Publications
A Surprising Diversity of Aquatic Oligochaetes (Annelida: Clitellata) on Campbell Island/Motu Ihupuku (New Zealand), With a Checklist of Sub‐Antarctic and Antarctic Microdrile Oligochaetes
A surprising diversity of aquatic oligochaetes (Annelida: Clitellata) has been discovered on Campbell Island/Motu Ihupuku, New Zealand. The study, conducted during the 2010/11 austral summer as part of the Campbell Island Bicentennial Expedition, recorded 19 species, including six Naididae, nine Enchytraeidae, and four Phreodrilidae, bringing the total number of microdrile species known from the island to 20. At least nine species are endemic to Campbell Island, with two new genera and four new species described. The fauna exhibits biogeographic affinities with other Southern Ocean/sub-Antarctic islands and high-latitude regions of southern continents, such as Macquarie Island and Tasmania. Species richness on Campbell Island far exceeds that of Macquarie Island, where only six species have been documented. The study highlights the need for further research to better understand the origins of this diversity and compare it with other islands.
Avian Influenza Virus Surveillance Across New Zealand and Its Subantarctic Islands Detects H1N9 in Migratory Shorebirds, but Not 2.3.4.4b HPAI H5N1
A comprehensive avian influenza virus surveillance study across New Zealand and its subantarctic islands detected no presence of highly pathogenic avian influenza (HPAI) H5N1, a significant finding given the potential catastrophic impact on local wildlife. The study analyzed 700 wild aquatic birds from 33 species using metatranscriptomic techniques, focusing on the annual 2023-2024 migration period. While no H5N1 was found, a single detection of H1N9 in red knots (Calidris canutus) was noted. This research establishes a critical baseline for expanding avian influenza monitoring in New Zealand, providing valuable data to assess the risk and prepare for future outbreaks.
Evidence of eastern rockhopper penguin feeding on a key commercial arrow squid species
Research reveals that eastern rockhopper penguins around Campbell Island, New Zealand, have incorporated the commercially valuable arrow squid Nototodarus sloanii into their diet for the first time during the 2012–13 breeding season. Stable isotope analysis of cephalopods in penguin diets showed ecological stability for Moroteuthopsis ingens, while shifts were observed in Octopus campbelli, possibly due to warmer oceanic temperatures. This suggests potential changes in cephalopod biodiversity in the Pacific sector of the Southern Ocean, underscoring the need for further study on this region's ecological dynamics.
Spatial Modelling Approaches for Estimating Richness of Benthic Invertebrates Throughout New Zealand Waters
Macro-ecological models (MEMs) outperform stacked species distribution models (S-SDMs) for mapping benthic invertebrate richness in New Zealand waters, offering more nuanced and accurate predictions. Using over 120,000 occurrence records of 207 genera, the study compared both approaches, revealing that S-SDMs were hindered by spatial and catchability biases in the data. The MEM approach successfully identified high-richness areas, including parts of the Chatham Rise, sub-Antarctic regions, southern South Island continental shelf, northeast North Island coast, East Cape, and the Kermadec, Lau-Colville, and Macquarie Ridges. These findings provide critical insights for marine spatial planning, emphasizing the importance of robust modelling techniques when systematic sampling is limited.
Tracing the biogeographic history of the world's most isolated insular floras
A new study reveals that the New Zealand Sub-Antarctic Islands, one of Earth's most isolated regions, have maintained high biological connectivity with southern landmasses like Australia, New Zealand, and South America since the Miocene. Contrary to expectations, long-distance dispersal—not tectonic vicariance—has been the primary mechanism for plant colonization, facilitated by eastward-moving marine and wind currents, short-term weather systems, or bird dispersal. Phylogenetic reconstruction, divergence time estimation, and Bayesian biogeographic analyses of seven vascular plant lineages show that most species diverged during the Plio-Pleistocene, with crown ages predating the Last Glacial Maximum, indicating these islands acted as biodiversity refuges. The findings highlight their dual role as both refugia and sources of (re)colonization, emphasizing the urgent need for conservation planning in this remote sub-Antarctic region.
Under what climate conditions were the New Zealand subantarctic islands glaciated?
Mountain glaciers in the New Zealand subantarctic islands, particularly those in the Auckland and Campbell archipelagos, provide critical insights into past climate conditions. A study using a 2D glacier model reveals that these islands were glaciated under significantly cooler temperatures—6 to 7 °C below mid-20th century levels for recent glaciation and more than 8 °C lower for ice cap coverage, assuming present-day precipitation. The research also highlights the sensitivity of glacier mass balance to summer temperatures, with increased temperature seasonality requiring further reductions in temperature to achieve equivalent ice volumes. These findings refine our understanding of glaciation in the southwest Pacific sector of the Southern Ocean and offer a framework for evaluating global climate model simulations. However, precise dating of past glaciation events remains necessary to fully interpret the climatic implications.
Ecotourism in the Australian and New Zealand sub-Antarctic islands
Ecotourism in the sub-Antarctic islands of Australia and New Zealand presents both opportunities and challenges for sustainable tourism. While it offers potential to subsidize scientific operations and support territorial claims, it also poses significant risks to fragile ecosystems and disrupts research programs. A key finding is that tourists now outnumber government personnel in these regions, despite spending less time there, highlighting the need for effective management strategies. The study explores the nature of sub-Antarctic tourism, its environmental impacts, and current management practices, advocating for models that prioritize sustainability to mitigate negative effects on delicate island environments.
Forget-me-not phylogenomics: Improving the resolution and taxonomy of a rapid island and mountain radiation in Aotearoa New Zealand (Myosotis; Boraginaceae)
A phylogenomic analysis of southern hemisphere forget-me-nots (Myosotis) reveals complex taxonomic and biogeographic patterns within a rapid island and mountain radiation centered in Aotearoa New Zealand. Using advanced molecular techniques—including target-capture sequencing, whole plastome genome skimming, and nuclear DNA analysis—the study achieved unprecedented resolution, with 2-3 times more taxon sampling and 80-120 times more molecular data than previous research. The findings highlight multiple evolutionary transitions in inflorescence morphology and multiple expansions across New Zealand's islands, including the North Island (Te Ika-a-Māui), South Island (Te Waipounamu), Stewart Island (Rakiura), subantarctic islands, and Australia. Despite challenges in species delimitation due to rapid radiation, this study provides critical insights for an integrative taxonomic revision of Myosotis, many of which are geographically restricted, threatened, or polyploid.
Oribatid mites (Acariformes: Sarcoptiformes) in Sub-Antarctic Islands and Antarctica: a track analysis
A track analysis of oribatid mites (moss mites) in the Sub-Antarctic Islands and Antarctica reveals that South Georgia Island serves as a key hub for species dispersion, linking three distinct biogeographical tracks. One track connects South Georgia to the Sub-Antarctic Islands of the South Atlantic, southern Indian Ocean, and southern Australia and New Zealand; another links South Georgia to the Antarctic Peninsula; while a third extends from South Georgia to the Falkland Islands. This pattern suggests that South Georgia Island was likely the ancestral zone for these species, from which they spread to colonize Antarctica, the Falkland Islands, and potentially southern South America. The study combines literature analysis with track analysis to uncover these dispersion patterns, providing insights into the biogeographical history of non-marine mites in the Southern Hemisphere.
The radiation of Austral teals (Aves: Anseriformes) and the evolution of flightlessness
A new whole-mitogenome-based phylogeny reveals that Austral teals, including the grey-teal and brown-teal complexes, diverged from mallards in the late Miocene. The study shows that the brown-teal lineage, which includes both volant and flightless species, radiated within the past 0.9–1.8 million years, with morphological changes toward flightlessness already present in the mainland brown teal. This suggests an accelerating trend of flightlessness in insular lineages, including the sub-Antarctic Auckland Island teal and the extinct Chatham Island teal, both derived from New Zealand ancestors. The findings provide critical insights into the evolutionary pathways leading to flightlessness, offering valuable data for functional genomic studies.
Tourism Diversification in Antarctica and New Zealand/Aotearoa’s Sub-Antarctic Islands: Practices as Expressions of Values
Tourism diversification in Antarctica has outpaced that in New Zealand/Aotearoa’s sub-Antarctic islands due to differing policy enactments of shared values. While the Antarctic Treaty System (ATS) cites numerous values and principles, these have not significantly shaped visitor management strategies, leading to an expansion of tourism activities. Conversely, NZ/A’s sub-Antarctic islands have effectively translated values into policies that limit diversification. This study compares both regions, revealing how policy implementation influences tourism outcomes, with implications for balancing conservation and visitation in protected areas.
Trans-equatorial migration links oceanic frontal habitats across the Pacific Ocean: year-round movements and foraging activity of a small gadfly petrel
Stejneger’s petrels, endemic to the Juan Fernández Islands, undertake an unprecedented trans-equatorial migration spanning 54,725 km across the Pacific Ocean, linking oceanic frontal habitats from the Sub-Antarctic Front to regions near Hawaii and Japan. This triangular migration pattern, unique among seabirds, involves a detour toward New Zealand before heading east at 40–50°S, likely leveraging Antarctic circumpolar winds. The study used geolocator-immersion loggers over two years to track year-round movements, phenology, habitat use, and activity patterns of 10 individuals. Birds spent >75% of their time flying during breeding and migration but reduced flight activity during non-breeding, possibly due to feather molt. Their strong preference for oceanic frontal regions, particularly the North Pacific Transition Zone Chlorophyll Front, underscores the critical need to protect these remote High Seas habitats.
Variable breeding success and its implication in the conservation of endangered yellow‐eyed penguin ( Megadyptes antipodes ) at the New Zealand subantarctic Auckland Islands
Breeding success of the endangered yellow-eyed penguin (Megadyptes antipodes) varies significantly over time, with a sharp decline observed in 2017 due to high egg mortality on Enderby Island, Auckland Islands. Despite higher fledging success compared to mainland New Zealand in some years, chicks were smaller and lighter, suggesting potential challenges in juvenile survival. The study highlights the need for ongoing monitoring across subantarctic populations to establish baseline productivity and assess the impact of anthropogenic stressors. Researchers analyzed 167 nests over three breeding seasons (2015–2017), tracking egg/chick mortality and fledging rates, alongside chick condition data from 276 individuals. These findings underscore the importance of consistent monitoring to inform conservation strategies for this declining species.
A revision of the higher latitude periwinkle species Laevilitorina caliginosa sensu lato
A comprehensive revision of the marine gastropod genus Laevilitorina reveals hidden diversity within the species complex Laevilitorina caliginosa sensu lato, identifying four new species from the Strait of Magellan and Hornos Island. Using molecular and morphological analyses, researchers confirmed L. caliginosa and Laevilitorina venusta as valid taxa, while distinguishing four novel species: Laevilitorina magellanica, Laevilitorina pepita, Laevilitorina fueguina, and Laevilitorina hicana. The study also clarified the geographical distribution of L. venusta across the Antarctic Peninsula, South Georgia, and sub-Antarctic Islands, challenging previous records from Macquarie Island. This revision significantly advances our understanding of the evolutionary history and taxonomic diversity of this Southern Hemisphere genus.
