Despite their importance in food webs and predominance among species bycaught in Southern Ocean toothfish fisheries, the trophic ecology of grenadiers of the genus Macrourus, remains poorly understood. Here, we provide the first comprehensive assessment of trophic position, niche segregation and dietary composition of four Macrourus species: M. caml, M. carinatus, M. holotrachys, and M. whitsoni. M. holotrachys had the highest trophic position (highest δ15N values) and the highest mean δ13C values, indicative of a benthic diet; M. caml and M. carinatus had intermediate and to some extent overlapping δ15N and δ13C values, and the widest isotopic niches, and; M. whitsoni, had the lowest δ15N and δ13C values, indicative of a lower trophic position and more pelagic diet. These differences in stable isotope values were reflected in their feeding strategies and diets; although all four species are generalist feeders, with crustaceans and fish as their main prey, M. holotrachys exhibited a more specialized benthic feeding strategy (hence a higher vulnerability to bycatch), whereas M. caml and M. carinatus had broader benthopelagic diets. The niche segregation is likely shaped by depth distribution and habitat preferences, which reduces competition for prey and enables their coexistence. This study is the most comprehensive assessment to date of the trophic ecology of Macrourus species in the Southern Ocean, increasing our understanding of their ecological role in the deep-sea food web and providing valuable insights for their management.

Cephalopods play a key role in marine ecosystems but are difficult to study directly; hence, beaks recovered from predator stomachs are critical to further understand their distribution and ecology. Cephalopod species have traditionally been identified from beak morphology, a time-consuming method limited by degree of beak digestion, lack of specialist expertise, and limited coverage in reference collections. Here, we provide the first detailed methodology to identify cephalopod species through DNA analysis of their beaks. By extracting, amplifying and sequencing the cytochrome c oxidase I (COI) gene, we successfully annotated DNA sequences to species level in 50.5% of samples and 60% of beaks, obtained from predator stomachs and scientific nets. There was no statistically significant effect of beak section (untanned, tanned, rostrum tip), storage condition, or bleach treatment on assignment success (GLMM; all p > 0.05). Although formal statistical comparison was not possible because collection method and storage condition were confounded, success rates appeared to vary by sample origin, with lower success in samples from albatrosses (Thalassarche spp.) boluses than either stomachs of toothfish (Dissostichus spp.) or scientific nets (27.3%, 59.5% and 55.6%, respectively). Our results show that DNA analysis from cephalopod beaks can enable species-level identification, though expanding genetic databases with sequences from additional taxa and populations is crucial to improve accuracy. This approach enhances the recovery of ecological data from samples that were previously challenging to identify, supporting biodiversity monitoring, food-web research, and assessments of ecosystem change in rapidly shifting oceans.

Understanding the risk of introduction of marine non-native species requires data on pathways, including the level of biofouling present on vessels, vessel operating profiles and maintenance regimes. This study presents the first snapshot of the levels of biofouling associated with vessels operating around the sub-Antarctic islands of South Georgia and the South Sandwich Islands (SGSSI), revealing moderate levels of all types of biofouling combined (including visible biofilms) but low levels of macrofouling across the vessels surveyed. Our results add to the body of evidence that suggests that assessing biofouling associated with the upper hull may be indicative of the amount of fouling in niche areas, providing a less resource-intensive approach for future strategic monitoring. Data collected through a voluntary questionnaire to vessel operators indicate that vessels operating around SGSSI are regularly dry-docked, cleaned or inspected, with more than one third cleaned or dry docked in the year prior to the study, indicating that monitoring could be prioritised on those vessels with a longer period between cleaning/drydocking and entrance into SGSSI waters. However, this study revealed no relationship between the level of fouling and commonly used risk indicators, which makes it challenging to develop robust quantitative risk assessment processes for the region. Establishing strategic monitoring of vessels at gateway ports to the region and collecting further data on risk indicators through permitting and licensing regimes would enable a better understanding of the magnitude of risk. To conclude, this study demonstrates that species are being transported through biofouling on a range of vessel types in the region and that the risk of marine introductions could be reduced through ensuring effective biofouling management and strategic monitoring.

