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Marine ecosystems in the United Arab Emirates: an educational resource

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... L'influence des forces génératrices de marée est faible dans le Golfe persique en raison de ses faibles dimensions. Les ondes de marées diurnes et semi-diurnes se propageant depuis l'Océan Indien engendrent néanmoins des oscillations de résonance amplifiant modérément le marnage : il varie entre 1 et 3,5 m dans le Golfe persique (Carpenter et al. 1997a : 4 ;Jabado & Javelle 2012 ;Riegl & Purkis 2012). Le schéma est ainsi celui d'une marée semidiurne à nette inégalité diurne, constituant une grande et une petite marée chaque jour. ...
... Cette importante variation est essentiellement due à l'action du shamal. Dans la moitié nord du Golfe persique, près de la côte et dans les faibles profondeurs, les températures de surface peuvent exceptionnellement tomber à 4-7°C (relevées à Qatar et Koweït), jusqu'à 14°C au large (Jabado & Javelle 2012). ...
... On dénombre 26 espèces de coraux au Koweït, et environ 50 en Arabie saoudite. Ils se développent entre la surface et 18-20 m en raison de la faible profondeur du Golfe persique et de sa forte turbidité, notamment dans sa moitié nord (Jabado & Javelle 2012 ...
Thesis
Cette thèse intègre l'analyse inédite de plus de 80 000 restes provenant des sites néolithiques d'Akab, de Dalma et de Marawah MR11 (Emirats Arabes Unis) – occupés entre la moitié du VIe et la fin du IVe millénaire av. n. è. Les résultats dévoilent des pêcheries déjà investies dans l'exploitation d'une grande variété de milieux marins. Les poissons capturés et consommés par ces pêcheurs incluent de nombreux sargues, pagres (Sparidae), empereurs (Lethrinidae) et petites aiguilles (Belonidae) qui témoignent avant tout de l'exploitation des eaux côtières peu profondes : le long des rivages ainsi que dans les zones d'herbiers et de récif frangeant. À Akab, la pêche dans la lagune et la mangrove est également reflétée par la présence de nombreux poissons‐chats marins (Ariidae) et mulets (Mugilidae) dans l'assemblage. Les techniques impliquées dans ce type de pêche sont peu sélectives et relativement simples : la prospection des petits fonds à l'aide de senne, la pose de filets calés, voire l'utilisation de barrages à poissons. À Dalma, des nasses étaient probablement déjà employées dans les zones de récifs moyennement profondes, pour la capture de mérous en particulier (Serranidae). Les mangroves et les zones de récifs sont des environnements très productifs auprès desquels les pêcheurs pouvaient vraisemblablement se fournir en poissons et en coquillages tout au long de l'année. En l'occurrence, ceux d'Akab connaissaient et exploitaient probablement déjà les grands rassemblements de becs‐de-cane (Lethrinus nebulosus) près de la lagune d'Umm al‐Quwain, au printemps et à l'occasion de leur frai. L'étude du matériel d'Akab et de Dalma révèle toutefois aussi l'existence d'expéditions de pêche en mer ouverte, impliquant l'usage de bateaux. Ces expéditions sont notamment conduites à la recherche des bancs de thonines (Scombridae) voire de carangues (Carangidae). Leur pêche n'impliquait pas seulement l'emploi de lignes munies d'hameçons en nacre mais aussi celui de filets tels que des sennes tournantes. Ces filets ont également permis aux pêcheurs de Dalma de capturer de grands requins et quelques dauphins plus occasionnellement. Bien que la pêche des bancs de pélagiques soit aujourd'hui considérée comme une activité hivernale dans les pêcheries du Golfe persique, l'existence d'un climat plus humide au Néolithique, alors soumis au régime de la mousson de l'Océan Indien, invite à nuancer nos modèles de saisonnalité. Au Néolithique, la pêche était ainsi pratiquée à la fois de manière généraliste et de manière spécialisée en faisant contribuer un large panel de techniques et de savoirs écologiques aux besoins d'une économie de subsistance reposant principalement sur l'exploitation des ressources marines.
... The Gulf is the warmest sea in the world [12], and environmental conditions within this body of water are among the most extreme on the planet [22]. Air temperatures in the region can drop to 0˚C in winter and reach in excess of 50˚C in summer, strongly influenced by the prevailing winds [12] while sea surface temperature fluctuates from 10˚C in winter to up to 39˚C in summer [23]. The Gulf has limited water exchange with the Gulf of Oman through the Strait of Hormuz and Musandam area of Oman to the northeast. ...
... Tracked rehabilitated green turtles also heavily used this same area [5], which makes it an ideal location for targeted management applications to improve protection for turtles in the UAE. This area is made up of coral reefs and seagrass beds which are ideal feeding grounds for these two species [23]. ...