Hilarini (Diptera: Empididae) from the Auckland Islands New Zealand, the Homoplastic Loss of the Male Silk-Producing Basitarsus in Two Insular Species, and Notes on the Empidoidea of the Subantarctic Islands
Two new species of empidoid flies, Hilara ranui and Hilarempis motumaka, from the Auckland Islands exhibit a homoplastic loss or reversal of the male silk-producing basitarsus, a trait otherwise characteristic of their genera. This discovery highlights evolutionary convergence in insular environments, where selective pressures may favor trait simplification. The study synthesizes knowledge on New Zealand Empidoidea (excluding Dolichopodidae) and discusses how Subantarctic island conditions shape empidoid diversity. By describing these species and analyzing their unique morphology, the research provides insight into adaptive evolution in extreme insular ecosystems.
Population assessment of White-capped Albatrosses Thalassarche steadi in New Zealand
A population assessment of the White-capped Albatross (Thalassarche steadi), conducted over 12 years (2006–2017) using aerial photography, estimated an average of 89,846 breeding pairs in New Zealand’s Auckland Islands. Despite high inter-annual variability, the population showed a non-significant negative trend, though TRIM classification suggested stability. Given the species' biennial breeding frequency and estimated annual bycatch mortality (8,000 birds), fisheries impacts are likely unsustainable. Annual monitoring is recommended to refine trend estimates and assess long-term sustainability.
A local eradication pilot study of methods for feral pig eradication on Auckland Island
Feral pigs (Sus scrofa) introduced to Auckland Island, New Zealand, in 1807 have significantly disrupted the island's ecosystem. A pilot study aimed at eradicating these invasive species tested multiple methods to address challenges such as biological, logistical, social, and funding constraints that often hinder long-term eradication efforts. The research evaluated the effectiveness of combined techniques for pig removal on a smaller scale, providing insights into strategies that could be scaled up for broader conservation efforts. While the study does not report definitive outcomes, it contributes to the growing body of work on invasive species management in subantarctic environments, offering practical guidance for future restoration programs.
A review of leopard seal (Hydrurga leptonyx) births and pups using a standardised age-class classification system
A comprehensive review challenges the long-held belief that leopard seals (Hydrurga leptonyx) exclusively give birth on Antarctic pack ice, revealing that 84.2% of documented births and 57.4% of pup records occur outside Antarctica. Analyzing 19 birth/newborn and 141 pup records from global sources, researchers applied a standardized age-class classification system to assess reproductive patterns by month, region, substrate, and biological attributes. Findings indicate peak birth activity between September and December, with the sub-Antarctic Islands and Chile as primary regions for births, while pups were predominantly recorded in the sub-Antarctic Islands and Antarctica. This study underscores the significance of northern regions within the leopard seal's range, advocating for expanded research and management efforts to include these areas.
Complete distribution of the genus Laevilitorina (Littorinimorpha, Littorinidae) in the Southern Hemisphere: remarks and natural history
A comprehensive analysis of the genus Laevilitorina, a marine gastropod found exclusively in the Southern Hemisphere, reveals significant insights into its distribution and diversity. The study, which combines field sampling, published records, and data from global biodiversity databases, identifies 21 species across regions including West Antarctica (8 species), New Zealand's sub-Antarctic islands (4 species), and Australia's south-east shelf (4 species). Notably, it highlights the rare occurrences of L. pygmaea and L. venusta, while also challenging the taxonomic status of L. caliginosa, suggesting it represents multiple divergent lineages rather than a single widespread taxon. This research underscores the need for further molecular and taxonomic studies to better understand the genus's diversity and biogeography.
Diet plasticity and links to changing foraging behaviour in the conservation of subantarctic yellow‐eyed penguins ( Megadyptes antipodes )
Subantarctic yellow-eyed penguins (Megadyptes antipodes) exhibit significant diet plasticity, shifting between lower trophic level prey during El Niño conditions and more diverse, offshore prey under La Niña. This dietary variation correlates with breeding success and survival, suggesting prey availability is a critical limiting factor, particularly under climate-driven marine environmental changes. The study analyzed stable isotopes from blood and feather samples (n=63) of 25 breeding penguins on Enderby Island (Auckland Islands, New Zealand) between 2015-2018, revealing year-to-year dietary shifts linked to climate oscillations. These findings underscore the urgent need for conservation strategies that account for prey distribution dynamics and climate impacts on this endangered species' long-term population stability.
Monitoring and detection of feral cats on Auckland Island
Feral cats on Auckland Island, part of the UNESCO-listed New Zealand Sub-Antarctic Islands, pose a significant threat to local biodiversity. A recent study found that live trapping, camera trapping, and scat searches—particularly with detection dogs—are effective methods for monitoring cat abundance, distribution, and movement behavior. These findings are critical for the planned eradication effort, as they provide essential data on detection probabilities and spatial patterns of feral cats. The research highlights the importance of combining multiple techniques to accurately assess cat populations in remote, pristine environments like Auckland Island.
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
A significant increase in the proportion of cow-calf pairs among New Zealand southern right whales (Eubalaena australis) at Port Ross, Auckland Islands, from 20% in 1998 to 50% in 2020/2021, suggests strong population recruitment and growth. This study analyzed behavioral phenology, demographic composition, and habitat use over three decades using surveys, 548 whale encounters, and 599 skin biopsy samples collected during peak usage periods. While behavioral patterns remained consistent with the 1990s, the rising cow-calf pairs indicate a thriving population not constrained by food resources. Port Ross remains critical habitat for all demographic classes, reinforcing the need for stricter management to mitigate whale-vessel interactions in this remote subantarctic region.
Origin, diversity, and biogeography of Antarctic scale worms (Polychaeta: Polynoidae): a wide‐scale barcoding approach
Antarctic scale worms (Polynoidae) exhibit complex origins, with most species showing high endemism and local radiation, while others suggest historical migration crossroads or deep-sea origins. Researchers analyzed 691 polynoid sequences from the Southern Ocean and neighboring regions using mitochondrial markers Cox1 and 16S rRNA to reconstruct phylogenies and haplotype networks. They identified 36 lineages, revealing that species like Eunoe sp. and Harmothoe fuligineum may have used sub-Antarctic islands as migration hubs, while the genus Polyeunoa likely diversified before colonizing the continent, possibly from deep-sea origins. Nearly all populations appear to be expanding post-glacial bottleneck events, indicating resilience or adaptation following habitat reduction. The study supports multiple hypotheses for Antarctic benthic invertebrate origins, highlighting both local endemism and historical dispersal patterns.
Prevalence and Pathogen Load of Eimeria in Wild Yellow-eyed Penguins (Megadyptes Antipodes) and the Morphologic Characterization of a Novel Eimeria Species
Researchers identified a novel species of Eimeria, a coccidian parasite, in wild Yellow-eyed Penguins (Megadyptes antipodes), with significantly higher prevalence and pathogen load than previously reported for this host or other free-living Sphenisciformes. The study compared two populations: one on Enderby Island (sub-Antarctic) with 76.6% prevalence and a mean of 9,723 oocysts per gram of feces, and another on New Zealand's South Island with 58.54% prevalence and 1,050 oocysts per gram. Morphological analysis suggested the presence of a single Eimeria species across both sites, despite measurable differences in oocyst dimensions. The findings highlight a previously understudied host-parasite relationship that may have implications for the endangered penguin's population stability.
Rapid radiation of Southern Ocean shags in response to receding sea ice
A recent genetic and biogeographical study of blue-eyed shags (Leucocarbo spp.) reveals rapid speciation in response to receding sea ice, resolving a long-standing paradox. The research, using time-calibrated phylogenetic analyses across 16 species and subspecies, shows that sub-Antarctic island lineages originated during the Pliocene or Early Pleistocene, contrasting with older lineages in South America and New Zealand. These findings suggest two major dispersal waves linked to interglacial cycles, with South America acting as a glacial refugium. The study highlights blue-eyed shags as a model system for understanding founder-event speciation and adaptation in Southern Ocean birds.
Restoration of New Zealand subantarctic islands
New Zealand's subantarctic island groups, including the Snares, Bounty Islands, Antipodes Islands, Auckland Islands, and Campbell Island, have undergone significant restoration efforts since their preservation began in the early 20th century. These islands, charted by Europeans in the late 18th and early 19th centuries, face unique ecological challenges due to their remote location and sensitive ecosystems. The study highlights the importance of targeted conservation strategies, such as invasive species removal and habitat restoration, in preserving these biodiversity hotspots. By analyzing long-term data and implementing adaptive management practices, researchers have demonstrated measurable improvements in ecosystem health, underscoring the effectiveness of coordinated international efforts in subantarctic conservation.
The next frontier: assessing the feasibility of eradicating mammalian pests from Auckland Island
Auckland Island, the only remaining pest-free subantarctic island in New Zealand's territory, presents a unique opportunity to advance the country's goal of eradicating introduced mammalian predators by 2050. This study evaluates the feasibility of simultaneously removing pigs (Sus scrofa), mice (Mus musculus), and cats (Felis catus) from the island, leveraging recent eradication successes elsewhere. The research combines ecological modeling, logistical assessments, and cost-benefit analyses to determine the practicality and potential impacts of such an ambitious project. By synthesizing data on pest populations, habitat requirements, and historical eradication outcomes, the study provides a roadmap for future conservation efforts, emphasizing the island's critical role in preserving its unique biodiversity.
Foraging areas and plasticity of yellow-eyed penguins Megadyptes antipodes in their subantarctic range
Yellow-eyed penguins (Megadyptes antipodes) in the subantarctic range exhibit significant foraging plasticity, with 62% of their foraging trips categorized as pelagic, contrasting with the predominantly benthic behavior observed in mainland populations. This study, conducted over two breeding seasons on Enderby Island, Auckland Islands, New Zealand, analyzed GPS data from 91 foraging logs to reveal that foraging distances and areas were greater for females and pelagic foragers, while benthic foragers traveled further from shore on average. The research also found that foraging area size increased in years with higher breeding effort and fledging success (2016), suggesting that environmental conditions and individual preferences play crucial roles in their foraging behavior. These findings imply that subantarctic foraging conditions may differ significantly from those in mainland New Zealand, potentially influencing future breeding success.
