Zealand Coastal Waters Research Articles

The benthic and epiphytic marine dinoflagellates of Aotearoa New Zealand and Rangitāhua Kermadec Islands, an updated checklist from 2018 to 2024

ABSTRACT A checklist collating records of New Zealand’s benthic and epiphytic dinoflagellate species was published on-line in 2018 [Rhodes L, Smith KF. 2019. A checklist of the benthic and epiphytic marine dinoflagellates of New Zealand, including Rangitāhua/Kermadec Islands. N Z J Mar Freshw Res. 53:258–277. doi:10.1080/00288330.2018.1492425]. Over the last six years, seventeen species from nine genera (three newly reported genera) have been documented, including sand-dwelling species. Isolation and identification of species using traditional microscopic techniques combined with analysis of DNA sequencing data has been supplemented by high-throughput sequencing techniques (i.e. metabarcoding). Toxin data, based on liquid chromatography mass spectrometry (LC-MS/MS), and toxicity of isolates are included where applicable. Forty-two benthic and epiphytic dinoflagellate genera, including genera having benthic life stages, have now been recorded in Aotearoa New Zealand coastal waters including Rangitāhua Kermadec Islands (new record genera in bold): Adenoides , Alexandrium, Amphidinium, Archaeperidinium, Azadinium, Biecheleria, Blastodinium, Bysmatrum, Cachonina, Coolia, Crypthecodinium, Cryptoperidiniopsis, Dinophysis, Durinskia, Ensiculifera, Fukuyoa, Fragilidium, Gambierdiscus, Gonyaulax, Gymnodinium, Gyrodinium, Heterocapsa, Karenia, Karlodinium, Kryptoperidinium, Lepidodinium, Ostreopsis, Pelagodinium, Pentapharsodinium, Pfiesteria, Polarella, Prorocentrum, Protodinium, Protoperidinium, Pseudadenoides , Pseudopfiesteria, Scrippsiella, Symbiodinium, Thecadinium , Togula, Vulcanodinium and Woloszynskia.

Anti-Fouling Properties of Phosphonium Ionic Liquid Coatings in the Marine Environment.

Biofouling is the buildup of marine organisms on a submerged material. This research tests the efficacy of phosphonium ion gels comprising phosphonium monomers ([P444VB][AOT] and [P888VB][AOT]) and free ionic liquid ([P4448][AOT], [P88814][AOT]) (10 to 50 wt%), varying copper(II) oxide biocide concentrations (0 to 2 wt%), and the docusate anion [AOT]- for added hydrophobicity. The efficacy of these formulations was tested using a seachest simulator protected from light and tidal currents in New Zealand coastal waters over the summer and autumn periods. Anti-fouling performance was correlated with the hydrophobicity of the surface (water contact angle: 14-131°) and biocide concentration. Formulations with higher hydrophobicity (i.e., less free ionic liquid and longer alkyl chain substituents) displayed superior anti-fouling performance. The presence of the copper(II) biocide negatively affected anti-fouling performance via significant increases to hydrophilicity. No correlation was observed between antimicrobial activity and anti-fouling performance. Overall, phosphonium ion gels show potential for combining anti-fouling and foul release properties.

New records of Charybdis japonica (A. Milne-Edwards, 1861) (Crustacea: Decapoda: Portunidae) in the Adriatic Sea

Fifteen years after the first capture of a specimen of Charybdis japonica in the Adriatic Sea, we report the collection of two more specimens near the port of Ravenna. This swimming crab, native from the North Western Pacific, has already proved its invasive capacity in New Zealand coastal waters. Its possible establishment in the northern Adriatic lagoons may represent a treat for the local Manila clam fishery and aquaculture activities.

