surcharge. We investigate perceived licence value within a discriminatory pricing regime, exploring behavioural and socio-demographic variables, and underlying beliefs that influence this. Findings suggest that changes to the licence fee can have some effect on angler perceptions of value and intentions to revisit. Importantly, angler reactions are not uniform, varying according to origin and angler profile. We explore and discuss the possible management implications of this heterogeneity for the application of discriminatory pricing in angling tourism. [ABSTRACT FROM AUTHOR]

New Zealand has led the world in restoration of marine fisheries since the introduction of the Quota Management System in 1986, but challenges remain in minimizing the ecosystem‐level effects of industrialized fishing. We analysed existing long‐term fisheries data sets from 1931 to 2015 in New Zealand to resolve trends in important ecological properties of major exploited fish communities. Increases in community dissimilarities of catch composition in 1931 and 1972, followed by increasing total landings, highlight major expansions of fishing grounds and exploited species during these periods. Mirroring global patterns, the remarkable rise in fishing power, demand and generation of new markets in New Zealand have all contributed to this expansion. Marine Trophic Indices (MTIs) of landings have decreased together with total catch after the year 2000, reflecting smaller catches with a higher composition of lower trophic‐level species in recent years. Differences in relative abundance of species estimated between fisheries‐dependent and fisheries‐independent data were observed, where high‐value species displayed better agreement in relative abundance between data sets. Despite being under a Quota Management System, temporal development of MTI values relative to the timing of industrial expansion of fisheries was remarkably similar to those observed in the North Sea and Brazil, with a single expansion and decline. MTI values presented better long‐term stability in the US fisheries analysed. Analysis of long‐term data and the development of well‐resolved ecological baselines will be the first step towards applying EBM to New Zealand fisheries, in keeping with global trends in fisheries management. [ABSTRACT FROM AUTHOR]

Determining the genetic structure and population dynamics of harvested species are key aspects of effective fisheries management. New Zealand scampi (Metanephrops challengeri) is a species of nethropid lobster that supports a commercial fishery on the continental shelf and slope around New Zealand. To determine the genetic structure and historical population demography of New Zealand scampi, we sequenced a 623 base-pair fragment of the mitochondrial gene cytochrome c oxidase subunit one (CO1) from 321 individuals across six widely separated sites off the coast of mainland New Zealand and the subantarctic Auckland Islands, representing much of the species' distribution. The Auckland Islands population was found to be genetically distinct from all other sampled populations, potentially resulting from an absence of continuous suitable habitat between the central-eastern South Island and the Auckland Islands. An isolation-by-distance pattern of genetic structure was also detected. With the exception of the Mercury Islands, all sampled populations showed signs of recent population expansion, potentially linked to changes in habitat availability during the glacial-interglacial cycles of the Pleistocene. We recommend that the current NZ scampi management areas and harvesting rates for each remain unchanged. [ABSTRACT FROM AUTHOR]

The growing awareness of the impact that recreational fishers can have on fish stocks has highlighted the paucity of information used to inform their management. Most of the available information on the scale and nature of recreational catch and effort has come from intermittent and labour‐intensive surveys that provide fragmented insights into often highly variable fisheries. Digital cameras offer a more cost‐effective means of continuously monitoring trends in recreational fishing effort, and it is surprising that greater use of this approach has not been made to date given its widespread use in other contexts. We share lessons learnt from four early adopter studies in New Zealand, Australia and Germany, where digital cameras have been used to monitor recreational fishing effort. Many of the challenges that we have encountered and overcome were initially unforeseen, and we suggest solutions and strategies to address these issues. We conclude that all aspects of a camera‐based monitoring system should be considered from the outset, to optimize the utility and value of the information they provide over the long term. Aspects to consider include the location and configuration of a camera system, ensuring service continuity, image quality, data storage, image interpretation and ultimately the analysis of any data collected. Robustly designed digital camera monitoring systems can be used to gain greater insight into recreational fishery dynamics, leading to more informed, responsive and effective fisheries management. [ABSTRACT FROM AUTHOR]

