Publications
Accumulation of stranded plastic objects and other artefacts at Inaccessible Island, central South Atlantic Ocean
A significant increase of 47% in stranded artefacts, particularly plastic objects (65%), was observed at Inaccessible Island between 1984 and 1987, with distant-source artefacts rising by at least 120%. This suggests a recent surge in debris adrift in the South Atlantic Ocean. The study surveyed a 900 m boulder beach using a repeated sampling method to quantify macro-artefacts (>10 mm diameter), revealing minimum accumulation rates of 88 objects per km per year. Local fishery-related artefacts showed minimal increase, contrasting with the sharp rise in distant-source debris, highlighting broader oceanographic trends.
Carex brevicaulis Thouars
A taxonomic clarification of Carex brevicaulis Thouars, a sedge endemic to the Tristan da Cunha archipelago (Gough and Inaccessible Islands), reveals its nomenclatural history and morphological distinctiveness. The study designates lectotypes for both C. brevicaulis and Uncinia brevicaulis var. gracilior, resolving ambiguities in prior classifications. Key findings include detailed descriptions of the plant's inflorescence, utricles, and achenes, highlighting unique traits such as adpressed hairs on utricle sides and a deltoid beak. The research also addresses etymological confusion surrounding the species name, which was coined to describe short-stemmed plants despite reaching up to 61 cm in height. This work contributes to the clarification of sedge taxonomy in the South Atlantic, with implications for conservation efforts at UNESCO World Heritage Sites.
Carex moro-ortegae Garcia-Moro & Jim. Mejias 2026, sp. nov.
A new species of sedge, Carex moro-ortegae, has been discovered on the Gough and Inaccessible Islands within the UNESCO World Heritage-listed Tristan da Cunha archipelago. This species is distinguished from its closest relative, C. austrocompacta, by smaller utricles and achenes. The discovery highlights significant morphological variability across different habitats, suggesting potential in situ diversification or ecological adaptation. Future research may clarify whether multiple taxa exist within the archipelago. The species is named in honor of the author's mother, grandmother, and aunt, symbolizing their resilience and unconditional love.
Investigating high pathogenicity avian influenza virus incursions to remote islands: detection of H5N1 on Gough Island in the South Atlantic Ocean
Scientists detected high pathogenicity avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b in three Tristan skua carcasses on Gough Island, a remote UNESCO World Heritage Site in the South Atlantic. Genomic analysis revealed that the strain was more closely related to one found in South Georgia than southern Africa, suggesting potential transmission during the birds' pre-laying exodus into frontal waters south of the island. The study combined genomic data with global tracking records from seabirds, highlighting the role of migratory scavengers like skuas as vectors for long-distance virus spread. While no further cases were confirmed on Gough Island, researchers emphasize the need for systematic monitoring and biosecurity measures to mitigate risks to globally significant seabird populations.
Melita tristanensis , K. H. Barnard 1965
A comprehensive redescription of the amphipod species Melita tristanensis, first documented by K.H. Barnard in 1965, reveals key morphological distinctions that differentiate it from related species. This study provides detailed illustrations and descriptions of both male and female specimens, addressing gaps left by Barnard's original work. Notably, M. tristanensis is distinguished by unique features such as the presence of a small acute spine on epimeron 3, differences in mandibular palp structure, and specific antenna and uropod characteristics. The species is confirmed to inhabit marine environments among kelp holdfasts, with a distribution limited to Tristan Da Cunha, including Gough Island, Inaccessible Island, and Nightingale Island. This redescription enhances taxonomic clarity and contributes to the understanding of biodiversity in this remote UNESCO World Heritage Site.
Uncovering genetic population structure in the Endangered northern rockhopper penguin (Eudyptes moseleyi) across islands in the Southern Atlantic and Indian oceans
Northern rockhopper penguins (Eudyptes moseleyi), classified as Endangered by the IUCN, exhibit distinct genetic populations across the Southern Atlantic and Indian oceans with minimal migration between these regions. This study, the first comprehensive analysis of its kind, reveals that while penguin populations on islands within each ocean basin show no significant substructure, low but sufficient gene flow exists to prevent differentiation among them. However, variations in genetic diversity and inbreeding suggest some island populations may face higher risks of inbreeding depression. The findings underscore the need for two distinct conservation management units—one for each ocean basin—to preserve genetic diversity and address region-specific threats, including climate-driven changes. This research provides critical insights to enhance resilience strategies for this vulnerable species.