Humans have transformed ecosystems through habitat modification, harvesting, species introduction, and climate change. Changes in species distribution and composition are often thought to induce biotic homogenization, defined as an increase in the spatial similarity of species compositions through time. However, it is unclear whether homogenization is common in ocean ecosystems and if changes in similarity exhibit linear or more complex dynamics. Here, we assessed patterns of homogenization or its converse (differentiation) across more than 175,000 samples of 2,006 demersal fish species from 34 regions spanning six decades and 20% of the planet's continental shelf area. While ten regions (29%) recorded significant homogenization, eleven (32%) recorded significant differentiation. Non-monotonic temporal fluctuations in species composition occurred in 15 regions, highlighting complex dynamics missed by before-and-after snapshots that can drive spurious conclusions about trends in similarity. Fishing pressure and temperature helped explain variance in similarity across years and regions. However, the strength and direction of these effects differed by region. Here we showed that, despite intense anthropogenic impacts on the oceans, the majority of demersal marine fish communities do not follow the global homogenization paradigm common in other realms.

Humans have transformed ecosystems through habitat modification, harvesting, species introduction, and climate change. Changes in species distribution and composition are often thought to induce biotic homogenization, defined as a decline in spatial beta diversity through time. However, it is unclear whether homogenization is common in ocean ecosystems and if changes in beta diversity exhibit linear or more complex dynamics. Here, we assessed patterns of homogenization or its converse (differentiation) across more than 175,000 samples of 2,006 demersal fish species from 34 regions spanning six decades and 20% of the planet’s continental shelf area. While ten regions (29%) recorded significant homogenization, eleven (32%) recorded significant differentiation. Non-monotonic temporal fluctuations in beta diversity occurred in 15 regions, highlighting complex dynamics missed by before-and-after snapshots that can drive spurious conclusions about trends in beta diversity. Fishing pressure and temperature helped explain variance in beta diversity across years and regions. However, the strength and direction of these effects differed by region. Here we showed that, despite intense anthropogenic impacts on the oceans, the majority of demersal marine fish communities do not follow the global homogenization paradigm common in other realms.

Food-webs are a major component of ecosystems and determinant for their functioning and structure. The food chain length (FCL) is a key feature of food-webs and it is crucial for the resistance of the community to external stressors. The Southern Ocean (SO) food-web is known for being short and dominated by an Antarctic krill Euphausia superba surplus, though recent studies proved the existence of different pathways. However, previous studies focused on the pelagic realm, with the deep-sea and benthopelagic coupling remaining poorly understood. Using stable isotopes of delta 13C and delta 15N in muscle from individuals collected during toothfish fishing seasons 2020, 2021 and 2022, we 1) studied the bathyal food-web structure at South Sandwich Islands; 2) evaluated the interannual variability of FCL; and 3) tested which FCL hypothesis better explains the variability at the SO deep-sea. Our results show that this food-web is composed of five trophic levels with both Patagonian Dissostichus eleginoides and Antarctic Dissostichus mawsoni toothfish as top predators. The 4th and 5th trophic levels are mostly composed of fish, while in the 3rd trophic level we mainly found cephalopods and crustaceans. The benthopelagic coupling occurs at different trophic levels, though mostly between the 3rd and 4th trophic level. The FCL varied between years, being in 2022 0.30 trophic levels shorter than in 2020. Our results suggest that food-webs including a benthic component are longer than pelagic and coastal SO food-webs. The FCL is positively related with net primary productivity, supporting that the productivity hypothesis explains the variability in FCL in SO bathyal food-webs in slope and seamount areas. With climate change, the productivity in the SO is expected to increase which will increase the length of the food-web. This change will affect the structure of the ecosystem, increasing assimilation losses, exposure to biomagnifying contaminants and changing nutrient cycles.

The sub-Antarctic and polar fronts are features of the Antarctic Circumpolar Current that separates the South Atlantic and Southern Ocean. These fronts act as both a physical and physiological barrier to the introduction and establishment of marine non-native species. Vessel movements provide a mechanism for transiting over this barrier, acting as a vector for marine non-native species. However, species transported must be able to survive the rapid change in environment. This transit is specifically characterized by the reduced sea temperatures of the Southern Ocean. Several species of concern are already established in the Falkland Islands and pose a risk of being transported through vessel movements to South Georgia, including the invasive ascidian Ciona spp. We used an experimental approach to test whether Ciona spp. could tolerate the temperature change consistent with a ship hull transit across the sub-Antarctic and polar fronts in winter and summer. The results suggest that adult individuals of Ciona spp. would be able to survive. Ciona spp. showed a reduction in metabolic rate (Q10 of 2.09 in winter and 2.39 in summer), consistent with the normal physiological effect of temperature on ectotherms. These findings confirm that marine non-native species present in the Falkland Islands could pose a risk to South Georgia. The sub-Antarctic and polar fronts may have little or no impact on the fitness of the species to establish, although longer term studies are required to understand their capacity to establish.

