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The current study focuses on four species from the primarily marine diatom genus Craspedostauros that were observed growing attached to numerous sea turtles and sea turtle-associated barnacles from Croatia and South Africa. Three of the examined taxa, C. danayanus sp. nov., C. legouvelloanus sp. nov., and C. macewanii sp. nov., are described based on morphological and, whenever possible, molecular characteristics. The new taxa exhibit characters not previously observed in other members of the genus, such as the presence of more than two rows of cribrate areolae on the girdle bands, shallow perforated septa, and a complete reduction of the stauros. The fourth species, C. alatus, itself recently described from museum sea turtle specimens, is reported for the first time from loggerhead sea turtles rescued in Europe. A 3-gene phylogenetic analysis including DNA sequence data for three sea turtle-associated Craspedostauros species and other marine and epizoic diatom taxa indicated that Craspedostauros is monophyletic and sister to Achnanthes. This study, being based on a large number of samples and animal specimens analyzed and using different preservation and processing methods, provides new insights into the ecology and biogeography of the genus and sheds light on the level of intimacy and permanency in the host-epibiont interaction within the epizoic Craspedostauros species.

International audience; Phenological shifts, by initiating reproductive events earlier, in response to advanced seasonal warming is one of the most striking effects currently observed in wild populations. For sea turtles, phenological adjustment to warming conditions could be the most effective short-term adaptation option against climate change. We calculated future phenological changes required in seven important loggerhead (Caretta caretta) nesting populations to continue achieving a high hatching success and a sex ratio that lies within current ranges. Considering temperature-mediated phenological changes, we found that most populations (six out of seven) will not be able to keep pace with a warming climate. Under an optimistic climate warming scenario (RCP4.5), these populations will face a climatic debt, that is, a difference between required and expected phenological changes, and warming will substantially reduce hatching success and induce a feminization of hatchlings, which may jeopardize their reproductive sustainability. Our approach offers the possibility to quantify the efficiency of phenological shifts in oviparous reptiles by considering physiological, developmental and phenological processes.

A new Lucanicum species, L. ashworthianum Majewska, K.Robert & Van de Vijver sp. nov., was found in multiple samples of biofilm growing on loggerhead sea turtles Caretta caretta and their symbiotic barnacles Chelonibia testudinaria collected on the beaches of Kosi Bay, eastern coast of South Africa, during the two nesting seasons (the austral summers of 2017/2018 and 2018/2019). The new species possesses several features typical of the genus Lucanicum, including the uniseriate striae composed of one large macroareola, the presence of large apical slit fields and transapically elongated rimoportulae at both poles, and a cingulum composed of numerous open, doubly perforated copulae. It differs from the only other Lucanicum species known to date, the coral-associated L. concatenatum, in having considerably smaller cells with clearly rostrate or sub-capitate apices and internal rimoportula opening composed of a C-shaped inner lip and an oval, flap-like outer lip - a feature not observed previously in Lucanicum. Based on these new observations, an amendment of the genus description is proposed.

The diatom genus Proschkinia is a common element of biofilms covering diverse substrata in saline inland or shallow coastal environments. It can be distinguished from other naviculoid taxa by its lanceolate valves with a fistula located within the central area and numerous open girdle bands with a U-shaped cross-section and a single row of perforations on the internal side of the fold. Despite this distinct morphology, frustules of Proschkinia are typically weakly silicified and often overlooked when cleaned diatom material is analysed. The current paper describes six new species of Proschkinia: P. browderiana sp. nov., P. lacrimula sp. nov., P. maluszekiana sp. nov., P. sulcata sp. nov., P. torquata sp. nov. and P. vergostriata sp. nov., found in numerous samples of marine organisms, such as sea turtles (including sea turtle museum specimens), sea turtle-associated barnacles and seagrass from across the three oceans. Some of the newly described taxa were found on multiple individuals belonging to different sea turtle species, whereas others were in samples collected from different continents. Molecular phylogenetic analysis indicated that examined Proschkinia strains formed a monophyletic clade, sister to Fistulifera.