Abstractions and diversions are prevalent in river networks worldwide; however, specific mechanisms and measures reflecting changes in functional characteristics of aquatic assemblages in response to flow abstraction have not been well established. In particular, the influence of small takes on fish assemblages is poorly understood.Field surveys and stable‐isotope analyses were used to evaluate the impact of differing levels of flow abstraction on fish assemblage structure, and native–non‐native patterns of coexistence, associated with small surface water abstractions in four streams in New Zealand. Study design accounted for longitudinal processes (spatial autocorrelation) to isolate the effects of abstractions on fish assemblages.Reaches with reduced flows downstream of abstraction points had significantly lower fish abundances per metre of stream length, probably because of decreased habitat size, altered interspecific interactions and barriers to movement. The loss of larger fish in reaches with high abstraction resulted in shallower mass–abundance slopes and shorter stable isotope‐derived food‐chain lengths, likely to have been caused by fewer trophic links in the food web. The large fish absent from these reaches were flow‐sensitive introduced salmonids, resulting in higher relative abundances of small‐bodied native fish, probably as a result of predatory and competitive release.Quantification of metrics designed to characterize ecosystem functioning as well as abundance and species composition indicated that small water abstractions can alter both the structure and composition of stream fish assemblages and modify the outcomes of native–non‐native species interactions. Thus, a better understanding of the effects of small abstractions could be used to improve the strategic management of fish in invaded riverscapes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Several histological factors correlate with the growth of Haliotis iris. • Poor nutrition correlates with poor growth and ceroid accumulation. • Prevalence of birefringent kidney stones was higher in the slow-growing population. • Histological surveying of various tissues provided insight into the health of H. iris. The black-foot abalone (pāua), Haliotis iris , is a unique and valuable species to New Zealand with cultural importance for Māori. Abalone are marine gastropods that can display a high level of phenotypic variation, including slow-growing or 'stunted' variants. This investigation focused on identifying factors that are associated with growth performance, with particular interest in the slow-growing variants. Tissue alterations in H. iris were examined using histopathological techniques, in relation to growth performance, contrasting populations classified by commercial harvesters as 'stunted' (i.e., slow-growing) and 'non-stunted' (i.e., fast-growing) from four sites around the Chatham Islands (New Zealand). Ten adults and 10 sub-adults were collected from each of the four sites and prepared for histological assessment of condition, tissue alterations, presence of food and presence of parasites. The gut epithelium connective tissue, digestive gland, gill lamellae and right kidney tissues all displayed signs of structural differences between the slow-growing and fast-growing populations. Overall, several factors appear to be correlated to growth performance. The individuals from slow-growing populations were observed to have more degraded macroalgal fragments in the midgut, increased numbers of ceroid granules in multiple tissues, as well as increased prevalence of birefringent mineral crystals and haplosporidian-like parasites in the right kidney. The histopathological approaches presented here complement anecdotal field observations of reduced seaweed availability and increased sand incursion at slow-growing sites, while providing an insight into the health of individual abalone and sub-populations. The approaches described here will ultimately help elucidate the drivers behind variable growth performance which, in turn, supports fisheries management decisions and future surveillance programs. [ABSTRACT FROM AUTHOR]

Amphidromy is a form of migratory life history typified by the reproduction of fish in freshwater environments, the early downstream dispersal of post‐hatch larvae to marine environments, and the return of small‐bodied young juveniles to freshwater environments for growth to adulthood. Island freshwater fish communities are frequently dominated by fish species with amphidromous life histories.Amphidromous life cycles leave fish communities highly susceptible to habitat modification and disruptions to connectivity across marine and freshwater environments. This means that managing waterway connectivity is fundamental to their conservation; however, the unique and often geographically restricted amphidromous communities that characterize many small island nations have received little consideration in the development of strategies for the management of fish passage.The ecology and locomotory capabilities of amphidromous species are often poorly studied, partly because their small size at migratory life stages renders current state‐of‐the‐art in situ biotelemetry methods unsuitable. The small size of fish also means that seemingly small obstructions can severely impede migrations.The steps necessary to advance the management of fish passage for island fish communities are: curating and maintaining barrier inventories; evaluating barrier permeability; developing effective barrier mitigation options; and prioritizing restoration and conservation efforts.New methods for understanding the ecology and locomotory capabilities and behaviour of amphidromous fishes are required to advance the management of fish passage for island fish communities. Fish passage solutions that imitate natural streams, such as those promoted in new guidelines in New Zealand, may be the most effective way of improving waterway connectivity; however, integrated approaches to freshwater fish conservation that account for meta‐population dynamics, in combination with the management of fish passage, are necessary to optimize conservation outcomes for amphidromous species. [ABSTRACT FROM AUTHOR]