Suspended sediment and faecal contamination in a stormflow plume from the Hutt River in Wellington Harbour, New Zealand

ABSTRACT Muddy, faecally-contaminated river flood plumes in coastal waters are a hazard to contact recreation and bivalve shellfish consumption but are difficult to study, being episodic and transient. We used a new underway flow-through sampler in a small, fast boat, to map a flood plume within Wellington Harbour, while simultaneously sampling water in the Hutt River inflow. Faecal contamination (indexed by E.coli) correlated with flow, salinity, coloured dissolved organic matter, total suspended solids (TSS) and water clarity (light beam attenuation and visual clarity). The freshwater content of the plume agreed well with time-integrated river discharge. Despite the relatively short time-scale (<12 h) of the event, a 21% loss of TSS (particle flocculation and settling), and 30% loss in E. coli (suggesting some die-off) occurred in the plume compared to river loads. E. coli relative to TSS varied up to two orders of magnitude over a year of river flood sampling. A rapid survey of plumes combined with long-term river observations is expected to augment monitoring and inform the extension of remote sensing and modelling efforts to faecal contamination of New Zealand coastal waters.

Modelling the effects of food limitation and temperature on the growth and reproduction of the krill Nyctiphanes australis

The krill Nyctiphanes australis is the most abundant and ecologically important euphausiid in southern Australia and New Zealand coastal and shelf waters. The species lives in coastal environments which are currently susceptible to shifts in temperature and productivity. Due to its abundance, it sustains many inshore fisheries and, for this reason, determining the potential outcome of future changes in sea temperature and productivity for Nyctiphanes is important. The temperature- and food-dependence of growth and reproduction of Nyctiphanes species can be made through Dynamic Energy Budget models (DEB), developed here to quantify how temperature and food availability affects growth, fecundity, egg size, and the energetic content of the eggs throughout the krill life-span. The DEB model predictions are in good agreement with measured life-history traits for the species and show that krill grows slower during winter while females do not always reach sexual maturity when temperatures are below 8 °C and food levels are low. We found that higher temperatures and low food levels decrease the energetic content and diameter of the eggs by ∼20%, affecting the length and age at which N. australis commence reproduction. Under current scenarios of future ocean warming, these results indicate that populations of N. australis are likely to decline, with potential knock-on effects on coastal marine ecosystems and inshore fisheries.

Amino acid nitrogen stable isotopes as biomarkers of coastal phytoplankton assemblages and food web interactions

Marine phytoplankton and zooplankton face rapidly changing environments in the face of global warming and climate change. We investigated the effect of warmer water and lower pH conditions—projected for New Zealand coastal waters at the start of the next century—on both phytoplankton and zooplankton in a 20 d mesocosm experiment to determine whether amino acid stable isotopes could be used as biomarkers of environmental change. We also assessed whether key environmental drivers, such as those linked to climate change, altered the processing of amino acids at the base of the food web. Despite changes in phytoplankton biomass and community composition, we found no significant difference in either particulate organic matter (POM) bulk or amino acid-specific δ15N values, indicating that the trophic status of POM was not significantly influenced by lower pH and warming. Threonine δ15N values were the most sensitive to changes in the phytoplankton community and showed correlations with diatoms (positive) and small flagellates (negative), demonstrating potential as a biomarker for detecting changes related to these phytoplankton groups and thus making threonine a promising indirect indicator of climate change. Finally, δ15NPhe values tracked changes in the lower food web, likely due to faster turnover times, showing its valuable role as a tracer of the nitrogen baseline, even during accelerated metabolism in zooplankton.

Update of the Planktonic Diatom Genus Pseudo-nitzschia in Aotearoa New Zealand Coastal Waters: Genetic Diversity and Toxin Production.

