South Atlantic Islands Research Articles

Evidence for a floristically diverse rainforest on the Falkland archipelago in the remote South Atlantic during the mid- to late Cenozoic

Abstract We report the discovery of an ancient forest bed near Stanley, on the Falkland Islands, the second such ancient deposit identified on the South Atlantic island archipelago that is today marked by the absence of native tree species. Fossil pollen, spores and wood fragments preserved in this buried deposit at Tussac House show that the source vegetation was characterized by a floristically diverse rainforest dominated by Nothofagus-Podocarpaceae communities, similar to cool temperate Nothofagus forests/woodlands and Magellanic evergreen Nothofagus rainforests. The age limit of the deposit is inferred from the stratigraphic distribution of fossil pollen species transported by wind, birds or ocean currents from southern Patagonia, as well as similar vegetation types observed across the broader region. The deposit is suggested to be between Late Oligocene and Early Miocene, making it slightly older than the previously analysed Neogene West Point Island forest bed (200 km west of Tussac House). The combined evidence adds to our current knowledge of the role of climate change and transoceanic dispersal of plant propagules in shaping high-latitude ecosystems in the Southern Hemisphere during the late Palaeogene and Neogene.

Phylogenetic placement of Carex dianae Steud., a sedge endemic to the South Atlantic island of St. Helena

Carex dianae Steud. is an endemic sedge of St. Helena, an isolated island in the South Atlantic. Our study provides the first molecular sequence data for this taxon. We generated sequence data for plastid matK and trnK regions and nuclear internal transcribed spacer and external transcribed spacer regions to determine the placement of C. dianae in the broader Carex phylogeny. The placement of C. dianae falls within Carex sect. Spirostachyae Drejer, and it is sister to a clade including Carex clavata Thunb., Carex aethiopica Schkuhr (both from the Cape region of S. Africa), and Carex gunniana Boott (southern Australia). The existence of three divergent nucleotype groups and two plastotypes is revealed from genetic variation within C. dianae. The results suggest that the ancestor of C. dianae likely originated in the Cape region of South Africa, followed by transoceanic dispersal to St. Helena estimated at 4.4–4.9 million years ago, likely by a bird vector. The most divergent population is that on an isolated hill known as “The Barn”, which may represent a distinct taxon. The existence of highly structured molecular variation within an island only 16 km long is discussed.

Distribution patterns of meiofauna and free-living nematodes in beaches of a remote tropical South Atlantic Island (Trindade, Brazil)

Distribution patterns of meiofauna and free-living nematodes in beaches of a remote tropical South Atlantic Island (Trindade, Brazil)

Diversity of mitochondrial DNA in 3 species of great whales before and after modern whaling.

The 20th century commercial whaling industry severely reduced populations of great whales throughout the Southern Hemisphere. The effect of this exploitation on genetic diversity and population structure remains largely undescribed. Here, we compare pre- and post-whaling diversity of mitochondrial DNA (mtDNA) control region sequences for 3 great whales in the South Atlantic, such as the blue, humpback, and fin whale. Pre-whaling diversity is described from mtDNA extracted from bones collected near abandoned whaling stations, primarily from the South Atlantic island of South Georgia. These bones are known to represent the first stage of 20th century whaling and thus pre-whaling diversity of these populations. Post-whaling diversity is described from previously published studies reporting large-scale sampling of living whales in the Southern Hemisphere. Despite relatively high levels of surviving genetic diversity in the post-whaling populations, we found evidence of a probable loss of mtDNA lineages in all 3 species. This is evidenced by the detection of a large number of haplotypes found in the pre-whaling samples that are not present in the post-whaling samples. A rarefaction analysis further supports a loss of haplotypes in the South Atlantic humpback and Antarctic blue whale populations. The bones from former whaling stations in the South Atlantic represent a remarkable molecular archive for further investigation of the decline and ongoing recovery in the great whales of the Southern Hemisphere.