Estimates of connectivity are vital for understanding population dynamics and for the design of spatial management areas. However, this is still a major challenge in the marine environment because the relative contributions of factors influencing connectivity amongst subpopulations are difficult to assess. This study combined population genetics with hydrodynamic modelling (Regional Ocean Modeling System, ROMS) to assess spatial and temporal exchange of individuals among subpopulations of the New Zealand scallop, Pecten novaezelandiae , within the Coromandel fishery area open to commercial fishing. Significant genetic differentiation was revealed among subpopulations with variable levels of recruitment. Connectivity, as assessed by ROMS, was a significant explanatory variable of genetic differentiation when accounting for the spatial dependency between locations. Although additional research is needed before source-sink population dynamics can be confidently used in management, these results imply that higher yields could be available from this fishery at lower risk of over-exploitation if the fishing of each subpopulation could be tailored to its contribution to recruitment, perhaps using subpopulation catch limits. This study highlights inter-annual patterns of connectivity, the importance of combining different methods for a better prediction of population dynamics, and how such an approach may contribute to management of living marine resources. [ABSTRACT FROM AUTHOR]

Full no-take marine reserves (MRs) act as tools for biodiversity protection that reduce or remove human-induced disturbances and support the recovery of harvested species. Even if not designed specifically for fisheries management, MRs have the potential to enhance locally and distantly fished populations. This study quantified contemporary catch per unit effort (CPUE) of rock lobsters (RLs) with respect to weight and abundance inside and outside two central New Zealand MRs (Kapiti MR established in 1992, Taputeranga MR established in 2008) using commercial fishing methods (pots), and compared it to historical CPUE data. On average, mean CPUE and mean RL size were significantly greater inside than outside at both MRs. Contemporary CPUE at both MRs was approximately twice that of historical CPUE prior to the reserves being established. At Taputeranga, but not at Kapiti MR, we observed a gradient in CPUE with distance from the centre of the reserve. MRs had higher CPUE at reefs that were fully protected (entire reef in the MR) than at partially protected reefs (reef spans the MR boundary), which in turn had higher CPUE than unprotected reefs (entire reef outside the MR). Our results indicate that RL populations are responding positively to protection, but that factors such as the amount of reef area protected and proximity to reserve boundary contribute differently to RL responses. Our findings contribute to the design of MRs with respect to the habitat they protect and to a better understanding of the interactions between MRs and local fisheries. [ABSTRACT FROM AUTHOR]

The Chatham Rise is a highly productive deep-sea ecosystem that supports numerous substantial commercial fisheries, and is a likely candidate for an ecosystem based approach to fisheries management in New Zealand. We present the first end-to-end ecosystem model of the Chatham Rise, which is also to the best of our knowledge, the first end-to-end ecosystem model of any deep-sea ecosystem. We describe the process of data compilation through to model validation and analyse the importance of knowledge gaps with respect to model dynamics and results. The model produces very similar results to fisheries stock assessment models for key fisheries species, and the population dynamics and system interactions are realistic. Confidence intervals based on bootstrapping oceanographic variables are produced. The model components that have knowledge gaps and are most likely to influence model results were oceanographic variables, and the aggregate species groups 'seabird' and 'cetacean other'. We recommend applications of the model, such as forecasting biomasses under various fishing regimes, include alternatives that vary these components. [ABSTRACT FROM AUTHOR]

