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Climate change is already affecting the distributions of marine fish, and future change is expected to have a particularly large impact on small islands that are reliant on the sea for much of their income. This study aims to develop an understanding of how climate change may affect the distribution of commercially important tuna in the waters arou...
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... Inshore boats as well as larger vessels from Cape Town use traps to catch the target species with little to no by-catch (typically only small numbers of two species of octopus). Around Saint Helena, commercial fishing has a reasonably long history (Edwards 1990). Today, pole and line is the only fishing method permitted within its EEZ, targeting yellowfin, bigeye, albacore, and skipjack tuna as well as wahoo. ...
... The equatorial and tropical region of the South Mid Atlantic Ridge features three oceanic islands and their respective Exclusive Economic Zones (EEZ): Saint Peter and Saint Paul's Archipelago (St Paul's Rocks), Ascension and St Helena Islands (Figure 1). The island´s EEZs and the ABNJ between them support populations of late-maturing and long-lived species (Shackeroff et al., 2009); they are critical habitats for species with long migratory pathways such as sharks, sea turtles and whales (Edwards, 1990;Burns et al., 2020;IUCN, 2022). These regions host a diversity of uses, including navigation, fishing, and scientific research, with energy resources and mineral extraction being considered as emerging issues (IUCN, 2022). ...
... These islands are topographic manifestations of the Mid-Atlantic Ridge that extends in the meridional direction in the Mid-Atlantic basin. The three islands have many aspects in common, including that they are small, very isolated, equidistant from South America and Africa, and located within an area of relatively warm and oligotrophic oceanic waters (Edwards and Lubbock, 1983a;Edwards and Lubbock, 1983b;Edwards, 1990). They share many species, including some endemics and sister-species that are exclusive to the three islands (Edwards and Lubbock, 1983a;Joyeux et al., 2001;Floeter et al., 2008;Wirtz et al., 2014;Brown et al., 2019;Pinheiro et al., 2020). ...
The South Mid Atlantic Ridge comprises three main oceanic islands in the equatorial and tropical portions of the Atlantic Ocean. These islands are isolated from each other and equidistant from both the continental margins of South America and Africa, sharing common patterns but with different types of human use and pressures. Moreover, the areas beyond national jurisdiction between those islands are visited and exploited by distant fishing fleets and include large areas of shipping activity for commodities. Here, a pioneering integrated ecosystem assessment (IEA) process is constructed for the region among Saint Peter and Saint Paul’s Archipelago (Brazil), Saint Helena Island and Ascension Island (UK overseas territories). For that, we used a qualitative assessment of risks arising from anthropogenic activities, representing a novel contribution to the field. The Options for Delivering Ecosystem-Based Marine Management (ODEMM) approach was applied to trace sector–pressure–component pathways. A ‘linkage framework’ was outlined including pressures affecting each ecosystem component, and supported a process of knowledge attributions that scored the impact risks. All results were validated with regional stakeholders through workshops, including local and international management bodies, non-governmental organizations (NGOs) and scientists. The approach focused on a significant area among encompassing the open ocean, shallow and deep-sea biomes, analyzing the main sectors and pressures affecting the ecological components. Our results identified 14 sectors and 16 key pressures associated with 23 ecosystem components, totaling 780 impact chains. Fishing, shipping, wastewater, and tourism/recreation appeared as the top impacting sectors. Fishing and shipping were the most connected with ecosystem components links. Litter, species extraction, contaminants, and bycatch were the pressures that had the highest risk of impact values. Lastly, demersal and pelagic fish and pelagic and demersal elasmobranchs were the groups with the highest risk related to overall impacts, which were supported by local and regional evidence from long term monitoring programs and local studies. Our study demonstrated that these seemingly pristine islands and oceanic waters are already experiencing human impacts that should be addressed by local both conservation measures and international agreements. We also highlight the pressures that should be prioritized for better monitoring and policy, as well as those linkage components that have been less investigated.