Domoic acid (DA) is produced by almost half of the species belonging to the diatom genus Pseudo-nitzschia and causes amnesic shellfish poisoning (ASP). It is, therefore, important to investigate the diversity and toxin production of Pseudo-nitzschia species for ASP risk assessments. Between 2018 and 2020, seawater samples were collected from various sites around Aotearoa New Zealand, and 130 clonal isolates of Pseudo-nitzschia were established. Molecular phylogenetic analysis of partial large subunit ribosomal DNA and/or internal transcribed spacer regions revealed that the isolates were divided into 14 species (Pseudo-nitzschia americana, Pseudo-nitzschia arenysensis, Pseudo-nitzschia australis, Pseudo-nitzschia calliantha, Pseudo-nitzschia cuspidata, Pseudo-nitzschia delicatissima, Pseudo-nitzschia fraudulenta, Pseudo-nitzschia galaxiae, Pseudo-nitzschia hasleana, Pseudo-nitzschia multiseries, Pseudo-nitzschia multistriata, Pseudo-nitzschia plurisecta, Pseudo-nitzschia pungens, and Pseudo-nitzschia cf. subpacifica). The P. delicatissima and P. hasleana strains were further divided into two clades/subclades (I and II). Liquid chromatography-tandem mass spectrometry was used to assess the production of DA and DA isomers by 73 representative strains. The analyses revealed that two (P. australis and P. multiseries) of the 14 species produced DA as a primary analogue, along with several DA isomers. This study is the first geographical distribution record of P. arenysensis, P. cuspidata, P. galaxiae, and P. hasleana in New Zealand coastal waters.

Molecular detection and distribution of the genera Amphidoma and Azadinium (Amphidomataceae, Dinophyceae) in the coastal waters of Aotearoa/New Zealand

ABSTRACT Molecular-based approaches for harmful algal bloom species, which can be difficult to identify by light microscopy, are important tools for detecting and predicting the blooms. In this study, 84 samples from Aotearoa/New Zealand coastal waters that contained Azadinium-like cells were analysed using an Amphidomataceae real-time PCR assay. Nineteen samples were positive, and 24 Azadinium-like clonal isolates were established from these samples. Subsequently, only five isolates from one sampling point were positive using the real-time PCR assay. Four of the five isolates were genetically identified as Amphidoma languida and one as Azadinium dalianense. The field samples were analysed retrospectively using the species-specific real-time PCR assays; Am. languida was detected from the temperate areas, while Az. poporum and Az. spinosum were detected at one site. Two representative strains of each species were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), including Am. languida, which is known as toxic in the previous studies, but neither produced the currently monitored azaspiracids (AZAs). These two newly recorded species for New Zealand are important findings. The results highlight the need for more information on the spatio-temporal variations of potentially toxic Amphidomataceae species and the risk of AZAs in New Zealand coastal waters.

Correlations between environmental conditions and Vibrio parahaemolyticus or Vibrio vulnificus in Pacific oysters from New Zealand coastal waters

ABSTRACT Vibrio parahaemolyticus and Vibrio vulnificus can be found in oysters in coastal environments. Vibrio vulnificus can induce life-threatening illness when ingested with oysters, while V. parahaemolyticus usually causes self-limiting gastroenteritis. This study investigated correlations between concentrations of these Vibrio species in Pacific oysters from eight New Zealand coastal regions (2008–2017), and seawater surface temperature (SST), salinity and rainfall. In the pooled data, most (88%) of the oyster samples were collected during summer and autumn. The prevalence of V. parahaemolyticus and V. vulnificus was 85% and 15%, respectively. Vibrio vulnificus was always detected in the presence of V. parahaemolyticus. Across all regions, V. parahaemolyticus concentration positively correlated with SST (rS = 0.60), but not with salinity (rS = −0.01). Vibrio vulnificus concentration weakly correlated with SST (rS = 0.26) and salinity (rS = −0.21). Linear and generalised additive models were investigated but none were satisfactory for prediction. Salinity and SST explained < 50% of the variability in V. parahaemolyticus concentrations, indicating that other environmental or biological factors contributed. When SST, salinity and rainfall 15 days prior to harvesting were investigated for one region, SST was the best pre-harvest indicator for elevated concentrations of both Vibrio species.

