Quantifying the relative intensity of fishing on New Zealand seamounts

New Zealand seamounts support major fisheries for several deepwater fish species, including orange roughy (Hoplostethus atlanticus) and smooth oreo (Pseudocyttus maculatus). Although a high proportion of features in the depth range 500–1000 m have been fished, very little is known about the ecological impacts of bottom trawling on seamounts. The potential impact is likely to be influenced by the spatial extent and frequency of fishing. A new index is presented to assess the relative intensity of trawling on New Zealand seamounts. The fishing effects index (FEI) incorporates information on the density of fishing on the seamount as a proportion of the seabed area and also on tow direction. Detailed fisheries data from more than 250 000 tows were examined to calculate FEI for New Zealand seamounts. The most intensively fished seamounts were on the south Chatham Rise, an area characterised by a large number of relatively small features which were fished serially for orange roughy in the 1980s and 1990s. Other seamounts with high FEI were on the north Chatham Rise, Challenger Plateau, and off the east coast of the North Island. A range of sensitivity analyses indicated that the general rankings of seamounts were relatively robust to the choice of arbitrary thresholds used to assign tows to seamounts.     

Two new species of hatschekia (copepoda,dichelesthiidae) from New Zealand waters

Two new species of Hatschekia Poche, 1901 are described from New Zealand specimens of Allomycterus jaculiferus (Cuvier, 1818) and Lepidopus caudatus (Euthrasen, 1878) respectively. Comment is made on the need for revision within the genus Hatschekia.     

Spatial conflicts in New Zealand fisheries: The rights of fishers and protection of the marine environment

New Zealand fisheries legislation provides commercial fishing rights to holders of individual transferable quota (ITQ). The settlement of fisheries claims against the Crown by Mäori, New Zealand's indigenous people, brought about the transfer of ITQ holdings to Mäori, and an obligation on the Crown to recognise and provide for indigenous (customary) fishing rights over fishing grounds and other areas that have been of special significance to Mäori. Some types of customary fishing areas exclude commercial fishing and could affect recreational fishing. Fisheries legislation requires that regulatory measures be put in place to avoid, remedy or mitigate the adverse effects of fishing. The Government also aims to protect marine biodiversity by having 10% of New Zealand waters in some form of protection by 2010. The legislative processes for protecting the marine environment and establishing customary fishing areas include assessment of effects on fishing rights. This paper explores the conflicts that arise from legislative obligations to uphold the rights of fishers, to sustain fishstocks and to protect the marine environment. The paper concludes that inconsistent legislative obligations and their disparate processes have led to spatial conflicts and a race for the allocation of space. Legislative obligations need to be integrated to maintain a balance between use of fisheries resources and protection of the marine environment.     

Maintaining a balance between resource utilisation and protection of the marine environment in New Zealand

New Zealand's brief history of human habitation has led to widespread and often irreversible change in the biophysical environment. Most of the wetlands were drained and de-forestation led to major gully and channel erosions and high amounts of sediment yield in the estuarine and marine environments. The scale of land-based effects on marine species is indeterminable. The legislation for managing the land–sea interface is widely acknowledged as having fallen short of its full potential. After the 2008 general election the new government commenced review of this legislation while consideration was given to ‘unlocking New Zealand's energy potential’ as a key component to an export-led economic recovery. The government is promoting oil, gas and mineral exploration on land and at sea. The government is also enacting boundaries that extend continental shelf jurisdiction. These developments may lead to further progress on an integrated system that covers all aspects of marine management that began in 2000. In any case, New Zealanders face important decisions regarding the tradeoffs between further resource utilisation and environmental protection. This article contributes to the discussion on integrated management to maintain a balance between utilisation and protection and does not reflect the view of the Ministry of Fisheries.     