... Interface 19: 20210859 observations of turtles in unusual locations. For example, during the green turtle breeding season at Ascension Island, some turtle mating pairs are also seen on the island of St Helena, 1100 km to the south, even though that island has no nesting beaches [48]. The implication is that these mating turtles at St Helena were likely trying to find Ascension Island but became lost. ...
How animals navigate across the ocean to isolated targets remains perplexing greater than 150 years since this question was considered by Charles Darwin. To help solve this long-standing enigma, we considered the likely resolution of any map sense used in migration, based on the navigational performance across different scales (tens to thousands of kilometres). We assessed navigational performance using a unique high-resolution Fastloc-GPS tracking dataset for post-breeding hawksbill turtles ( Eretmochelys imbricata ) migrating relatively short distances to remote, isolated targets on submerged banks in the Indian Ocean. Individuals often followed circuitous paths (mean straightness index = 0.54, range 0.14–0.93, s.d. = 0.23, n = 22), when migrating short distances (mean beeline distance to target = 106 km, range 68.7–178.2 km). For example, one turtle travelled 1306.2 km when the beeline distance to the target was only 176.4 km. When off the beeline to their target, turtles sometimes corrected their course both in the open ocean and when encountering shallow water. Our results provide compelling evidence that hawksbill turtles only have a relatively crude map sense in the open ocean. The existence of widespread foraging and breeding areas on isolated oceanic sites points to target searching in the final stages of migration being common in sea turtles.
... The movements of both the surface and subsurface currents over many years has resulted in a mixed marine fauna in the waters of St Helena including western Atlantic, eastern Atlantic and circumtropical species. and Edwards & Glass (1987a & b) provided the first lists of fish records for St Helena Island which were summarised in a book by Edwards (1990). He described 138 species from 61 families from St Helena Island. ...
... Ichthyapus ophioneus (Evermann & Marsh, 1900)-Surf eel , Sand eel (St H) References: in part as Sphagebranchus sp. vel S. acutirostris, Blache & Bauchot (1972) as Rhinechelys ophioneus, , Edwards (1990:70), McCosker (2004 , , Edwards (1990) and Wirtz et al. (2014) should thus be referred to I. insularis. St. Helena BMNH specimens of I. ophioneus were checked by E. Boehlke and apparently do not belong to the Ascension endemic species I. insularis McCosker, 2004 (McCosker pers. ...
... Ichthyapus ophioneus (Evermann & Marsh, 1900)-Surf eel , Sand eel (St H) References: in part as Sphagebranchus sp. vel S. acutirostris, Blache & Bauchot (1972) as Rhinechelys ophioneus, , Edwards (1990:70), McCosker (2004 , , Edwards (1990) and Wirtz et al. (2014) should thus be referred to I. insularis. St. Helena BMNH specimens of I. ophioneus were checked by E. Boehlke and apparently do not belong to the Ascension endemic species I. insularis McCosker, 2004 (McCosker pers. ...
A check-list of the fishes of St Helena Island is presented. The following species are recorded for the first time from St. Helena Island: Rhincodon typus, Mobula tarapacana, Muraena melanotis, Caranx latus, Seriola rivoliana, Balistes capriscus, Lutjanus jocu, Centropyge aurantonotus, Acanthurus coeruleus, Lepidocybium flavobrunneum, Tetrapturus pfluegeri, Coelorinchus geronimo, Pentaceros richardsoni, Gephyroberyx darwinii, Brotula cf multibarbata, Poromitra crassiceps, Echiostoma barbatum, Malacosteus niger, Pachystomias microdon. Including these nineteen new records there are 189 fish species currently known from St Helena. Three of them appear to be undescribed. Eight species and two subspecies are currently considered endemic to St. Helena Island.
... Cadenat & Marchal, 1963;Lubbock, 1980;Bingeman & Bingeman, 2005, p. 51. Lubbock, 1980;Edwards & Glass, 1987a;Edwards, 1990, p. 133. Melichthys niger (Bloch, 1786 Black triggerfish References: Cadenat & Marchal, 1963 as Mellichthys buniva;Lubbock, 1980;Edwards & Glass, 1987a;Edwards, 1990, pp. 133 -134;Bingeman & Bingeman, 2005, p. 51. ...