Microplastics in the New Zealand green lipped mussel Perna canaliculus

Abstract Microplastics are increasingly being recognised as a potential threat to New Zealand's coastal waters, however there is limited data on abundance of microplastics in marine organisms for New Zealand. Microplastic ingestion by the iconic green-lipped mussel Perna canaliculus was assessed. Microplastics were found in Perna canaliculus from 6 out of 9 locations sampled at abundances ranging from 0 to 1.5 particles per mussel and tissue microplastic concentrations ranged from 0 to 0.48 particles g tissue -1 (wet wt). The microplastics ranged in size from 50 to 700 μm with a median diameter of 100 μm. Polyethylene was the most frequently detected polymer with fragments the most common morphotype. These results indicate that microplastics are widespread in New Zealand's coastal waters and further assessment of microplastic contamination of New Zealand coastal environments and biota is warranted.

Oceanic nomad or coastal resident? Behavioural switching in the shortfin mako shark (Isurus oxyrinchus)

Pelagic sharks are vulnerable to overfishing because of their low reproductive rates, generally low growth rates, and high catch rates in tuna and billfish fisheries worldwide. Pelagic sharks often migrate long distances, but they may also occur close to shore, making it difficult to classify their behaviour on the continuum from oceanic nomad to coastal resident. This has important implications for fishery management, which must be targeted at an appropriate spatial scale. Conventional tagging indicates that shortfin mako sharks move widely around the southwest Pacific Ocean, but there is little information on their habitat use or mobility in the region. This study deployed electronic tags on 14 mostly juvenile New Zealand mako sharks to investigate their habitat use, and the spatial and temporal scale of their movements. Movement behaviour was classified as Resident or Travel, with the former focused in New Zealand coastal waters, and the latter in oceanic waters around New Zealand and along oceanic ridges running north towards the tropical islands of Fiji, Vanuatu and New Caledonia. Sharks regularly switched between Resident and Travel behavioural states, but their residency periods sometimes lasted for several months. Sharks spent most of their time in the New Zealand Exclusive Economic Zone (median 77%, five sharks > 90%), presumably because of the high coastal productivity and access to abundant prey. These results challenge the conventional view that mako sharks are nomadic wanderers, and suggest that fishing mortality should be managed at a local as well as a regional scale.

First report of Toxoplasma gondii sporulated oocysts and Giardia duodenalis in commercial green-lipped mussels (Perna canaliculus) in New Zealand.

Pollution of marine ecosystems with the protozoan parasites Toxoplasma gondii, Cryptosporidium spp. and Giardia duodenalis can be studied using bivalve shellfish as biosentinels. Although evidence suggests that these parasites are present in New Zealand coastal waters, the extent of protozoal pollution has not been investigated. This study used optimised molecular methods to detect the presence of Cryptosporidium spp., G. duodenalis and T. gondii in commercially sourced green-lipped mussel (Perna canaliculus), an endemic species found throughout coastal New Zealand. A nested polymerase chain reaction was validated for detection of T. gondii DNA and applied to 104 commercially sourced mussels. Thirteen mussels were positive for T. gondii DNA with an estimated true prevalence of 16.4% using Bayesian statistics, and the presence of T. gondii in mussels was significantly associated with collection during the summer compared with that in the winter (P = 0.003). Consumption of contaminated shellfish may also pose a health risk for humans and marine wildlife. As only sporulated T. gondii oocysts can be infectious, a reverse transcriptase-polymerase chain reaction was used to confirm presence of a sporozoite-specific marker (SporoSAG), detected in four mussels. G. duodenalis assemblage B, known to be pathogenic in humans, was also discovered in 1% mussels, tested by polymerase chain reaction (n = 90). Cryptosporidium spp. was not detected in the sampled mussel haemolymph. Results suggest that New Zealand may have high levels of coastal contamination with T. gondii, particularly in summer months, and that naturally exposed mussels can ingest and retain sporulated oocysts, further establishing shellfish consumption as a health concern.

