Zealand Waters Research Articles

New Zealand southern right whale (Eubalaena australis; Tohorā nō Aotearoa) behavioural phenology, demographic composition, and habitat use in Port Ross, Auckland Islands over three decades: 1998–2021

Changes in habitat availability and prey abundance are predicted to adversely influence survival and reproduction of wildlife in the Southern Ocean. Some populations of southern right whale (SRW; Eubalaena australis) are showing dramatic changes in habitat use. Surveys were undertaken in the austral winters of 2020 and 2021 at the key nursery and socialising ground for New Zealand SRWs: Port Ross, Auckland Islands, with 548 encounters and 599 skin biopsy samples collected. Data from these two surveys spanned peak periods of use and were used to test the hypothesis there have been shifts in the phenology, demographic composition and behaviour of SRWs using the Auckland Islands over the past three decades. The behavioural phenology and demographic composition of SRW resembles that observed in the 1990s. In contrast, the proportion of groups containing cow-calf pairs increased from 20% in the 1998 survey to 50% in 2020/21. These changes are consistent with a growing population undergoing strong recruitment, not limited by food resources. Continued use of Port Ross by all SRW demographic classes confirms this as key habitat for SRW in New Zealand waters, and we support increased enforcement of existing management measures to reduce whale-vessel interactions in this remote subantarctic archipelago.

So Close Yet So Far: Age and Growth of Blue Antimora Antimora rostrata (Moridae, Gadiformes, Teleostei) off New Zealand and Macquarie Island (Southwestern Pacific Ocean)

Age and growth of blue antimora Antimora rostrata were examined in the waters off New Zealand and Macquarie Island (southwestern Pacific). Samples off Macquarie Island were collected from bycatch in the Patagonian toothfish longline fishery. Individuals between 20 and 44 years in age measured between 37.6–71.1 cm in total length. Bottom trawl catches from New Zealand waters consisted of smaller and younger fish (11 to 38 years), measuring 22.5–52.5 cm long. The age classes with the greatest numbers in the former area were represented by fish aged 33–34 years (25.7%). In the latter area, the most numerous age classes were 21–23 years (12.1%), 28–29 years (17.6%), and 32 years (6.6%). The blue antimora from off the Macquarie Island show similar growth rates to those of individual fish from the Ross, Lazarev and Weddell Seas, waters off the Kerguelen and Crozet Islands, and southeastern Greenland. Individuals from New Zealand waters demonstrate the slowest growth rates compared to other parts of the species’ range but are quite similar to individuals from the Flemish Cap area. Further research to identify the stock structure of this broadly distributed species is warranted to provide context to differences in growth rates observed between populations.

Social media and citizen science records are important for the management of rarely sighted whales

Social media content is increasingly being validated and used as a valuable source of data within conservation science. Metadata obtained from social networking sites (SNS) can supplement knowledge and data gaps in traditional ecological monitoring programs by increasing the spatiotemporal extent of sampling. Here we consider SNS in the context of rare and threatened species, which are difficult to monitor due to their often-inaccessible habitat, or elusive and unpredictable occurrences. We focus on a recovering large whale population, as charismatic megafauna often appear on SNS and are ideal for public outreach sightings data. Southern right whales (Eubalaena australis, SRW) were once abundant throughout New Zealand waters. However, following widespread population decline during whaling, no SRW was reported around the mainland for 35 years, with the remnant population persisting only in the remote subantarctic islands. By using sightings data from 2011 to 2021 in the New Zealand Department of Conservation's (DOC) Marine Mammal Database and supplementing with crowd-sourced sightings reports made on SNS (Facebook and iNaturalist), we present evidence that SRWs are continuing to recover slowly around the mainland compared to their subantarctic breeding grounds. All sightings' data were categorised based on confidence of accuracy, for example, accompanying genetic or photographic confirmation of species identity. Sightings remain rare with only 116 sightings from both DOC and SNS sources reported over the 11-year research period (2011–2021), hindering efforts to identify key habitats and implement conservation measures. SNS sightings increased the overall number and quality of sightings. Specifically, as SNS sightings were all accompanied by images permitting confident species ID, they increased the overall quality of the dataset and provided new information on the fine-scale movement and residency times of SRW. Although opportunistic data such as these have limitations, our work suggests that the recolonisation of SRWs around mainland New Zealand has not increased in the past decade. This could reflect historic loss of matrilineal knowledge of the mainland, or it could also be an artifact of very few whales, resulting in less social aggregations frequenting the region. Citizen science and the use of SNS data are important for the continued monitoring of the New Zealand SRW population, with SNS data creating further opportunities to monitor similarly rare and data deficient populations.