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The rehabilitation of wildlife can contribute directly to the conservation of threatened species by helping to maintain wild populations. This study focused on determining the post-rehabilitation survival and spatial ecology of sea turtles and on comparing the movements of individuals with flipper amputations (amputees) to non-amputee animals. Our aims were to assess whether rehabilitated sea turtles survive after release, to compare and contrast the movement characteristics of the different species of sea turtles we tracked, and to examine whether amputees and non-amputees within species behaved similarly post-release. Twenty-six rehabilitated sea turtles from four species, including hawksbill Eretmochelys imbricata (n = 12), loggerhead Caretta caretta (n = 11), green Chelonia mydas (n = 2), and olive ridley Lepidochelys olivacea (n = 1) sea turtles from the United Arab Emirates were fitted with satellite tags before release. Rehabilitation times ranged from 89 to 817 days (mean 353 ± 237 days). Post-release movements and survival were monitored for 8 to 387 days (mean 155 ± 95 days) through satellite tracking. Tag data suggested that three tracked sea turtles died within four days of release, one after 27 days, and one after 192 days from what are thought to be anthropogenic factors unrelated to their pre-rehabilitation ailments. We then compared habitat use and movement characteristics among the different sea turtle species. Although half of all turtles crossed one or more international boundaries, dispersal varied among species. Loggerhead turtles had a high dispersal, with 80% crossing an international boundary, while hawksbill turtles displayed higher post-release residency, with 66% remaining within UAE territorial waters. Amputee turtles moved similarly to non-amputee animals of the same species. Loggerhead turtles travelled faster (mean ± sd = 15.3 ± 8 km/day) than hawksbill turtles (9 ± 7 km/day). Both amputee and non-amputee sea turtles within a species moved similarly. Our tracking results highlight that rehabilitated sea turtles, including amputees, can successfully survive in the wild following release for up to our ~one-year monitoring time therefore supporting the suitability for release of sea turtles that have recovered from major injuries such as amputations. However, more broadly, the high mortality from anthropogenic factors in the Arabian Gulf region is clearly a serious issue and conservation challenge.
... Air temperatures in the region can drop to 0˚C in the winter and reach in excess of 50˚C in the summer, resulting in fluctuations in nearshore waters of up to 29˚C over the year, from 10˚C in winter to 39˚C in summer. Deeper waters vary between 18˚C and 33˚C [48]. Despite these physical extremes, the Gulf is a highly productive and diverse basin, supporting important habitats such as seagrass beds, mangroves, salt marshes and coral reefs [45,48]. ...
... Deeper waters vary between 18˚C and 33˚C [48]. Despite these physical extremes, the Gulf is a highly productive and diverse basin, supporting important habitats such as seagrass beds, mangroves, salt marshes and coral reefs [45,48]. The UAE lies along the southeastern coast of the Gulf, and has two separate coastal areas: the low, sandy Gulf coast, and the rocky and somewhat steep Gulf of Oman coast [49]. ...
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We collected movement data for eight rehabilitated and satellite-tagged green sea turtles Chelonia mydas released off the United Arab Emirates between 2005 and 2013. Rehabilitation periods ranged from 96 to 1353 days (mean = 437 ± 399 days). Seven of the eight tagged turtles survived after release; one turtle was killed by what is thought to be a post-release spear gun wound. The majority of turtles (63%) used shallow-water core habitats and established home ranges between Dubai and Abu Dhabi, the same area in which they had originally washed ashore prior to rescue. Four turtles made movements across international boundaries, highlighting that regional cooperation is necessary for the management of the species. One turtle swam from Fujairah to the Andaman Sea, a total distance of 8283 km, which is the longest published track of a green turtle. This study demonstrates that sea turtles can be successfully reintroduced into the wild after sustaining serious injury and undergoing prolonged periods of intense rehabilitation.
... Sharks within the Arabian Gulf have limited access to waters in excess of 90 m [34]. Transmission locations and bathymetry data showed that most transmissions were from areas with bottom depth between 40 and 60 m, corresponding to the depth of the majority of the central Arabian Gulf ridge. ...
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The Arabian Gulf is the warmest sea in the world and is host to a globally significant population of the whale shark Rhincodon typus. To investigate regional whale shark behaviour and movements, 59 satellite-linked tags were deployed on whale sharks in the Al Shaheen area off Qatar from 2011-14. Four different models of tag were used throughout the study, each model able to collect differing data or quantities of data. Retention varied from one to 227 days. While all tagged sharks crossed international maritime boundaries, they typically stayed within the Arabian Gulf. Only nine sharks dispersed through the narrow Strait of Hormuz into the Gulf of Oman. Most sharks stayed close to known or suspected feeding aggregation sites over summer months, but dispersed throughout the Arabian Gulf in winter. Sharks rarely ventured into shallow areas (
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