Temperature and UV light affect the activity of marine cell-free enzymes

Abstract. Microbial extracellular enzymatic activity (EEA) is the rate-limiting step in the degradation of organic matter in the oceans. These extracellular enzymes exist in two forms: cell-bound, which are attached to the microbial cell wall, and cell-free, which are completely free of the cell. Contrary to previous understanding, cell-free extracellular enzymes make up a substantial proportion of the total marine EEA. Little is known about these abundant cell-free enzymes, including what factors control their activity once they are away from their sites (cells). Experiments were run to assess how cell-free enzymes (excluding microbes) respond to ultraviolet radiation (UVR) and temperature manipulations, previously suggested as potential control factors for these enzymes. The experiments were done with New Zealand coastal waters and the enzymes studied were alkaline phosphatase (APase), β-glucosidase, (BGase), and leucine aminopeptidase (LAPase). Environmentally relevant UVR (i.e. in situ UVR levels measured at our site) reduced cell-free enzyme activities by up to 87 % when compared to controls, likely a consequence of photodegradation. This effect of UVR on cell-free enzymes differed depending on the UVR fraction. Ambient levels of UV radiation were shown to reduce the activity of cell-free enzymes for the first time. Elevated temperatures (15 °C) increased the activity of cell-free enzymes by up to 53 % when compared to controls (10 °C), likely by enhancing the catalytic activity of the enzymes. Our results suggest the importance of both UVR and temperature as control mechanisms for cell-free enzymes. Given the projected warming ocean environment and the variable UVR light regime, it is possible that there could be major changes in the cell-free EEA and in the enzymes contribution to organic matter remineralization in the future.

Molecular Identification of Gambierdiscus and Fukuyoa (Dinophyceae) from Environmental Samples.

Ciguatera Fish Poisoning (CFP) is increasing across the Pacific and the distribution of the causative dinoflagellates appears to be expanding. Subtle differences in thecal plate morphology are used to distinguish dinoflagellate species, which are difficult to determine using light microscopy. For these reasons we sought to develop a Quantitative PCR assay that would detect all species from both Gambierdiscus and Fukuyoa genera in order to rapidly screen environmental samples for potentially toxic species. Additionally, a specific assay for F. paulensis was developed as this species is of concern in New Zealand coastal waters. Using the assays we analyzed 31 samples from three locations around New Zealand and the Kingdom of Tonga. Fourteen samples in total were positive for Gambierdiscus/Fukuyoa and two samples were also positive using the F. paulensis assay. Samples from the Kermadec Islands were further characterized using high-throughput sequencing metabarcoding. The majority of reads corresponded to Gambierdiscus species with three species identified at all sites (G. australes, G. honu and G. polynesiensis). This is the first confirmed identification of G. polynesiensis, a known ciguatoxin producer, in New Zealand waters. Other known toxin-producing genera were also detected, included Alexandrium, Amphidinium, Azadinium, Dinophysis, Ostreopsis, and Prorocentrum.

Review and phylogeny of the New Zealand hagfishes (Myxiniformes: Myxinidae), with a description of three new species

Hagfishes from New Zealand are reviewed and a phylogeny proposed using morphological and genetic data (DNA sequences of cytochrome c oxidase subunit I gene, COI, and the small subunit RNA, 16S). Eptatretus cryptus sp. nov. was previously confused with Eptatretus cirrhatus (Forster in Bloch & Schneider, 1801) because of their similar morphology, and is found from the Three Kings Islands to Stewart Island and in the eastern part of the Chatham Rise (at depths of 96–922 m). Eptatretus poicilus sp. nov. is endemic to the Three Kings Islands, where it is common and associated with soft sediment and deep-sea coral-sponge habitats (114–842 m). Neomyxine caesiovitta sp. nov. is a slender hagfish found along the east coast of the North Island south to the Chatham Rise (430–1083 m). A neotype is erected for E. cirrhatus (type locality: Breaksea Sound, Fiordland), occurring widely in New Zealand coastal, shelf, and slope waters (1–922 m), but not at the Three Kings Islands. Eptatetrus goliath Mincarone & Stewart, 2006, Neomyxine biniplicata (Richardson & Jowett, 1951), and Nemamyxine elongata Richardson, 1958 are further described using additional material. Rubicundus eos (Fernholm, 1991) is still only known from the holotype (type locality: Challenger Plateau). Genetic results showed that the New Zealand Eptatretus species form a monophyletic group within the subfamily Eptatretinae, indicating likely speciation from a single common ancestor within the area. Eptatretus poicilus sp. nov. is the sister species of E. cirrhatus, and E. cryptus sp. nov. is closely associated with the clade formed by these two species. Eptatretus goliath is most closely associated with Eptatretus minor Fernholm & Hubbs, 1981 (Gulf of Mexico), these two species basally diverging within New Zealand hagfishes. The endemic genus Neomyxine forms a well-supported monophyletic group of as yet uncertain position within the phylogenetic tree. A key to the New Zealand hagfishes, fresh colour photographs, distribution maps, and in situ video recordings are presented. © 2015 The Linnean Society of London

