The 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. southeastern 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.

No abstract

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 mats. 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 YO respectively, while, polychaetes had increased to 38 Yo becoming the most dominant taxon. Bivalves and echinoderms also increaseld 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. 0 1999 Ifremer / CNRS / IIRD / Editions scientifiques et medicales Elsevier SAS Lessepsian migrant I Caulerpa racemosa I benthos I community composition I' Moni Bay, Cyprus Resume-Expansion de la macroalgue Caulerpa racemosa et variations de la ma.crofaune des fonds meubles dans la baie de Moni, Chypre. L'expansion recente de la macroalgue de mer Rouge Caulerpa racemosa et son impact sur la diversite et l'abondance du macrobenthos ont Cte compares dans la baie de Moni, a Chypre, entre les et& 1992 et 1997. La communaute phytobenthique de la baie Ctait dominee en 1992 par l'algue Posidonia oceanica, alors qu'en 1997, l'immigrant lessepsien C. .racemosa dominait, formant de vastes prairies. Les changements de vegetation dans la baie de Moni ont entrain6 des moldifications significatives dans la composition de la macrofaune. Au total, 178 individus de 62 espbces ont ttt examines. L,a composition de la macrofaune Ctait dominee en 1992 par les gasteropodes (44 Yo), les crustaces (22 %), les bivalves (17 %), les polychetes (11 %) et les echinodermes (6 %). En 1997, les gasteropodes et les crustaces Ctaient r&kits a 13 et 16 % respectivement, tandis que le polychbtes devenaient le taxon dominant (38 Yo) ; les bivalves et les Cchinodermes progressaient tgalement jusqu'a 22 et 11 % respectivement. La croissance proliferante de C. racemosa a provoque une s&L: de changements dans la macrofaune de la baie de Moni entre 1992 et 1997.11 reste a Ctablir si l'expansion de C. racemosa est due a l'tlevation de la temperature de l'eau associee au rechauffement global, a l'apport des nutriments, ou aux differences entre les caracteristiques de l'evolution de cet immigrant et c...

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). 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.

No abstract