Green turtles (Chelonia mydas) foraging at Arvoredo Island in Southern Brazil: Genetic characterization and mixed stock analysis through mtDNA control region haplotypes

We analyzed mtDNA control region sequences of green turtles (Chelonia mydas) from Arvoredo Island, a foraging ground in southern Brazil, and identified eight haplotypes. Of these, CM-A8 (64%) and CM-A5 (22%) were dominant, the remainder presenting low frequencies (< 5%). Haplotype (h) and nucleotide (π) diversities were 0.5570 ± 0.0697 and 0.0021 ± 0.0016, respectively. Exact tests of differentiation and AMOVA ΦST pairwise values between the study area and eight other Atlantic foraging grounds revealed significant differences in most areas, except Ubatuba and Rocas/Noronha, in Brazil (p > 0.05). Mixed Stock Analysis, incorporating eleven Atlantic and one Mediterranean rookery as possible sources of individuals, indicated Ascension and Aves islands as the main contributing stocks to the Arvoredo aggregation (68.01% and 22.96%, respectively). These results demonstrate the extensive relationships between Arvoredo Island and other Atlantic foraging and breeding areas. Such an understanding provides a framework for establishing adequate management and conservation strategies for this endangered species

Foraging by Immature Hawksbill Sea Turtles at Brazilian Islands

Submitted by Marcela Polino ([email protected]) on 2016-01-19T21:03:37Z No. of bitstreams: 1 Proietti_2012_2.pdf: 993808 bytes, checksum: cf8f2b912c8c6651cd9cf4981bd4f53a (MD5)Approved for entry into archive by Lilian M. Silva ([email protected]) on 2016-01-20T11:59:39Z (GMT) No. of bitstreams: 1 Proietti_2012_2.pdf: 993808 bytes, checksum: cf8f2b912c8c6651cd9cf4981bd4f53a (MD5)Made available in DSpace on 2016-01-20T11:59:39Z (GMT). No. of bitstreams: 1 Proietti_2012_2.pdf: 993808 bytes, checksum: cf8f2b912c8c6651cd9cf4981bd4f53a (MD5) Previous issue date: 201

Ingestion of plastics at sea: does debris size really matter?

Submitted by Marcela Polino ([email protected]) on 2016-01-19T16:33:41Z No. of bitstreams: 1 fmars-01-00070.pdf: 1375867 bytes, checksum: 672b445cb153f8b2a392df6089e7c815 (MD5)Approved for entry into archive by Lilian M. Silva ([email protected]) on 2016-01-19T19:12:20Z (GMT) No. of bitstreams: 1 fmars-01-00070.pdf: 1375867 bytes, checksum: 672b445cb153f8b2a392df6089e7c815 (MD5)Made available in DSpace on 2016-01-19T19:12:20Z (GMT). No. of bitstreams: 1 fmars-01-00070.pdf: 1375867 bytes, checksum: 672b445cb153f8b2a392df6089e7c815 (MD5) Previous issue date: 201

Photographic identification of sea turtles: method description and validation, with an estimation of tag loss

Recognition of individual sea turtles is mostly achieved by checking artificial tags previously attached to them, a method which is made difficult by the considerable tag loss rate and which requires repeated manipulation of the marked individuals. We describe an individual recognition method for sea turtles of the family Cheloniidae based on a mark-recapture study that relied on both artificial tagging (Inconel tags, style 681) and natural marks (facial profile photographs). Juvenile green Chelonia mydas and hawksbill Eretmochelys imbricata turtles were manually caught at Arvoredo Island, southern Brazil, and through visual comparison of facial profile photographs we were able to identify recaptured individuals with 2, 1, or no artificial tags. Additionally, Bayesian inference based on tag loss information indicated that the way a tag is attached (position and distance from the flipper edge) affects significantly the probability of its loss. We encourage the use of photographic identification (facial profile) as a reliable method for individual recognition in studies of cheloniid turtles

Spatio-temporal characterization of litter at a touristic sandy beach in South Brazil

Litter is an ecological, economic, and social problem that impacts marine environments around the world. To create prevention and mitigation measures to solve this issue, it is necessary to understand the amounts and sources of this type of pollution. Cassino Beach is an extensive sandy beach located in South Brazil (~220 km in length) that presents multiple uses, such as touristic, portuary and fishery activities. In order to evaluate the spatial and seasonal variation of litter amounts, types and sources at Cassino Beach, litter (>2.5 cm) was collected over 27 months at two urban and two non-urban sites. At each site, the litter present in three 200 m2 areas was sampled and evaluated. A total of 19,457 items were collected, mostly composed by plastic (~88%). Paper, metal, and cloth items were also present, but in low amounts. Fragments and cigarette butts were the major types of plastic litter, with abundances of 28.4% and 17.0%, respectively. Urban sites presented higher amounts of litter, with those related to beach use being more common, emphasizing the contribution of beachgoers to litter input at these sites. During the summer season, when beach use increases, the highest total litter concentration was found. Undefined and/or beach use-related sources were dominant in all sites and seasons. Mapping the predominant materials, types and potential sources of litter creates important baseline data that can contribute not only to beach monitoring, but also to the development of litter reduction strategies

Feeding ecology of the green turtle (Chelonia mydas) at rocky reefs in western South Atlantic

Feeding ecology of green turtles was investigated between January 2005 and April 2008 at Arvoredo Reserve, Brazil (27°17′S, 48°18′W). Data were obtained through the performance of observational sessions, georeferenced counts, benthic surveys, capture and recapture of individuals, and oesophageal lavages. This protected area was identified as an important green turtle feeding ground, used year-round by juveniles (curved carapace length = 32–83 cm). Turtles fed close to the rocky shores of the area and selected grazing sites commonly at hardto- reach, near-vertical portions of the rocks. They wereless active in cold months, and more abundant at shallow areas of the reef (0–5 m), where their preferred food items occurred. Their diet was dominated by macroalgae species but invertebrates were also present. Their main food item was the red algae Pterocladiella capillacea, which seems to be eaten through periodical cropping of its tips. Observational methods such as the ones applied here could be incorporated to other research programs aiming to understand the relationships between Chelonia mydas feeding populations and their environment

The vertical distribution of buoyant plastics at sea: an observationalstudy in the North Atlantic Gyre

Millimetre-sized plastics are numerically abundant and widespread across the world’s ocean surface. These buoyant macroscopic particles can be mixed within the upper water column by turbulent transport. Models indicate that the largest decrease in their concentration occurs within the first few metres of water, where in situ observations are very scarce. In order to investigate the depth profile and physical properties of buoyant plastic debris, we used a new type of multi-level trawl at 12 sites within the North Atlantic subtropical gyre to sample from the air–seawater interface to a depth of 5 m, at 0.5m intervals. Our results show that plastic concentrations drop exponentially with water depth, and decay rates decrease with increasing Beaufort number. Furthermore, smaller pieces presented lower rise velocities and were more susceptible to vertical transport. This resulted in higher depth decays of plastic mass concentration (milligramsm\u100000����3) than numerical concentration (piecesm\u100000����3). Further multilevel sampling of plastics will improve our ability to predict at-sea plastic load, size distribution, drifting pattern, and impact on marine species and habitats