First record of the epizoic red seaweed Polysiphonia carettia Hollenberg in the Mediterranean Sea.

Primera cita del alga roja epizoica Polysiphonia carettia Hollenberg en el mar Mediterráneo Key words. Caretta caretta, epibionts, Mediterranean Sea, Polysiphonia carettia. Palabras claves. Caretta carom, cpibiontes, Mar Mediterráneo, Polysiphonia carettia

Fishing activity and impacts along the main nesting area of loggerhead sea turtle <i>Caretta caretta</i> in Italy: overwhelming discrepancy with the official data

The southern coast of Ionian Calabria was recently recognized as the main nesting area of the loggerhead sea turtle Caretta caretta in Italy. The aim of this study was to characterize the fishing fleet in this area in terms of number of boats, economic situation, social aspects and impact on sea turtle specimens and target species. A multidisciplinary approach was essential to understand how the conservation problems of C. caretta are linked to various characteristics of the fishing fleet. Our data showed a vast discrepancy between the official census and the actual number of boats fishing in the area: 87% of the observed artisanal vessels lacked a required registration number, and thus were fishing illegally. This has caused serious social problems that worsened over the summer of 2007, when the presence of non-local registered vessels, using drift nets, generated a spatial conflict with the local artisanal fishermen. We identified 11 fishing gears used in the area and four of them were studied with on board observations: illegal drift nets, trammel nets, bottom longlines and longlines targeting swordfish. The total number of turtles caught during the summer in the area by longliners targeting swordfish was calculated to be 500 (±180 SE). In addition the presence of drift netters had a negative impact from an ecological and social point of view

Sea turtles in the eastern margin of the North Atlantic: the northern Ibero-Moroccan Gulf as an important neritic area for sea turtles

This study summarizes nearly 20 years (1997-2015) of tracking strandings of sea turtles along the Andalusian coast. In this period 2495 specimens were recorded, most of them loggerhead turtles Caretta caretta (92.6%) and leatherback turtles Demochelys coriacea (7.1%). Two other species were almost insinificant, green turtle Chelonia mydas (0.2%) and Kemp’s ridley Lepidochelys kempi (0.1%). Significant part of the turtles were recorded in the Atlantic coast, although in this area the incidence of alive specimens was low. Spring and summer were the seasons with more specimens stranded, probably related to warmer and more productive waters. The size of the loggerhead turtles observed highlights an important presence of inmature specimens in Andalusian waters, although mature individuals were not rare. In the case of leatherback turtles, adult stage is the only detected in the specimens recorded.These results, combined with the fact that the Atlantic coast has a large continental shelf and a high primary productivity near the coast, suggesting that the gulf of Cádiz may represent a neritic habitat used by the sea turtles. In this case, new and more effective politics of conservation are needed in order to protect sea turtles in this area

Expertos del IEO y del INRH (Marruecos) actualizan la evaluación del voraz del estrecho de Gibraltar

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When non‑target wildlife species and alien species both affect negatively to an artisanal fishery: the case of trammel net in the Alboran Sea