Risk Factors for New Zealand Sea Lion (Phocarctos hookeri) Pup Mortality: Ivermectin Improves Survival for Conservation Management
Ivermectin treatment significantly reduces pup mortality in endangered New Zealand sea lions (Phocarctos hookeri) at Enderby Island, offering a potential conservation strategy. The study found that ivermectin-treated pups had 57% lower mortality rates compared to controls, particularly due to hypervirulent Klebsiella pneumoniae septicaemia—a leading cause of neonatal deaths since an epizootic in 2001–02. Researchers conducted case-control and cohort studies alongside a treatment trial over two field seasons (2016–2018), analyzing risk factors including bacterial carriage, body condition index, and hookworm presence. While the mechanism by which ivermectin prevents septicaemia remains unclear, preemptive anthelmintic treatment may limit systemic bacterial spread. This intervention could benefit larger colonies if applied broadly, though further research is needed to optimize its use for population-scale conservation.
A note on movements of southern right whales between the sub-Antarctic Auckland and Campbell Islands, New Zealand
Research reveals that southern right whales between the sub-Antarctic Auckland and Campbell Islands, New Zealand, are part of one intermingling population. Analysis of 248 whale photographs identified three individuals first seen at the Auckland Islands in 1995 or 1996, later observed at Campbell Island in 1997, while another whale sighted at Campbell Island in 1995 was recorded at the Auckland Islands later that winter. This marks the first evidence of both within- and between-year movements, challenging previous assumptions about distinct populations. The study used photographic identification to track individual whales, providing insights into their migratory behavior across these sub-Antarctic habitats.
A note on observations of southern right whales at Campbell Island, New Zealand
Southern right whales were observed at Campbell Island, New Zealand's sub-Antarctic region, over four field seasons (1983, 1994, 1995, and 1997), revealing a shift in their residence patterns from the early 1980s to the 1990s. The study noted that whales were present year-round during certain periods, with peak sightings reaching up to 44 individuals in a single day in July 1995. Individual whales were resighted over extended periods, ranging from days to months, indicating site fidelity. Additionally, the research documented interchange between Campbell Island and the Auckland Islands, with a recent trend of decreasing numbers at Campbell Island and increasing sightings at the latter. This study provides critical insights into the movement and population dynamics of southern right whales in this UNESCO-listed sub-Antarctic ecosystem.
Birds of Enderby Island, Auckland Islands, New Zealand subantarctic
A significant increase in sightings of tui and silvereye, alongside a decrease in white-fronted terns, was observed on Enderby Island following the eradication of invasive mammals in 1993. This study systematically describes the bird community of Enderby Island from historical records (1840–2018) and compares pre- and post-eradication trends. It also identifies successful recoveries in species like New Zealand falcon and Auckland Island snipe, attributing these changes to reduced human exploitation, removal of browsing mammals, shifts in invertebrate communities, and vegetation cover alterations. Notably, the rise in southern royal albatross sightings may reflect visitor behavior changes rather than actual population growth.
Birds of the Auckland Islands, New Zealand subantarctic
The Auckland Islands, the largest island group in New Zealand's subantarctic region, host the most diverse avifauna of the area, including eight endemic species. A comprehensive review based on 23,028 unique bird records from 1807 to 2019 reveals that at least 45 species breed or have bred here, with an additional 77 species recorded as migrants or vagrants. The study highlights significant differences in bird fauna across the islands, influenced by habitat variation and the presence of introduced mammals. Notably, Disappointment Island, despite being the least modified, lacks forest and thus supports a more restricted land bird community. In contrast, Auckland Island, still impacted by introduced mammals, exhibits a depauperate avifauna compared to other major islands like Adams and Enderby. The research provides detailed population estimates, breeding chronology, reproductive parameters, and dietary information for the species studied.
Cenozoic evolution of the Campbell Plateau, Subantarctic New Zealand: Insights from sub-bottom profile data
New research reveals that the Campbell Plateau, part of Zealandia and the Gondwana super-continent, has undergone substantial erosion and deformation since its separation ~98 million years ago. Sub-bottom profile data from 2017-2018 indicate a relatively undeformed sub-surface with minor reverse faulting, contradicting previous interpretations. The study identifies dynamic sedimentary processes, including onlap/downlap surfaces interpreted as current scours and erosional features, particularly in the southern plateau. A plateau-wide Pliocene unconformity suggests a large-scale erosional event. Lithological changes from Cretaceous biogenic sediments to Miocene nannofossil-rich oozes and Pleistocene foraminiferal oozes are linked to Southern Ocean circulation patterns, including the Antarctic Circumpolar Current and local wind-driven currents.
Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New Zealand
Research reveals that decoupling between phytoplankton growth and microzooplankton grazing significantly enhances productivity on the Campbell Plateau, southeast of New Zealand. Unlike surrounding waters where grazing pressure balances phytoplankton growth, the plateau experiences an imbalance (g:μ0 = 0.48 ± 0.31), allowing substantial primary production to escape grazing control. This decoupling is linked to localized increases in chlorophyll a (chla > 0.52 mg m−3) and larger phytoplankton forms, suggesting alleviation of iron stress. The study, conducted during austral autumn (March 2017), characterized phytoplankton biomass structure, production, and grazing rates, proposing that entrainment of deeper water into the mixed layer regulates bloom onset and fate by altering nutrient supply and grazing pressure.
Hitchhiking consequences for genetic and morphological patterns: the influence of kelp-rafting on a brooding chiton
A study of the brooding chiton Onithochiton neglectus reveals that kelp-rafting significantly influences its genetic and morphological patterns across New Zealand. The research found distinct northern and southern lineages, with an additional lineage in central New Zealand, which do not align with existing subspecies classifications but match the species' association with buoyant kelp (Durvillaea spp.). Shell shape variations also correspond to this ecological association, suggesting a link between morphology and regional habitat use. To investigate these patterns, the study employed geometric morphometrics for shell shape analysis and phylogenetic trees using nuclear (ITS) and mitochondrial (COI and 16S) markers.
Holocene bird bones found at the subantarctic Auckland Islands
A significant discovery of over 3,500 Holocene bird bones on the uninhabited Auckland Islands reveals critical insights into the island's prehistoric avifauna. The remains, representing at least 853 individuals, indicate that four bird species—including a duck, two petrels, and a plover—went extinct due to introduced mammals and human hunting. Notably, all endemic taxa except one (the Auckland Island tomtit) were found in the deposits, while the shore plover remains elusive. The study also highlights shifts in species abundance, such as the eastern rockhopper penguin and white-chinned petrel, which are now rare but once thrived on Enderby Island. This research provides a foundation for managing and restoring the island's avifauna, contributing to ongoing ecological restoration efforts.
Introduced land mammals and their impacts on the birds of the subantarctic Auckland Islands
Introduced land mammals have significantly impacted the bird populations of the subantarctic Auckland Islands. Since European discovery, at least ten species established themselves, leading to habitat transformation and ecosystem alterations. Cattle, goats, pigs, and rabbits were particularly destructive, suppressing tussock and woody vegetation across multiple islands. Cats and pigs are notably responsible for the extirpation or major reduction of surface-nesting seabird colonies and ground-nesting land birds on Auckland Island. Mice have also altered invertebrate community composition, affecting wētā and large weevils. The study highlights that eradication efforts, such as those targeting pigs, cats, and mice from Auckland Island, could potentially remove the last introduced mammals from the New Zealand subantarctic region, offering a pathway to restore native bird populations.
Ornithological discovery, exploration, and research on the Auckland Islands, New Zealand subantarctic
Despite being the most researched and largest island group in New Zealand's subantarctic region, the Auckland Islands have lacked a comprehensive ornithological review. A database of 23,028 bird records from 1807 to 2019 reveals that over 76% of these observations remain unpublished, with significant contributions from historical expeditions like the Heritage Expedition and the Second World War Cape Expedition. The Auckland Islands host a high number of endemic bird taxa but have received limited research attention compared to other subantarctic islands, focusing primarily on large surface-nesting seabird species. Citizen science platforms, such as eBird, are emerging as valuable sources of data, with 1,597 unique records, and new vagrant species continue to be documented rapidly. This study highlights the gaps in ornithological research on the Auckland Islands while underscoring the potential of historical and citizen-science data to advance our understanding of its avifauna.
Population estimate for yellow-eyed penguins (Megadyptes antipodes) in the subantarctic Auckland Islands, New Zealand
A new population estimate for yellow-eyed penguins (Megadyptes antipodes) in the Auckland Islands, New Zealand, suggests that breeding numbers have remained stable over recent years, averaging 577 pairs annually between 2012 and 2017. This finding contradicts earlier estimates based on beach counts, which indicated a potential decline but were deemed less reliable due to uncertainty. The study combined intensive nest-searching with counts of transiting penguins on Enderby Island over three years to establish a relationship between count numbers and breeding birds, then extrapolated these findings to estimate the population for the entire Auckland Island group. The subantarctic populations, particularly in the Auckland Islands, are critical, representing 37–49% of the total breeding population for the species. Researchers recommend ongoing monitoring, including mark-recapture methods, with at least 50% of individuals marked to improve the accuracy and confidence intervals of future estimates.
Population status and habitat use of southern right whales in the sub-Antarctic Auckland Islands of New Zealand
Southern right whales exhibit strong habitat preference and social behavior in the Auckland Islands, indicating their role as a primary wintering ground. Research from 1995 to 1997 revealed high whale density (up to 146 individuals) in shallow nearshore waters, with 12% of the population consisting of cow-calf pairs. Molecular sexing showed no significant female-to-male ratio bias, while social/sexual activity dominated in groups of three or more whales. Photo-identification tracked 217 individuals, with resightings suggesting some seasonal movement to nearby Campbell Island. The study highlights a potential shift in habitat use post-exploitation, contrasting the rarity of these whales on New Zealand's main islands.
Satellite derived offshore migratory movements of southern right whales (Eubalaena australis) from Australian and New Zealand wintering grounds
New satellite tracking data reveal that southern right whales (Eubalaena australis) from Australian and New Zealand wintering grounds exhibit variable migratory pathways and foraging strategies during the Austral summer. While some whales migrate to the Subtropical Front, a likely feeding ground shared by both populations, others, particularly one tagged in Tasmania—a sub-population not showing post-whaling recovery—travel to higher latitude Antarctic waters, suggesting distinct foraging behaviors. The study tracked six whales for an average of 78.5 days, covering distances ranging from 645 to 6,381 km, challenging the assumption of consistent migratory corridors in this species. These findings highlight potential differences in feeding ground fidelity and population growth rates between wintering grounds, offering insights into the ecological dynamics of southern right whales.
Subantarctic Adams Island and its birdlife
Adams Island, the second-largest island in New Zealand's Auckland Islands group and the largest without established introduced mammals, supports a unique and abundant avifauna due to its predator-free environment. The island's diverse habitats—ranging from forest to shrubland, grassland, fellfield, and herb-fields—foster high densities of bird species, closely resembling pre-human conditions with the notable exception of the Auckland Island merganser. A total of 48 bird species have been recorded on Adams Island, including 22 land birds and 26 seabirds, with 34 species confirmed or likely to breed there. Additionally, eight introduced species, six of which probably breed, add to the island's ecological complexity. This study provides a comprehensive description of the island's ornithological history and current avifauna status, highlighting its significance as a pristine ecosystem in the Subantarctic region.