Sea spiders (Arthropoda, Pycnogonida) from ten recent research expeditions to the Antarctic Peninsula, Scotia Arc and Weddell Sea - data.

This dataset contains information on specimens of Southern Ocean Pycnogonida (Arthropoda), that were collected from ten different research cruises, spanning 13 years. The individual aims and objectives of each cruise can be found in their cruise reports. The specimens have been collated into a single dataset, forming the basis of J. Maxwell's PhD. The dataset will be used to investigate the community structure of Antarctic pycnogonids and the factors which influence its composition. This dataset is published by SCAR-AntOBIS under the licence CC-BY 4.0. Please follow the guidelines from the SCAR and IPY Data Policies (https://www.scar.org/excom-meetings/xxxi-scar-delegates-2010-buenos-aires-argentina/4563-scar-xxxi-ip04b-scar-data-policy/file/) when using the data. If you have any questions regarding this dataset, please do not hesitate to contact us via the contact information provided in the metadata or via data-biodiversity-aq@naturalsciences.be. This dataset adds vital occurrence and abundance data for pycnogonids from 10 previously unexamined research cruises from the Weddell Sea, Antarctic Penisula and the islands of the Scotia Arc. It includes the first pycnogonid data from the Prince Gustav Channel. The 197 sampling stations within this dataset represent an 11% increase in the number of stations where pycnogonids have been recorded in the Southern Ocean, southern South America and New Zealand waters and an 18% increase for above 60 degrees latitude. Presence data for any observed epifauna are also included.

The first record of Australian flatback mangrove goby Mugilogobius platynotus (Günther 1861) (Gobiidae; Tridentigerinae) from New Zealand

ABSTRACT The eastern Australian flatback mangrove goby Mugilogobius platynotus (Günther 1861) is recorded for the first time from Aotearoa, New Zealand. Three voucher specimens (two males and one female) were collected using fish traps submerged in tidal drains of a saltmarsh wetland edged by mangroves adjacent to Ngunguru River, Northland. Key characters for identification: the colour of freshly thawed specimens, meristic counts, and morphometric measurements are presented and compared with the same characters described by Larson (2001) for all Mugilogobius. We discuss this major range extension from its natural Australian distribution, concluding it is an adventive species, probably carried across the Tasman Sea into New Zealand waters by shipping, not ocean currents. Our analysis of goby species recorded from northern New Zealand mainland waters concludes seven (86%) are probably adventive and introduced from Australia. We recommend a further survey of mangrove and saltmarsh estuary habitats to discover if this new goby has established a breeding population and is expanding its current limited distribution within northern New Zealand.

