Mediterranean sea turtles: Current knowledge and priorities for conservation and research

This is the final version. Available on open access from Inter Research via the DOI in this recordThe available information regarding the 2 sea turtle species breeding in the Mediterranean (loggerhead turtle Caretta caretta and green turtle Chelonia mydas) is reviewed, including biometrics and morphology, identification of breeding and foraging areas, ecology and behaviour, abundance and trends, population structure and dynamics, anthropogenic threats and conservation measures. Although a large body of knowledge has been generated, research efforts have been inconsistently allocated across geographic areas, species and topics. Significant gaps still exist, ranging from the most fundamental aspects, such as the distribution of major nesting sites and the total number of clutches laid annually in the region, to more specific topics like age at maturity, survival rates and behavioural ecology, especially for certain areas (e.g. south-eastern Mediterranean). These gaps are particularly marked for the green turtle. The recent positive trends of nest counts at some nesting sites may be the result of the cessation of past exploitation and decades of conservation measures on land, both in the form of national regulations and of continued active protection of clutches. Therefore, the current status should be considered as dependent on such ongoing conservation efforts. Mitigation of incidental catch in fisheries, the main anthropogenic threat at sea, is still in its infancy. From the analysis of the present status a comprehensive list of re search and conservation priorities is proposed.C.C. is supported by the project CTM2013-48163 of the Spanish Ministry of Economy and Competitivity. The Cyprus Wildlife Society (CWS) acknowledges the financial support of the Department of Fisheries and Marine Research of the Government to the CWS for the implementation of the Turtle Conservation Project in the period 2010−2016 and for all its assistance to the Society in previous years. J.T. is supported by project Prometeo II (2015-018) of the Generalitat Valenciana and projects MEDSEALITTER-INTERREG and INDICIT of the European Union

Investigating differences in population recovery rates of two sympatrically nesting sea turtle species

This is the final version. Available on open access from Wiley via the DOI in this recordData Availability Statement: Data are available from corresponding author upon reasonable request.Estimating life‐history traits and understanding their variation underpins the management of long‐lived, migratory animals, while knowledge of recovery dynamics can inform the management of conservation‐dependent species. Using a combination of nest counts and individual‐based life‐history data collected since 1993, we explore the drivers underlying contrasting population recovery rates of sympatrically nesting loggerhead (Caretta caretta) and green (Chelonia mydas) turtles in North Cyprus. We found that nest counts of loggerhead and green turtles from 28 beaches across the island increased by 46% and 162%, respectively over the past 27 years. A Bayesian state‐space model revealed that, at our individual‐based monitoring site, nesting of green turtles increased annually at four times the rate of that of loggerhead turtles. Furthermore, we found that loggerhead turtles nesting at the individual‐based monitoring site had stable reproductive parameters and average adult survival for the species and are the smallest breeding adults globally. Based on results from multiple matrix model scenarios, we propose that higher mortality rates of individuals in all age classes (likely driven by differences in life history and interaction with fisheries), rather than low reproductive output, are impeding the recovery of this species. While the increase in green turtles is encouraging, the Mediterranean population is estimated to have around 3,400 adults and is restricted to the Eastern Basin. The recovery of loggerhead turtles is likely to be compromised until mortality rates in the region are adequately quantified and mitigated. As survival of immature individuals is a powerful driver for sea turtle population numbers, additional efforts should target management at pelagic and neritic foraging areas. Understanding threats faced by immature life stages is crucial to accurately parameterise population models and to target conservation actions for long‐lived marine vertebrates

Cyprus fisheries

Fisheries make up about 1.7% of the value of the gross domestic agriculture production of Cyprus and about 2.8% in terms of 'value added' of this production (1981 data). Production in 1982 was about 1 564 tons, valued at about C£2708000 (Table 1).1

Expansion of the macroalga Caulerpa racemosa and changes in softbottom macrofaunal assemblages in Moni Bay, Cyprus

The recent expansion of the Red Sea macroalga Caulerpa racemosa and its impact on the diversity and abundance of macrobenthos were examined and compared in the summers of 1992 and 1997, in Moni Bay, Cyprus. The phytobenthic community of the bay in 1992 was dominated by the seagrass Posidonia oceanica while, in 1997, the Lessepsian migrant C. racemosa became the most dominant, forming extensive mars. Changes in the vegetation system in Moni Bay have caused significant compositional changes in macrofaunal assemblages. A total of 178 individuals of 62 species are recorded. The composition of the macrofauna in 1992 was dominated by gastropods (44 %), crustaceans (22 %), bivalves (17 %), polychaetes (11 %) and echinoderms (6 %). In 1997, the gastropods and crustaceans had decreased to 13 % and 16 % respectively, while, polychaetes had increased to 38 % becoming the mast dominant taxon. Bivalves and echinoderms also increased to 22 % and 11 %, respectively, in 1997. The proliferative growth of C. racemosa imposed successional changes on the macrofaunal assemblages in Moni Bay, Cyprus, between 1992 and 1997. It remains to be tested whether the expansion of C. racemosa is related to the increase of water temperature associated with global warming or nutrient inputs or with the differences in the life history characteristics of this migrant vs. native algal species.L'expansion récente de la macroalgue de mer Rouge Caulerpa racemosa et son impact sur la diversité et l'abondance du macrobenthos ont été comparés dans la baie de Moni, à Chypre, entre les étés 1992 et 1997. La communauté phytobenthique de la baie était dominée en 1992 par l'algue Posidonia oceanica, alors qu'en 1997, l'immigrant lessepsien C. racemosa dominait, formant de vastes prairies. Les changements de végétation dans la baie de Moni ont entraîné des modifications significatives dans la composition de la macrofaune. Au total, 178 individus de 62 espèces ont été examinés. La composition de la macrofaune était dominée en 1992 par les gastéropodes (44 %), les crustacés (22 %), les bivalves (17 %), les polychètes (11 %) et les échinodermes (6 %). En 1997, les gastéropodes et les crustacés étaient réduits à 13 et 16 % respectivement, tandis que le polychètes devenaient le taxon dominant (38 %) ; les bivalves et les échinodermes progressaient également jusqu'à 22 et 11 % respectivement. La croissance proliférante de C. racemosa a provoqué une série de changements dans la macrofaune de la baie de Moni entre 1992 et 1997. Il reste à établir si l'expansion de C. racemosa est due à l'élévation de la température de l'eau associée au réchauffement global, à l'apport des nutriments, ou aux différences entre les caractéristiques de l'évolution de cet immigrant et celles des espèces algales indigènes