A Review of the Research on the Australasian Sea Cucumber,Australostichopus mollis(Echinodermata: Holothuroidea) (Hutton 1872), with Emphasis on Aquaculture

ABSTRACT The Australasian sea cucumber, Australostichopus mollis, has an extensive distribution; it is found along the coast of southern Australia and throughout New Zealand's coastal waters. This species is very similar in appearance to the highly prized Japanese sea cucumber, Apostichopus japonicus, and as a consequence has attracted increasing interest for commercial fishing and aquaculture. The sea cucumber A. mollis currently supports a small commercial fishery in New Zealand of 10–20 t/y. A review of the research on this sea cucumber indicates that the development of aquaculture for this species has been impeded by a general lack of background biological knowledge. Future research needs to be targeted toward resolving the constraints the aquaculture industry is facing for this species, including reliable methods for broodstock conditioning, mass larval rearing, juvenile nutrition and husbandry, as well as development of effective grow-out technology and identification of suitable farming sites.

The genus Pseudo-nitzschia (Bacillariophyceae) in New Zealand: analysis of the last decade's monitoring data

The diatom genus Pseudo-nitzschia blooms throughout New Zealand's coastal waters. More than a decade of monitoring data were analysed in this study and seasonality was a significant factor in the appearance of Pseudo-nitzschia blooms. Austral spring and summer were the main bloom periods, although there were regional differences. Between January 2000 and August 2011, 8.4% of 29,000 seawater samples analysed for Pseudo-nitzschia exceeded the voluntary trigger level for biotoxin testing (10×104 cells l−1), and these were analysed by fluorescent in situ hybridisation (FISH) assays. Pseudo-nitzschia fraudulenta and P. pseudodelicatissima (low domoic acid [DA] producers) were the dominant bloom formers throughout New Zealand (each contributing 25%) followed by the highly toxic P. australis (10%). Shellfish flesh testing for DA was triggered on 8477 occasions between 2000 and 2011, but no samples exceeded the regulatory limit (20 mg/kg); the maximum concentration was 13 mg/kg (Marlborough Sounds, mid-winter 2010).

Molecular phylogenetics of the genus Physalia (Cnidaria: Siphonophora) in New Zealand coastal waters reveals cryptic diversity

Physalia is a genus of pelagic colonial hydrozoans often known by common names such as ‘Portuguese-man-of-war’ or ‘bluebottle’. Siphonophore systematists generally recognise only a single species in this genus, Physalia physalis, however the name Physalia utriculus is also still in common use, which has led to considerable taxonomic confusion. With some morphological variation between global regions there is the possibility that this genus holds a substantial amount of cryptic variation. We seek to examine the genetic structure of Physalia present in New Zealand coastal waters. Fifty-four specimens collected from 13 locations around New Zealand and Australia were sequenced for both mitochondrial cytochrome c oxidase I (COI) and the first internal transcribed spacer (ITS1) of the nuclear ribosomal cistron. Sequences were analysed using maximum likelihood and split decomposition neighbour networks to determine conflict between clans (the unrooted analog of clades). Three clans were identified from both the COI and ITS sequences. The results are complex and clans are not consistent between the two genes. Nevertheless, it seems that there is substantial cryptic diversity amongst Physalia present in New Zealand coastal waters.