Marine recreational fishing is a popular pastime in a growing number of countries. Obtaining reliable harvests estimates is important to produce more accurate stock assessments and more certain management decisions, however, accurate measurement of marine recreational harvest is challenging. Previous national fisher diary surveys undertaken in New Zealand during the 1990s gave inconstant estimates of marine recreational harvests. Landline telephone listings and interviews were used to estimate the proportion of New Zealand residents who had fished during the previous 12 months and to recruit diarists. Slight changes in survey method produced variable and at times implausible results. After three years of planning and pre-testing a large-scale project was undertaken to develop a robust off-site harvest survey method and corroborate the results using with two concurrent on-site survey methods. For the off-site survey, the method was based on a national population proportionate sample of dwellings to recruit a panel of 7000 fishers and 3000 non-fishers using a face-to-face household survey. Panellists were contacted regularly by SMS and telephone for a year with a 94% completion rate. Computer assisted telephone interviews collected details of all species of fish harvested by fishing method. The second was a regional aerial-access survey that collected peak period vessel counts from the air to scale up boat-based harvest from concurrent all-day creel surveys on 45 days. Harvest estimates were generated for the most commonly encountered species, snapper, kahawai, trevally, tarakihi and red gurnard. The third and smallest survey was a combined access point survey in a sub-region using fixed and bus route creel surveys covering all significant access points on different set of random stratified days to the areal access survey. The main objective was to estimate the boat-based harvest by specialist fishers targeting scallop and rock lobster. The three concurrent surveys were designed to generate harvest estimates by fishing platform (boat or land based) at overlapping spatial scales. Harvest, in numbers of fish, were estimated independently for recreational fishers using boats. However, the on-site surveys relied on the proportion of harvest from land-based platforms provided by the off-site survey to derive total regional harvest estimates for all methods. The off-site panel survey relied on average weight data for each fish stock provided by the on-site surveys to convert harvest numbers to weight for management purposes. Choosing a sample frame and survey method that is reliable and repeatable into the future is critical to providing comparable estimates and the ability to monitor trends over time. Harvest estimates for the most common species in Fisheries Management Area 1, snapper and kahawai, were very similar. The estimates for snapper ranged from 3754 t (cv 0.06) to 3981 t (cv 0.08) and for kahawai 983 t (cv 0.32) to 942 t (cv 0.08). There were greater differences in estimates between surveys for secondary species. Each survey had independent error structures and this multi-method approach has provided valuable insight into likely sources of bias. High quality recreational harvest estimates are important to support management changes in high profile fisheries. [ABSTRACT FROM AUTHOR]

Marine protected areas (MPAs) are a critical element of fisheries management and biodiversity conservation strategies. However, MPA planning is a complex undertaking that requires consideration of ecological and other knowledge, including indigenous knowledge, as well as balancing social, cultural, and economic interests. Engaging a range of stakeholders and indigenous partners in MPA planning, establishment, and management has consistently been identified as key to successful MPA implementation. This paper interrogates MPA planning in Aotearoa New Zealand, with a focus on the role of participation and collaboration in the development and implementation of MPAs. Previous and current MPA processes were evaluated using best practice principles drawn from international MPA and other participatory process literature. Several factors hypothesised to be associated with improvements and efficiencies in the involvement of participants in MPA decision making are assessed, including aspects of participation, best available information, social learning and capacity, fair and respective process, and efficiency of administration. Processes were compared before and after introduction of the New Zealand Marine Protected Areas Policy and Implementation Plan in 2005. Areas for improvement in future evolutions of MPA planning also emerged from this research; these centre primarily on the need for inclusive and balanced participation; inclusion of multiple values and information types in MPA decision-making; time to build trust and establish shared understanding; and resourcing. These recommendations represent a conceptualisation of MPAs operating within holistic social-ecological systems frameworks that encompass more than biodiversity conservation or extractive use, potentially redefining how MPAs are conceived of, developed, implemented and valued. [ABSTRACT FROM AUTHOR]

New Zealand has rightly been admired for a new and innovative system of fishery management (the QMS) where ITQs to commercial fishers have been granted in perpetuity. By the turn of the century, the system was seen as a model for how to get the incentives right. 15 years later, it is worthwhile considering the challenges that have not been solved. The article focusses in particular on social aspects such as the labour conditions in the charter fleet, the discard problems, the relationship between the commercial and the recreational sector, the complicated procedures involved in setting and changing TACs, the involvement of Maori in fisheries management and finally on the relationship to the aquaculture sector. The main message is that strong rights to one group (the quota owners), without sorting out the rights for the other stakeholders in the marine area, have created long-term problems, which now partly paralyses the entire QMS. This also implies some serious lessons for countries who would like to copy the QMS; the system comes with a cost. [ABSTRACT FROM AUTHOR]