Feasibility of using very high-resolution satellite imagery to monitor Tristan albatrosses Diomedea dabbenena on Gough Island
A study assessing the feasibility of using very high-resolution satellite imagery to monitor Tristan albatrosses (Diomedea dabbenena), a Critically Endangered species, on Gough Island found that current methods are unreliable due to persistent cloud cover and incomplete detection. Despite analyzing 31 cm resolution images over eight seasons, only one cloud-free image was obtained, limiting the ability to accurately count nests. While specialists detected birds at 67.8% of active nests in cloud-free regions, challenges like orographic clouds and limited imagery availability hinder effective monitoring. The research concludes that on-the-ground monitoring remains essential for accurate population tracking, especially as commercial satellites may offer future improvements.
Nape Coloration Varies with Sex, not Age, Among Great Shearwaters Ardenna gravis
Nape coloration in Great Shearwaters (Ardenna gravis) varies significantly with sex, not age, contrary to previous suggestions. A study analyzing 328 birds—through necropsies and colony photographs from Gough Island (South Atlantic) and Massachusetts Bay (USA)—found no significant difference in nape color ratios between age classes, with classification accuracy based on putative variation only at chance levels (52%). However, light-colored napes were more prevalent in adult females in Massachusetts Bay, hinting at a potential sexual function. The research challenges the use of nape coloration as an age indicator and proposes it may instead play a role in mate choice, warranting further behavioral studies.
Recent changes in plastic bottles washing ashore on Inaccessible Island, Tristan da Cunha
Plastic bottle litter on Inaccessible Island, part of the UNESCO-listed Gough and Inaccessible Islands, has doubled since 2018, with drink containers now constituting 90% of all washed-up debris. A striking shift toward smaller, predominantly Asian-produced bottles—now accounting for 88% of arrivals—has intensified marine pollution. Most bottles originate from China and are less than two years old upon arrival, indicating recent production and rapid dispersal. The study, published in Marine Pollution Bulletin, analyzed trends in bottle litter to assess the impact on this remote World Heritage Site.
Territoriality in adult male sub-Antarctic fur seals at Gough Island
Adult male sub-Antarctic fur seals at Gough Island hold territories averaging 21.9 m² during the peak breeding season, with tenure lasting approximately 45 days. Territory size varies significantly by beach type, ranging from 13.8 to 28.3 m². The study analyzed unpublished data from the 1975/76 austral summer and found that both territory tenure and size align with established patterns in fur seal species where males defend land-based territories as a primary reproductive strategy. However, the research also underscores multiple confounding factors that complicate comparative studies on territorial behavior in otariids, emphasizing the need for careful consideration when interpreting theoretical or modeling approaches in this area.
Genetics of behavioural evolution in giant mice from Gough Island
Research identifies 41 quantitative trait loci (QTL) influencing boldness and exploration behaviors in giant mice from Gough Island, revealing unique genetic pathways distinct from laboratory mouse strains. The study used F2 hybrids from Gough Island mice—free from predators or human commensals—and mainland conspecifics, assessing seven behaviors across open field and light/dark box tests in juveniles and adults. Dynamic function-valued trait mapping showed age- and behavior-specific effects of QTL, offering insights into the genetic basis of island-associated behavioral evolution. Candidate genes were nominated by integrating mapping results with extensive phenotypic and genetic data from laboratory mice.
Genetics of evolved load resistance in the skeletons of unusually large mice from Gough Island
Researchers have uncovered the genetic basis for extreme skeletal load resistance in the largest wild house mice on record, found on Gough Island. Unlike laboratory studies that typically focus on one or two bones, this study analyzed seven bones—femur, tibia, scapula, humerus, radius, ulna, and mandible—in 760 mice from a cross between Gough Island mice and a smaller mainland strain. The findings reveal 153 quantitative trait loci (QTL) associated with load resistance, distributed across nearly all chromosomes, with minimal overlap with QTL for bone length, width, or body weight. Notably, these mice exhibit bone geometries that enhance load resistance without increased bone mineral density, suggesting distinct evolutionary adaptations. This study provides a rare genetic portrait of how natural selection shapes skeletal structure in extreme environments.
Long-term changes in petrel populations on Inaccessible Island, Tristan da Cunha, inferred from the diet of Brown Skuas Stercorarius antarcticus
A four-decade analysis of Brown Skuas' diet on Inaccessible Island reveals minimal long-term changes, despite shifts in prey composition. Petrels dominate the skua diet (94%), with Fregetta storm petrels, White-faced Storm Petrels, and Broad-billed Prions comprising over 98% of avian prey. Seasonal variations align with petrel breeding phenology, while increases in fur seals and Great Shearwaters in the diet suggest population growth, contrasting with potential declines in Common Diving Petrels and Subantarctic Shearwaters. Tarsal length changes hint at species composition shifts within Fregetta storm petrels. The study infers petrel population trends by analyzing regurgitated pellets and prey remains, offering insights into the dynamics of burrowing seabird communities on this remote World Heritage Site.