Climatic data comparison between mid-latitude Azores (North Atlantic) and Tristan da Cunha (South Atlantic) islands

"The Azores islands in the North Atlantic and the Tristan da Cunha islands in the South Atlantic are approximately located at the same latitude, stretching between 36 and 41 degrees North and South respectively. Nevertheless, there are important climatic differences between the two archipelagos. The average annual temperature is higher in the Azores by more than 3 degrees, while the amount of precipitation is higher in Tristan da Cunha by about 600 mm/year on average. The warmer climate of the Azores may be explained by several contributing factors, such as: the smaller distance to the nearest continental landmass – less than 1500 km, compared to more than 2700 km in the case of Tristan da Cunha; the land mass of the islands themselves, as the Azores are much larger; the location of the Azores in the area of the North Atlantic High, with more stable weather and a higher amount of sunshine hours compared to the Tristan da Cunha islands, where westerlies prevail; and, not in the least, the influence of the Gulf Stream in the case of the Azores. The larger amount of precipitation in the case of Tristan da Cunha islands is due to their location on the southern flank of the South Atlantic High, which causes a higher degree of cloudiness and therefore more precipitation. The altitude is also a factor, as both archipelagos feature volcanic mountains rising above 2000 metres, providing a barrier for the air masses and determining orographic precipitation, especially on the windward side of the islands. The climate has had an impact on the settlement and human life on the islands. The Azores were settled immediately after their discovery in the 15th century and there is a rich social and economic life ever since. By contrast, the small community on Tristan da Cunha main island was formed only in the 19th century and has endured many hardships. Keywords: climatic comparison, Azores, Tristan da Cunha, average temperature, precipitation."

Unveiling the hidden threat of microplastics to coral reefs in remote South Atlantic islands

The widespread presence of marine microplastics (< 5 mm) is a significant concern, as it may harm marine biodiversity and ocean ecosystems. Corals' capacity to ingest microplastics has emerged as a significant threat to reef ecosystems, owing to the detrimental physiological and ecological effects it can trigger. The extent of the impact of microplastics on Brazilian corals remains unclear and this study aimed to investigate its distribution and characteristics in four coral species: Favia gravida, Mussismilia hispida, Montastrea cavernosa, and Siderastrea stellata, found in the Trindade and Martim Vaz Islands – the most isolated archipelago of Brazil, located about 1200 km (680 miles) east of the coast. This study aims to reveal the extent of microplastic distribution in the coral reef environment, assess the amount of microplastics in different coral species, and compare each species' capacity to adhere and accumulate microplastics. A high concentration of ingested and adhered microplastics was detected in all coral species evaluated in the present study. No significant differences were observed in the sampling points which indicates that although the sampling points are located at different distances from the coast, the microplastic pollution is equally distributed in the region. Polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), poly(methyl methacrylate) (PMMA), Rayon, and Nylon particles were detected, with a predominance of PE (45.5 %). No significant differences in microplastic concentration were detected among the various species and locations studied. Our research presents findings that demonstrate the extensive occurrence of microplastic contamination in coral colonies located on remote islands.

Lemon Valley, St Helena: an East India Company and British Colonial landscape in the South Atlantic

SUMMARY This article presents the results of an historical and archaeological survey of Lemon Valley, in the South Atlantic island of St Helena. The valley was periodically used by 16th-century mariners during the early years of the Age of Discovery and permanently settled by the English East India Company from the 1660s. The survey reveals a palimpsest landscape which preserves extensive military and civilian ‘plantation’ remains. Together, these provide a rare insight into the character and evolution of the English settlement of the island from the late 17th century, through to the abandonment of the valley in the mid-20th century.

Evolutionary Tracks of Chromosomal Diversification in Surgeonfishes (Acanthuridae: Acanthurus) Along the World's Biogeographic Domains.

Fishes of the genus Acanthurus (Acanthuridae) are strongly related to reef environments, in a broad biogeographic context worldwide. Although their biological aspects are well known, cytogenetic information related to this genus remains incipient. In this study, Acanthurus species from populations inhabiting coastal regions of the Southwest Atlantic (SWA), South Atlantic oceanic islands (Fernando de Noronha Archipelago and Trindade Island), Greater Caribbean (GC), and Indo-Pacific Ocean (the center of the origin of the group) were analyzed to investigate their evolutionary differentiation. For this purpose, we employed conventional cytogenetic procedures and fluorescence in situ hybridization of 18S rDNA, 5S rDNA, and H3 and H2B-H2A histone sequences. The Atlantic species (A. coeruleus, A. chirurgus, and A. bahianus) did not show variations among them, despite their vast continental and insular distribution. In contrast, A. coeruleus from SWA and GC diverged from each other in the number of 18S rDNA sites, a condition likely associated with the barrier created by the outflows of the Amazonas/Orinoco rivers. The geminate species A. tractus had a cytogenetic profile similar to that of A. bahianus. However, the chromosomal macrostructures and the distribution of rDNA and hisDNA sequences revealed moderate to higher rates of diversification when Acanthurus species from recently colonized areas (Atlantic Ocean) were compared to A. triostegus, a representative species from the Indian Ocean. Our cytogenetic data covered all Acanthurus species from the Western Atlantic, tracked phylogenetic diversification throughout the dispersive process of the genus, and highlighted the probable diversifying role of ocean barriers in this process.