Warmer temperature decreases the maximum length of six species of marine fishes, crustacean, and squid in New Zealand

As global oceans continue to warm and deoxygenate, it is expected that marine ectotherms will reduce in body size resulting from the interactive effects of temperature and dissolved oxygen availability. A temperature-size response describes how wild populations of ectothermic species grow faster and reach a smaller size within warmer temperatures. While temperature-size responses are well observed in marine ectotherms, the mechanisms underpinning such a reduction in body size remain debated. Here, we analyse the relative influence of temperature, dissolved oxygen concentration, and geographic location (which encompasses multiple latent variables), on the maximum body length of four fish, one crustacean, and one squid species, which inhabit shallow to deep sea (1000 m) New Zealand waters across a temperature gradient of 1.5 to 18 °C. We found that all study species displayed a temperature-size response, with the strongest response exhibited by the largest species, hoki (Macruronus novaezelandiae). We also found that temperature was more important than dissolved oxygen concentration in determining maximum body length, as dissolved oxygen levels were at or near saturation in the study area. Our results suggest that larger-bodied species may experience the strongest temperature-size responses, and support expectations from the gill-oxygen limitation theory (GOLT) and the oxygen and capacity limited thermal tolerance (OCLTT) concept that increases in oxygen demand may be size- and temperature-dependent, thus driving a reduction in maximum body length of marine ectotherms with warming.

Feeding tactics of resident Bryde's whales in New Zealand

AbstractLarge predators typically feed on proportionally sized prey but the world's largest animals, baleen whales, bulk feed on plankton and small fishes. While most baleen whales migrate to feed on polar aggregations of nutritious zooplankton prey, Bryde's whales (Balaenoptera edeni brydei and B. e. edeni) inhabit less productive warm‐temperate waters with variable prey abundance and quality. Off New Zealand, Bryde's whales target both fish and zooplankton, some with lower calorific value. We use multisensor tags (n = 4) and visual observations from drones and boats (n = 52) to reveal that Bryde's whales employ specialized feeding tactics matched to prey type. Zooplankton‐feeding at the surface involved multiple head‐slaps that presumably aggregate zooplankton followed by a side‐lunge. Whales exploiting plankton patches swam in tight circles, performing up to 33 lunges (M = 5.5 ± 6.1) per feeding bout. In contrast, whales targeting fish performed faster vertical lunges. With both prey types, whales concluded lunges with a ~90° roll probably to minimize prey escape at the surface. The diet plasticity and dynamic behaviors of Bryde's whales are key to increasing their foraging efficiency. This may be essential for the whales to meet energetic demands year‐round with a variety of prey in New Zealand waters.

Second records and redescriptions of two rare thecate hydroids (Cnidaria: Hydrozoa) from the southwestern Pacific.

Two thecate hydroids, Carpocladus fertilis Vervoort Watson, 2003 (family Aglaopheniidae Marktanner-Turneretscher, 1890) and Gonaxia constricta (Totton, 1930) (family Gonaxiidae Maggioni, in Galea Maggioni, 2021), are recorded for the first time from off New Caledonia, thus outside their original area of distribution in New Zealand waters. Specimens of both sexes of C. fertilis occur in the present collection, allowing the first description of its so far unknown female gonothecae. The trophosome of G. constricta, the only known to date, is thoroughly redescribed, pending the discovery of its gonothecae.

Leopard Seals (Hydrurga leptonyx) in New Zealand Waters Predating on Chondrichthyans

Leopard seals (Hydrurga leptonyx) are top-order predators that prey on a wide variety of species including crustaceans, cephalopods, fishes, birds, and pinnipeds. While multiple diet studies have been conducted worldwide, there are no previous accounts of leopard seals predating on chondrichthyans. As part of a wider study on the diet of leopard seals in New Zealand (NZ) waters, researchers and citizen scientists recorded 39 observations of predation and collected 127 scats (166 total records) between 1942 and 2019. Predation on chondrichthyans was detected in 23.1% (n = 9) of observations of predation and 7.1% (n = 9) of scats (the latter via morphological examination and DNA sequencing). From both observations of predations and scats, three chondrichthyan species or genus were identified; elephantfish (Callorhinchus milii), ghost sharks (Hydrolagus spp.) and spiny dogfish (Squalus acanthias). While this is the first published record of leopard seals feeding on chondrichthyans, the relatively high frequency of occurrence within our NZ records, and that certain individuals appeared to target this type of prey, indicates that these species could constitute a substantial, or important, part of the diet for some leopard seals in this region. As chondrichthyans form an important part of the NZ marine ecosystems, our recognition of an additional top-order predator of these species contributes to understanding the overall health of, and future impacts of predators on, the wider NZ marine ecosystem.

