scholarly journals The rat problem on oceanic islands—research is needed

Oryx ◽  
1986 ◽  
Vol 20 (2) ◽  
pp. 79-86 ◽  
Author(s):  
N. M. Wace
Keyword(s):  
Oceanic Islands ◽  
South Atlantic ◽  
Conservation Strategy ◽  
The South ◽  
World Conservation ◽  
Tristan Da Cunha ◽  
Gough Island ◽  
Small Team

In October 1983 a rat was reported to have been seen on Gough Island, an outlier of the Tristan da Cunha Group in the South Atlantic. Gough Island has no permanently resident human inhabitants, but supports one of the largest and most diverse assemblages of breeding seabirds now remaining anywhere in the temperate zones. The author was a member of a small team of biologists that spent three weeks on Gough Island, in October-November 1984, to try to confirm whether there were any rats on the island, and if so to make recommendations for their control and extermination. The following proposals result from experience in carrying out this survey, and from writing World Conservation Strategy proposals for Oceanic Islands for the IUCN.

scholarly journals Fur Seals Return to Gough Island

Oryx ◽  
1981 ◽  
Vol 16 (1) ◽  
pp. 46-47 ◽  
Author(s):  
W.R.P. Bourne
Keyword(s):  
South Atlantic ◽  
The South ◽  
Tristan Da Cunha ◽  
Fur Seals ◽  
Gough Island

After a somewhat perilous landing on Gough Island, south of Tristan da Cunha in the South Atlantic, the author was able to confirm the remarkable comeback of the fur seals there, once heavily exploited but now numbering over a hundred thousand.

scholarly journals Demography and Population Trends of the Atlantic Yellow-Nosed Albatross

The Condor ◽  
2003 ◽  
Vol 105 (3) ◽  
pp. 439-452 ◽  
Author(s):  
Richard Cuthbert ◽  
Peter G. Ryan ◽  
John Cooper ◽  
Geoff Hilton
Keyword(s):  
Atlantic Ocean ◽  
Conservation Status ◽  
South Atlantic ◽  
Population Trends ◽  
South Atlantic Ocean ◽  
Adult Survival ◽  
The South ◽  
Apparent Survival ◽  
Tristan Da Cunha ◽  
Gough Island

Abstract The Atlantic Yellow-nosed Albatross (Thalassarche chlororhynchos) breeds only at the Tristan da Cunha archipelago and Gough Island in the central South Atlantic Ocean, and is threatened by mortality from longline fisheries operating in the South Atlantic. Demographic data have been collected from two study colonies on Gough Island and Tristan da Cunha for 20 years. Annual variation in the number of breeding birds was strongly correlated between the two islands, and over the whole study period both study populations have trended downward at around 1.2% per year. The number of established breeders on Gough Island has declined more rapidly, and significantly, at an annual rate of 2.3%. Monitoring established breeders may be a sensitive means of detecting population trends. Average breeding success (67–69%) and breeding frequency (66–65%) were very similar on the two islands. On Gough Island immature and adult annual apparent survival averaged 88 ± 3% and 92 ± 1%, respectively, and apparent survival from fledging to age 5 has averaged 31 ± 8%. Apparent adult survival on Tristan da Cunha averaged only 84 ± 2%. Annual survival of Tristan birds was negatively correlated with longline fishing effort in the South Atlantic Ocean. Population modeling predicts annual rates of decrease of 1.5–2.8% on Gough Island and 5.5% on Tristan da Cunha. Comparison with congeners suggests that the observed and predicted decreases are most likely to be caused by low adult and immature survival. The conservation status of Atlantic Yellow-nosed Albatrosses should be changed from Near Threatened to Endangered. Demografía y Tendencias Poblacionales del Albatros Thalassarche chlororhynchos Resumen. El albatros Thalassarche chlororhynchos sólo se reproduce en el archipiélago Tristan da Cunha y en la isla Gough en el Océano Atlántico Sur central, y se encuentra amenazado debido a la mortalidad causada por las pesqueras de espinel que operan en el Atlántico Sur. Se colectaron datos demográficos durante 20 años en dos colonias reproductivas en el archipiélago Tristan da Cunha y en la isla Gough. La variación anual en el número de aves reproductivas se correlacionó fuertemente entre las dos islas, y durante todo el período de estudio ambas poblaciones han presentado tendencias de decrecimiento de aproximadamente un 1.2% por año. El número de reproductores establecidos en la isla Gough ha disminuido significativamente y más rápidamente, a una tasa anual de 2.3%. El monitoreo de los reproductores que se establecen puede ser un medio sensible para detectar tendencias poblacionales. El éxito reproductivo promedio (67–69%) y la frecuencia de cría (66–65%) fueron muy similares en ambas islas. En la isla Gough la sobrevivencia aparente de inmaduros y adultos fue en promedio de 88 ± 3% y 92 ± 1%, respectivamente. La sobrevivencia de volantones a la edad de 5 años fue en promedio de 31 ± 8%. La sobrevivencia aparente de adultos en Tristan de Cunha fue en promedio sólo de 84 ± 2%. La sobrevivencia anual de las aves de Tristan se correlacionó negativamente con el esfuerzo de la pesca de espinel en el Océano Atlántico Sur. Los modelos poblacionales predicen tasas de disminución anuales de un 1.5–2.8% en la isla Gough y de un 5.5% en Tristan da Cunha. Comparaciones con congéneres sugieren que las disminuciones observadas y predichas son muy probablemente causadas por la baja sobreviviencia de adultos e inmaduros. La categoría de conservación del albatros T. chlororhynchos debería ser cambiada de “casi amenazada” a “en peligro.”