The potential for expansion of whale shark (Rhincodon typus) tourism in St. Helena: stakeholder engagement and willingness to pay

ABSTRACT Whale shark (Rhincodon typus) tourism is increasingly popular wherever the species occur, including a fledgling industry on the South Atlantic island of St. Helena. We interviewed 154 people to elicit the social and economic value of whale shark tourism on the island. Additionally, 77 survey participants were queried about their willingness to pay, 32% of those responding indicated that they would be willing to pay at least £10 more, a 20% increase from existing charges. Tourists also supported the concept that the local population should pay less for whale shark snorkel tours. Perceptions among visitors and locals were that the marine environment was well managed on St. Helena and that protecting it was important. Results from this study could help inform St. Helena Government policy and support MWT operators on the island to further develop a sustainable and equitable whale shark tourism industry.

Combining survey and remotely sensed environmental data to estimate the habitat associations, abundance and distribution of breeding thin-billed prions Pachyptila belcheri and Wilson\u2019s storm-petrels Oceanites oceanicus on a South Atlantic tussac island

Small petrels are the most abundant seabirds in the Southern Ocean. However, because they breed in burrows on remote and often densely vegetated islands, their colony sizes and conservation status remain poorly known. To estimate the abundance of these species on Bird Island in the Falkland archipelago, we systematically surveyed their breeding burrow density and occupancy across this near-pristine tussac (Poa flabellata)-covered island. By modelling burrow density as functions of topography and Sentinel 2 satellite-derived Normalised Difference Vegetation Index data, we inferred habitat associations and predicted burrow abundance of the commonest species—Thin-billed Prions (Pachyptila belcheri) and Wilson’s Storm-petrels (Oceanites oceanicus). We estimate that there are 631,000 Thin-billed Prion burrows on the island (95% CI 496,000–904,000 burrows). Assuming that burrow occupancy lies between 12 and 97%, this equates to around 76,000–612,000 breeding pairs, making Bird Island the second or third largest P. belcheri colony in the world, holding approximately 3–27% of the species’ breeding population. We estimate that 8200–9800 (95% CI 5,200–18,300 pairs) pairs of Wilson’s Storm-petrels also breed on the island. Notably, the latter burrowed predominantly under and within tussac pedestals, whereas they are usually assumed to breed in rock cavities. Thin-billed Prions are declining in the Kerguelen archipelago, but their population trends in the Falklands are unknown. Given the wide confidence intervals around our own and other population estimates for these cryptic species, we recommend that their populations should be monitored regularly, at multiple sites.

Compatibility and strategic convergence military and environmental approaches towards south atlantic brazilian oceanic islands

Several Marine Protected Areas have been created in the world, in part to fulfill one of the United Nations Convention on Biodiversity goals as to preserve at least 10% of each country’s coastal and marine areas. This study aims at analyzing military presence in the Brazilian oceanic islands of Fernando de Noronha, Trindade &amp; Martin Vaz and São Pedro &amp; São Paulo and how it interacts with the environmental approach, since the three encompass Large Scale Marine Protected Areas. A brief overview about the importance of the islands to Brazilian geopolitical thinkers is shown, as well as the theoretical issues regarding the military presence in preserved environmental areas. Those results are then applied to the three Large Scale Marine Protected Areas’ present situation, with the conclusion pointing to a positive feedback loop, with significant and favorable results on environmental and military approaches, as well as regarding geopolitical goals.

EVOLUCIÓN DE LAS CONCEPCIONES DOCENTES SOBRE LAS ACTIVIDADES PRÁCTICAS DE LABORATORIO A PARTIR DE UNA FORMACIÓN DE POSGRADO REFLEXIVA