CSI – Cuttlefish Sepion Investigation: overview of cuttlebones found on Aotearoa New Zealand shores and analysis of predation and scavenging marks

ABSTRACT Despite the absence of cuttlefish in Aotearoa New Zealand waters, cuttlebones and cuttlebone fragments have been reported and collected in the country since the early twentieth century. Not all could be reliably identified. As such, here we review all cuttlebone material collected from New Zealand shores available in natural history collections, as well as literature and online records. Species were identified, through morphological features and, for the first time, DNA barcoding, as: the Australian endemic Sepia apama Gray, 1849 (and possibly S. grahami A. Reid, 2001) and the widely distributed Indo-Pacific S. latimanus Quoy & Gaimard, 1832. In addition, the predation/scavenging marks (praedichnia) left on the cuttlebones by other organisms are assigned to four major types and attributed to albatrosses, sharks, and dolphins. The successful extraction of DNA from cuttlebones has potential future applications, including the examination of type specimens, since species were described based only on cuttlebones.

Geographic concordance of genetic barriers in New Zealand coastal marine species

Abstract Comparative phylogeography is recognized as a powerful tool to discern common patterns of connectivity across species, information that can be crucial in assisting the design of protected area networks. Previously, qualitative analyses have been undertaken in New Zealand waters in order to find concordance in marine dispersal barriers. This study presents the first attempt to quantitatively measure the congruence in genetic divergence breaks among 21 New Zealand marine coastal invertebrates, while accounting for the effects of variable sampling scale, life history traits and marker type. Previously recognized phylogeographic barriers to dispersal were found to be significant across species, such as the North–South Island differentiation and a northern genetic break at Cape Reinga. Low‐dispersal species exhibited additional locations of common significant divergence. Some of the differences in genetic barriers observed among species may be more related to the habitat type of the species (intertidal zone or subtidal) and the marker type used in the study (mitochondrial DNA or microsatellites), than to the dispersal traits of the species (high or low dispersal). Despite some limitations, the approach implemented here has significant advantages and permits the use of data from a wide variety of studies. This study provides the first quantitative insight into community‐wide genetic barriers within New Zealand's coastal marine ecosystem and provides directions for future investigations of this type in other regions.

Fourier transform infrared (FTIR) analysis identifies microplastics in stranded common dolphins (Delphinus delphis) from New Zealand waters

Here we provide a first assessment of microplastics (MPs) in stomach contents of 15 common dolphins (Delphinus delphis) from both single and mass stranding events along the New Zealand coast between 2019 and 2020. MPs were observed in all examined individuals, with an average of 7.8 pieces per stomach. Most MPs were fragments (77%, n = 90) as opposed to fibres (23%, n = 27), with translucent/clear (46%) the most prevalent colour. Fourier transform infrared (FTIR) spectroscopy revealed polyethylene terephthalate (65%) as the most predominant polymer in fibres, whereas polypropylene (31%) and acrylonitrile butadiene styrene (20%) were more frequently recorded as fragments. Mean fragment and fibre size was 584 μm and 1567 μm, respectively. No correlation between total number of MPs and biological parameters (total body length, age, sexual maturity, axillary girth, or blubber thickness) was observed, with similar levels of MPs observed between each of the mass stranding events. Considering MPs are being increasingly linked to a wide range of deleterious effects across taxa, these findings in a typically pelagic marine sentinel species warrants further investigation.