Santidrián Tomillo, Pilar et al., The most recent climate change projections show a global increase in temperatures along with precipitation changes throughout the 21 century. However, regional projections do not always match global projections and species with global distributions may exhibit varying regional susceptibility to climate change. Here we show the effect of local climatic conditions on the hatchling output of leatherback turtles (Dermochelys coriacea) at four nesting sites encompassing the Pacific, Atlantic and Indian Oceans. We found a heterogeneous effect of climate. Hatchling output increased with long-term precipitation in areas with dry climatic conditions (Playa Grande, Pacific Ocean and Sandy Point, Caribbean Sea), but the effect varied in areas where precipitation was high (Pacuare, Caribbean Sea) and was not detected at the temperate site (Maputaland, Indian Ocean). High air temperature reduced hatchling output only at the area experiencing seasonal droughts (Playa Grande). Climatic projections showed a drastic increase in air temperature and a mild decrease in precipitation at all sites by 2100. The most unfavorable conditions were projected for Sandy Point where hatching success has already declined over time along with precipitation levels. The heterogeneous effect of climate may lead to local extinctions of leatherback turtles in some areas but survival in others by 2100., Funding for the study was provided by a Marie Curie International Incoming Fellowship within the 7th European Community Framework Programme. Specific funding for each site was provided by the Earthwatch Institute, the Betz Chair of Environmental Science at Drexel University, the Schrey Chair of Biology at IPFW and The Leatherback Trust (Playa Grande), the US Fish and Wildlife Service (USFWS) (Sandy Point), the Endangered Wildlife Trust (Pacuare) and NRF/Thuthuka and NMMU Postgraduate Research Scholarship (Maputaland)

Previous genetic studies have demonstrated that natal homing shapes the stock structure of marine turtle nesting populations. However, widespread sharing of common haplotypes based on short segments of the mitochondrial control region often limits resolution of the demographic connectivity of populations. Recent studies employing longer control region sequences to resolve haplotype sharing have focused on regional assessments of genetic structure and phylogeography. Here we synthesize available control region sequences for loggerhead turtles from the Mediterranean Sea, Atlantic, and western Indian Ocean basins. These data represent six of the nine globally significant regional management units (RMUs) for the species and include novel sequence data from Brazil, Cape Verde, South Africa and Oman. Genetic tests of differentiation among 42 rookeries represented by short sequences (380 bp haplotypes from 3,486 samples) and 40 rookeries represented by long sequences (~800 bp haplotypes from 3,434 samples) supported the distinction of the six RMUs analyzed as well as recognition of at least 18 demographically independent management units (MUs) with respect to female natal homing. A total of 59 haplotypes were resolved. These haplotypes belonged to two highly divergent global lineages, with haplogroup I represented primarily by CC-A1, CC-A4, and CC-A11 variants and haplogroup II represented by CC-A2 and derived variants. Geographic distribution patterns of haplogroup II haplotypes and the nested position of CC-A11.6 from Oman among the Atlantic haplotypes invoke recent colonization of the Indian Ocean from the Atlantic for both global lineages. The haplotypes we confirmed for western Indian Ocean RMUs allow reinterpretation of previous mixed stock analysis and further suggest that contemporary migratory connectivity between the Indian and Atlantic Oceans occurs on a broader scale than previously hypothesized. This study represents a valuable model for conducting comprehensive international cooperative data management and research in marine ecology.

Sea turtles are highly migratory and usually dispersed, but aggregate off beaches during the nesting season, rendering them vulnerable to coastal threats. Consequently, coastal Marine Protection Areas (MPAs) have been used to facilitate the recovery of turtle populations, but the effectiveness of these programs is uncertain as most have been operating for less than a single turtle generation (or1700 nests pa (index area) especially over the last decade, while leatherback abundance increased initially∼10 to 70 nests pa (index area), but then stabilized. Although leatherbacks have higher reproductive output per female and comparable remigration periods and hatching success to loggerheads, the leatherback population failed to expand. Our results suggest that coastal MPAs can work but do not guarantee the recovery of sea turtle populations as pressures change over time. Causes considered for the lack of population growth include factors in the MPA (expansion into unmonitored areas or incubation environment) of outside of the MPA (including carrying capacity and fishing mortality). Conservation areas for migratory species thus require careful design to account for species-specific needs, and need to be monitored to keep track of changing pressures.