Determining factors that influence the dispersal of a pelagic species: A comparison between artificial neural networks and evolutionary algorithms

Because of increasing transport and trade there is a growing threat of marine invasive species being introduced into regions where they do not presently occur. So that the impacts of such species can be mitigated, it is important to predict how individuals, particularly passive dispersers are transported and dispersed in the ocean as well as in coastal regions so that new incursions of potential invasive species are rapidly detected and origins identified. Such predictions also support strategic monitoring, containment and/or eradication programs. To determine factors influencing a passive disperser, around coastal New Zealand, data from the genus Physalia (Cnidaria: Siphonophora) were used. Oceanographic data on wave height and wind direction and records of occurrences of Physalia on swimming beaches throughout the summer season were used to create models using artificial neural networks (ANNs) and Naϊve Bayesian Classifier (NBC). First, however, redundant and irrelevant data were removed using feature selection of a subset of variables. Two methods for feature selection were compared, one based on the multilayer perceptron and another based on an evolutionary algorithm. The models indicated that New Zealand appears to have two independent systems driven by currents and oceanographic variables that are responsible for the redistribution of Physalia from north of New Zealand and from the Tasman Sea to their subsequent presence in coastal waters. One system is centred in the east coast of northern New Zealand and the other involves a dynamic system that encompasses four other regions on both coasts of the country. Interestingly, the models confirm, molecular data obtained from Physalia in a previous study that identified a similar distribution of systems around New Zealand coastal waters. Additionally, this study demonstrates that the modelling methods used could generate valid hypotheses from noisy and complicated data in a system about which there is little previous knowledge.

Marine Biodiversity of Aotearoa New Zealand

The marine-biodiversity assessment of New Zealand (Aotearoa as known to Māori) is confined to the 200 nautical-mile boundary of the Exclusive Economic Zone, which, at 4.2 million km2, is one of the largest in the world. It spans 30° of latitude and includes a high diversity of seafloor relief, including a trench 10 km deep. Much of this region remains unexplored biologically, especially the 50% of the EEZ deeper than 2,000 m. Knowledge of the marine biota is based on more than 200 years of marine exploration in the region. The major oceanographic data repository is the National Institute of Water and Atmospheric Research (NIWA), which is involved in several Census of Marine Life field projects and is the location of the Southwestern Pacific Regional OBIS Node; NIWA is also data manager and custodian for fisheries research data owned by the Ministry of Fisheries. Related data sources cover alien species, environmental measures, and historical information. Museum collections in New Zealand hold more than 800,000 registered lots representing several million specimens. During the past decade, 220 taxonomic specialists (85 marine) from 18 countries have been engaged in a project to review New Zealand's entire biodiversity. The above-mentioned marine information sources, published literature, and reports were scrutinized to give the results summarized here for the first time (current to 2010), including data on endemism and invasive species. There are 17,135 living species in the EEZ. This diversity includes 4,315 known undescribed species in collections. Species diversity for the most intensively studied phylum-level taxa (Porifera, Cnidaria, Mollusca, Brachiopoda, Bryozoa, Kinorhyncha, Echinodermata, Chordata) is more or less equivalent to that in the ERMS (European Register of Marine Species) region, which is 5.5 times larger in area than the New Zealand EEZ. The implication is that, when all other New Zealand phyla are equally well studied, total marine diversity in the EEZ may be expected to equal that in the ERMS region. This equivalence invites testable hypotheses to explain it. There are 177 naturalized alien species in New Zealand coastal waters, mostly in ports and harbours. Marine-taxonomic expertise in New Zealand covers a broad number of taxa but is, proportionately, at or near its lowest level since the Second World War. Nevertheless, collections are well supported by funding and are continually added to. Threats and protection measures concerning New Zealand's marine biodiversity are commented on, along with potential and priorities for future research.