Hydrography and circulation south of Cyprus in late summer 1995 and in spring 1996

The hydrodynamical characteristics of the area south of Cyprus in the Levantine Sea were examined in late summer 1995 and in spring 1996. Analysis of the CTD data collected, provided a new dynamic picture of the Cyprus Basin and revealed the existence of the Cyprus Basin cyclonic eddy. The latter circulated to the south of Cyprus and exhibited marked seasonality. Production of Levantine Intermediate Water in the area of the latter eddy occurred. Occasionally, between the Cyprus Basin cyclonic eddy and the southern coast of Cyprus a warm current, the Cyprus coastal current appears to intrude from the east. In late summer 1995, the spatial fluctuations of the mid-Mediterranean jet, the main current of the Eastern Mediterranean Sea, caused the splitting of the Cyprus Basin cyclonic eddy, into two smaller cyclonic ones. During spring 1996, however, the Cyprus Basin cyclonic eddy appears as a single large vortex, occupying the greater part of the area south of Cyprus, and flanked to the south by the Cyprus anticyclonic eddy. (C) Elsevier, Paris

structuring and migration routes of an endangered marine turtle

1. The assessment of the composition and dynamics of endangered populations is crucial for management and conservation, and appropriate genetic markers are critical. 2. The genetic structuring of the Mediterranean green turtle ( Chelonia mydas) populations and the origin of the stranded animals found along the Israeli coast was investigated using new highly polymorphic short tandem repeat ( STR) markers. 3. The structuring of nesting populations was studied using pairwise genetic distances and a principal coordinates analysis ( PCoA). 4. The contribution of the different nesting populations to the stranded sample was assessed by using a mixed- stock analysis. 5. A clear population genetic structure, not detected before, has been revealed. The four nesting populations are genetically well differentiated, and thus should be considered as different management units. The populations from Turkey and Israel showed higher resemblance, despite residing at opposite ends of the Mediterranean distribution. TheTurkish nesting population is the main source of the stranded turtles sampled along the Israeli shore, confirming that individuals from this population migrate from north to south along the eastern shore of the Mediterranean, as previously shown by telemetry studies. 6. The use of a highly polymorphic haplotyping method enabled the detection of a clear genetic structuring of the green turtle populations in the eastern Mediterranean Sea that was not revealed in previous studies, demonstrating the importance of marker selection in population genetics. 7. The analysis of the genetic composition of the stranded turtles allowed us to investigate the migration patterns from nesting to foraging areas, supporting previous satellite- tracking and stable- isotope results. 8. These results will help to delineate conservation management units for the species in the Mediterranean, and reveal connectivity among beaches and mixed aggregations

Mitochondrial DNA reveals Pleistocenic colonisation of the Mediterranean by loggerhead turtles (Caretta caretta)

As the loggerhead turtle (Caretta caretta) is a philopatric species with a strong genetic structure, the analysis of mtDNA can be used to track evolutionary and colonisation events. In this study we use a genetic approach to understand the population structure of C. caretta in the Mediterranean Sea and to test whether loggerheads could have colonised the Mediterranean during the Pleistocene and survived the cold phases in warm refugia. We amplified a long mtDNA D-loop fragment (815. bp) from 168 dead hatchlings sampled from a selection of rookeries in the Eastern Mediterranean: Libya, Israel, Lebanon, Cyprus and Greece. Previously published data from Turkey and Calabria (Southern Italy) were also included in the analyses. The population nesting in Libya emerged as the oldest population in the Mediterranean, dating from the Pleistocene ca. 65,000. years ago (20,000-200,000). This reveals that the Libyan population might have settled in the Mediterranean basin before the end of the last glacial period. The remaining nesting sites, except Calabria, were subsequently colonised as the population expanded. The populations nesting in Eastern Turkey and Western Greece settled ca. 30,000. years ago (10,000-100,000), whereas the remaining populations originated as a result of a more recent Holocenic expansion. As Calabria presented a unique Atlantic haplotype, found nowhere else in the Mediterranean, we consider this nesting site as the result of an independent colonisation event from the Atlantic and not the recent spread of Mediterranean populations. This reveals that the current genetic structure of C. caretta rookeries in the Mediterranean would be the result of at least two colonisation events from the Atlantic, the oldest one in Libya and a most recent in Calabria, combined with local extinctions during Pleistocenic glaciations and re-colonisations from glacial refugia in Libya, Eastern Turkey and Western Greece. © 2012 Elsevier B.V.Peer Reviewe