In the Northern Alboran Sea, artisanal small-scale fisheries using trammel nets suffer economic losses, and local fishermen see their way-of-life endangered, due to interactions with wildlife species such as alien species and dolphins. On the one hand, the alien seaweed Rugulopteryx okamurae, which was first recorded in the Alboran Sea in 2015, has undergone an intensive expansion in the sub-region, monopolizing the available seabed, causing radical changes in the underwater seascape and clogging the trammel nets. On the other hand, the damage caused to the fishing nets by dolphin fish predation is an ancient problem worldwide, but it is intensifying in the last years. The main objective of this study is to understand the main environmental and technical conditions that favor damages of fishing trammel nets in the Alboran Sea, which entails an important loss of catchability, due to (i) the clogging of the artisanal fishing trammel nets by invasive seaweed, and (ii) the breaking of the nets by dolphin predation. Through close monitoring of fishermen in port, we obtained direct information of 548 sets. Our results indicate that approximately 30% of trammel sets suffered a damage due to unwanted interaction with alien seaweeds and dolphins. As seaweeds invasion is a global problem while dolphin-fishing gear interaction is more local, we concluded that only a large-scale management of exotic algae, together with the involvement of local fishermen, could solve the economic problems of this activity.This study has been financed by MAVA Foundation through an agreement between ACCOBAMS (Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area) and the Spanish Herpetological Society (AHE, Asociación Herpetológica Española), under the project: “CETAFISHBE, Interactions between air breathing marine vertebrates, particularly cetaceans, and artisanal fisheries in northern` Alboran Sea”. We thank the fishermen, skippers and shipowners who have helped us during this study. We also recognize the support provided by the fishermen’s associations from the ports of Caleta de Vélez and Fuengirola (Southern Spain). We are grateful for the comments of anonymous reviewers who improved a previous paper version. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature

Tagging reveals limited exchange of immature loggerhead sea turtles (Caretta caretta) between regions in the western Mediterranean

El marcaje revela un intercambio limitado de inmaduros de tortuga boba (Caretta caretta) entre regiones en el Mediterráneo occidental. – Se investigó el intercambio de inmaduros de tortuga boba (Caretta caretta) entre las regiones septentrional y meridional del Mediterráneo occidental a partir de los datos obtenidos por varios programas españoles de marcaje. El rango de la longitud recta de caparazón de las tortugas marcadas fue de 23 a 74 cm. 36 de ellas se recapturaron tras un intervalo medio de 390,5±462,6 días (DS). Como la distancia media de dispersión (MDD) de una población de tortugas que se dispersan por el Mediterráneo occidental se estabilizaría al cabo de 117 días (IC 95%: 98-149), se llevaron a cabo dos análisis incluyendo los datos de las tortugas recapturadas después de 98 y 149 días, respectivamente. En ambos análisis, la frecuencia de recaptura en la misma región donde fueron marcadas fue mayor a la esperada. En un segundo análisis se comparó la distancia media entre las localizaciones de captura y recaptura de las tortugas de cada región con la MDD esperada si permanecieran confinadas en la región de la primera captura. Se excluyeron de este análisis aquellas tortugas recapturadas en un plazo inferior a 15 días (región septentrional) y 25 días (región meridional) para garantizar la independencia entre la localidad de primera captura y de recaptura. No se hallaron diferencias significativas entre la MDD esperada y la distancia media entre las localizaciones de liberación y captura para ninguno de los dos grupos de tortugas. El conjunto de los datos disponibles demuestran la fidelidad de las tortugas inmaduras a ciertas áreas y la existencia de una fuerte barrera a la dispersión de tortugas entre las regiones septentrionales y meridionales del Mediterráneo occidental, por lo que las tortugas bobas del Mediterráneo occidental se deben dividir en al menos dos unidades de manejo.Exchange of immature loggerhead sea turtles (Caretta caretta) between the northern and southern regions of the western Mediterranean was investigated using data obtained from several Spanish tagging programmes. Tagged turtles ranged in straight carapace length from 23.0 to 74.0 cm. Thirty-six turtles were recaptured after an average interval of 390.5±462.6 days (SD). As the mean dispersal distance (MDD) of a turtle population that spreads over the western Mediterranean would stabilize after 117 days (CI 95%: 98 to 149), two analyses were conducted that included data from turtles recaptured after 98 and 149 days respectively. In both analyses, turtles were recaptured more often than expected in the same region where they had been tagged. No difference was found in either of the two regions between the average distance between the capture and recapture locations and the expected MDD if the turtles were to remain in the region where they were first captured. Turtles recaptured after 15 and 25 days respectively were excluded from the analysis to ensure data independence. The overall evidence indicates that immature turtles exhibit strong site fidelity to certain areas and that there is a strong barrier to dispersal between the northern and southern parts of the western Mediterranean. Therefore, loggerhead turtles in the western Mediterranean should be split into at least two management [email protected]