Understanding food-web structure is crucial to determine the functioning of ecosystems and sustainably manage resources. The Scotia Sea is an important area for Antarctic krill and toothfish fisheries, and one of the regions most impacted by climate change in the Southern Ocean. Whilst the pelagic Antarctic krill-centric food web has been investigated in reasonable detail, the structure of deep-sea food webs associated with toothfish fisheries remain largely unknown. Utilising stable isotopes and fatty acids as trophic proxies, we studied the deep-sea food-web structure in three locations of the Scotia Sea, from South Georgia (SG) to the South Sandwich Islands (SSI; divided into north and south). Our analyses indicate that all food webs were similar, presenting high trophic redundancy and similar vertical structure. All food webs had five trophic levels, with the 5th and 4th trophic levels mainly constituted of fish and the 3rd trophic level of cephalopods and crustaceans. However, some differences existed with the SG food web presenting larger diversity of producers and the bigeye grenadier Macrourus holotrachys in the highest trophic position, while Patagonian toothfish Dissostichus eleginoides and both Patagonian and Antarctic toothfish D. mawsoni were the top predators at SSI-North and SSI-South, respectively. Compared to coastal and pelagic food webs in the Southern Ocean, our results suggest that deep-sea food webs, including the benthic/demersal components, have a longer food-chain length. This study provides essential knowledge of the ecological variability of Southern Ocean deep-sea food webs while contributing to the management of resources within the SG and SSI Marine Protected Area.

Understanding the biodiversity of an ecosystem is crucial to determine its structure and resistance to climate change. The South Sandwich Islands (SSI) are located in the Scotia Sea (Southern Ocean), within the South Georgia and the South Sandwich Islands Marine Protected Area. However, the biodiversity of the archipelago remains poorly studied, whilst climate change has the potential for wide-ranging impacts in the Antarctic and Subantarctic regions. Here we used predators as biological samplers to study the bathyal communities of SSI. A total of 61 species including fish, cephalopods and crustaceans, were identified from the diet of 13 predatory taxa (11 fish and two cephalopod). Common Subantarctic and Antarctic species were found, with Moroteuthopsis longimana being the species with the highest density (1.74 individuals per stomach at Montagu Island). Eleven fish and one cephalopod species were recorded for the first time at the archipelago. Furthermore, 16 fish species had their bathymetric range increased. Fifteen fish and one crustacean appear to have SSI as the northern or southern limit of their distribution. Community analysis found two major groups at SSI, one in the north and one in the south, with the southern group subdivided into two groups. This separation is related to the environmental conditions at the archipelago that abruptly change at Saunders Islands. Latitude (correlated with sea surface temperature) and sea surface height (proxy for upwelling) both correlated with the dissimilarity between communities. These results suggest that climate change may affect the biodiversity at SSI in the future as warming waters of the Scotia Sea and changes in the upwelling system may favour range extensions of more northerly species into the archipelago. Furthermore, it could lead to local extinctions of some species exclusively found in the southernmost areas of the archipelago.