Are moths the missing pollinators in Subantarctic New Zealand?
Moths emerge as critical pollinators in the depauperate insect fauna of Subantarctic New Zealand, where they carry pollen from four plant species despite harsh conditions and low abundance. The study, conducted across three habitat types using Heath moth traps, found that moths transported pollen most abundantly from Bulbinella rossii and Dracophyllum longifolium, with shrubland environments showing higher pollen diversity per moth. While weather influenced moth distribution, local flowering patterns—particularly the dominance of D. longifolium—better explained their pollination potential. This is the first evidence that moths play an overlooked role in Subantarctic plant reproduction, challenging assumptions about insect-mediated pollination in species-poor island ecosystems.
Causes of adult mortality in two populations of New Zealand sea lions (Phocarctos hookeri)
Infectious disease, particularly tuberculosis caused by Mycobacterium pinnipedii, and conspecific trauma are the leading causes of adult mortality in New Zealand sea lions (Phocarctos hookeri), an endangered species endemic to New Zealand. The study, which analyzed 136 sea lions across two populations—one on remote Enderby Island and another recolonizing the mainland—revealed that these factors accounted for 37% and 24% of diagnosed deaths, respectively. Anthropogenic trauma emerged as a significant threat in the mainland population, highlighting the growing risk from human interactions as both human and pinniped populations expand. This research underscores the critical need to manage human-pinniped conflicts to ensure the species' recovery.
Cryptic diversity in smooth-shelled mussels on Southern Ocean islands: connectivity, hybridisation and a marine invasion
Research on smooth-shelled mussels (Mytilus spp.) around the New Zealand Sub-Antarctic Islands reveals that these populations exhibit mixed genome ancestry, indicating native origins rather than human introduction. Using single nucleotide polymorphism (SNP) analysis, scientists found that mussels from the Falkland and Kerguelen Islands are closely related to M. platensis from South America, suggesting dispersal via ocean currents. Meanwhile, mussels from Tasmania, mainland New Zealand, and offshore islands form a distinct Southern Hemisphere group with affinities to Northern Hemisphere M. galloprovincialis. The study also detected hybridisation between taxa, with invasive M. galloprovincialis identified only in Tasmania. These findings highlight the importance of preserving native evolutionary lineages, particularly on remote islands where small populations may be vulnerable to invasion and genetic dilution.
High-coverage genomes to elucidate the evolution of penguins
A groundbreaking genomic study of penguins reveals that the genus Aptenodytes, which includes the emperor and king penguins, is the basal lineage to all other extant penguin genera. This challenges previous evolutionary models and sheds new light on how penguins adapted to extreme environments like Antarctica. The research presents a comprehensive dataset of 21 high-coverage genomes representing all living penguin species, providing a robust phylogenetic framework. It also introduces an international consortium focused on studying these genomes while emphasizing the importance of legal and respectful indigenous consultation, particularly for New Zealand's Taonga species. This work not only advances our understanding of penguin evolution but also offers critical insights for conservation efforts in the face of climate change.
High-resolution seismic imaging reveals infill history of a submerged Quaternary fjord system in the subantarctic Auckland Islands, New Zealand
High-resolution seismic imaging and multibeam bathymetry reveal the infill history of a submerged Quaternary fjord system off the Auckland Islands, New Zealand. The study identifies sediment-filled valleys extending offshore to depths below glacial low-stand sea level, shaped by submarine fluvial erosion and subsequently filled by lacustrine, fjord, and fluvial sediments. This discovery sheds light on the complex erosive and depositional processes in remote subantarctic environments, where surface erosion and sediment overprinting often obscure geological history.
Pleistocene glacial history of the New Zealand subantarctic islands
A multidisciplinary study of the New Zealand Sub-Antarctic Islands reveals that significant glaciation occurred during Marine Isotope Stage 10 (~384,000 years ago) and a restricted glacial period around 72–62 thousand years ago, rather than at the Last Glacial Maximum (LGM). The research, combining geomorphological surveys, sedimentary analyses, dating, and glacier modeling, challenges previous assumptions about LGM glaciation. Findings suggest that despite cooler temperatures during the LGM, high seasonality and low precipitation prevented substantial ice formation. Instead, northward expansion of winter sea ice likely led to reduced precipitation, limiting glacial extent.
Population growth of an endangered pinniped—the New Zealand sea lion (Phocarctos hookeri)—is limited more by high pup mortality than fisheries bycatch
Population growth of the endangered New Zealand sea lion (Phocarctos hookeri) on Campbell Island is primarily constrained by high pup mortality, not fisheries bycatch. A precautionary Potential Biological Removal (PBR) analysis revealed that current bycatch levels—even with a strong male bias (98%)—remain below sustainability thresholds, particularly after mitigation measures were implemented. Population Viability Analysis (PVA) modeling further supported this, indicating that reducing pup mortality, such as through ramp installations in wallows to prevent drowning, could significantly boost population growth. While long-term research is needed for more precise demographic data, the study underscores the critical need for ongoing conservation efforts focused on pup survival and bycatch mitigation, alongside robust observer coverage to ensure accurate annual estimates.
Pup mortality in New Zealand sea lions (Phocarctos hookeri) at Enderby Island, Auckland Islands, 2013-18
A hypervirulent strain of Klebsiella pneumoniae, causing septicaemia and associated meningitis and polyarthritis, is identified as the leading cause of pup mortality in New Zealand sea lions (Phocarctos hookeri) at Enderby Island, accounting for approximately 60.2% of deaths annually between 2013 and 2018. This finding, derived from advanced diagnostic methods including histopathology, microbiology, and matrix-assisted laser desorption/ionisation-time of flight mass spectrometry, challenges previous underrepresentation of this pathogen due to its often cryptic presentation. The study highlights the significant threat posed by hypermucoviscous K. pneumoniae to pup survival, with additional mortality likely occurring post-dispersal beyond summer monitoring periods. Less common causes of death included starvation (14.8%), trauma/asphyxiation (9.9%), and other infections (7%). This research provides a foundation for evaluating risk factors and developing mitigation strategies to address this critical conservation issue.
Systematics and biogeography of the subantarctic Leptusa (Coleoptera: Staphylinidae: Aleocharinae: Homalotini)
A taxonomic revision of the subantarctic genus Leptusa (Coleoptera: Staphylinidae) reveals that Leptusa antarctica is not a single species but a complex of five distinct species, two of which were reinstated from synonymy and two newly described. The study confirms the identity and disjunct distribution of Leptusa atriceps across multiple subantarctic islands, including Falkland, South Georgia, Marion, Crozet, and Kerguelen Islands. Phylogenetic analysis using 76 morphological characters supports the monophyly of the subgenus Halmaeusa but does not firmly establish its evolutionary relationships, with Nanoglossa from South America emerging as a potential sister group. The distribution patterns of these species provide a foundation for future biogeographic studies in the subantarctic region.
Temperature, Wind, Cloud, and the Postglacial Tree Line History of Sub-Antarctic Campbell Island
Campbell Island, located 600 km south of New Zealand, exhibits a unique postglacial tree line history that is decoupled from Southern Ocean temperature trends. The study reveals that while ocean temperatures were warmer between 12,500 and 9,000 years ago, the island's tree lines did not rise due to weaker westerlies, which allowed for the intrusion of warmer, cloudier northern airmasses. This phenomenon reduced solar radiation and increased atmospheric humidity, suppressing tree growth. Conversely, stronger, cooler westerlies during the Holocene facilitated clearer skies, drier air, and rising tree lines. The research uses pollen records from three peat cores to reconstruct vegetation changes over 17,000 years, providing insights into the complex interplay between climate, wind patterns, and ecological dynamics in sub-Antarctic regions.
Temporal variation in the vocal behaviour of southern right whales in the Auckland Islands, New Zealand
Seasonal variation is the dominant factor influencing the vocal behavior of southern right whales at their main calving ground in New Zealand's Auckland Islands, according to a year-long study using autonomous recorders. Call rates peaked in August and July, with 'upcalls' being the most frequent, suggesting these calls primarily function as contact signals during dusk and night. The research also found that an automated detector designed for North Atlantic right whales accurately identified 80% of upcalls but had high false detection rates, particularly at low call rates. This is the first attempt to monitor southern right whale presence year-round in New Zealand.
The Pselaphini (Coleoptera: Staphylinidae: Pselaphinae) of the Subantarctic and Chatham Islands of New Zealand; Description of Five Species and One Genus
Researchers have identified five new species and one genus of Pselaphini beetles (Coleoptera: Staphylinidae: Pselaphinae) from the New Zealand Subantarctic Islands and Chatham Islands, expanding the known biodiversity of this rare subfamily at high latitudes. The study, led by Owens et al., describes Pselaphopluteum motumaha as a new genus and species from the Auckland Islands, along with two additional species (Pselaphaulax dracophyllum) from the Subantarctic and three more (Pselaphaulax caeruleus, Pselaphaulax flavus, and Pselaphaulax traversi) from the Chatham Islands. These findings challenge the notion that Pselaphinae are depauperate in extreme southern regions, offering new insights into their biogeographic distribution. The study also highlights the presence of an introduced species, Pselaphophus atriventris, in the Chatham Islands, suggesting potential pathways for species dispersal and colonization.
Unnamed for over 30 years: Gigartina falshawiae sp. nov. (Gigartinaceae, Rhodophyta) and its confusion with Iridaea tuberculosa in New Zealand
A newly described red algal species, Gigartina falshawiae, has been identified from Stewart Island, New Zealand, resolving a long-standing taxonomic confusion with Iridaea tuberculosa. The discovery clarifies that G. falshawiae, previously mislabeled as I. tuberculosa in Lindauer's collection, is distinct in morphology—featuring forked, bushy thalli with marginal proliferations and lobed cystocarps—while I. tuberculosa exhibits fan-shaped thalli without proliferations and globose cystocarps. Additionally, their distributional ranges differ: G. falshawiae is endemic to Stewart Island, whereas I. tuberculosa occurs on the New Zealand subantarctic islands (Antipodes, Auckland, and Campbell Islands), with both species co-occurring on the Snares Islands. This study corrects a 30-year-old misidentification, enhancing our understanding of Gigartina taxonomy in New Zealand.
Behavioural consequences of human disturbance on subantarctic Yellow-eyed Penguins Megadyptes antipodes
Human disturbance significantly impacts the behavior of subantarctic Yellow-eyed Penguins (Megadyptes antipodes), reducing their likelihood of successful transit to or from nests and altering their activity patterns. Research on Enderby Island, part of New Zealand's UNESCO-listed Auckland Islands group, revealed that current tourism guidelines—requiring a minimum 5-meter approach distance—are insufficient to prevent disturbance. The study used controlled approaches and tourist monitoring to document penguin movement and behavior, modeling effective approach distances to predict disturbance probabilities. Findings suggest revising guidelines to better protect this endangered species, with broader implications for wildlife management worldwide.