Las creencias o concepciones que poseen los docentes sobre determinados contenidos, en este caso sobre las actividades prácticas de laboratorio en Biología, tienen una fuerte influencia en la enseñanza. Por este motivo es imprescindible ocuparse de ellas y analizar como transformarlas. En este caso se hizo mediante una intervención didáctica en un seminario de posgrado en la Universidad Nacional de Tierra del Fuego Antártida e Islas del Atlántico Sur, Argentina. El grupo de cursantes, estuvo conformado por 4 profesoras con características y perfiles diversos. Se empleó una entrevista basada en un cuestionario que se analizó cualitativamente utilizando el método comparativo constante. En las profesoras en formación de posgrado (PFP) existen concepciones y creencias sobre las actividades prácticas de laboratorio similares a las halladas en otros estudios. Además reconocen que les cuesta salir de las prácticas tipo receta y de su zona de confort, por añadidura piensan que esta situación también se produce en los estudiantes. Se observan diferencias entre las PFP con y sin experiencia docente ya que las que no poseen experiencia plantean temores en relación a la conducta de los estudiantes. También hay diferencias importantes entre las profesoras que poseen formación inicial como docentes y aquellas que se formaron solamente en la disciplina Biología (o afín). Se ha hallado que es necesario considerar las emociones y el dominio afectivo como parte del Conocimiento Didáctico del Contenido (CDC) sobre las actividades practicas. Las PFP dieron cuenta de algunos obstáculos epistemológicos que dan forma a su CDC y de alguna manera condicionan su desempeño durante las actividades de laboratorio. Estos están relacionados con cuestiones personales y de formación, de contenidos, relacionadas con estudiantes e institucionales. Es necesario diseñar un proceso de formación continua específico con el objetivo de promover el cambio de las creencias previas.

St. Helena: An Important Reproductive Habitat for Whale Sharks (Rhincodon typus) in the Central South Atlantic

A reliable aggregation of whale sharks (Rhincodon typus) takes place in waters surrounding the remote South Atlantic island of St. Helena from December to May each year, peaking in January. A total of 277 individual sharks were identified over the course of the study, consisting of a 1.1:1 sex ratio of mature male and female sharks estimated to be between 5-12 m in total length. The SOCPROG best fit models estimated ~102 individual whale sharks at any one time with a decline to complete absence at ~75 days and an interannual periodicity for some sharks returning each season. Eyewitness accounts of mating behavior have been reported by reliable local observers on two separate occasions, which comprise the first observations of copulation in this species and are consistent with the size and sex demographics of the population. Horizontal movements away from the island proved difficult to track, due to extraordinarily deep-diving behavior that either damaged or caused premature detachment of the archival satellite tags, however, some individuals showed large scale movement away from the island towards both Africa and South America. Acoustic telemetry showed that animals use the habitats around the entire island, but are focused on the leeward side, particularly from James Bay to Barn Cap. Due to its likely role in the reproductive ecology of the whale shark, St. Helena represents a critical habitat for this endangered species and deserves concerted research efforts.

Spatial variability of the ichthyoneuston around oceanic islands at the tropical Atlantic

Oceanic tropical waters are characteristically oligotrophic. However, current-topography interaction around oceanic islands promotes bio-physical processes, which may enrich surface waters. The ichthyoneuston assemblage at three areas around oceanic islands in the tropical Atlantic was investigated. The aim was to evaluate if the ichthyoneuston was influenced by physical oceanographic processes, such as possible mechanisms of plankton retention promoted by the presence of the islands. Samplings were performed by 20 min long diurnal and nocturnal 500-μm plankton net hauls using a David-Hempel Catamaran at two transections in each area (Saint Peter and Saint Paul's archipelago, Fernando de Noronha archipelago, and Rocas Atoll). The transections were composed by three stations and were located at opposite sides of the archipelagos (windward and leeward sides of the archipelago). A total of 131 larvae and 3027 eggs, belonging to 16 families and 28 species were collected. Higher densities of eggs were found at the leeward side, which indicates the occurrence of a retention mechanism or spawning at this side. Higher densities of larvae were found at Fernando de Noronha, especially during the nocturnal period. Only one species, Ceratoscopelus warmingii, co-occurred at the three islands. Fernando de Noronha was highlighted as the area with the higher density, abundance and species richness. The waters around this island were positively correlated with chlorophyll-a, which indicates a higher availability of food items and stimulates the selection of this area as a favorable spot for reproduction and early nursery zone. This work highlighted the importance of the relation between abiotic factors and the distribution of fish eggs and larvae inhabiting the neustonic layer around South Atlantic oceanic islands, showing that favorable conditions, e.g. higher phytoplanktonic biomass, may be of fundamental importance to the spawning by adult individuals.

Moth versus fly: a preliminary study of the pollination mode of two species of endemic Asteraceae from St Helena (Commidendrum robustum and C. rugosum) and its conservation implications.