The exploitation of marine resources of the South Sandwich Islands (SSI) began with the hunting of fur seals for their pelts in the early decades of the 19th Century. Pelagic whaling in the region started a century later with catches recorded until the mid-1970s. Blue and fin whales dominated the catches accounting for 80% of the total. Trawl fisheries for demersal finfish and krill (Euphausia superba) were established around many sub-Antarctic islands in the late 1960s and through the 1970s, but they did not become established at the South Sandwich Islands despite fisheries research expeditions from several nations visiting the region during this period. The first licensed demersal longline fishery for toothfish (Dissostichus spp.) was initiated by a UK flagged vessel in 2005 following earlier expeditions by Chilean and Bulgarian fishing vessels. The fishery for toothfish is now conducted by a maximum of two vessels and represents the only fishing carried out in the SSI region with total annual catches of around 40 t per annum, with a fishing footprint restricted to less than 4% of the SSI Maritime Zone (MZ). This MZ extends 200 nm from the island chain and forms the eastern half of the 1.24 million km2 MZ of the UK Overseas Territory of South Georgia & the South Sandwich Islands (SGSSI) which was established in 1993. The MZ around the SSI lies within the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) management Subarea 48.4. Fishing within the MZ is licensed by the Government of South Georgia & the South Sandwich Islands (GSGSSI) who, under domestic legislation, are required to adopt all fisheries management regulations that have been agreed for the region each year by CCAMLR. In addition, a suite of additional management measures are enforced. In 2012, GSGSSI established a sustainable use Marine Protected Area (MPA) within the SGSSI MZ to conserve the marine biodiversity of the region. Enhancements were introduced in 2013 and 2019 extending No-Take Zones (NTZs), where all fishing is prohibited, across 261,000 km2 of the MZ around the SSI including the deepest regions of the Southern Ocean, the South Sandwich Trench. The SSI marine ecosystem has been relatively poorly studied but has recently been a focus of two dedicated UK research cruises providing a considerable new amount of information to assist with the management of this remote marine region.

The South Sandwich Islands (SSI), a chain of volcanic islands in the Atlantic sector of the Southern Ocean, are home to two large notothenoid species: the Patagonian toothfish Dissostichus eleginoides and the Antarctic toothfish Dissostichus mawsoni. Both species support valuable fisheries throughout the Southern Ocean under management of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). The SSI region, which is located south of the Southern Antarctic Circumpolar Current Front, has a diverse and distinct biodiversity and it represents a range edge for the distribution of both toothfish species. In this paper we have updated and expanded previous biological analyses with recent data, explored the stock hypotheses and links of these species to other regions, and investigated the role of the SSI archipelago in the life cycles of both toothfish species, where they overlap in their distribution. We conclude that Patagonian toothfish around the SSI are linked to the adjacent South Georgia population, but have some unique characteristics, including faster growth and better somatic condition, possibly reflecting ???Bergmann???s rule??? which states that body size increases with decreasing temperature and increasing latitude. By comparison, the Antarctic toothfish at the SSI appear to be the northern extent of a larger stock connecting further south towards the Antarctic continent. Finally, we consider the relative importance of the SSI in the life cycle of both species, including in the context of climatic changes to this region.

The South Sandwich Islands (SSI) are a volcanic archipelago in the Atlantic sector of the Southern Ocean; they are a biologically rich area, home to a range of benthic habitats such as hydrothermal vents and seamounts. A commercial longline fishery for two congeneric species of deep-sea fish, the Patagonian (Dissostichus eleginoides) and Antarctic (D. mawsoni) toothfish has been in operation annually at the SSI since 2005 and throughout its history has employed scientific observers to collect detailed information on the species caught during fishing operations. Previous studies have investigated the distributions and communities of benthic invertebrates, sampled via scientific cruises. Here we highlight the utility of demersal longlines as spatially extensive sampling tools to investigate both invertebrate and fish communities at the SSI. A clear gradient in the distribution of many fish and invertebrate species is evident across the latitudinal range of the archipelago, these distributions result in clear differences in fish communities between the north, mid, and south of the islands, whilst the invertebrate communities are less clearly delineated. Environmental variables were investigated as drivers in these communities, and seawater temperature appears to be a key abiotic factor in mediating the distributions of species and communities. As many of these communities are structured based on temperature dependent species distributions, it is likely climate change will alter these communities with poleward shifts in the ranges of many species.

Exploitation is one of the major drivers of change in marine ecosystems. Following discovery in 1775, South Georgia saw sequential overexploitation of living resources, including seals, whales, and fish. Although exploitation is now tightly regulated, the ecosystem is still recovering. Marbled rockcod, Notothenia rossii (Richardson 1844), was the first fish species to be commercially exploited and high catches between 1967 and 1972 resulted in dramatic stock decline. Here, we use 30 years of trawl survey data to provide the first evidence of a sustained increase in the N. rossii population starting two decades after the prohibition of targeted fishing in 1985. The way species respond to change is mediated in part by trophic relationships with other organisms. We present the first multi-year, spatially-resolved comparison of adult N. rossii diet at South Georgia, highlighting a variable diet with less reliance on Antarctic krill than previously thought. Life history factors and possible heavy predation on early life stages might have delayed their recovery while diet plasticity potentially supported recent population growth. Due to the dynamic ecosystem at South Georgia and questions over catch reports from the period of heaviest exploitation, it is unlikely the current ecosystem could support a recovery to estimated pre-exploitation levels.