Where conservation resources are limited and conservation targets are diverse, robust yet flexible priority-setting frameworks are vital. Priority-setting is especially important for geographically widespread species with distinct populations subject to multiple threats that operate on different spatial and temporal scales. Marine turtles are widely distributed and exhibit intra-specific variations in population sizes and trends, as well as reproduction and morphology. However, current global extinction risk assessment frameworks do not assess conservation status of spatially and biologically distinct marine turtle Regional Management Units (RMUs), and thus do not capture variations in population trends, impacts of threats, or necessary conservation actions across individual populations. To address this issue, we developed a new assessment framework that allowed us to evaluate, compare and organize marine turtle RMUs according to status and threats criteria. Because conservation priorities can vary widely (i.e. from avoiding imminent extinction to maintaining long-term monitoring efforts) we developed a ‘‘conservation priorities portfolio’’ system using categories of paired risk and threats scores for all RMUs (n = 58). We performed these assessments and rankings globally, by species, by ocean basin, and by recognized geopolitical bodies to identify patterns in risk, threats, and data gaps at different scales. This process resulted in characterization of risk and threats to all marine turtle RMUs, including identification of the world’s 11 most endangered marine turtle RMUs based on highest risk and threats scores. This system also highlighted important gaps in available information that is crucial for accurate conservation assessments. Overall, this priority-setting framework can provide guidance for research and conservation priorities at multiple relevant scales, and should serve as a model for conservation status assessments and prioritysetting for widespread, long-lived taxa.

BackgroundResolving threats to widely distributed marine megafauna requires definition of the geographic distributions of both the threats as well as the population unit(s) of interest. In turn, because individual threats can operate on varying spatial scales, their impacts can affect different segments of a population of the same species. Therefore, integration of multiple tools and techniques--including site-based monitoring, genetic analyses, mark-recapture studies and telemetry--can facilitate robust definitions of population segments at multiple biological and spatial scales to address different management and research challenges.Methodology/principal findingsTo address these issues for marine turtles, we collated all available studies on marine turtle biogeography, including nesting sites, population abundances and trends, population genetics, and satellite telemetry. We georeferenced this information to generate separate layers for nesting sites, genetic stocks, and core distributions of population segments of all marine turtle species. We then spatially integrated this information from fine- to coarse-spatial scales to develop nested envelope models, or Regional Management Units (RMUs), for marine turtles globally.Conclusions/significanceThe RMU framework is a solution to the challenge of how to organize marine turtles into units of protection above the level of nesting populations, but below the level of species, within regional entities that might be on independent evolutionary trajectories. Among many potential applications, RMUs provide a framework for identifying data gaps, assessing high diversity areas for multiple species and genetic stocks, and evaluating conservation status of marine turtles. Furthermore, RMUs allow for identification of geographic barriers to gene flow, and can provide valuable guidance to marine spatial planning initiatives that integrate spatial distributions of protected species and human activities. In addition, the RMU framework--including maps and supporting metadata--will be an iterative, user-driven tool made publicly available in an online application for comments, improvements, download and analysis.