Recommendations on rock lobster TAC’s for the Tristan Group of Islands for the 2012/13 season
A significant reduction in the total allowable catch (TAC) for rock lobster is recommended for Inaccessible and Gough Islands in the Tristan Group, primarily due to declining catch per unit effort (CPUE) at Inaccessible and a reversal of previous growth trends at Gough. These findings stem from updated models accounting for recent environmental incidents and revised growth rate estimates. To align with an impending transition to a more stable management procedure, the reductions are proposed to be phased in over two years. This approach aims to balance immediate conservation needs with long-term sustainability, with further refinements expected by September 2012.
A complex genetic architecture underlies mandibular evolution in big mice from Gough Island
Research reveals that the evolution of large mandibles in Gough Island mice is driven by a complex genetic architecture, with multiple quantitative trait loci (QTL) contributing to mandibular shape and size. Unlike mainland mice, these island-dwelling rodents exhibit significant divergence in traits like temporalis lever arm length and condyle length, which influence jaw function. While most QTL effects are additive and dispersed, some, particularly those linked to body size, suggest directional selection may have played a role in the evolution of larger mandibles, possibly as a correlated response to overall body growth.
A lesson for planning rodent eradications: interference of invasive slugs during the Gough Island mouse eradication attempt in 2021
Invasive slugs, overlooked during planning, significantly interfered with the Gough Island mouse eradication attempt in 2021 by consuming bait pellets at rapid rates, leading to a critical drop in rodent bait availability. This unexpected challenge necessitated major adjustments to the baiting strategy, including a third application at higher rates, yet mice remain present on the island. The study highlights that non-target species interference could pose risks to future pest eradication efforts using baits and underscores the importance of early assessment during planning phases.
Detections of house mice on Gough Island approach zero within days of aerial baiting
Aerial baiting of house mice on Gough Island led to a dramatic and rapid decline in mouse activity, with detections dropping from 9.6 to zero per camera within four days post-baiting. This decline occurred faster than laboratory trials predicted, suggesting that most wild mice consumed the bait immediately upon availability. The study used trail cameras—both with and without lures—to monitor mouse activity before and after bait application in June–August 2021. While detections remained extremely rare from one week post-baiting onward, a single late detection (27 days post-baiting) hinted at potential delays due to rapid bait disappearance. Opportunistic camera traps later confirmed the absence of survivors six months after the first bait drop, indicating successful eradication. The findings suggest that future similar operations can expect sharp declines in mouse activity within a week, though some mice may survive longer. This research highlights the effectiveness of trail cameras with lures as a tool for monitoring eradication outcomes and informs operational decisions, such as timing second bait applications or assessing non-target impacts.
Notes on the seabirds of Gough Island and at sea between Gough and Cape Town, March–June 2021
A diverse seabird community of at least 43 species was documented around Gough Island and the South Atlantic Ocean between March and June 2021, including penguins, albatrosses, petrels, shearwaters, gannets, terns, and skuas. The study revealed higher species richness per day in June compared to March, though fewer individuals were recorded at sea, primarily due to the dominance of Great Shearwaters (Ardenna gravis) in March. Observations focused on abundance, phenology, and moult patterns, providing new insights into the seasonal dynamics of seabirds in this remote UNESCO World Heritage Site.
Recommendations on rock lobster TACs for the Tristan group of islands for the 2013/14 season.
The study recommends Total Allowable Catches (TACs) for rock lobster populations in the Tristan group of islands, specifically focusing on the 2013/14 season. Due to increased workload and delays caused by the OLIVA incident, operational models could only be developed for Tristan Island, leaving assessments for Inaccessible and Gough Islands incomplete. The recommendations are based on available data, prioritizing Tristan Island while acknowledging limitations in broader coverage. This approach aims to balance immediate management needs with long-term sustainability, though it highlights gaps in comprehensive population assessments for the entire group.
Recommendations on rock lobster TACs for the Tristan group of islands for the 2015/16 season.