AIM: Management of competition with predators is an important consideration for fisheries, particularly within marine protected areas (MPAs) where conservation is a primary objective. We aimed to test whether static no-take zones within a large, sustainable-use MPA prevented overlap between gentoo penguins and a krill fishery during two winters with contrasting prey fields. LOCATION: South Georgia, Southwest Atlantic Ocean. METHOD: We used satellite tracking (N = 16, June-September 2018) to describe gentoo penguin movements and distribution and quantified their overlap with the MPA's no-take zone (NTZ) and the krill fishing grounds. DNA metabarcoding of scats (N = 220, April-September 2018) was used to quantify diet. RESULTS: When krill were at moderate densities and evenly distributed in 2001, gentoo penguins would have spent all of their time within the 12 NM NTZ, but when availability was low in 2018, they spent 46.3% of their time outside the NTZ and 9.6% within the krill fishing grounds. The extension of the NTZ to 30 km in response to this finding would have produced a 14.9% increase in protection for penguins and displaced 4% of fishery hauls. Gentoo penguin diet comprised 25.8% krill, which is lower than in the late 1980s but more than in 2009. MAIN CONCLUSIONS: Gentoo penguins extend their foraging range when krill is scarce, which increases the potential for spatial overlap with the krill fishery during periods of nutritional stress. Current regulations allow for expansion of both extent and catches by the krill fishery and, should this occur, gentoo penguins may face heightened risks from competition. A dynamic ocean management framework, that extends closed areas in response to near real-time data on penguin movements and krill density estimates, may reduce the potential for competition in this sustainable-use MPA while allowing a profitable krill fishery.

As the role of mercury is poorly known in Southern Ocean biota, the total mercury (T-Hg) concentrations were evaluated in upper/lower beaks, digestive gland, gills and mantle muscle of Adelieledone polymorpha and Pareledone turqueti, two of the most abundant octopod species around South Georgia. Beaks had the lowest T-Hg concentrations (A. polymorpha: [T-H](Upper) = 27.2 +/- 12.9 ng.g(-1) and [T-Hg](Lower) = 27.5 +/- 20.0 ng.g(-1); P. turqueti: [T-Hg](Upper) = 34.6 +/- 13.9 ng.g(-1) and [T-Hg](Lower) = 56.8 +/- 42.0 ng.g(-1)), followed by gills and muscle. The highest values were recorded in the digestive gland (A. polymorpha: 251.6 +/- 69.7 ng.g(-1) ; P. turqueti: 347.0 +/- 177.0 ng.g(-1)). Significant relationships were found between the concentrations of T-Hg in the beaks and muscle of A. polymorpha (T-Hg in muscle is 10 times higher than in beaks). This study shows that beaks can be used as proxy for T-Hg in muscle for some octopod species, and a helpful tool for estimating total Hg body burden from beaks.

Aim Marine protected areas can serve to regulate harvesting and conserve biodiversity. Within large multi-use MPAs, it is often unclear to what degree critical sites of biodiversity are afforded protection against commercial activities. Addressing this issue is a prerequisite if we are to appropriately assess sites against conservation targets. We evaluated whether the management regime of a large MPA conserved sites (Key Biodiversity Areas, KBAs) supporting the global persistence of top marine predators. Location Southwest Atlantic Ocean. Method We collated population and tracking data (1,418 tracks) from 14 marine predator species (Procellariiformes, Sphenisciformes, Pinnipedia) that breed at South Georgia and the South Sandwich Islands, and identified hotspots for their conservation under the recently developed KBA framework. We then evaluated the spatiotemporal overlap of these sites and the different management regimes of krill, demersal longline and pelagic trawl fisheries operating within a large MPA, which was created with the intention to protect marine predator species. Results We identified 12 new global marine KBAs that are important for this community of top predators, both within and beyond the focal MPA. Only three species consistently used marine areas at a time when a potentially higher-risk fishery was allowed to operate in that area, while other interactions between fisheries and our target species were mostly precluded by MPA management plans. Main conclusions We show that current fishery management measures within the MPA contribute to protecting top predators considered in this study and that resource harvesting within the MPA does not pose a major threat-under current climate conditions. Unregulated fisheries beyond the MPA, however, pose a likely threat to identified KBAs. Our approach demonstrates the utility of the KBA guidelines and multispecies tracking data to assess the contributing role of well-designed MPAs in achieving local and internationally agreed conservation targets.