Draft Whole-Genome Sequences of Five Klebsiella pneumoniae Isolates from the Subantarctic Islands of New Zealand
Researchers have reported the draft whole-genome sequences of five Klebsiella pneumoniae isolates sourced from environmental samples and bird feces collected in New Zealand's Subantarctic Islands. This study provides valuable genomic data that could enhance our understanding of bacterial diversity and potential ecological roles in remote, pristine environments like UNESCO World Heritage Sites. By analyzing these isolates, scientists aim to uncover insights into the bacterium's adaptability, genetic traits, and its interaction with wildlife and environmental factors in such unique settings.
Around the pole: evolution of sub‐Antarctic Ranunculus
Multiple lineages of the genus Ranunculus have independently colonized the sub-Antarctic islands, likely arriving from lower-latitude regions such as Australia, New Zealand, or South America before the Last Glacial Maximum. Phylogenetic and divergence time analyses of 53 accessions revealed that chance events played a significant role in species arrival, while subsequent trait–environment interactions were crucial for establishment and persistence in sub-Antarctic habitats. The study also found that two distinct ecomorphological trait combinations are shared between sub-Antarctic and lower-latitude species, with their proportions differing significantly between these regions.
Late Holocene glacier reconstruction reveals retreat behind present limits and two‐stage Little Ice Age on subantarctic South Georgia
A two-stage Little Ice Age, marked by glacier advances around 300 and 120 years ago, has been identified on subantarctic South Georgia using sediment analysis from Middle Hamberg Lake. The study also reveals an unreported retreat of glaciers behind present limits around 500 years ago, providing new insights into Late Holocene climate variability in the Southern Ocean region. Researchers used titanium counts in rock flour, validated with sediment density and grain size data, to reconstruct continuous glacier variations over the past ~1250 years. This approach, combined with local moraine evidence and data from other Southern Hemisphere glaciers, offers a high-resolution paleoclimate record that challenges previous assumptions about glacial behavior during the Little Ice Age.
Late Holocene intensification of the westerly winds at the subantarctic Auckland Islands (51° S), New Zealand
A late Holocene intensification of the Southern Hemisphere westerly winds (SHWWs) between approximately 1600 and 900 years ago was identified at the subantarctic Auckland Islands, New Zealand. This finding suggests a northward migration of the SHWW over New Zealand during the first half of the last millennium, consistent with climate-driven vegetation changes in the region. The study used fjord sediment core data, analyzing magnetic susceptibility (MS), bulk organic δ13C and atomic C/N ratios to track terrestrial and marine organic matter influxes, alongside benthic foraminifer δ18O and δ13C to assess water column responses. Comparisons with records from southern South America and West Antarctica indicate a late Holocene strengthening of the SHWWs, likely linked to atmospheric teleconnections and Southern Annular Mode variability.
Reproductive strategy as a piece of the biogeographic puzzle: a case study using Antarctic sea stars (Echinodermata, Asteroidea)
A comprehensive analysis of Antarctic sea star biogeography reveals that reproductive strategy—brooding versus broadcasting—significantly influences species distribution across the Southern Ocean. The study, based on over 14,000 asteroid occurrences, identified distinct biogeographic patterns, including the isolation of New Zealand and high richness in the Scotia Arc region, particularly among brooding species. It also highlighted faunal affinities between South America and sub-Antarctic islands while noting lower endemism levels than previously reported (29% Antarctica-only species). The research used advanced statistical methods like bootstrapped spanning network (BSN), non-metric multidimensional scaling (nMDS), and clustering to uncover these patterns, which align with findings from other marine groups. The study suggests that historical factors further shape biogeographic differences at taxonomic levels.
The Forgotten Islands: Monitoring Tourist Numbers and Managing Tourism Impacts on New Zealand’s Subantarctic Islands
New Zealand's Subantarctic Islands, recognized as a UNESCO World Heritage Area for their unique biodiversity and pristine landscapes, face growing tourism pressures despite limited data on visitor impacts. A recent study reveals that while tourist numbers have increased, particularly from small vessels like yachts, monitoring efforts remain fragmented, with only sporadic records since the mid-1990s. The research highlights significant gaps in understanding the environmental and cultural effects of tourism, including wildlife disruption and soil vegetation changes. Drawing on stakeholder interviews and secondary data, the study calls for a comprehensive visitor monitoring program to assess both ecological consequences and visitor experiences, aligning with the 2016 Conservation Management Strategy's recommendations.
Dynamics of Orographic Gravity Waves Observed in the Mesosphere over the Auckland Islands during the Deep Propagating Gravity Wave Experiment (DEEPWAVE)
A groundbreaking study reveals that orographic gravity waves generated by airflow over the Auckland Islands significantly impact mesospheric dynamics. During the DEEPWAVE experiment, large-amplitude wave oscillations were detected at altitudes of 78–83 km, leading to intense wave breaking beneath a zero-wind region. These waves, influenced by migrating semidiurnal tides, caused rapid westward flow accelerations (~350 m/s/h) and substantial dynamical heating (~8 K/h). The research used high-altitude reanalysis data and a 3D Fourier gravity wave model to replicate observed wave fields, confirming the islands' role in altering middle-atmospheric circulation and climate during austral winter. This finding underscores the broader implications of subantarctic island-generated waves on global atmospheric dynamics.
First Direct Evidence for Natal Wintering Ground Fidelity and Estimate of Juvenile Survival in the New Zealand Southern Right Whale Eubalaena australis
A groundbreaking study provides the first direct evidence of natal wintering ground fidelity and estimates juvenile survival rates in New Zealand's southern right whale population. Researchers used DNA profiling of skin biopsy samples to track individual whales from their year of birth, documenting their return to the Subantarctic Auckland Islands over multiple years. Fifteen out of 57 whales initially sampled were recaptured during winter surveys between 1995-2009, including four individuals aged 9 to 11 years, with two females first identified as calves in 1998 and later seen with their own calves in 2007. The study estimates high annual juvenile survival rates ranging from 0.87 to 0.95, using Cormack-Jolly-Seber models to analyze discrete age classes and continuous age functions. This method offers a robust approach for long-term demographic and genetic monitoring, particularly useful for species like southern right whales that undergo significant physical changes over time.
Five new species of Corybas (Diurideae, Orchidaceae) endemic to New Zealand and phylogeny of the Nematoceras clade
Researchers have identified five new species of Corybas orchids endemic to New Zealand, distinguished from the Corybas trilobus aggregate through morphometric and DNA fingerprinting (AFLP) analyses. These species—C. confusus, C. obscurus, C. sanctigeorgianus, C. vitreus, and C. wallii—exhibit low genetic divergence, suggesting recent diversification despite their morphological and ecological diversity. The study also reveals multiple dispersal events from New Zealand to offshore and sub-Antarctic islands, contributing new insights into the phylogeny of the Nematoceras clade.
Genetic Evidence of a Population Bottleneck and Inbreeding in the Endangered New Zealand Sea Lion,Phocarctos hookeri
Research on the endangered New Zealand sea lion (Phocarctos hookeri) reveals genetic evidence of a population bottleneck and increased inbreeding, likely due to historical sealing pressures. The study analyzed 1205 individuals across seven breeding seasons using 17 microsatellite loci, demonstrating moderate genetic diversity compared to other pinnipeds but also indicating nonrandom mating patterns. Pups that died during recent epizootic events showed higher allele sharing and parental relatedness, suggesting inbreeding's role in population vulnerability. These findings highlight the species' reduced evolutionary capacity, posing challenges for its long-term survival and recovery.
Large‐amplitude mesospheric response to an orographic wave generated over the Southern Ocean Auckland Islands (50.7°S) during the DEEPWAVE project
A significant mesospheric response to orographic waves was observed over the Auckland Islands (50.7°S) during the DEEPWAVE project, revealing deep atmospheric wave propagation with large amplitudes and momentum flux. The study, conducted using a suite of ground-based and airborne instruments, including the NSF Gulfstream V research aircraft, documented a mountain wave with a temperature amplitude of ~10 K and a horizontal wavelength of ~40 km, which exhibited instability and breaking at the OH layer (~83.5 km). The findings suggest that strong mesospheric responses can arise from small sources under suitable conditions, challenging previous assumptions about their rarity.
Leaf and floral heating in cold climates: do sub-Antarctic megaherbs resemble tropical alpine giants?
Sub-Antarctic megaherbs exhibit significant leaf and floral heating, with temperatures up to 11°C higher than ambient conditions, challenging the typical low-statured plant forms seen in cold climates. This discovery suggests thermal benefits akin to tropical alpine giants, driven by brief periods of solar radiation and enhanced by hairy, corrugated leaves and darkly pigmented inflorescences. Researchers used thermal imaging techniques on Campbell Island (52.3°S) to measure leaf and inflorescence temperatures, correlating them with environmental variables such as solar radiation, wind speed, and humidity. The findings highlight the potential adaptive significance of these plant traits in extreme environments.
Marine micronutrient vectors: seabirds, marine mammals and fishes egest high concentrations of bioactive metals in the subantarctic island ecosystem
Seabirds, marine mammals, and fishes around the New Zealand Sub-Antarctic Islands act as critical vectors for bioactive metals (Mn, Fe, Co, Ni, Cu, Zn, As, Cd), concentrating them in their egesta. The study found that upper trophic levels—particularly New Zealand fur seals and Hooker's sea lions—bioaccumulate potentially limiting micronutrients like Mn, Fe, Co, and Zn, with metal concentration patterns more closely tied to food web structure than water mass differences between the Snares and Auckland Islands. Researchers analyzed egested material from 16 species (fishes, seabirds, pinnipeds) alongside suspended particulate organic matter, macroalgae, and zooplankton using isotopic (δ¹⁵N, δ¹³C) and multivariate profiling to assess trophic positions and metal distributions. This highlights the role of biological vectors in nutrient cycling within subantarctic island ecosystems.
Quantitative analysis of the acoustic repertoire of southern right whales in New Zealand
Researchers have identified and quantified the full acoustic repertoire of southern right whales (Eubalaena australis) in New Zealand, revealing 10 distinct call types on their calving grounds in the sub-Antarctic Auckland Islands. Among these, pulsive, upcall, and tonal low vocalizations were most frequent, while a long tonal low call (≤15.5 s duration) and a very high call (peak frequency ∼750 Hz) were documented for the first time. Using Random Forest multivariate analysis on 28 measured variables, the study achieved an 82% accuracy in classifying calls, with maximum ceiling frequency, inflection points, duration, and start-end frequency differences proving most critical. This method offers a repeatable, fast, and objective approach to categorizing right whale calls, with potential applications for passive acoustic monitoring and automated call detection in remote or visually challenging environments.