scholarly journals Marine hotspots of activity inform protection of a threatened community of pelagic species in a large oceanic jurisdiction in the South Atlantic

2019 ◽  
Author(s):  
Susana Requena-Moreno ◽  
Steffen Oppel ◽  
Alex Bond ◽  
Jonathan Hall ◽  
Jaimie Cleeland ◽  
...  
Keyword(s):  
Management Strategies ◽  
Oceanic Islands ◽  
South Atlantic ◽  
The South ◽  
Animal Tracking ◽  
Marine Management ◽  
Tristan Da Cunha ◽  
Fur Seals ◽  
Four Seasons ◽  
Marine Areas

Remote oceanic islands harbour unique biodiversity, especially of species that rely on pelagic resources around their breeding islands. Identifying marine areas used by such species is important to reduce or limit threats that may put these species at risk. The Tristan da Cunha group of islands in the South Atlantic Ocean hosts several endemic and globally threatened seabirds and pinnipeds; how they use the waters surrounding the islands must be considered when planning industrial activities in the entire Exclusive Economic Zone (EEZ). We identified hotspots of activity by collating animal tracking data from nine breeding seabirds and one marine mammal to inform marine management in the Tristan da Cunha EEZ.To detect statistically significant areas of concentrated activity, we calculated the time-spent-in-area that tracked individuals (breeding adults) of 10 focal species (mainly breeding adults of nine seabirds and adult female Subantarctic fur seals Arctocephalus tropicalis) invested in a grid of regular 10 × 10 km cells within the EEZ, for each of four seasons to account for temporal variability in space use. Applying a spatial aggregation statistic over these grids by each species we detected areas that are used more than expected by chance. Most of the activity hotspots were either within 100 km of the islands or were associated with seamounts being spatially constant across several seasons. Moreover, some species spend a large proportion of their time-at-sea inside the EEZ during certain breeding stages, rendering the sites we identified critical for their fitness. Our approach provides a simple and effective tool to highlight important areas for pelagic biodiversity that will benefit Tristan da Cunha’s conservation planning and marine management strategies.

Use of sound-recording equipment by small expeditions

Polar Record ◽  
1957 ◽  
Vol 8 (55) ◽  
pp. 322-328 ◽  
Author(s):  
P. J. Mullock
Keyword(s):  
Good Deal ◽  
South Atlantic ◽  
Sound Recording ◽  
The South ◽  
Recording Equipment ◽  
Sound Recordings ◽  
Tristan Da Cunha ◽  
Gough Island ◽  
In Transit ◽  
Scientific Survey

This issue contains an account of the Gough Island Scientific Survey which spent the southern summer of 1955–56 exploring this previously little known island in the South Atlantic. One of the tasks the expedition set itself was the making of sound recordings of the birds and seals to be found there—especially those of the rarer species. As the expedition spent, rather unexpectedly, a good deal of time on Tristan da Cunha in transit to Gough Island, it was possible to make a great many valuable recordings there also.

scholarly journals Benthic Assemblage Composition of South Atlantic Seamounts

2021 ◽  
Vol 8 ◽  
Author(s):  
Amelia E. H. Bridges ◽  
David K. A. Barnes ◽  
James B. Bell ◽  
Rebecca E. Ross ◽  
Kerry L. Howell
Keyword(s):  
Benthic Communities ◽  
Oceanic Islands ◽  
South Atlantic ◽  
Environmental Drivers ◽  
Suitable Habitat ◽  
Benthic Assemblage ◽  
The South ◽  
Diverse Range ◽  
Assemblage Composition ◽  
Tristan Da Cunha

Seamounts and oceanic islands rise from the seafloor and provide suitable habitat for a diverse range of biological assemblages including Vulnerable Marine Ecosystems (VMEs). Whilst they have been the focus of some work globally, there has been little description of the biological and physical environments of seamounts in the South Atlantic Ocean. In this study, we characterized benthic assemblage composition from 13 seamounts and oceanic islands spanning 8–40°S within the exclusive economic zones (EEZs) of Ascension Island, Saint Helena and Tristan da Cunha. Drop camera imagery was collected between 170 and 1000 m. All fauna present in images were identified and quantified, and multivariate statistics were used to describe biological assemblages and identify their environmental drivers. Benthic communities of temperate regions (Tristan da Cunha archipelago) were shown to be distinct from those found in the tropics, with latitude and depth identified as key environmental drivers of assemblage composition. Our results are consistent with the current understanding of the biogeography of the South Atlantic, both in terms of the distinction between tropical and temperate regions, and the influence of depth and water mass structure on assemblage distribution. Faunal assemblages are similar to those observed in the North Atlantic in terms of functional groups. VMEs are present within the EEZs of all three territories and are potentially protected from some threats by large marine protected areas (MPAs). Our imagery, data and analyses provide a baseline for south Atlantic seamounts so that future monitoring can establish whether existing protected status is sufficient to conserve both unique biodiversity and considerable potential for vital ecosystem services.