Checklist of the planktonic marine dinoflagellates of New Zealand

ABSTRACT

Planktonic dinoflagellate records for New Zealand are substantial due to intense monitoring programmes that have taken place on behalf of New Zealand’s biotoxin regulators and the shellfish industry since 1993. At that time a Karenia bloom caused human illnesses and shellfish harvesting ceased until monitoring was instigated. Phytoplankton records are based on morphological identification using light microscopy but are backed up by government funded research programmes which implement techniques such as electron microscopy, DNA sequencing, molecular detection assays and high throughput sequencing of environmental DNA. This checklist will support management of aquaculture industries, recreational shellfish harvests and environmental health initiatives. Some genera are considered benthic or epiphytic, but have lengthy planktonic life stages. Forty-five genera in the class Dinophyceae Fritsch are reported: Akashiwo, Alexandrium, Amphidinium, Amylax, Azadinium, Biecheleria, Bysmatrum, Cachonina, Cochlodinium (synonym: Margalefidinium), Coolia, Dicroerisma, Dinophysis, Diploneis, Diplopsalis, Fragilidium, Glenodinium, Gonyaulax, Gymnodinium, Gyrodinium, Heterocapsa, Karenia, Karlodinium, Lepidodinium, Lingulodinium, Margalefidinium, Ostreopsis, Oxyphysis, Pelagodinium, Pentapharsodinium, Phalacroma, Podolampas, Polarella, Polykrikos, Prorocentrum, Protodinium, Protoodinium, Protoperidinium, Pseliodinium, Scrippsiella, Takayama, Togula, Torodinium, Tripos, Vulcanodinium, Wolosynska. Other genera belonging to the Infraphylum Dinoflagellata also occur in New Zealand waters. They are not in the list but include Noctiluca, Pronoctiluca and Spatulodinium (Class: Noctilucophyceae) and Oxyrrhis (Class: Oxyrrhidophyceae).     

The influence of habitat availability on juvenile fish abundance in a northeastern New Zealand estuary

Management of fish populations is often focused on the exploitation of adult fish. Maintaining the habitat requirements of all life stages may also be an important consideration. We investigated the value of structured habitat to juvenile fishes within a northeastern New Zealand harbour using artificial seagrass units (ASUs). Specifically, we deployed ASUs across treatments with high vs. low habitat manipulations. We hypothesised that if the abundance of recruiting juvenile fishes was greater on the high habitat availability treatments this would suggest that the availability of habitat was limiting juvenile fish abundance. Our analyses were focused on the four most abundant fishes that settled on our ASUs: snapper (Pagrus auratus); spotty (Notolabrus celidotus); trevally (Pseudocaranx dentex); and an assemblage of pipefish species. For snapper, spotty and pipefish, abundance was greater on the high habitat availability treatments. This result would be unlikely to occur if the availability of juvenile fishes was limiting, suggesting that juvenile fish abundance is more likely to be limited by habitat. In terms of spatial gradients, spotty abundance and size increased with distance into the harbour. The spatial gradient present for spotty indicates the importance of placing the habitat dependency of juvenile fish into a landscape context. Overall, these results demonstrate that maintaining structured habitats may be an important consideration for some valuable inshore fish populations in northeastern New Zealand.     

The application of multivariate statistical methods to phytoplankton counts from the Hauraki Gulf,New Zealand

The phytoplankton population from a station in the Jellicoe Channel area of the Hauraki Gulf, New Zealand, was fairly constant, in terms of total population and species composition, throughout the year. Correspondence analysis enabled us to identify 3 groups of species. The largest of these comprised the core species which were present most of the time and included some, such as the coccolithophores, with a strongly seasonal occurrence. The species in the second group were mainly large centric diatoms and appeared for short periods during the winter months, apparently brought in by incursions of oceanic water. The third group of species occurred between April 1970 and October 1971 when there was a period of unusually warm weather: the winds were lighter and more often blowing onshore and this perhaps led to warmer, less nutrient‐rich surface waters being brought into the Gulf.     

The demise of the small fisher? A profile of exiters from the New Zealand fishery

New Zealand's exclusive economic zone encompasses a significant fishery that is managed by a market-based quota management system. Since the introduction of this regime in 1986 over 3000 fishers have exited the industry. These exiters are predominantly small-scale fishers. This study profiles a sample of the exiters, using information provided on the Ministry of Fisheries database and through a questionnaire sent to the exiters themselves. The profile includes information on the scale of exiters, their typical methods of fishing, the importance of time and exit price to the exit decision, and post-exit employment outcomes.     