Rock lobster total allowable catches (TACs) for the Tristan group of islands, including Inaccessible and Gough, were recommended to increase for the 2015/16 season due to high catch rates exceeding operational management procedure (OMP) targets. Specifically, TACs for Inaccessible and Gough were raised from 73 MT to 77 MT and 100 MT to 105 MT, respectively. For Nightingale Island, despite unclear reasons for sustained high catch rates, projections remain positive even with a future TAC of 75 MT, leading to an increase from 65 MT. Conversely, Tristan’s 2014 catch per unit effort (CPUE) fell below OMP expectations, prompting a reduction in its TAC from 161 MT to 153 MT, with potential further decreases anticipated for subsequent seasons unless CPUE improves significantly. A more precautionary approach suggests setting lower initial TACs with mid-season reviews based on biomass surveys and CPUE data.
Diet of the introduced Gough Moorhen Gallinula comeri on Tristan da Cunha
Introduced Gough Moorhens (Gallinula comeri) on Tristan da Cunha exhibit a generalist diet, primarily consisting of vegetation but also including arthropods, earthworms, introduced rodent remains, and anthropogenic debris. This mirrors their dietary behavior on native Gough Island, where they consume a varied range from plants to scavenging and predatory items. The study analyzed stomach contents of four birds, revealing their adaptability and potential ecological impact in the restored Tristan da Cunha ecosystem.
Evolution of boldness and exploratory behavior in giant mice from Gough Island
Giant house mice from Gough Island exhibit significantly bolder and more exploratory behaviors compared to mainland counterparts, even when shelter is available, while retaining avoidance responses to predator urine. This suggests that behavioral evolution on islands can be specific to perceived dangers. Researchers profiled anxiety and exploration in island and mainland inbred mouse strains raised under identical laboratory conditions, demonstrating heritability of these traits. F1 offspring from crosses between the two strains behaved more like mainland mice for most traits, indicating recessive mutations likely contributed to behavioral changes on Gough Island. The study provides rare evidence of inherited behavioral evolution in an island population, offering insights into how such adaptations arise in isolated ecosystems.
Inaccessible Island CMP results
A revised management approach for the Tristan rock lobster fishery at Inaccessible Island, one of UNESCO's World Heritage Sites, has been identified as optimal with a trap limit (Itar) set at 5.0 kg/trap. This recommendation is based on analyzing both commercial catch per unit effort (CPUE) and biomass survey data to refine the total allowable catch (TAC) setting formula. The study integrates multiple data sources to enhance fishery sustainability, balancing commercial and conservation objectives in this remote and ecologically significant marine environment.
Mouse eradication is required to prevent local extinction of an endangered seabird on an oceanic island
Introduced house mice pose a severe threat to the endangered MacGillivray’s prion (Pachyptila macgillivrayi), driving its population on Gough Island toward potential local extinction within decades. Analysis of breeding data from 2014–2020, combined with historic records, predicts a 9% annual decline in this burrow-nesting seabird if mouse predation continues unchecked—with a 31% chance of the population becoming critically vulnerable by 2057. Mouse eradication could restore breeding success to levels observed in closely related species on predator-free islands, stabilizing the population and reducing extinction risk below 10%. The study underscores the urgent need for invasive mammal removal from oceanic islands to safeguard small, burrow-nesting petrels.
Sulfur isotopic composition of the Tristan-Gough plume source
A new study reveals distinct sulfur isotopic signatures in the Tristan-Gough plume system, offering insights into Earth's mantle heterogeneity. The research analyzed 46 mineral-hosted sulfide inclusions from Tristan and Gough islands, part of a long-lived EMI-type plume with roots at the core-mantle boundary. Findings show that Gough exhibits positive mass-independent fractionated sulfur (MIF-S) averaging Δ33S = +0.25‰, while Tristan shows no clear MIF-S indication. This suggests that recycled surface material older than 2.45 billion years is present in the EMI-type sources of both Pitcairn and Gough plumes, despite their distinct isotopic characteristics. The study highlights the potential for MIF-S to serve as a tracer for ancient recycled crustal material in mantle plumes.
Summary of recommendations on rock lobster TACs for the Tristan group of Islands for the 2017/18 season
Researchers recommend annual quotas for rock lobster fishing around the Tristan group of islands, including Inaccessible, Gough, and Tristan islands, to ensure sustainable management. The study, conducted by Butterworth and Holloway (2021), provides scientific guidance on Total Allowable Catches (TACs) for the 2017/18 fishing season using established Operational Management Procedures (OMPs). These recommendations aim to balance conservation needs with fishing industry requirements, ensuring the long-term viability of rock lobster populations in this UNESCO-listed marine area. The approach relies on data-driven assessments to inform quota setting, supporting sustainable fisheries practices in one of the most remote and ecologically significant regions in the South Atlantic.