scholarly journals A juvenile Tristan albatross (Diomedea dabbenena) on land at the Crozet Islands

Polar Biology ◽  
2020 ◽  
Author(s):  
Alexander L. Bond ◽  
Christopher Taylor ◽  
David Kinchin-Smith ◽  
Derren Fox ◽  
Emma Witcutt ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Cytochrome B ◽  
Adult Male ◽  
Mitochondrial Gene ◽  
Small Population ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
Tristan Da Cunha ◽  
Gough Island ◽  
Dispersal Events

AbstractAlbatrosses and other seabirds are generally highly philopatric, returning to natal colonies when they achieve breeding age. This is not universal, however, and cases of extraordinary vagrancy are rare. The Tristan Albatross (Diomedea dabbenena) breeds on Gough Island in the South Atlantic Ocean, with a small population on Inaccessible Island, Tristan da Cunha, ca 380 km away. In 2015, we observed an adult male albatross in Gonydale, Gough Island, which had been ringed on Ile de la Possession, Crozet Islands in 2009 when it was assumed to be an immature Wandering Albatross (D. exulans). We sequenced 1109 bp of the cytochrome b mitochondrial gene from this bird, and confirmed it to be a Tristan Albatross, meaning its presence on Crozet 6 years previous, and nearly 5000 km away, was a case of prospecting behaviour in a heterospecific colony. Given the challenges in identifying immature Diomedea albatrosses, such dispersal events may be more common than thought previously.

Gondwanorchestia tristanensis gen. nov. sp. nov., a new southern hemisphere genus and species of talitrid amphipod (Amphipoda, Senticaudata, Talitridae)

Zootaxa ◽  
2020 ◽  
Vol 4748 (2) ◽  
pp. 375-381
Author(s):  
JAMES K. LOWRY ◽  
ALAN A. MYERS ◽  
JORGE PÉREZ-SCHULTHEISS
Keyword(s):  
Atlantic Ocean ◽  
Southern Hemisphere ◽  
New Genus ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
New Genus And Species ◽  
The South ◽  
Tristan Da Cunha

Material collected by the Norwegian Scientific Expedition to Tristan Da Cunha in the South Atlantic Ocean in the years 1937–1938 and later attributed by Stephensen, 1949 to Orchestia scutigerula Dana, 1852 has been re-examined and is described as a new genus and species, Gondwanorchestia tristanensis sp. nov. Orchestia scutigerula Dana, 1852 is transferred to Gondwanorchestia gen nov. and compared with G. tristanensis sp. nov. 

Echinoidea and Holothuroidea (Echinodermata) of the Trindade and Martin Vaz Archipelago, off Brazil, with new records and remarks on taxonomy and species composition

2016 ◽  
Vol 98 (3) ◽  
pp. 521-555 ◽  
Author(s):  
Luciana Martins ◽  
Camilla Souto ◽  
Joel Braga ◽  
Marcos Tavares
Keyword(s):  
Species Composition ◽  
Oceanic Islands ◽  
South Atlantic ◽  
Brazilian Coast ◽  
The South ◽  
Stepping Stones ◽  
Morphological Variations ◽  
Fernando De Noronha ◽  
Brazilian Province ◽  
Oceanic Archipelagos

The degree of isolation of oceanic islands makes these environments an excellent model for evolutionary studies. Proper knowledge of the species composition of oceanic islands, however, is required to better understand evolutionary processes (e.g. speciation events). A 3-year survey in the shallow waters (up to 30 m) of the Trindade and Martin Vaz oceanic insular complex, and a literature review on the data published for these islands and for Fernando de Noronha and São Pedro and São Paulo oceanic archipelagos have been conducted to document the biodiversity of echinoids and holothuroids from these isolated Brazilian oceanic islands. Sixteen species were collected and characterized morphologically, including two first records for the South Atlantic and one for Brazil. Comparison with conspecific specimens from the Brazilian coast and congeners was also done. Species richness increased from six to 18; the richness in Trindade Island being the highest among the South Atlantic oceanic islands. However, these islands remain undersampled beyond 30-m depth. Endemism was very low, suggesting the potential role of oceanic currents and seamounts as stepping-stones in transoceanic dispersal of species to remote islands. The Brazilian oceanic islands are impoverished oceanic outposts of the Brazilian Province; nevertheless, endemic species and intraspecific morphological variations compared with the mainland suggest they may also be regions of speciation. Documenting their biodiversity is critical for effective management and conservation of their marine ecosystems.

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