Caught in a vicious cycle: Connecting forced labour and environmental exploitation through a case study of Asia–Pacific

Several studies have documented the increasing use of forced/trafficked labour on long-haul fishing vessels, while others have documented illegal, unreported and unregulated (IUU) fishing practices. Recent observations document the existence of both practices occurring together on the same vessel or within the same fishing fleet, in what is characterised as 'convergence crime'. Building on these observations, this paper examines the precise interconnections between forced labour of fishers and IUU fishing on distant waters fishing vessels in the Asia–Pacific. It argues that identifying the dynamics of these connections necessitates a more detailed examination of both practices at the scale of individual fishing vessels and crew. Such an examination allows the reasons trafficked fishers engage in IUU fishing practices to be better understood. A twofold characterisation of exploitation involving the two interlinked aspects of 'labour' and 'situation' frames the analysis. The paper draws on two contrasting case studies to make its argument: first, semi-structured interviews with 50 Cambodian and Filipino migrant fishers deployed on Taiwanese fishing vessels, and second, 32 semi-structured interviews with Indonesian fishers on South Korean vessels fishing in New Zealand's waters as well as court documents pertaining to the engagement of the South Korean officers in IUU fishing practices. A key contribution of the paper is to understand the unwitting role forced labourers can play in exacerbating degradation in marine environments.

Decadal changes in exploited fish communities and their relationship with temperature, fisheries exploitation, and ecological traits in New Zealand waters

ABSTRACT 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.

Seas and swells throughout New Zealand: A new partitioned hindcast

A high resolution partitioned wave hindcast of New Zealand waters is presented together with validation results against 9 buoy deployments that are representative of the local wave climate. An analysis of integrated and partitioned mean wave parameters was conducted together with a study of the correlation between wave height anomalies and atmospheric indices. A directional spatial analysis was also performed to identify and quantify wave systems that are not detectable by in situ buoys or hindcast integrated parameters. The presented study outlines a framework of how partitions can be analyzed in order to improve our understanding of the local wave climate in terms of wind-sea and swell waves.

First satellite‐tracked movements of pygmy blue whales (Balaenoptera musculus brevicauda)in New Zealand waters