Two new species of the marine genus Limnodriloides and a record of Tubificoides fraseri Brinkhurst (Oligochaeta: Tubificidae) from New Zealand

We characterised seasonal and ontogenetic changes in diet and prey energy density of rainbow trout (Oncorhynchus mykiss) in Lake Rotoiti, New Zealand, to better understand the prey requirements of trout in central North Island lakes. Common smelt (Retropinna retropinna) was the dominant prey item of rainbow trout larger than 200 mm (77.8% of diet by weight), followed by kōura (freshwater crayfish Paranephrops planifrons; 6.3%), common bully (Gobiomorphus cotidianus; 5.5%), and kōaro (Galaxias brevipinnis; 3.4%). Juvenile rainbow trout (<200 mm) consumed amphipods, aquatic and terrestrial insects, oligochaetes, tanaid shrimps, and smelt. Trout consumed kōaro only in autumn and winter; consumption of other species did not vary seasonally. The maximum size of smelt consumed increased with increasing trout size, but trout continued to consume small smelt even as large adults. Consumption of larger prey items (kōaro and kōura) also increased with increasing trout size. This study indicates the importance of smelt for sustaining rainbow trout populations, as predation on other species was relatively low. These findings provide a basis for bioenergetic modelling of rainbow trout populations in lakes of the central North Island of New Zealand.     

An examination of the trout population of five lakes near Rotorua,New Zealand

Five lakes, varying from 10 to 100 hectares in area and each containing an existing population of Salmo gairdneri, were gill‐netted and stocked with tagged fish each year from 1960 to 1965 to determine the effect of regular stocking on the size and numbers of fish present. There was little natural spawning of trout in most of the lakes. Growth in length and weight of tagged fish was computed and an annual estimate of population calculated from the netting returns. Appendices give details of the statistical analyses of the data.

Fish production has been correlated with the trophic status of the lakes as indicated by their temperature and oxygen content. There was no clear relationship between lake size and trout production but trout production decreased as the environment became more eutrophic. Results also showed a close inverse relationship between numbers supported and average weight achieved by the trout. It is concluded that the angling potential of local lakes can be maintained despite the eutrophication resulting from intensive agricultural development of the catchments. These lakes will produce large‐sized fish if the trout population is kept relatively small.

Loss in weight in brown and rainbow trout as a result of spawning activities in local lakes and streams was found to be similar. Both male and female fish lost between 22 and 40 percent of their weight over a spawning period. This probably accounted for the observed low‐condition factor among older fish in the lake populations.     

Compliance costs and the small fisher: A study of exiters from the New Zealand fishery

Over 3000 predominantly small-scale fishers have exited the New Zealand's quota management system (QMS) between its inception in 1986 and 2000. This study, based on the Ministry of Fisheries database and a questionnaire sent to the exiters, establishes that compliance costs in general, and those specifically related to the QMS, were one of the most consistent reasons for exit. Uncertainty about future QMS policy and the high cost of quota were also significant factors. It appears that the small fishers’ perception of high compliance cost can be supported by industry data.     

Distribution and relative density of cetaceans in the Hauraki Gulf,New Zealand

Understanding species distributions, and how they change in space and time, is vital when prioritising conservation or management initiatives. We assessed the distribution and density patterns of common dolphins (Delphinus sp.), bottlenose dolphins (Tursiops truncatus) and Bryde’s whales (Balaenoptera edeni) in the Hauraki Gulf, New Zealand. Dedicated boat-based surveys were conducted in the inner Hauraki Gulf (IHG) and off Great Barrier Island (GBI) during 2010–2012. Generalised linear models were used to investigate temporal changes in relative densities and kernel density estimation was implemented to examine spatial trends. Common dolphins were widely distributed during all seasons, with higher densities observed during winter and spring in the IHG but during autumn off GBI. There was inter-annual variation in Bryde’s whale distribution, with high densities recorded off GBI in 2011. Bottlenose dolphins were infrequently sighted in the IHG but regularly encountered off GBI, with the highest densities during spring and summer.     