... Finally and surprisingly, a small fraction of the Ascension (and St Helena) marine fauna is of Indian Ocean origin. In the Atlantic Ocean, the Indo-Pacific carangid Uraspis helvola is only known from Ascension and St Helena Islands (Edwards, 1990) and the endemic Helcogramma ascensionis is the only Atlantic member of this otherwise Indo-Pacific genus (Holleman, 2007). The link with the Indo-Pacific is confirmed by the presence on Ascension Island of the crab Percnon abbreviatum, not know from any other Atlantic locality (Manning & Chace, 1990). ...
The species Rhincodon typus, Alopias superciliosus, Isurus oxyrinchus, Carcharhinus obscurus, Galeocerdo cuvier, Sphyrna lewini, Hexanchus griseus, Manta birostris, Gymnothorax vicinus, Hippocampus sp., Epinephelus itajara, Cookeolus japonicus, Apogon pseudomaculatus, Phaeoptyx pigmentaria, Remora albescens, Caranx bartholomaei, Carangoides ruber, Decapterus tabl, Seriola dumerili, Thalassoma sanctaehelenae, Cryptotomus sp., Ruvettus pretiosus, Acanthocybium solandri, Auxis rochei, Auxis thazard, Euthynnus alletteratus, Katsuwonus pelamis, Thunnus alalunga, Thunnus obesus, Xiphias gladius, Istiophorus platypterus, Kajikia albida, Makaira nigricans, Tetrapturus pfluegeri, Hyperoglyphe perciformis, Schedophilus sp., Cantherhines macrocerus, Sphoeroides pachygaster and Diodon eydouxii are recorded for the first time from Ascension Island. We have recognized two previous records as identification errors and indicate 11 other records as doubtful. Including the 40 new records, we now list 173 fish species from Ascension Island, of which 133 might be considered ‘coastal fish species’. Eleven of these (8.3%) appear to be endemic to the island and a further 16 species (12%) appear to be shared endemics with St Helena Island.
... Similar examples of apparent disconnections follow Reuvens' (1897) report of the alga Fucus vesiculosus L. and that of a single two-foot-long specimen of Spanish ling Molva macrophthalma (Rafinesque, 1810) observed by Fraser-Brunner (1951). These reports seem likely to have prompted multiple unsupported prey item listings of algae or "seaweeds" (e.g., Fraser-Brunner 1951, Bigelow and Schroeder 1953, Hart 1973, Hooper et al. 1973, Edwards 1990, Thys 1994, Matsuura 2002) and "larger" or "deep-sea" fishes (Hart 1973, Hooper et al. 1973, Matsuura 2002. Pope et al. (2010) structured much of their discussion of diet around questioning the often-repeated but rarely-supported hypothesis that M. mola was a primary or obligate gelativore. ...
... We fully concur with the overall characterization by Pope et al. (2010) of such publications as rare, scattered, and often lacking in empirical data. Indeed, here for example we have failed to identify any unambiguous firsthand accounts of brittle stars from the gut of a specimen of M. mola of any size, despite their inclusion in many prey lists (e.g., Fraser-Brunner 1951, Bigelow and Schroeder 1953, Clemens and Wilby 1961, Hart 1973, Edwards 1990, Matsuura 2002, Bass et al. 2005, Desjardin 2005, Pope et al. 2010, Nakamura and Sato 2014. Pope et al. (2010) drew attention to several field guides and reference books for their failure to provide empirical support for their lists of prey items, but this implied criticism seems misplaced as works intended for popular consumption should not be expected to present this type of information. ...
Reports on the gut contents of ocean
sunfish, Mola mola (Linnaeus, 1758), are rare, and those
for sharptail mola, Masturus lanceolatus (Liénard, 1840),
are almost nonexistent. Here, we report new diet data
obtained during opportune sampling of a small number of
stranded specimens of both species, and discuss our data in
the context of hypotheses on feeding behavior of M. mola.