Capture by pelagic longline fisheries has been identified as a key threat to turtle populations. This study is the first assessment of turtle bycatch in the South African pelagic longline fishery for tunas Thunnus spp. and swordfish Xiphias gladius. A total of 181 turtles was caught on observed sets between 1998 and 2005, at a rate of 0.04 per 1 000 hooks (0–15.5 per 1 000 hooks, SD = 1.28). Loggerhead turtles Caretta caretta comprised 60.0% of the total turtle capture and were caught at rate of 0.02 per 1 000 hooks. The second most commonly caught species was the leatherback turtle Dermochelys coriacea (33.8%), which were caught at rate of 0.01 per 1 000 hooks. Five hawksbill turtles Eretmochelys imbricata were caught at a rate of 0.001 per 1 000 hooks and three green turtles Chelonia mydas at a rate of 0.001 per 1 000 hooks. Catches were clustered, with 70% of turtles caught on 1% of sets. Apart from one set on the Agulhas Bank, on the southern coast of South Africa, all sets that caught three or more turtles were on the Walvis Ridge and on the shelf edge north of the Orange River (25°–31° S and 0°–15° E). Most of the variance in turtle bycatch was accounted for by ‘vessel’. Five vessels (of a total of 50) caught 65% of turtles, at a rate of 0.4 per 1 000 hooks. The target species (swordfish or tunas) was the second most important explanatory variable; 89.5% of turtles were caught by swordfish Thunnus spp. and swordfish Xiphias gladius. A total of 181 turtles was caught on observed sets between 1998 and 2005, at a rate of 0.04 per 1 000 hooks (0–15.5 per 1 000 hooks, SD = 1.28). Loggerhead turtles Caretta caretta comprised 60.0% of the total turtle capture and were caught at rate of 0.02 per 1 000 hooks. The second most commonly caught species was the leatherback turtle Dermochelys coriacea (33.8%), which were caught at rate of 0.01 per 1 000 hooks. Five hawksbill turtles Eretmochelys imbricata were caught at a rate of 0.001 per 1 000 hooks and three green turtles Chelonia mydas at a rate of 0.001 per 1 000 hooks. Catches were clustered, with 70% of turtles caught on 1% of sets. Apart from one set on the Agulhas Bank, on the southern coast of South Africa, all sets that caught three or more turtles were on the Walvis Ridge and on the shelf edge north of the Orange River (25°–31° S and 0°–15° E). Most of the variance in turtle bycatch was accounted for by ‘vessel’. Five vessels (of a total of 50) caught 65% of turtles, at a rate of 0.4 per 1 000 hooks. The target species (swordfish or tunas) was the second most important explanatory variable; 89.5% of turtles were caught by swordfish Thunnus spp. and swordfish Xiphias gladius. A total of 181 turtles was caught on observed sets between 1998 and 2005, at a rate of 0.04 per 1 000 hooks (0–15.5 per 1 000 hooks, SD = 1.28). Loggerhead turtles Caretta caretta comprised 60.0% of the total turtle capture and were caught at rate of 0.02 per 1 000 hooks. The second most commonly caught species was the leatherback turtle Dermochelys coriacea (33.8%), which were caught at rate of 0.01 per 1 000 hooks. Five hawksbill turtles Eretmochelys imbricata were caught at a rate of 0.001 per 1 000 hooks and three green turtles Chelonia mydas at a rate of 0.001 per 1 000 hooks. Catches were clustered, with 70% of turtles caught on 1% of sets. Apart from one set on the Agulhas Bank, on the southern coast of South Africa, all sets that caught three or more turtles were on the Walvis Ridge and on the shelf edge north of the Orange River (25°–31° S and 0°–15° E). Most of the variance in turtle bycatch was accounted for by ‘vessel’. Five vessels (of a total of 50) caught 65% of turtles, at a rate of 0.4 per 1 000 hooks. The target species (swordfish or tunas) was the second most important explanatory variable; 89.5% of turtles were caught by swordfish-directed vessels at a rate of 0.15 per 1 000 hooks. Season was the third most important explanatory variable, with more turtles caught between January and June (0.13 per 1 000 per hooks) than in the remainder of the year (0.03 per 1 000 hooks), although leatherback turtles tended to be caught throughout the year. Extrapolations based on stratification by 5° grid cell, by season and by target species estimated that a total of 190 turtles was caught per year (approximately 100 loggerheads and 50 leatherbacks). Using three different techniques, the extrapolations varied between 190 and 560 turtles per year. However, if the proposed increase in fishing effort to 50 rights-holders is effected, turtle bycatch is likely to increase to about 770 turtles per year. Leatherback turtles caught by the South African pelagic longline fisheries are likely to be from the local nesting population. That population has been protected at its nesting beaches but has not recovered as expected. The overlap of turtle tracks and fishing effort suggests that the longline fishery could be partially responsible for the slow recovery. Keywords: bycatch; conservation; pelagic longline; South Africa; turtlesAfrican Journal of Marine Science 2009, 31(1): 87–96