Summary of recommendations on rock lobster TACs for the Tristan group of islands for the 2020/21 season
A new framework for setting rock lobster total allowable catches (TACs) has been established for the Tristan group of islands, including Inaccessible, Nightingale, Gough, and Tristan. This approach, based on accepted operational management procedures (OMPs), aims to ensure sustainable fishing practices while balancing conservation needs. The recommendations are designed to maintain healthy rock lobster populations by setting annual TACs that account for biological and environmental factors. The study provides a science-based method to guide fisheries management in this remote UNESCO World Heritage Site, ensuring long-term viability of marine resources.
Summary of recommendations on rock lobster TACs for the Tristan group of islands for the 2021/22 season
Scientists recommend annual catch limits for rock lobster to ensure sustainable fishing around the Tristan group of islands, including Inaccessible, Nightingale, Gough, and Tristan. These recommendations are based on accepted operational management procedures (OMPs) designed to balance fishing pressure with ecosystem health. The study provides a concise overview of the proposed total allowable catches (TACs) for the 2021/22 season, aiming to support long-term conservation efforts in this UNESCO World Heritage Site while maintaining economic benefits for local fisheries.
Abundance, distribution and breeding success of the endemic Gough Island Finch Rowettia goughensis between 2009 and 2018
Research reveals that the Critically Endangered Gough Island Finch (Rowettia goughensis) maintains a stable population of approximately 1,917 individuals (95% CI: 1550–2500) across Gough and Inaccessible Islands, with no significant change in upland habitat density between 2009 and 2018. Nest survival rates remained consistent at 55%, while fecundity averaged 1.31 fledglings per pair in 2018. Habitat-specific surveys identified higher densities in moorland (55.4 birds/km²) and wet heath (29.5 birds/km²), compared to coastal tussock (10.9 birds/km²) and lowland fern bush (2.6 birds/km²). This population estimate serves as a critical baseline ahead of the planned 2021 eradication of invasive house mice (Mus musculus), though increased monitoring will be necessary to detect smaller post-eradication changes.
Genomic Targets of Positive Selection in Giant Mice from Gough Island
Researchers identified 1,463 genomic regions under strong positive selection in giant house mice from Gough Island, distinct from mainland populations. These regions, enriched with genes linked to neurological functions and body size, suggest adaptive mutations—including missense and regulatory variants—that may drive island-specific traits like exploratory behavior. The study employed massively parallel sequencing, demographic modeling via approximate Bayesian computation, and machine learning to pinpoint selection targets, offering a genomic framework for understanding rapid adaptation in isolated ecosystems.
Giant Island Mice Exhibit Widespread Gene Expression Changes in Key Metabolic Organs
Giant island mice, the largest wild house mice globally, exhibit widespread gene expression changes in key metabolic organs, providing insights into the genomic basis of extreme body size evolution. Researchers compared gene expression patterns between Gough Island mice and mainland mice using RNA-seq on gonadal adipose depot, hypothalamus, and liver tissues. They identified significant differential expression in 20% to 50% of detected transcripts, with fold changes of at least 2× in each organ. Among the findings, 73 candidate genes for extreme size evolution were pinpointed by integrating gene expression data with quantitative trait loci, whole-genome sequencing, and regulatory elements. Functional enrichment analyses suggested that cell cycling, mitochondrial function, signaling pathways, inflammatory response, and nutrient metabolism contribute to weight accumulation in these mice. The study highlights the rapid evolutionary changes in metabolic organs accompanying gigantism on Gough Island.
Three new seabird species recorded at Tristan da Cunha archipelago
Researchers have identified three new seabird species recorded at the Tristan da Cunha archipelago, expanding the known biodiversity of this remote South Atlantic region. The study, conducted between 2017 and 2019, builds on previous observations to document additional seabird sightings, contributing to the understanding of avifaunal diversity in one of the world's most isolated oceanic island systems. Tristan da Cunha, alongside Gough Island, serves as a critical breeding ground for numerous seabird species, with this discovery further underscoring its ecological significance.
Using playback to estimate the distribution and density of the world’s smallest flightless bird, the Inaccessible Island Rail Atlantisia rogersi
The Inaccessible Island Rail, the world's smallest flightless bird, is estimated to have a population of approximately 10,300 individuals on its namesake island. This study utilized playback surveys at 350 sites to overcome the challenges posed by the bird's secretive behavior and the rugged terrain, revealing a stable population that warrants continued 'Vulnerable' status. The research highlights the critical threat of alien mammal introductions, emphasizing the need for their removal from neighboring islands to mitigate potential catastrophic impacts on this unique species.
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