The Antarctic is considered to be a pristine environment relative to other regions of the Earth, but it is increasingly vulnerable to invasions by marine, freshwater and terrestrial non-native species. The Antarctic Peninsula region (APR), which encompasses the Antarctic Peninsula, South Shetland Islands and South Orkney Islands, is by far the most invaded part of the Antarctica continent. The risk of introduction of invasive non-native species to the APR is likely to increase with predicted increases in the intensity, diversity and distribution of human activities. Parties that are signatories to the Antarctic Treaty have called for regional assessments of non-native species risk. In response, taxonomic and Antarctic experts undertook a horizon scanning exercise using expert opinion and consensus approaches to identify the species that are likely to present the highest risk to biodiversity and ecosystems within the APR over the next 10 years. One hundred and three species, currently absent in the APR, were identified as relevant for review, with 13 species identified as presenting a high risk of invading the APR. Marine invertebrates dominated the list of highest risk species, with flowering plants and terrestrial invertebrates also represented; however, vertebrate species were thought unlikely to establish in the APR within the 10 year timeframe. We recommend (a) the further development and application of biosecurity measures by all stakeholders active in the APR, including surveillance for species such as those identified during this horizon scanning exercise, and (b) use of this methodology across the other regions of Antarctica. Without the application of appropriate biosecurity measures, rates of introductions and invasions within the APR are likely to increase, resulting in negative consequences for the biodiversity of the whole continent, as introduced species establish and spread further due to climate change and increasing human activity.

In the marine environment, understanding the biophysical mechanisms that drive variability in larval dispersal and population connectivity is essential for estimating the potential impacts of climate change on the resilience and genetic structure of populations. Species whose populations are small, isolated and discontinuous in distribution will differ fundamentally in their response and resilience to environmental stress, compared with species that are broadly distributed, abundant and frequently exchange conspecifics. Here, we use an individual‐based modelling approach, combined with a population genetics projection model, to consider the impacts of a warming climate on the population connectivity of two contrasting Antarctic fish species, Notothenia rossii and Champsocephalus gunnari. Focussing on the Scotia Sea region, sea surface temperatures are predicted to increase significantly by the end of the 21st century, resulting in reduced planktonic duration and increased egg and larval mortality. With shorter planktonic durations, the results of our study predict reduced dispersal of both species across the Scotia Sea, from Antarctic Peninsula sites to islands in the north and east, and increased dispersal among neighbouring sites, such as around the Antarctic Peninsula. Increased mortality modified the magnitude of population connectivity but had little effect on the overall patterns. Whilst the predicted changes in connectivity had little impact on the projected regional population genetic structure of N. rossii, which remained broadly genetically homogeneous within distances of ~1,500 km, the genetic isolation of C. gunnari populations in the northern Scotia Sea was predicted to increase with rising sea temperatures. Our study highlights the potential for increased isolation of island populations in a warming world, with implications for the resilience of populations and their ability to adapt to ongoing environmental change, a matter of high relevance to fisheries and ecosystem‐level management.

This research is the first to investigate deepwater demersal fish distribution and community structure around South Georgia and Shag Rocks. Analysis of catch data from a trawl survey conducted in 2003 indicated that depth and location have a marked influence over demersal fish community structure in the region. Three distinct, depth-stratified fish assemblages were observed. The demersal fish assemblage found on the shelf to depths of around 400 m was dominated by nototheniids and was comprised largely of species endemic to the Southern Ocean and Scotia Sea. At the greatest depths sampled (>600 m) the demersal fish community was dominated by gadiform fishes including members of the Macrouridae and Moridae, many of which are not endemic to the Southern Ocean. From 400 to 600 m there was a transitional zone with demersal fish representatives of both the shelf and deeper slope communities. Clear geographic differences in the shelf community were apparent with differences observed in community structure between South Georgia and Shag Rocks to depths of around 400 m. These data provide valuable baseline information to aid environmental management decisions and assess potential impacts of rapid ocean warming around South Georgia.