Commidendrum robustum (Roxb.) DC. (St Helena gumwood) and C. rugosum (Dryand.) DC. (St Helena scrubwood) are ecologically important, endemic woody Asteraceae from the isolated South Atlantic island of St Helena. Once very abundant, they now exist in sparse fragmented populations due to 500 years of environmental destruction. They are sister taxa that evolved on the island and are reported to hybridise. Commidendrum rugosum has a saucer-like erect capitulum, whereas C. robustum has a somewhat globular hanging capitulum. Using daytime timelapse photography to follow capitula through their life cycle, we found that C. rugosum appears to be myophilous, visited largely by flies (including the endemic syrphid, Sphaerophoria beattiei Doesburg & Doesburg) and occasionally by Lepidoptera. Commidendrum robustum, on the other hand, although visited by flies, strongly attracts moths (especially noted at the Millennium Forest site). Our data suggest that moth visits may reduce visits from flies due to the sensitivity of flies to interference by other insects. We conclude that C. robustum may have a mixed syndrome of myophily/phalaenophily and that there is apparently some divergence of the pollination niche between the two species. Its potential in attracting moths, coupled with its former abundance, suggests that it may have been a major food source for adults of the numerous endemic moths. Pollinator activity was measured by insect visitation rates (mean visits per capitulum per day, V) and insect residence time (mean pollinator kiloseconds per capitulum per day, R). Both are higher for C. robustum (C. rugosum, V = 16.4, R = 3.101; C. robustum, V = 34.0, R = 8.274), reflecting the abundance of moths on the capitula at the Millennium Forest site. The conservation implications of the pollination mode are that: (1) there is considerable pollinator activity on the capitula and pollination is not currently a limiting factor for plant reproduction; (2) gene exchange between geographically-isolated populations of C. rugosum is likely to be minimal due to the apparent reliance of the species for pollination on small flies (especially Sphaerophoria beattiei), which are believed to be not effective as pollinators over long distances (> 1 km). A possible exception is the strong-flying drone-fly, Eristalis tenax Linn. which, although not as abundant as Sphaerophoria, does visit the flowers; (3) there is considerable overlap between the two species in flower visitors and interspecific pollen transfer is possible where the two species grow intermixed (which has potential positive and negative implications for species survival).

Genesis and evolution of the South Atlantic volcanic islands offshore Brazil

The Brazilian continental margin includes several volcanic islands, submerged volcanic seamounts, and a unique non-volcanic archipelago located in a transform segment of the Equatorial South Atlantic. The mechanism of formation of these islands is related to post-breakup magmatic episodes dated as Late Cretaceous to Pleistocene. Diverse Late Cretaceous to Paleogene alkaline magmatic episodes are registered in southeast Brazil, resulting in igneous plugs onshore and volcanic structures offshore. The Abrolhos Volcanic Complex in eastern Brazil is characterized by several volcanic features on the continental shelf, including small islands that expose Paleogene sedimentary layers interbedded with volcanic sequences. The adjacent Vitoria-Trindade Chain extends to oceanic crust forming basaltic to alkaline seamounts that outcrop at the Trindade Archipelago, the easternmost islands in Brazil with the youngest volcanic eruptions. The Fernando de Noronha lineament in northeast Brazil is characterized by Neogene alkaline igneous plugs. The small islets in the Sao Pedro—Sao Paulo archipelago, located near the mid-Atlantic ridge, are formed by exhumed mantle rocks related to compressional episodes a transform fault zone. The Rio Grande Rise in southern Brazil is characterized by shallow Paleogene seamounts and a large oceanic plateau probably related to subaerial spreading centers formed in the Late Cretaceous. Multiple mechanisms are responsible for the origin and evolution of the volcanic islands offshore Brazil in continental, transitional, and oceanic crust settings, including volcanic build-ups, leaking fracture zones, and hotspots. Some of the islands might be related to mantle plume activity, as indicated by comparisons with modern mantle plume analogues in the South Atlantic.

Operation Rosario and the Escalation of the Anglo-Argentinian Conflict in 1982

A small garrison of the British Royal Navy was swallowed up by the superior forces of a much larger nation in just a few hours. This may be the title of a report from the beginning of April 1982. The impact of Operation Rosario on the international arena and the evolution of the conflict was much more complex and had major repercussions on maintaining world peace. Why Argentina chose to invade the Falkland Islands and what caused the "spark" of the conflict to erupt at alarming levels, are questions whose answers you can find in this article. The Battle of Stanley was one of the most unequal armed actions between two states during the 20th century and drew a small group of South Atlantic islands to the attention of the whole world.