Marine Mammal ScienceEarly View NOTE First satellite-tracked movements of pygmy blue whales (Balaenoptera musculus brevicauda) in New Zealand waters Kimberly T. Goetz, Corresponding Author Kimberly T. Goetz kim.goetz@noaa.gov orcid.org/0000-0002-1356-0512 National Institute of Water & Atmospheric Research, Wellington, New Zealand Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, Washington, USA Correspondence Kimberly T. Goetz, Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA 98115-6349. Email: kim.goetz@noaa.govSearch for more papers by this authorSimon J. Childerhouse, Simon J. Childerhouse Cawthron Institute, Nelson, New Zealand Contribution: Data curation, Writing - review & editingSearch for more papers by this authorDavid Paton, David Paton Blue Planet Marine, Canberra, Australia Contribution: Data curation, Writing - review & editingSearch for more papers by this authorMike Ogle, Mike Ogle Department of Conservation, Takaka, New Zealand Contribution: Data curation, Writing - review & editingSearch for more papers by this authorKrista van der Linde, Krista van der Linde National Institute of Water & Atmospheric Research, Wellington, New ZealandSearch for more papers by this authorRochelle Constantine, Rochelle Constantine orcid.org/0000-0003-3260-539X University of Auckland, School of Biological Sciences and Institute of Marine Sciences, Auckland, New Zealand Contribution: Conceptualization, Formal analysis, Methodology, Writing - original draftSearch for more papers by this authorMichael C. Double, Michael C. Double Australian Marine Mammal Center, Australian Antarctic Division, Hobart, Australia Contribution: ​Investigation, Methodology, Resources, Writing - review & editingSearch for more papers by this authorVirginia Andrews-Goff, Virginia Andrews-Goff orcid.org/0000-0002-4609-7317 Australian Marine Mammal Center, Australian Antarctic Division, Hobart, Australia Contribution: Methodology, Writing - review & editingSearch for more papers by this authorAlexandre N. Zerbini, Alexandre N. Zerbini orcid.org/0000-0002-9776-6605 Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, Washington, USA Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle, Washington, USA Marine Ecology and Telemetry Research, Seabeck, Washington, USASearch for more papers by this authorPaula A. Olson, Paula A. Olson Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, La Jolla, California, USA Contribution: Data curation, ​Investigation, Methodology, Resources, Writing - review & editingSearch for more papers by this author Kimberly T. Goetz, Corresponding Author Kimberly T. Goetz kim.goetz@noaa.gov orcid.org/0000-0002-1356-0512 National Institute of Water & Atmospheric Research, Wellington, New Zealand Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, Washington, USA Correspondence Kimberly T. Goetz, Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA 98115-6349. Email: kim.goetz@noaa.govSearch for more papers by this authorSimon J. Childerhouse, Simon J. Childerhouse Cawthron Institute, Nelson, New Zealand Contribution: Data curation, Writing - review & editingSearch for more papers by this authorDavid Paton, David Paton Blue Planet Marine, Canberra, Australia Contribution: Data curation, Writing - review & editingSearch for more papers by this authorMike Ogle, Mike Ogle Department of Conservation, Takaka, New Zealand Contribution: Data curation, Writing - review & editingSearch for more papers by this authorKrista van der Linde, Krista van der Linde National Institute of Water & Atmospheric Research, Wellington, New ZealandSearch for more papers by this authorRochelle Constantine, Rochelle Constantine orcid.org/0000-0003-3260-539X University of Auckland, School of Biological Sciences and Institute of Marine Sciences, Auckland, New Zealand Contribution: Conceptualization, Formal analysis, Methodology, Writing - original draftSearch for more papers by this authorMichael C. Double, Michael C. Double Australian Marine Mammal Center, Australian Antarctic Division, Hobart, Australia Contribution: ​Investigation, Methodology, Resources, Writing - review & editingSearch for more papers by this authorVirginia Andrews-Goff, Virginia Andrews-Goff orcid.org/0000-0002-4609-7317 Australian Marine Mammal Center, Australian Antarctic Division, Hobart, Australia Contribution: Methodology, Writing - review & editingSearch for more papers by this authorAlexandre N. Zerbini, Alexandre N. Zerbini orcid.org/0000-0002-9776-6605 Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, Washington, USA Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle, Washington, USA Marine Ecology and Telemetry Research, Seabeck, Washington, USASearch for more papers by this authorPaula A. Olson, Paula A. Olson Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, La Jolla, California, USA Contribution: Data curation, ​Investigation, Methodology, Resources, Writing - review & editingSearch for more papers by this author First published: 25 September 2021 https://doi.org/10.1111/mms.12876 Funding information: National Institute of Water and Atmospheric Research; New Zealand Department of Conservation; OMV Ltd Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. 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Rossellid glass sponges (Porifera, Hexactinellida) from New Zealand waters, with description of one new genus and six new species.

New Zealand’s surrounding deep waters have become known as a diversity hotspot for glass sponges (Porifera: Hexactinellida) in recent years, and description and collection efforts are continuing. Here we report on eight rossellids (Hexasterophora: Lyssacinosida: Rossellidae) collected during the 2017 RV Sonne cruise SO254 by ROV Kiel 6000 as part of Project PoribacNewZ of the University of Oldenburg, Germany. The material includes six species new to science, two of which are assigned to a so far undescribed genus; we further re-describe two previously known species. The known extant rossellid diversity from the New Zealand region is thus almost doubled, from nine species in five genera to 17 species in eight genera. The specimens described here are only a small fraction of hexactinellids collected on cruise SO254. Unfortunately, the first author passed away while working on this collection, only being able to complete the nine descriptions reported here. The paper concludes with an obituary to him, the world-leading expert on glass sponge taxonomy who will be greatly missed.