DIFFERENTIAL TEMPORAL AND SPATIAL DISTRIBUTION OF ADULT LOGGERHEAD SEA TURTLES FROM GULF OF CÁDIZ TO WESTERN MEDITERRANEAN SEA

The aim of this paper was to search for and model spatial and seasonal trends in occurrences (stranding or by-catches) of adult loggerhead turtles in the western Mediterranean area and Gulf of Cádiz (Atlantic) independently of their origin. Adult turtles were only bycaught on longlines from May to August. Adults were stranded in the eastern and western areas of the Strait of Gibraltar threshold throughout the year. In the Gulf of Cádiz (Atlantic), strandings were significantly concentrated in May and June, whereas in the Alboran Sea (Mediterranean), strandings mainly occurred in June and July. The probability of catching a mature loggerhead increases during June and July south of the Balearic Islands. The results suggest that adult loggerhead turtles move (migrate) from the Atlantic area (Gulf of Cádiz) to the Mediterranean (Alboran Sea) from May to June, and subsequently move to the Balearic Sea from June to July. These results are in line with those obtained by previous studies.Postprin

Factors Associated with the Differential Distribution of Cetaceans Linked with Deep Habitats in the Western Mediterranean Sea

Deep-habitat cetaceans are generally difficult to study, leading to a limited knowledge of their population. This paper assesses the differential distribution patterns of three deep-habitat cetaceans (Sperm whale—Physeter macrocephalus, Risso’s dolphin—Grampus griseus & Cuvier’s beaked whale—Ziphius cavirostris). We used data of 842 opportunistic sightings of cetaceans in the western Mediterranean sea. We inferred environmental and spatio-temporal factors that affect their distribution. Binary logistic regression models were generated to compare the presence of deep-habitat cetaceans with the presence of other cetacean species in the dataset. Then, the favourability function was applied, allowing for comparison between all the models. Sperm whale and Risso’s dolphin presence was differentially favoured by the distance to towns in the eastern part of the western Mediterranean sea. The differential distribution of sperm whale was also influenced by the stability of SST, and that of the Risso’s dolphin by lower mean salinity and higher mean Chlorophyll A concentration. When modelling the three deep-habitat cetaceans (including Cuvier’s beaked whale), the variable distance to towns had a negative influence on the presence of any of them more than it did to other cetaceans, being more favourable far from towns, so this issue should be further investigated.Postprint2,92

Tuna regional fisheries management organizations and the conservation of sea turtles: a reply to Godley et al

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Using opportunistic sightings to infer differential spatio-temporal use of western Mediterranean waters by the fin whale

The fin whale (Balaenoptera physalus) is a cosmopolitan species with a resident population in the Mediterranean Sea. Due to its habitat, open seas often far from ports and airfields, and its long-distance migratory behaviour, studying and monitoring its distribution is costly. Currently, many opportunistic sightings (OS) reports are available, which provide a source of potentially useful, low-cost information about the spatio-temporal distribution of this species. Since 1993, the Spanish Institute of Oceanography has compiled a dataset comprising 874 records of OS of nine species of cetaceans in the western Mediterranean Sea and adjacent waters. The aim of this study was to use this dataset to investigate the differential use of these waters by the fin whale when compared with other cetaceans. We compared the presence of fin whales with the presence of any other cetacean species in the dataset. Binary logistic regression was then used to model these occurrences according to several spatio-temporal variables expected to reflect their habitat use. Several significant models reveal that fin whales are more prone than other cetaceans to use the waters over the slope of the Gulf of Lion in summer. This finding confirms that the Gulf of Lion is an area of importance for this species and suggests that the slope of the continental shelf could be particularly important. Our study shows how OS can be a source of useful information when appropriately analyzed