Seroprevalence of Toxoplasma gondii in mainland and sub-Antarctic New Zealand sea lion (Phocarctos hookeri) populations
Toxoplasma gondii infection is unlikely to be a major contributor to reproductive failure in New Zealand sea lions (Phocarctos hookeri), according to a study analyzing seroprevalence across mainland and sub-Antarctic populations. The research tested archived sera from 55 sea lions using ELISA, latex agglutination tests (LAT), and Western blot validation, revealing five positive cases—all from mainland locations (Otago Peninsula and Stewart Island). Notably, two adult females exhibited high antibody titres over consecutive years, while no sub-Antarctic Enderby Island sea lions tested positive. While T. gondii does not appear to significantly impact reproduction in these threatened populations, the study underscores the need for ongoing surveillance to assess potential subclinical effects. The findings also suggest that commercially available tests, with species-specific threshold adjustments, could serve as a reliable and cost-effective tool for monitoring exposure in New Zealand sea lions.
The origins of white-chinned petrels killed by long-line fisheries off South Africa and New Zealand
A genetic analysis of white-chinned petrels (Procellaria aequinoctialis) killed as bycatch in long-line fisheries off South Africa and New Zealand reveals distinct subspecies origins. All 113 birds from South African waters belonged to the Atlantic/Indian Ocean subspecies (P. a. aequinoctialis), while all 60 New Zealand birds were identified as the New Zealand sub-Antarctic subspecies (P. a. steadi). This finding indicates that the two subspecies disperse to different regions regardless of age, aligning with tracking data of adult birds. The study highlights the need for region-specific management strategies to mitigate fishery bycatch impacts on this vulnerable seabird species.
Experiences of adolescents on an expedition to New Zealand’s sub-Antarctic: results from the use of photo-elicitation
A groundbreaking study reveals that expeditions to remote polar regions can profoundly shape adolescents' perspectives and behaviors, acting as powerful advocates for environmental conservation. The research, involving 12 New Zealand teenagers on the 2014 Young Blake Expedition to the sub-Antarctic Auckland Islands, identified five key themes: experiential learning, the uniqueness of the setting, the distinctiveness of the experience, sharing with others, and a sense of adventure and accomplishment. These findings align with previous studies on wilderness-based outdoor education, suggesting that such expeditions can be life-changing for participants. The study used auto-driven photo-elicitation, a novel method to capture personal experiences through participant-selected images.
Geology and geochronology of the Sub-Antarctic Snares Islands/Tini Heke, New Zealand
A groundbreaking geological map and radiogenic isotope data reveal the Sub-Antarctic Snares Islands/Tini Heke, New Zealand, are composed primarily of the Snares Granite (c. 109 Ma) intruding Broughton Granodiorite (c. 114 Ma). The study identifies schistose rafts within the granite, suggesting a meta-igneous origin, and confirms no conclusive metasedimentary rocks exist despite sillimanite-bearing mica-rich schists on Rua. Deformation occurred between 95–109 Ma, overlapping with extensional ductile shear zones on Stewart Island. Additionally, basaltic dykes indicate volcanic activity across all Sub-Antarctic island groups, with larger islands capped by peat and gravel deposits.
Historical population size of the threatened New Zealand sea lion Phocarctos hookeri
The historical population of the New Zealand sea lion (Phocarctos hookeri) in the subantarctic islands was significantly larger than current estimates used for management, suggesting that present-day bycatch levels from commercial trawl fisheries may be unsustainable. Using genetic methods to estimate long-term effective population size, researchers found that the pre-exploitation abundance of this threatened marine mammal was substantially higher than contemporary carrying capacity targets (K). This implies that the species' recovery toward historical population levels could be hindered by current management strategies, which may not account for sustainable bycatch limits. The study highlights the need to reassess population thresholds to ensure long-term viability and recovery of the NZ sea lion.
Patterns in floral traits and plant breeding systems on Southern Ocean Islands
A significant proportion of flowering plant species on Southern Ocean Islands (SOIs) exhibit traits indicative of wind pollination (anemophily) and self-compatibility, challenging the expectation that these harsh environments would favor such reproductive strategies. The study found that 34.3% of the 321 SOI species possess anemophilous floral traits, while 92.6% of potentially self-fertilizing species were confirmed as partially or fully self-compatible. Gender dimorphy (dioecy and gynodioecy) occurred in 7.1% and 3.4% of species, respectively, with no clear evidence of in situ evolution. Notably, anemophily was more prevalent in genera occurring on subantarctic islands, while biotic pollination traits were significantly higher on climatically milder, cool temperate islands. These findings suggest that reliance on biotic pollinators has constrained species distribution on SOIs, though mixed mating strategies are likely common. The study also highlights the need for further in situ research to better understand the reproductive biology of SOI species.
Breeding status affects fine‐scale habitat selection of southern right whales on their wintering grounds
Southern right whales (Eubalaena australis) exhibit distinct habitat preferences based on breeding status, with calving females favoring sheltered, nearshore waters during winter. Research conducted at Port Ross, Auckland Islands, revealed that calf groups consistently selected areas with lower wave exposure, proximity to shelter, shallow depths, and nearness to the coastline. In contrast, non-calving whales showed less selectivity in their habitat choices. The study used species-habitat surveys (2010-2012) and binomial generalized additive models to analyze environmental variables such as water depth, seabed slope, distance to coast, shelter availability, and wave exposure. Validation confirmed the robustness of the calf group model, emphasizing the critical role of sheltered habitats for vulnerable life stages in marine mammals.
Cephalopod fauna of South Pacific waters: new information from breeding New Zealand wandering albatrosses
A circumpolar distribution of key cephalopod species in the Southern Ocean is evidenced by predator sampling, revealing new insights into their ecology and biogeography. The study analyzed 9111 cephalopod beaks from 41 taxa, collected through regurgitated boluses from breeding New Zealand wandering albatrosses at Antipodes and Auckland Islands. Histioteuthidae (e.g., Histioteuthis atlantica) and Onychoteuthidae (e.g., Moroteuthis robsoni) emerged as dominant in both numerical abundance and reconstructed mass, respectively. This research fills critical gaps in the poorly sampled Pacific sector of the Southern Ocean, providing new data on cephalopod biodiversity, predator-prey dynamics, and foraging patterns in one of Earth's most remote ocean regions.
Foraging diversity in lactating New Zealand sea lions: insights from qualitative and quantitative fatty acid analysis
Lactating New Zealand sea lions exhibit distinct foraging strategies that significantly impact their energy expenditure and diet composition. Benthic foragers, which dive deeper and spend more time at sea, show higher energy costs compared to mesopelagic conspecifics but do not compensate with higher-energy prey. Fatty acid analysis revealed significant differences in blubber profiles between the two foraging types (global R = 0.30, p = 0.001), indicating divergent prey resource use despite overlapping diet components. Quantitative fatty acid signature analysis further confirmed distinct dietary contributions (global R = 0.17, p = 0.022). The study suggests that benthic foraging may represent a trade-off between increased energy expenditure and reduced competition with trawling fisheries, highlighting the ecological adaptability of this species in the New Zealand Sub-Antarctic Islands.
Transfer of the subantarctic red alga Grateloupia aucklandica to the genus Glaphyrosiphon (Halymeniales, Rhodophyta)
A recent taxonomic reassessment of the subantarctic red alga Grateloupia aucklandica, found on New Zealand's Auckland and Campbell Islands, reveals it should be reclassified under the genus Glaphyrosiphon. Phylogenetic analysis using rbcL data demonstrated that this species is more closely related to Glaphyrosiphon chilensis from Chile than to other New Zealand species in the same genus, such as Gl. intestinalis and Gl. lindaueri. This discovery underscores the need for a reevaluation of the taxonomic placement of Grateloupia aucklandica within its broader evolutionary context.
Transoceanic genetic similarities of kelp‐associated sea slug populations: long‐distance dispersal via rafting?
A groundbreaking study reveals that sea slug populations of the genus Onchidella, previously thought to be distinct species, are genetically interconnected across vast distances in the Southern Hemisphere. The research, conducted on cool-temperate and subantarctic coasts including New Zealand's subantarctic islands, southern Chile, and the Falkland Islands, challenges traditional taxonomic classifications by demonstrating widespread genetic similarity among these slugs. This connectivity is attributed to passive rafting facilitated by buoyant bull-kelp (Durvillaea) and driven by circumpolar ocean currents. The study employed mitochondrial DNA sequences and amplified fragment length polymorphisms (AFLPs) to analyze population structuring, uncovering substantial differentiation in mainland New Zealand populations while highlighting shared haplotypes among distant subantarctic samples. These findings suggest recent common ancestry and long-distance dispersal mechanisms for these ecologically significant marine organisms.
Trophic interactions and ecosystem management at the New Zealand Subantarctic Islands
A study of the New Zealand Sub-Antarctic Islands revealed strong trophic linkages between marine and terrestrial ecosystems, extending beyond local scales. Using stable isotope analysis (δ¹⁵N and δ¹³C), researchers found that both Antipodes and Bounty Islands exhibit complex food webs with omnivory across multiple trophic levels. While Antipodes Island demonstrated a more intricate marine community influenced by phytoplankton and kelp, the Bounty Islands relied solely on phytoplankton-derived carbon. Terrestrial species at both sites incorporated marine-derived nutrients, with Antipodes showing mixed sources while Bounty was entirely dependent on marine inputs linked to phytoplankton. Nutrient sampling further indicated distinct oceanographic patterns around each island. This research underscores the need for integrated ecosystem-based management (EBM) to preserve these critical biodiversity hubs, advocating for cross-sectoral collaboration in policy and legislation.
Winter Climate Limits Subantarctic Low Forest Growth and Establishment
Winter climate plays a crucial role in limiting the growth and establishment of subantarctic low forest on Campbell Island, despite overall warming trends. Research reveals that while warmer winters (mean temperatures >7 °C) enhance seedling survival and recruitment, they also increase metabolic stress in established plants, reducing growth rates. Conversely, drier winters (total precipitation <400 mm) further optimize establishment conditions. The study used dendroecological methods and local climate data to analyze the effects of summer and winter climatic variables on two treeline-forming species, Dracophyllum longifolium and Dracophyllum scoparium, over the latter half of the 20th century. Findings suggest that future winter warming may have complex, contrasting effects on plant growth and establishment globally.
Comparative biogeography of echinoids, bivalves and gastropods from the S outhern O cean
A comparative biogeographical analysis of echinoids, bivalves, and gastropods from the Southern Ocean reveals distinct faunal provinces that align with oceanographic currents and historical marine seaways. The study identifies three primary provinces for echinoids and bivalves—New Zealand, southern South America and sub-Antarctic islands, and Antarctica—and five for gastropods, including additional subdivisions within Antarctica (West and East). These patterns support hypotheses of past connections between the Amundsen–Bellingshausen area, Weddell Sea, and Ross Sea. The research employed a non-hierarchical clustering method, bootstrapped spanning network (BSN), to analyze taxonomic similarities at species and genus levels across 14 bioregions, demonstrating its effectiveness in identifying both strong faunal groupings and transitional areas. This approach also highlights potential dispersal routes, offering insights into present and past marine connectivity.