Diversity of tropical macroalgae in the New Zealand marine aquarium trade

ABSTRACT Exotic species often slip through international borders undetected. Increased global trade has increased the frequency of species introductions. The marine aquarium trade is a significant vector of species introductions, including algal introductions. Molecular barcoding of tropical macroalgae entering the New Zealand aquarium trade was implemented using various molecular markers. Both NCBI BLAST searches and maximum-likelihood phylogenies were used to identify the isolates. A total of 62 species of tropical macroalgae were identified from coral rocks. Some species found are known as invasive elsewhere, for example, Caulerpa cylindracea, C. racemosa, C. sertularioides, Ulva ohnoi and Chaetomorpha vieillardii. All three major groups of algae were well represented with 26 species of red algae, 24 species of green algae and 12 species of brown algae. Temperature tolerance of some of these algae to minimum sea surface temperatures was tested. Results show that one species Chaetomorpha vieillardii can survive at Auckland minimum winter sea surface temperatures. Our findings have important implications for New Zealand biosecurity, as not only are a large diversity of exotic macroalgae entering the New Zealand marine aquarium trade unregulated, but there is also the potential for them to survive in New Zealand waters.

Population genomic structure of killer whales (Orcinus orca) in Australian and New Zealand waters

AbstractPopulation genomic data sets have enhanced power to detect cryptic and complex population structure and generate valuable information for the conservation and management of wildlife species. Globally, killer whales (Orcinus orca) are considered to have a complex population structure due to their ability to specialize in a variety of ecological niches. In the Australasian region, they are found year round in New Zealand waters and are sighted in all Australian waters, with seasonal aggregations in the northwest (NWA) and southwest (SWA). Regionally, there is some knowledge regarding killer whale abundance, diet, acoustics, and social structure, but limited information about their population structure. Here, we present a population structure assessment of Australasian killer whales using 17,491 high quality genome‐wide single nucleotide polymorphisms (SNPs), combined with sequences of the mitochondrial DNA control region. The results indicate a minimum of three populations: New Zealand, NWA, and SWA. These populations present moderate levels of genomic diversity, negligible levels of inbreeding, small effective population sizes, and low contemporary migration rates among them. Mitochondrial DNA analysis elucidated five closely related haplotypes, suggestive of matrilineal societies, consistent with killer whales elsewhere. This information will assist conservation management of killer whales in the Australasian region.

Fin whale acoustic populations present in New Zealand waters: Description of song types, occurrence and seasonality using passive acoustic monitoring.

Southern fin whales (Balaenoptera physalus) are known to migrate from the Antarctic to mid-latitudes during winter for breeding, but the occurrence and distribution of this species is not well known in the waters around New Zealand. The ‘doublet’ calls are one of the main calls emitted specifically by fin whales and repeated in a regular pattern, which make the acoustic detection of these calls relevant to detect the presence of fin whales. Using a signal processing algorithm to detect ‘doublet’ calls emitted by fin whales, we studied the occurrence, characteristics and seasonality of these ‘doublet’ calls in two regions around New Zealand; Cook Strait in 2016/2017 and offshore Gisborne in 2014/2015. The call detection procedure consisted of binarization of the spectrogram and a cross-correlation between the binarized spectrogram and a template of binarized ‘doublet’ calls spectrogram. A binarization threshold for the data spectrograms and a cross correlation threshold were then determined through multiple trials on a training dataset and a Receiver Operating Characteristics (ROC) curve. Fin whale ‘doublet’ calls occurred on the east side of New Zealand’s Cook Strait during austral winter, specifically in June 2017 and offshore Gisborne in June-August 2014. No ‘doublet’ calls were detected on the west side of Cook Strait. The ‘doublet’ calls’ Inter-Note Interval (INI) was similar in both datasets. However, there was a difference in alternation of the mean frequency for both HF components of ‘doublet’ calls in Cook Strait and Gisborne. As the song types were compared with those previously described in the literature, our findings suggest that some fin whales wintering in New Zealand waters may be part of a broader ‘acoustic population’ whose range extends west to southern Australia and south to Antarctica.