Managing fishing threats to populations of endemic, threatened Hector’s and Māui dolphins around New Zealand is a complex and controversial issue, underpinned by uncertain scientific knowledge. As such, it can be argued that it falls into the realm of post-normal science, which advocates transparency about uncertainties and stakeholder peer review of knowledge feeding into decision-making. This paper focuses on selected examples of modelling and risk assessment research relating to Hector’s and Māui dolphin threat management. It explores how knowledge is developed, shared and utilised by decision-makers, finding that uncertain scientific knowledge may be shared in ways that make it appear more certain, with some of the subjectivities involved in knowledge production hidden from view. Interviews with stakeholders illustrate how some stakeholders are aware of the subjectivities involved when uncertain knowledge underpins decision-making, so a lack of transparency may be leading to erosion of social trust in decisions made. This in turn can lead to a lack of support for dolphin conservation measures from key stakeholders such as the commercial fishing industry. The paper concludes that while moves towards increasing transparency and stakeholder involvement are apparent, a deeper embrace of post-normal science approaches to knowledge production and dissemination would contribute to effective dolphin threat management in New Zealand. [ABSTRACT FROM AUTHOR]

The annual catch entitlement (ACE) scheme was added to New Zealand's quota management system for fisheries in 2001. The scheme allocates quota owners an annual share of the total allowable commercial catch (TACC) in proportion to their quota holding of a particular fishstock. With ACE being transferable, the change made it simpler for fishers (permit holders) who did not own quota to purchase ACE to match catch for specific fishstocks. But to be viable, non-quota-owning (ACE reliant) fishers need access to a reliable, long-term supply of ACE. This study examines the relationships between ACE reliant purchasers and their suppliers of ACE in New Zealand's Fishing Management Area Three during the 2014-15 fishing year. The study found that most buyers and sellers of ACE form enduring relationships to their mutual benefit. This symbiotic relationship bodes well for the survival of small fishers with the expertise to land fish in an efficient manner. [ABSTRACT FROM AUTHOR]

Drivers of coastal fishery status are complex due to the broad range of stressors to which coastal species are subjected. For successful fisheries management it is essential to understand drivers of population variability. In Aotearoa New Zealand, the cultural keystone, pāua (Haliotis iris , blackfoot abalone) has undergone considerable stock declines, and stock enhancement efforts have had limited success. Multiple regression modelling, and generalised linear modelling were used to assess drivers of H. iris size and density at 50 sites around southern New Zealand. These data were gathered across six Customary fishery Protection Areas (CPAs, Mātaitai Reserves and Taiāpure Local Fisheries) across the takiwā (tribal area) of the Te Waipounamu (South Island) iwi (tribe) Ngāi Tahu. Our results suggest that H. iris density and size are driven by different factors: H. iris density was negatively correlated to time under fishing restrictions and macroalgal density, and shell length was larger in deep habitats and negatively related to the density of the gastropod, Cookia sulcata. This study highlights that fishing restrictions may not lead to an increase in population size, and that declines of cultural keystone species may have intergenerational impacts. Therefore, it is essential to empower local communities supporting management of reefs at small scales and very conservative catch levels to maintain the broad values of this species in customary protection areas while fisheries rebuilding occurs. [ABSTRACT FROM AUTHOR]