A South Atlantic island record uncovers shifts in westerlies and hydroclimate during the last glacial

Abstract. Changes in the latitudinal position and strength of the Southern Hemisphere westerlies (SHW) are thought to be tightly coupled to important climate processes, such as cross-equatorial heat fluxes, Atlantic Meridional Overturning Circulation (AMOC), the bipolar seesaw, Southern Ocean ventilation and atmospheric CO2 levels. However, many uncertainties regarding magnitude, direction, and causes and effects of past SHW shifts still exist due to lack of suitable sites and scarcity of information on SHW dynamics, especially from the last glacial. Here we present a detailed hydroclimate multiproxy record from a 36.4–18.6 kyr old lake sediment sequence on Nightingale Island (NI). It is strategically located at 37∘ S in the central South Atlantic (SA) within the SHW belt and situated just north of the marine Subtropical Front (SF). This has enabled us to assess hydroclimate changes and their link to the regional climate development as well as to large-scale climate events in polar ice cores. The NI record exhibits a continuous impact of the SHW, recording shifts in both position and strength, and between 36 and 31 ka the westerlies show high latitudinal and strength-wise variability possibly linked to the bipolar seesaw. This was followed by 4 kyr of slightly falling temperatures, decreasing humidity and fairly southerly westerlies. After 27 ka temperatures decreased 3–4 ∘C, marking the largest hydroclimate change with drier conditions and a variable SHW position. We note that periods with more intense and southerly-positioned SHW seem to be related to periods of increased CO2 outgassing from the ocean, while changes in the cross-equatorial gradient during large northern temperature changes appear as the driving mechanism for the SHW shifts. Together with coeval shifts of the South Pacific westerlies, our results show that most of the Southern Hemisphere experienced simultaneous atmospheric circulation changes during the latter part of the last glacial. Finally we can conclude that multiproxy lake records from oceanic islands have the potential to record atmospheric variability coupled to large-scale climate shifts over vast oceanic areas.

Investigating Subantarctic14C Ages of Different Peat Components: Site and Sample Selection for Developing Robust Age Models in Dynamic Landscapes

ABSTRACTPrecise radiocarbon (14C) dating of sedimentary sequences is important for developing robust chronologies of environmental change, but sampling of suitable components can be challenging in highly dynamic landscapes. Here we investigate radiocarbon determinations of different peat size fractions from six peat sites, representing a range of geomorphological contexts on the South Atlantic subantarctic islands of the Falklands and South Georgia. To investigate the most suitable fraction for dating, 112 measurements were obtained from three components within selected horizons: a fine fraction &lt;0.2 mm, a coarse fraction &gt;0.2 mm, and bulk material. We find site selection is critical, with locations surrounded by high-ground and/or relatively slowly accumulating sites more susceptible to the translocation of older carbon. Importantly, in locations with reduced potential for redeposition of material, our results show that there is no significant or systematic difference between ages derived from bulk material, fine or coarse (plant macrofossil) material, providing confidence in the resulting age model. Crucially, in areas comprising complex terrain with extreme relief, we recommend dating macrofossils or bulk carbon rather than a fine fraction, or employing comprehensive dating of multiple sedimentary fractions to determine the most reliable fraction(s) for developing a robust chronological framework.

The status of the invertebrate fauna on the South Atlantic island of St Helena: problems, analysis, and recommendations

We present an analysis of the invertebrates of St Helena using an invertebrate conservation evaluation framework, to review invertebrate data, highlight knowledge gaps and prioritise invertebrate conservation needs that perhaps could be applied to other regions of the world. St Helena’s invertebrate fauna has 891 genera and 1133 species. The fauna has a high level of endemism with 450 species (equal to 96% of all native species) but the total species richness now comprises many introduced species (664) with 93 species in 24 orders that are entirely novel to St Helena. The elevation ranges of native species appear to be narrow, most being confined to higher elevations above 500 m. St Helena has had a large number of probable extinction events; 30 insects, and 19 molluscs, and the threat of further extinctions remains high. The cumulative invertebrate extinctions on St Helena exceed the global background extinction rate on an island barely covering 122 km2. We present actions and timelines to focus invertebrate conservation on St Helena; taxonomy, ecology, long term monitoring and invasive species control are priority areas to reduce extinction risk.