Biological and physical controls on dissolved dimethylsulfide over the north-eastern continental shelf of New Zealand

Data presented in this paper are part of an extensive investigation of the physics of cross-shelf water mass exchange in the north-east of New Zealand and its effect on biological processes. Levels of dissolved dimethylsulfide (DMS) were quantified in relation to physical processes and phytoplankton biomass. Measurements were made at three main sites over the north-east continental shelf of New Zealand's North Island during a current-driven upwelling event in late spring 1996 (October) and an oceanic surface water intrusion event in summer 1997 (January). DMS concentrations in the euphotic zone ranged between 0.4 and 12.9 nmol dm⁻³. Integrated water column DMS concentrations ranged from 33 to 173 μmol m⁻² in late spring during the higher biomass (15–62 Chl-a mg m⁻²) month of October, and from 25 to 38 μmol m⁻² in summer during the generally lower biomass (16–42 Chl-a mg m⁻²) month of January. We observed high levels of DMS in the surface waters at an Inner Shelf site in association with a Noctiluca scintillans bloom which is likely to have enhanced lysis of DMSP-producing algal cells during phagotrophy. Integrated DMS concentrations increased three-fold at a Mid Shelf site over a period of a week in conjunction with a doubling of algal biomass. A high correlation (r²=0.911, significant <0.001) of integrated DMS and chlorophyll-a concentrations for compiled data from all stations indicated that chlorophyll-a biomass may be a reasonable predictor of DMS in this region, even under highly variable hydrographic conditions. Integrated bacterial production was inversely correlated to DMS production, indicating active bacterial consumption of DMS and/or its precursor.     

New Zealand seafood firm competitiveness in export markets: The role of the quota management system and aquaculture legislation

New Zealand's quota management system (QMS) was implemented in 1986 to address problems caused by a regulated open entry management system in place for the previous two decades. Excess capacity in the inshore fisheries caused several stocks to become depleted and conflicts to intensify between fishing sectors. The allocation of individual transferable quota (ITQ) was viewed as the best way to improve efficiency within the over-capitalised inshore fisheries and provide incentives for developing the deepwater fisheries. The expected benefits of the QMS fit with the political climate at that time, as the government was using market forces to address the deteriorating economy. This article outlines the results of a research project that involved four medium to large-sized, highly vertically integrated New Zealand seafood firms. The purpose of the project was to identify these firms’ sources of competitiveness in export markets and the process the firms used to develop sources of competitiveness, while adapting to rapid and radical changes to the political and business environment and transformation of the fisheries management system. The project's results show that the basis to seafood firm competitiveness is the security of supply to the fisheries resource provided by the QMS and aquaculture legislation. The project also outlines the role that government policies have in sustaining firm- and industry-level competitiveness. This article contributes to the broader discussion on the application of ITQ and other types of long-term access rights to the management of fisheries and does not express the views of the Ministry of Fisheries.     

New species of benthopelagic copepod Xantharus (Calanoida: Scolecitrichidae) from the upper slope,eastern central New Zealand

Xantharus Andronov, 1981 is reported, for the first time from New Zealand, from the upper slope (306 m) off the southeastern coast of North Island (41°04.10′S, 176°22.05′E). Xantharus cryeri n. sp. females differ from the three known species by a combination of characters: antennules that extend to the distal border of pedigerous somite 2; ancestral segment XVIII of the antennule with 1 seta; mandible basis with 3 setae; maxilla endite 1 with 5 setae; leg 1 basis with inner distal border lined with small spinules; and leg 5 is squat, with all segments as long as wide and the 2 terminal spine‐like extensions of the terminal segment approximately as long as the articulated, inner, subterminal spine.     

Fishing the last frontier: The introduction of the marine aquarium trade and its impact on local fishing communities in Papua New Guinea