One specimen of only two M. mola had a gut full primarily
of filamentous algae, and the guts of two specimens of M.
lanceolatus collectively contained remains of small fish
and various invertebrates, indicative of both benthic and
pelagic foraging. Our limited data suggest that the diet of
M. lanceolatus overlaps that reported for M. mola. At high
taxonomic resolution, observed prey items suggest some
particulars of our specimens’ behavior just before death. We
emphasize the importance of meticulous presentation of
methods, data, and literature citations.
... Venter pale. Oval black spot above dorsal edge of operculum; conspicuous dark blotch below eye, extending from premaxilla to chin ( Fig. 3; Edwards, 1990;Böhlke & Chaplin, 1993). ...
Trachinocephalus, a formerly monotypic and nearly circumtropical genus of lizardfishes, is split into three valid species. Trachinocephalus gauguini n. sp. is described from the Marquesas Islands and is distinguished from the two other species in the genus by having a shorter snout, a narrower interorbital space, larger eye and modally fewer anal-fin and pectoral-fin rays. The distribution of Trachinocephalus myops (type species) is restricted to the Atlantic Ocean and the name Trachinocephalus trachinus is resurrected for populations from the Indo-West Pacific Ocean. Principal component analyses and bivariate plots based on the morphometric data differentiated T. gauguini from the other two species, but a substantial overlap between T. myops and T. trachinus exists. Phylogenetic evidence based on mtDNA COI sequences unambiguously supports the recognition of at least three species in Trachinocephalus, revealing deep divergences between the Atlantic Ocean, Indo-West Pacific Ocean and Marquesas entities. Additional analyses of species delimitations using the generalized mixed Yule coalescent model and the Poisson tree processes model provide a more liberal assessment of species in Trachinocephalus, indicating that many more cryptic species may exist. Finally, a taxonomic key to identify the three species recognized here is provided.
... Por su parte, A. rochei, la cachorreta alicorta, ha sido colectada junto con su congénere, en febrero y comienzos de marzo, cuando la surgencia costera samaria está en su pico más elevado (Bernal y Zea, 2000). Vale la pena tener en cuenta que de pocas localidades aisladas en el Atlántico hay registros de ambas especies; por ejemplo, Edwards (1990) las lista para la isla de Santa Helena en el Atlántico central. Un camino de investigación interesante sería la comparación detallada de las poblaciones atlánticas de A. rochei, incluyendo al menos material de EE. ...
The marine environment of the Santa Marta region (Colombian Caribbean) is unique in many ways. The coexistence there of both species of Auxis is herewith reported and discussed. Auxis thazard, the frigate tuna or frigate mackerel, has been reported several times from Santa Marta; however, the occurrence of A. rochei, the bullet tuna or bullet mackerel, is reported for the first time. Some inter and intraspecific differences are discussed; fishery aspects are commented as well.
... Cadenat & Marchal, 1963;Lubbock, 1980;Bingeman & Bingeman, 2005, p. 51. Lubbock, 1980;Edwards & Glass, 1987a;Edwards, 1990, p. 133. Melichthys niger (Bloch, 1786 Black triggerfish References: Cadenat & Marchal, 1963 as Mellichthys buniva;Lubbock, 1980;Edwards & Glass, 1987a;Edwards, 1990, pp. 133 -134;Bingeman & Bingeman, 2005, p. 51. ...
... Finally and surprisingly, a small fraction of the Ascension (and St Helena) marine fauna is of Indian Ocean origin. In the Atlantic Ocean, the Indo-Pacific carangid Uraspis helvola is only known from Ascension and St Helena Islands (Edwards, 1990) and the endemic Helcogramma ascensionis is the only Atlantic member of this otherwise Indo-Pacific genus (Holleman, 2007). The link with the Indo-Pacific is confirmed by the presence on Ascension Island of the crab Percnon abbreviatum, not know from any other Atlantic locality (Manning & Chace, 1990). ...