Most of the stock assessments conducted in the USA and in New Zealand are based on packages that have been developed for generic use, are well documented, and have been tested using simulation. However, this is not the case for assessments conducted in Australia and many other countries. This paper reviews all of the model-based stock assessments for Australian fisheries to evaluate how many of these assessments could have been conducted using the publicly-available stock assessment packages used widely in the USA and New Zealand. The 76 model-based assessments reflect 37% of the 2013 catch recorded in Australia's Status for Key Australian Fish Stocks Reports (or 34% of the total catch in 2013). All but 18 (or 24 if full rather than approximate age-size-structured models need to be used) of the stock assessments could have been conducted using stock assessment packages used in the United States and New Zealand. Adoption and use of packages for more stocks in Australia should increase the likelihood that results are based on correctly-coded models whose estimation performance is widely understood, reduce the time needed to conduct assessments, and speed up the peer-review process. The availability of training, manuals, and example data sets for stock assessment packages should partially address their additional complexity. Additional benefits, in terms of numbers of assessed stocks, could occur if Australian stock assessment scientists develop a forum to collaborate and share methods. These results are applicable to many other jurisdictions that undertake stock assessments. [ABSTRACT FROM AUTHOR]

Fisheries stock assessments typically determine stock-status using estimates of unfished biomass generated from fisheries dependent data. Due to limitations and biases in these data, modelled unfished estimates are reliant on assumptions regarding stock ecology. This can lead to a high degree of uncertainty in estimates of unfished biomass and can compromise sustainable management. We propose using the biomass of exploited species in no-take marine protected areas (marine reserves) as a proxy for unfished biomass to empirically assess stock status. Marine reserves provide contemporary examples of exploited populations in the absence of fishing under current conditions. Using lobster (Jasus edwardsii) potting and diver-based survey data from 2018 and 2019 we calculated fisheries relevant metrics from inside and outside two north-eastern New Zealand marine reserves. Based on marine reserve reference points, we found spawning stock catch rates and biomass of lobster in adjacent fished areas were 3 % and 2 % of unfished levels. Comparability of potting and dive survey estimates validates using dive survey data to estimate stock status, while differences in population information between survey methods highlights the limited ability of catch data to accurately inform on sub-legal abundances. Overall, our fisheries-independent approach suggests the fished population is at lower levels than latest estimates for the wider fishery and demonstrates how marine reserves can provide information on key parameters which can be incorporated into traditional stock assessments. Planning for future marine reserves should consider the value of such areas as tools to help manage fisheries in addition to protecting exploited species. [Display omitted] • Marine reserves can provide proxy estimates of unfished biomass. • Lobster population status empirically assessed relative to marine reserve reference point. • North-eastern New Zealand lobster population below 5 % proxy unfished levels • Potting and dive survey data provide comparable estimates of population status. • Dive survey data is a reliable tool to assess stock status. [ABSTRACT FROM AUTHOR]

Casal2 (pronounced Casal-two) has replaced CASAL, New Zealand’s integrated fish stock assessment package since 2002. Casal2 replicates most of CASAL’s functions such as many stocks, fisheries, and areas; age- or length-based dynamics; the use of several data sources (e.g., abundance indices, age frequencies, and tagging), but it has been extended into a generalised modelling tool and it uses more efficient programming practices and tools than CASAL. CASAL has enabled a more efficient use of resources for stock assessments, such as allowing a wider range of staff to conduct assessments, helped communication between members of the Assessment Working Groups, enabling a focus on fits of the models and model structure since standardised methods meant that model components were known and rigorous testing ensured confidence that the code base was validated. Design decisions taken at an early stage in CASAL’s development now limit its expansion. Re-coding CASAL was New Zealand’s best option to retain the benefits of CASAL and to control its own destiny over progress in new stock assessment techniques, such as easy use in management strategy evaluations. We have replicated many CASAL assessments successfully and so will release the first version of Casal 2 in 2016 as an open source package under the GPL-2.0 licence. A pre-release download of an executable, draft manual, examples, and source code are available from ftp://ftp.niwa.co.nz/Casal2/windows/Casal2.zip . [ABSTRACT FROM AUTHOR]

Australian and New Zealand fisheries are considered the best managed in the world. Much of this is due to the explicit recognition of the role of incentives in the management of fisheries, and the benefits that can be achieved through the maximisation of economic returns as a key management objective. However, while management of fisheries in Australia is supported through the application of bioeconomic models, these play virtually no role in fisheries management in New Zealand. This discrepancy is a direct result of the differing emphasis on how economic objectives are achieved, with Australia targeting maximum economic yield (MEY) while New Zealand targets maximum sustainable yield. We present case studies from Australia illustrating how bioeconomic models have been developed to support fisheries management and briefly discuss the situation in New Zealand. While economic considerations are important in both countries, we find that the explicit MEY target in Australian Commonwealth managed fisheries has been a key driver for the development and use of bioeconomic models in fisheries management. [ABSTRACT FROM AUTHOR]