Papua New Guinea has sometimes been called the world's last frontier for relatively undamaged coral reefs and their resources. In 2007, the country joined its neighbours in the marine aquarium trade. By licensing a private company, Papua New Guinea tried an alternative approach to the introduction of this activity. Under the so-called SeaSmart Programme, over 100 fishers were trained in sustainable collection techniques and handling of organisms, until the programme was shut down in 2010, and replaced by its successor, EcoAquariums PNG. This article contains the first study on the introduction of the marine aquarium trade into Papua New Guinea. It evaluates the overall outcomes of the SeaSmart Programme, lists targeted species, and their prices. The main focus is on the local collectors, and on the impacts of this new activity on them and their communities. Benefits from collecting marine ornamentals are assessed and their contribution to household income is quantified. Perceptions on non-financial benefits of the SeaSmart Programme are also gathered. The empirical work was carried out between September 2010 and February 2011 in the Central Province of Papua New Guinea. A total of 199 fishers including 44 aquarium fishers were interviewed in eight different communities in the Central Province of Papua New Guinea. The results show that marine aquarium fishing does provide benefits to local resource collectors, but also that this “sustainable” way of collecting of marine ornamentals might lead to some depletion.     

Phytoplankton biornass in relation to the surface hydrography of southern New Zealand and possible effects on the food chain

Abstract

The surface distribution of salinity, temperature, nitrate‐nitrogen (N0₃‐N), and chlorophyll a in the southern New Zealand, Foveaux Strait region in February 1977, 1978, 1979, and 1980 was highly variable. The source of new nitrogen appears to be incursions of high‐salinity water west and east of Stewart Island. Although it seems likely that the source of this high‐nutrient, high‐salinity water is vertical, a horizontal advective source cannot be ruled out The chlorophyll a content of surface waters was not related directly to the NO3‐N concentrations. This lower food chain variability may be linked to variability in economically important species. Oysters grew twice as fast in the summer of 1978/79 as they did in 1979/80. But the mean chlorophyll a values were very similar for February of both years (2.5 and 2.2 μg 1^?1, respectively). The elevated NO₃‐N levels in 1979 may have resulted in much higher phytoplankton levels later that summer and resulted in the higher oyster growth rate that year. The mechanisms driving this variability have yet to be determined.     

Long-term effects of a toxic algal bloom on subtidal soft-sediment macroinvertebrate communities in Wellington Harbour, New Zealand

The long-term effects (>1 year) of a naturally occurring toxic plankton bloom (Karenia brevisulcata) on subtidal benthic macroinvertebrate communities were investigated in Wellington Harbour, a semi-enclosed temperate embayment in New Zealand. For 3 years communities were sampled at three different sites in the harbour. Analyses revealed that community recovery following the bloom was site-specific. Multivariate analyses indicated that at one site community composition was approaching recovery 3 years post-bloom. At the second site, a sequential recovery process was indicated, whereas at the third site the community composition oscillated from year to year, but did not show any signs of a sequential recovery process. The nature of the hydrodynamic regime was identified as a major factor influencing the observed recovery processes. Communities exposed to an active hydrodynamic regime were less affected by the bloom and differed little in their composition pre- and post-bloom, as they were naturally in a perpetual state of recovery as indicated by a dominance of r-selected species. The community at the hydrodynamically less active site was more affected by the bloom and exhibited temporal differences in composition consistent with successional models. Complete recovery to a pre-disturbance climax community dominated by K-selected species is likely to take 4–5 years, if not interrupted by other disturbances. Given the increased occurrence of harmful algal blooms worldwide, more monitoring and manipulative studies are needed to further evaluate the effects of such disturbances on macrobenthic communities.     

Relationships between molecular bacterial diversity and chemistry of groundwater in the Wairarapa Valley,New Zealand

Groundwater plays an important role in New Zealand water supplies and hence monitoring activities are conducted regularly. Most monitoring programmes aim to evaluate groundwater chemistry and almost completely overlook the microbial component in this ecosystem. In our present study, the bacterial community structure of groundwater in the Wairarapa Valley was examined using the terminal restriction fragment length polymorphism (T-RFLP), and relationships between bacterial community structure and groundwater chemistry, aquifer confinement and groundwater usage were explored. In addition, the results from this study were compared with a previous T-RFLP survey of the same area in an attempt to detect changes in bacterial community structure over time. The data obtained suggested that bacterial community structure was related to groundwater chemistry, especially to redox conditions. Species composition showed minimal variation over time if groundwater chemistry remained unchanged. These findings reflect the potential of using bacterial communities as biological indicators to evaluate the health of groundwater ecosystems. We suggest that it is important to include this type of broad bacterial diversity assessment criteria into regular groundwater monitoring activities.