A checklist of the fishes of Ascension Island is presented. The species Rhincodon typus, Alopias superciliosus, Isurus oxyrinchus, Carcharhinus obscurus, Galeocerdo cuvier, Sphyrna lewini, Hexanchus griseus, Manta birostris, Gymnothorax vicinus, Hippocampus sp., Epinephelus itajara, Cookeolus japonicus, Apogon pseudomaculatus, Phaeoptyx pigmentaria, Remora albescens, Caranx bartholomaei, Carangoides ruber, Decapterus tabl, Seriola dumerili, Thalassoma sanctaehelenae, Cryptotomus sp., Ruvettus pretiosus, Acanthocybium solandri, Auxis rochei, Auxis thazard, Euthynnus alletteratus, Katsuwonus pelamis, Thunnus alalunga, Thunnus obesus, Xiphias gladius, Istiophorus platypterus, Kajikia albida, Makaira nigricans, Tetrapturus pfluegeri, Hyperoglyphe perciformis, Schedophilus sp., Cantherhines macrocerus, Sphoeroides pachygaster and Diodon eydouxii are recorded for the first time from Ascension Island. We have recognized two previous records as identification errors and indicate 11 other records as doubtful. Including the 40 new records, we now list 173 fish species from Ascension Island, of which 133 might be considered ‘coastal fish species’. Eleven of these (8.3%) appear to be endemic to the island and a further 16 species (12%) appear to be shared endemics with St Helena Island.
... L'espèce Acanthurus tractus, (figure 5.1), appelée « chirurgien marron », est une des espèces les plus communes de poissons herbivores des récifs coralliens dans toute son aire de répartition (Lewis et Wainwright, 1985;Edwards, 1990;Chapman et Kramer, 1999;Ferreira et coll., 2004). A. bahianus/A. ...
Dispersal of marine fishes mainly depends on passive transport of planktonic larvae driven by ocean currents. It allows populations to be connected through thousands of kilometers but also make them sensitive to factors limiting larval dispersion. In this regard it is known that there are several physical and biological factors that determine the distribution of marine species larvae and therefore population connectivity.The present work aims to study the effects of geographic traits of Cuban archipelago and biological characteristics of reef fishes inhabiting it on the genetic structure of their populations. Three different species with distinct biological characteristics and broadly distributed within the Caribbean were selected: Stegastes partitus, Haemulon flavolineatum and Acanthurus tractus. Individuals were sampled from five localities distributed around Cuba during the time period from 2005 to 2010. We analyzed mitochondrial DNA (mtDNA) polymorphism: a fragment of the non coding region (NCR) for the three species and cytb for A. tractus. The polymorphism of nuclear microsatellite loci was studied for S. partitus and H. flavolineatum.Genetic diversity, assessed by means of Ho and He have high values when analysing microsatellite loci. These molecular markers revealed the presence of contrasting geographic structure patterns for the two species. Low but significant pairwise FST estimates were obtained for S. partitus while H. flavolineatum was genetically homogenous. These results were supported by mtDNA analyses. Likewise, A. tractus showed no evidence of significant genetic differentiation at the level of the NCR and cytb gene. Differences in population genetic structure of surveyed species could be the result of extant marine currents acting distinctly on species dispersion according to their reproductive behaviour (i.e. spawning sites, benthonic or pelagic eggs and capacity of larvae to staying close to the natal reef or being driven away from it). Mitochondrial markers showed high levels of haplotypic diversity for the three species and contrasted nucleotide diversity, low for S. partitus, intermediate for H. flavolineatum and high for A. tractus. According to these observations and results of neutrality tests and mismatch distribution analyses, it is suggested that recent population expansion occurred in these species. However differences in population parameter estimations suggest that the time and the rate of population expansion were different for the different species.The analysis of A. tractus cytb haplotype relationships grouped some Cuban individuals with two haplotypes previously described as A. bahianus. This latter species has been recently proposed as restrict to South Atlantic and separated from A. tractus by the Amazon-Orinoco outflow barrier. The presence of mtDNA haplotypes from the southern region in Cuba suggests that A. bahianus may be able to overcome this barrier.