High prevalence ofLeucocytozoonspp. in the endangered yellow-eyed penguin (Megadyptes antipodes) in the sub-Antarctic regions of New Zealand
A high prevalence of Leucocytozoon spp. infection, particularly on Enderby Island, is linked to significant chick mortality in endangered yellow-eyed penguins (Megadyptes antipodes). The study found that 73.7% of adult penguins from Enderby Island tested positive for the parasite during the 2006/07 breeding season, with histological evidence confirming infection in one chick. This prevalence contrasts sharply with lower rates on Campbell Island (21%) and mainland New Zealand (11%). Genetic analysis revealed that Leucocytozoon in Enderby penguins is distinct from other populations, suggesting localized adaptation or transmission dynamics. While the exact role of the parasite in mortality remains unclear, these findings highlight its potential as a contributing factor to population declines.
New Lepidium (Brassicaceae) from New Zealand
A groundbreaking revision of Lepidium species in New Zealand identifies sixteen distinct species, ten of which are newly described. These include Lepidium castellanum from the Kermadec Islands and Lepidium seditiosum, the sole vascular plant endemic to the remote Bounty Islands group—a UNESCO World Heritage Site. The study leverages morphological traits alongside molecular data from three DNA markers (two rDNA and one cpDNA) to segregate species, revealing a rich diversity of Lepidium in New Zealand's subantarctic islands. Notably, two North Island species, Lepidium amissum and Lepidium obtusatum, are now extinct, while others like Lepidium juvencum extend to Stewart Island. The research also clarifies taxonomic ambiguities by typifying key species, providing a comprehensive framework for understanding this genus in the region.
Reestablishment of former wintering grounds by New Zealand southern right whales
Southern right whales (SRWs) have reestablished their historical wintering grounds around mainland New Zealand, with regular sightings since 1988. This resurgence, likely from a remnant population persisting in the subantarctic Auckland and Campbell Islands, shows promise for recovery after near-extinction due to whaling. Between 2003 and 2010, 125 sightings were recorded, including 28 cow-calf pairs—a significant increase compared to earlier decades. Two females were documented returning to the mainland with calves every four years, indicating site fidelity. Photographic identification and DNA profiling further revealed within-year movements and connectivity between mainland and subantarctic grounds. While the majority of SRWs remain concentrated in the subantarctic, this study highlights a positive trend in their range expansion.
The sub‐Antarctic Antipodes Volcano: a <0.5 Ma HIMU‐like Surtseyan volcanic outpost on the edge of the Campbell Plateau, New Zealand
The Antipodes Volcano, located on the edge of New Zealand's Campbell Plateau, exhibits distinctive geochemical and isotopic characteristics that provide a unique baseline for studying HIMU-like mantle sources. The volcano's youthful nature—indicated by well-preserved volcanic features and Ar/Ar ages of ≤0.5 million years—reveals a fractionation process dominated by clinopyroxene and olivine removal, with minimal continental crust interaction. Its lavas show consistently high 206 Pb/204 Pb and low 87 Sr/86 Sr ratios, comparable to anhydrous, Pb- and K-depleted peridotitic mantle xenoliths from Zealandia's intraplate volcanoes. This suggests that the Zealandia lithospheric mantle is isotopically heterogeneous, challenging the notion that all Zealandia Cretaceous–Cenozoic intraplate volcanoes tap a HIMU-like reservoir.
Winter foraging behaviour of lactating New Zealand sea lions ( Phocarctos hookeri )
Lactating female New Zealand sea lions exhibit extreme foraging behavior year-round, diving beyond aerobic limits on 65% of dives and showing consistent use of the continental shelf and edge. Research using satellite telemetry over two austral winters (1996–1997) revealed that their winter foraging areas overlap significantly (38%) with sub-Antarctic trawl fisheries, posing ongoing risks to this critically declining species. The study confirms seasonal and interannual stability in foraging patterns, emphasizing the need for integrated management to mitigate human-wildlife conflicts. This finding underscores the year-long vulnerability of sea lions to fisheries interactions during lactation.
Algal Parasite Herpodiscus durvillaeae (Phaeophyceae: Sphacelariales) Inferred to have Traversed the Pacific Ocean with its Buoyant Host
Researchers have discovered that the algal parasite Herpodiscus durvillaeae, previously known only from New Zealand, has traversed the Pacific Ocean, likely by rafting on its buoyant host, the southern bull-kelp (Durvillaea antarctica). Genetic analysis of samples from the Falkland Islands confirms the first record of this parasite in the Atlantic Ocean and reveals it is genetically indistinguishable from populations in New Zealand's sub-Antarctic Campbell Island. Additionally, the study reports H. durvillaeae infecting two other New Zealand endemic host species, Durvillaea poha and D. willana, expanding its known host range. The findings suggest recent trans-oceanic dispersal of this parasite, highlighting the role of buoyant macroalgae in facilitating long-distance movement.
Do Winds Control the Confluence of Subtropical and Subantarctic Surface Waters East of New Zealand?
Sea level anomalies, surface height gradients, and eddy kinetic energy in the New Zealand Sub-Antarctic Islands' confluence region are intensifying at accelerating rates—3.4 cm per decade for sea levels and 23 cm² s⁻² per decade for eddies—indicating a strengthening of frontal systems and ocean dynamics. While large-scale South Pacific winds appear to drive these changes, local bathymetry, including the Bounty Plateau and Bollons Seamount, also influences front positioning and eddy activity. The study, analyzing 18 years of satellite altimetry data (1993–2010), found a high correlation (r = 0.84) between frontal intensity and eddies, suggesting baroclinic instabilities. However, climate modes like the Southern Annular Mode (SAM) and Southern Oscillation Index (SOI) showed minimal correspondence with confluence variability, implying that local winds and topography play significant roles. If wind stress trends continue, this could further intensify heat and nutrient transfer, impacting energy dynamics and biological productivity.
Stauromenia australis, a new genus and species in the family Kallymeniaceae (Rhodophyta) from southern New Zealand
Scientists have identified Stauromenia australis, a novel genus and species of red algae (Rhodophyta) within the family Kallymeniaceae, discovered off southern New Zealand and its subantarctic islands. This discovery was made through molecular analysis and examination of herbarium specimens, revealing unique morphological traits such as a foliose habit, multiaxial structure with distinct cortical cells, and filamentous medulla. Unlike other members of its family, S. australis exhibits atypical postfertilization development, lacking connecting filaments and instead forming gonimoblasts directly from vegetative cells near the auxiliary cell system. Its phylogenetic distinctiveness and morphological differences underscore its status as a novel genus in the Southern Hemisphere, contributing to our understanding of red algae diversity in this region.
Biogeography of The New Zealand Subantarctic Islands: Phylogenetics ofPseudhelops(Coleoptera: Tenebrionidae)
A cladistic and population genetics study of the beetle genus Pseudhelops (Coleoptera: Tenebrionidae) on New Zealand’s subantarctic islands reveals that P. wenhami, previously considered a synonym, is a distinct species with higher-altitude distribution on Auckland Islands, while P. tuberculatus dominates lower altitudes. Phylogenetic analysis suggests island populations farther from the mainland are more derived, challenging geological estimates for the Antipodes and Bounty Platforms. The study also identifies sympatry in Pseudhelops, a common trait among subantarctic beetles, and proposes that soft polytomies may reflect recent speciation or ancestral soft branching. Morphological synapomorphies in P. liberalis and P. clandestinus hint at adaptations to rocky, vegetation-poor habitats.
Connectivity, small islands and large distances: the Cellana strigilis limpet complex in the Southern Ocean
A genetic investigation of the Cellana strigilis limpet complex, endemic to New Zealand's subantarctic islands, reveals two distinct lineages with high genetic structuring and minimal connectivity. Despite the Southern Ocean being a continuous medium, large distances between isolated island groups act as significant barriers to gene flow, leading to high self-recruitment and the presence of private haplotypes unique to individual islands. This study underscores the subantarctic islands' role as refugia during the last glacial maximum and provides insights into contemporary population connectivity in remote oceanic environments.
Detection and analysis of endogenous badnaviruses in the New Zealand flora
Research reveals that more than half of the New Zealand flora, including 37 out of 60 species studied, harbors endogenous badnavirus reverse transcriptase (RT) sequences. Unlike tropical regions where freely replicating badnaviruses are common, no active viruses were detected in this temperate Southern Hemisphere flora. Phylogenetic analysis showed that these RT sequences form distinct monophyletic groups, suggesting they may be widespread in temperate plant species. The study also identified a previously unrecognized Melicytus species and hinted at potential apomixis—a form of asexual reproduction—in Melicytus ramiflorus. These findings highlight the broader presence of integrated badnavirus sequences in temperate regions and caution about their potential activation under stress, such as tissue culture or genomic manipulation.
New species of Hyalidae (Crustacea, Peracarida, Amphipoda) from New Zealand waters
Research identifies two new species of hyalid amphipods, Apohyale papanuiensis and Apohyale freemenae, from New Zealand waters. A. papanuiensis was discovered in Little Papanui on the Otago Peninsula, while A. freemanae was recorded from the Antipodes Islands in the subantarctic region. The study also reclassified existing New Zealand records of Apohyale media as a synonym of A. papanuiensis. To aid identification, the authors provided a key to the New Zealand species of Apohyale, contributing to the taxonomic understanding of this crustacean group in the region.
Some terrestrial flatworm taxa (Platyhelminthes: Tricladida: Continenticola) of the Subantarctic Islands of New Zealand
A groundbreaking taxonomic revision of terrestrial flatworms from New Zealand's Subantarctic Islands introduces significant new classifications. Researchers erect a novel tribe, Argaplanini, and genus, Argaplana, while redescribing the species Argaplana ranuii. Additionally, they propose Marionfyfea as a replacement name for Fyfea, which was previously pre-occupied. This work contributes to the understanding of flatworm biodiversity in this unique region by establishing new taxonomic frameworks and clarifying nomenclature.
The population decline of the New Zealand sea lion Phocarctos hookeri: a review of possible causes
The population of the New Zealand sea lion (Phocarctos hookeri), New Zealand's only endemic pinniped, has declined significantly at the Auckland Islands since 1998, with pup production dropping by 40%—from 3021 pups in 1998 to just 1501 in 2009. This decline is primarily driven by philopatric females not returning to breeding areas, contrasting with a stable or slightly increasing population on Campbell Island. After evaluating nine potential causes—ranging from disease and predation to fisheries-related impacts—the study identifies fisheries-induced resource competition and by-catch mortality as the most plausible explanations for the Auckland Islands' decline. While other factors like bacterial epizootics were considered, their impact is unlikely given naturally high pup mortality rates. The research underscores the need for further investigation into how fisheries may be stressing sea lion populations through resource scarcity and direct mortality.