The history and management of the New Zealand fishery for the rock lobster Jasus edwardsii is described. The fishery was essentially open-access to 1979, with limited input controls. Access was strictly limited from 1979 to 1989, but effort increased to a peak in 1985, when the fishery was fully exploited. Early stock assessments suggested over-exploitation. Quotas were introduced in 1990 and catches were reduced from their then mean levels to promote stock rebuilding. Subsequently, the commercial fishing industry has exercised stewardship initiatives to maintain stocks. Operational management procedures have been developed and introduced since 1996. While overall catch is similar to 1990 levels, catch per unit of effort has more than doubled. Successes and challenges for future management are discussed. [ABSTRACT FROM AUTHOR]

Many fish species rely on estuarine nursery habitats as they transition to adult life stages. Quantifying nursery value, however, requires identification of the life stages (often small and short-lived) that utilise nursery habitats, and survey methods that provide comparable estimates across habitats. We focused our surveys on post-settlement snapper (Chrysophrys auratus) using video camera deployments across habitats within a northeastern New Zealand harbour. Post-settlement snapper abundance was higher among structured habitat types relative to bare sediments, with the type of structured habitat not influential. The exception appeared to be for reef habitat (although sampling was limited). Reef sites were structurally complex, but largely inhabited by older life stages (snapper and other fish species). Overall, nursery value for snapper appears to be connected to structure, rather than structure type. This result emphasises the importance of a broadened scope to coastal fishery management, one that incorporates not just fish extraction, but also habitat maintenance or restoration. [ABSTRACT FROM PUBLISHER]

In 1986, New Zealand introduced a radical new quota management system ( QMS) based on individual transferable quotas ( ITQ) for most of its key fisheries. New Zealand's QMS focuses primarily on the management of individual fish stocks through the setting of total allowable catches ( TAC) and total allowable commercial catches ( TACC, allocated as ITQ) and is therefore essentially a single species-focussed system. However, New Zealand's Fisheries Act 1996 is designed to ' provide for utilisation while ensuring sustainability' and the obligation to ensure sustainability has led to the introduction of many measures to deal with: incidental captures of protected species (primarily marine mammals and seabirds); benthic effects caused by bottom trawl and dredge gear; changes to marine biodiversity; and the protection of habitats of particular significance for fisheries management. Together with directed fish stock management, these measures could be considered to constitute a first-level ecosystem approach to fisheries management. Many authors have advocated incremental or evolutionary approaches to the implementation of ecosystem approaches, and this paper summarizes developments in New Zealand since 1986 that build on the success of the QMS in this way. [ABSTRACT FROM AUTHOR]

New Zealand's Quota Management System (QMS) consists of a two tier operational structure: Quota shares in a fishstock provide an Annual Catch Entitlement (ACE) of the total allowable commercial catch (TACC) of the specific fishstock. Fishers operating in a multispecies fishery need a portfolio of ACE that matches the mix of their annual catch. Fishers may own quota shares, and thereby receive the needed ACE allocations or they may operate without quota shares and rely on acquiring ACE in the ACE market. Whatever the fisher's situation, it is common for fishers to both buy and sell ACE during a fishing year as they seek to balance their actual catch against ACE. The incentive to achieve a balance is strong because at year-end fishers whose catch exceeds ACE are required to pay a fee called ‘deemed value’. For many fishstocks the deemed value fee increases sharply as the percentage by which a fisher's catch exceeds their ACE increases. When no ‘unbalanced’ ACE is available for purchase, an overfished fisher may attempt to mitigate their deemed value liability by engaging in arbitrage trading in ACE whereby they buy ACE from other overfished fishers. This study examines the nature and extent of ACE arbitrage behaviour in the New Zealand quota managed fishery. The study finds that the number of fishstocks where arbitrage trading occurs is relatively small and is declining. However, sizeable deemed value mitigation transactions are still evident. [ABSTRACT FROM AUTHOR]