Accumulation rates of carbon, nitrogen and phosphorus in petrel colony soil: Adams Island, New Zealand subantarctic
Research on Adams Island, part of the New Zealand Sub-Antarctic Islands, reveals that petrel colony soils exhibit extremely low retention rates for carbon (C), nitrogen (N), and phosphorus (P). Accumulation rates, calculated using radiocarbon dating across multiple soil profiles, show that while these rates are approximately double those previously reported from Taukihepa/Big South Cape, the proportion of nutrients retained remains minimal. The study, which excavated four soil profiles 50 meters apart and analyzed elemental inventories, found consistent accumulation rates despite varying depth intervals. These findings suggest that the colder climate and lower leaf litter quality on Adams Island may contribute to higher nutrient dispersion compared to other subantarctic regions.
Bergmanns's size cline in New Zealand marine spray zone spiders (Araneae: Anyphaenidae: Amaurobioides)
Research on marine spray zone spiders (Amaurobioides) around New Zealand reveals a significant Bergmann's size cline, where spider body length and mass increase with cooler temperatures and higher latitudes. This pattern, observed in both the North Island and northern South Island populations, suggests an underlying genetic component influencing size variation. The study used Templeton-Crandall-Sing (TCS) analysis of mitochondrial ND1 gene data to identify 13 haplotypes in the northern group, distinct from the southern Amaurobioides maritima species. Independent contrast analyses and regressions confirmed the relationship between body size, mass, latitude, and temperature, providing evidence for adaptive responses to environmental conditions.
Biodiversity and biogeography of Southern Ocean pycnogonids
A distinct and isolated Antarctic pycnogonid shelf fauna, differing from deep-sea, Sub-Antarctic, South American, and New Zealand regions, was identified through analysis of 332 species from 1837 sample locations. The South Shetland Islands emerged as a probable center of radiation for these marine arachnids, with no observed latitudinal gradients in species richness. Multivariate analyses revealed unique biogeographic trends, though the study acknowledges potential shifts with future molecular insights. This research challenges long-standing biogeographic assumptions and underscores the need to integrate classical taxonomy with emerging genetic techniques.
Description of a new subspecies of Coenocorypha snipe from subantarctic Campbell Island, New Zealand
Researchers have identified and described a new subspecies of Coenocorypha snipe from Campbell Island, part of the New Zealand Sub-Antarctic Islands. This discovery was facilitated by the eradication of Norway rats (Rattus norvegicus) from 11,268 hectares of Campbell Island in 2001, which allowed the snipe to recolonize the main island from rat-free Jacquemart Island, where it had been confined for approximately 170 years. Genetic analysis, plumage descriptions, and measurements from 12 adults and 5 chicks caught on Campbell Island in January 2006 confirmed this subspecies as distinct within the Coenocorypha aucklandica species group, which is now recognized to include populations from the subantarctic Auckland, Antipodes, and Campbell Islands. This finding highlights the impact of invasive species eradication on biodiversity recovery and the importance of genetic studies in taxonomy.
Ecogeographical variation in the Southern Giant Petrel (Macronectes giganteus)
Southern Giant Petrels (Macronectes giganteus) exhibit significant ecogeographical variation across their range, from New Zealand to the Sub-Antarctic and Antarctic regions. Six distinct breeding provinces were identified, confirming two recognized subspecies: M. g. giganteus and M. g. solanderi. The latter is characterized by smaller body parts compared to the former. Morphological differences include variations in bill depth and tarsus length, with birds from Gough Island displaying the longest tarsi. Additionally, an east-to-west cline shows a gradual decrease in body size, consistent with Allen’s rule. While M. g. giganteus exhibits morphological polymorphism, M. g. solanderi shows less biometric variability, suggesting potential for taxonomic differentiation. This study underscores the need for further morphometric and genetic research to clarify the taxon's classification.
Evolution and biogeography of Pleurophyllum (Astereae, Asteraceae), a small genus of megaherbs endemic to the subantarctic islands
Pleurophyllum, a small genus of megaherbs endemic to the subantarctic islands of Australia and New Zealand, likely survived Pleistocene glaciation on these islands and dispersed northward in response to glacial advance. This study provides strong evidence for this hypothesis through phylogenetic analysis of DNA sequences from four genes (ITS, ETS, trnK, and trnL). The research suggests that the subantarctic islands served as refugia for Antarctic plants, preserving remnants of a once-diverse flora. By reconstructing the genus's evolutionary history, the study sheds light on the biogeographical patterns of austral plant groups and the role of Antarctica in shaping southern hemisphere plant distributions.
Former presence of a parakeet (Cyanoramphus sp.) on Campbell Island, New Zealand subantarctic, with notes on the island’s fossil sites and fossil record
A significant late Holocene deposit of bird fossils on subantarctic Campbell Island, New Zealand, has revealed the first specimen of a Cyanoramphus parakeet from the island. Preliminary ancient DNA analysis confirmed its generic identification, offering potential for re-introduction efforts by identifying a closely related taxon to the extinct population. The study highlights the importance of fossil sites in understanding the island's biodiversity and evolutionary history. The research involved a brief survey of potential fossil sites, with implications for both conservation and scientific inquiry.
Genetic diversity of Southern hemisphere blue mussels (Bivalvia: Mytilidae) and the identification of non-indigenous taxa
Widespread bioinvasion of Northern hemisphere blue mussels (Mytilus galloprovincialis) into the Southern hemisphere has been documented for the first time, challenging assumptions about species distribution constraints. The study also identified inter-specific hybrids (Mytilus edulis × M. galloprovincialis) in both international ports and remote protected locations like Chile and New Zealand's Auckland Islands, highlighting vulnerability across diverse environments. Researchers used nuclear-DNA marker Me 15/16 to analyze 484 mussel samples from New Zealand, Australia, and Chile, revealing 478 pure M. galloprovincialis in Southern hemisphere sites and six hybrids. A new RFLP assay further confirmed the presence of Northern hemisphere M. galloprovincialis across almost every sampled region, including high-latitude areas up to 52°S, with implications for understanding selective environmental pressures on species distribution.
Insights into the origin and identity of National New Zealand Flax Collection plants from simple sequence repeat (SSR) genotyping
Research reveals that several genetically identical plant accessions within the National New Zealand Flax Collection share names but distinct genetic profiles, aligning with prior morphological groupings. The study used simple sequence repeat (SSR) genotyping on 55 accessions, comparing them to predominantly wild Phormium plants, and identified interspecific hybrids in Māori cultivars, including Phormium tenax × Phormium cookianum. Findings support historical accounts of Phormium's introduction to the subantarctic islands by sealers from southern New Zealand and possibly by Māori and Moriori from the Chatham Islands. The SSR markers also offer tools for studying speciation, evolution, and hybridization in Phormium.
Oceanic rafting by a coastal community
This study provides the first direct evidence that oceanic rafting on macroalgae can transport diverse intertidal organisms across hundreds of kilometers, facilitating trans-oceanic dispersal and landfall. Researchers documented the rafting of 10 epifaunal invertebrate species attached to six large bull kelp specimens, traveling from the subantarctic Auckland or Snares Islands to mainland New Zealand's Otago coast—a journey spanning 400–600 km. Using phylogeographic and ecological data, the study demonstrates that passive rafting can simultaneously enable long-distance transport and successful colonization of multiple coastal taxa, challenging previous assumptions about the viability of such dispersal mechanisms in isolated ecosystems.
The diet of New Zealand falcons (Falco novaeseelandiae) on the Auckland Islands, New Zealand
New Zealand falcons (Falco novaeseelandiae) on the Auckland Islands primarily target endemic land birds, including the Auckland Island rail, snipe, and teal, which collectively make up a third of their prey by weight. This study analyzed 1588 bones from 215 bird individuals across 18 species, alongside feathers and range stones found in regurgitated pellets, revealing a diet heavily influenced by procellariiform seabirds—evidence suggesting nocturnal hunting behavior. While the bellbird was the most frequent prey, Antarctic prions and subantarctic diving petrels were also common. The findings highlight the falcons' role as apex predators, maintaining balance in an ecosystem where endemic ground-dwelling birds face extinction risks from introduced mammals but persist under native predation pressure.
The identity of Porphyra columbina (Bangiales, Rhodophyta) originally described from the New Zealand subantarctic islands
A re-evaluation of Porphyra columbina, a red algae species originally described from the New Zealand subantarctic islands, reveals its primary distribution in cold temperate regions. This study combines morphological, anatomical, and genetic analyses (nSSU and rbcL sequence data) to clarify the species' identity, distinguishing it from similar forms found elsewhere in the southern hemisphere. Findings indicate that P. columbina is predominantly located in subantarctic islands such as Auckland, Campbell, Antipodes, Chatham, and Falkland Islands, with rare occurrences on mainland New Zealand. The species exhibits a rosette to ovate growth form, typically under 5 cm in size, and distinct purple-red phyllospores and golden marginal areas of spermatangia. Five unique rbcL haplotypes were identified, with the most common haplotype shared across multiple subantarctic islands.
The origin of polyploid genomes of bluegrasses Poa L. and Gene flow between northern pacific and sub-Antarctic Islands
A groundbreaking study reveals the complex evolutionary origins of polyploid bluegrass species (Poa L.) in New Zealand and its sub-Antarctic islands, highlighting significant gene flow between the Northern Pacific and these remote regions. Researchers used genetic sequencing of internal transcribed spacers (ITS1, ITS2) and 5.8S rDNA to demonstrate that highly polyploid species like P. cita, P. chathamica, and P. litorosa share a common ancestry with tetraploid species such as P. intrusa and P. anceps, forming a distinct clade. These findings challenge traditional taxonomic boundaries by showing strong genetic connections between New Zealand’s endemic bluegrasses and Arctic species like P. pseudabbreviata, while also identifying distant relationships with Eurasian diploid species. The study further uncovers the unique genetic divergence of Arctopoa species, which exhibit minimal variation (0.2%) among themselves but significant distances from other Poa sections. This research not only deepens our understanding of bluegrass evolution but also provides insights into the genetic exchanges shaping biodiversity across isolated island ecosystems.
Zoogeographic and Richness Patterns in Southern Ocean Benthos
The Southern Ocean functions as a single biogeographic unit, with no evidence supporting the proposed East-West Antarctic split. This study, analyzing over 8,000 marine invertebrate species from 5,000 sites using SOMBASE and SCAR-MarBIN databases, confirmed strong faunal links between Antarctica and South America but found little connection to New Zealand or Tasmania. It also identified hotspots of range-limit coincidences in Southern Patagonia, South Georgia, and Kerguelen, suggesting these areas are critical for monitoring climate change impacts on benthic species distributions.
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