scholarly journals West Florida Shelf pipeline serves as sea turtle benthic habitat based on in situ towed camera observations

2019 ◽  
Vol 29 ◽  
pp. 17-31 ◽  
Author(s):  
HA Broadbent ◽  
SE Grasty ◽  
RF Hardy ◽  
MM Lamont ◽  
KM Hart ◽  
...  
Keyword(s):  
Habitat Use ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Environmental Data ◽  
Benthic Habitat ◽  
West Florida Shelf ◽  
Benthic Habitats ◽  
Florida Shelf ◽  
Turtle Species

The use of marine offshore benthic habitats by sea turtles is poorly characterized due to the difficulty of obtaining in situ data. Understanding benthic habitat use that is important to the species’ reproduction, foraging, and migrations is critical for guiding management decisions. A towed camera-based assessment survey system (C-BASS) equipped with environmental sensors was used to characterize and assess benthic habitats on the West Florida Shelf (WFS) from 2014 to 2018. During these cruises, sea turtles were opportunistically observed during the surveys, and critical in situ data such as spatiotemporal information, species identification, habitat use, behavior, and environmental data were collected and evaluated. In total, 79 sea turtles were observed during 97 transects of approximately 2700 km of seafloor, which was recorded on 380 h of video. Several sea turtle species were spotted within the WFS, including loggerhead Caretta caretta, Kemp’s ridley Lepidochelys kempii, and green turtles Chelonia mydas. These opportunistic sightings revealed an area of high use on the WFS, an anthropogenic structure known as the Gulfstream natural gas pipeline (GSPL). C-BASS survey results suggest that 2 sea turtle species (C. caretta and L. kempii) utilize this artificial structure primarily as a resting area. We emphasize the importance of combining habitat mapping techniques (towed underwater video and multibeam bathymetry/backscatter) with tracking technology to better understand the fine-scale habitat use of sea turtles.

Comparative Cytogenetics of Four Sea Turtle Species (Cheloniidae): G-Banding Pattern and in situ Localization of Repetitive DNA Units

2020 ◽  
Vol 160 (9) ◽  
pp. 531-538
Author(s):  
Caroline R.D. Machado ◽  
Larissa Glugoski ◽  
Camila Domit ◽  
Marcela B. Pucci ◽  
Daphne W. Goldberg ◽  
...  
Keyword(s):  
Ribosomal Dna ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Marine Biodiversity ◽  
Comparative Cytogenetics ◽  
Turtle Species ◽  
Lepidochelys Olivacea ◽  
Karyotypic Formula

Sea turtles are considered flagship species for marine biodiversity conservation and are considered to be at varying risk of extinction globally. Cases of hybridism have been reported in sea turtles, but chromosomal analyses are limited to classical karyotype descriptions and a few molecular cytogenetic studies. In order to compare karyotypes and understand evolutive mechanisms related to chromosome dif­ferentiation in this group, <i>Chelonia mydas</i>, <i>Caretta caretta</i>, <i>Eretmochelys imbricata</i>, and <i>Lepidochelys olivacea</i> were cytogenetically characterized in the present study. When the obtained cytogenetic data were compared with the putative ancestral Cryptodira karyotype, the studied species showed the same diploid number (2n) of 56 chromosomes, with some variations in chromosomal morphology (karyotypic formula) and minor changes in longitudinal band locations. In situ localization using a 18S ribosomal DNA probe indicated a homeologous microchromosome pair bearing a 45S ribosomal DNA locus and size heteromorphism in all 4 species. Interstitial telomeric sites were identified in a microchromosome pair in <i>C. mydas</i> and <i>C. caretta</i>. The data showed that interspecific variations occurred in chromosomal sets among the Cheloniidae species, in addition to other Cryptodira karyotypes. These variations generated lineage-specific karyotypic diversification in sea turtles, which will have considerable implications for hybrid recognition and for the study, the biology, ecology, and evolutionary history of regional and global populations. Furthermore, we demonstrated that some chromosome rearrangements occurred in sea turtle species, which is in conflict with the hypothesis of conserved karyotypes in this group.

scholarly journals Insights Into Sea Turtle Population Composition Obtained With Stereo-Video Cameras in situ Across Nearshore Habitats in the Northeastern Gulf of Mexico

2021 ◽  
Vol 8 ◽  
Author(s):  
Tabitha Siegfried ◽  
Christopher Noren ◽  
Jackson Reimer ◽  
Matthew Ware ◽  
Mariana M. P. B. Fuentes ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Life Stages ◽  
Turtle Species ◽  
Stereo Video ◽  
Population Size Estimates ◽  
Turtle Population ◽  
Northeastern Gulf Of Mexico

Population size estimates are key parameters used in assessments to evaluate and determine a species’ conservation status. Typically, sea turtle population estimates are made from nesting beach surveys which capture only hatchling and adult female life stages and can display trends opposite of the full population. As such, in-water studies are critical to improve our understanding of sea turtle population dynamics as they can target a broader range of life stages – though they are more logistically and financially challenging to execute compared to beach-based surveys. Stereo-video camera systems (SVCS) hold promise for improving in-water assessments by removing the need to physically capture individuals and instead extract 3D measurements from video footage, thereby simplifying monitoring logistics and improving safety for the animals and surveyors. To demonstrate this potential, snorkel surveys were conducted at artificial habitats in the northeastern Gulf of Mexico (neGOM) to collect size and photo-identification data on sea turtles in situ using a SVCS. Over 29.86 survey hours, 35 sea turtles were observed across three species (Caretta caretta, Chelonia mydas, and Lepidochelys kempii) and all neritic life stages (juvenile, sub-adult, and adult) utilizing different habitats, including artificial reefs, jetties, and fishing piers. Greens straight carapace length ranged from 28.55 to 66.96 cm (n = 23, mean 43.07 cm ± 11.26 cm standard deviation; SD) and loggerheads ranged from 59.71 to 91.77 cm (n = 10, mean 74.50 cm ± 11.35 cm SD), and Kemp’s ridleys ranged from 42.23 cm to 44.98 cm (mean 43.61 cm ± 1.94 cm SD). Using a linear mixed model, we found that species and habitat type were the most important predictors of sea turtle body length distribution. Overall, this case study demonstrates the potential of SVCS surveys to enhance our understanding of the population structure of sea turtle species within the neGOM and elsewhere.

scholarly journals Physiological determinants of the internesting interval in sea turtles: a novel ‘water-limitation’ hypothesis

2019 ◽  
Vol 15 (6) ◽  
pp. 20190248 ◽  
Author(s):  
Edwin R. Price ◽  
Paul R. Sotherland ◽  
Bryan P. Wallace ◽  
James R. Spotila ◽  
Edward M. Dzialowski
Keyword(s):  
Sea Turtles ◽  
Sea Turtle ◽  
Capacity Limits ◽  
Turtle Species ◽  
Water Limitation ◽  
Physiological Limits ◽  
Adult Body Mass ◽  
Mixed Support ◽  
Egg Albumen ◽  
Excretion Rates

The internesting interval separates successive clutches of sea turtle eggs, and its duration varies both among and within species. Here, we review the potential physiological limits to this interval, and develop the hypothesis that desalination capacity limits the internesting interval owing to the requirement for water deposition in eggs. Sea turtles deposit 1–4 kg of water per clutch in egg albumen; for most species, this represents about 2% of adult body mass. We calculate how quickly turtles can recover this water by estimating maximal salt excretion rates, metabolic water production and urinary losses. From this water balance perspective, the ‘water-limitation’ hypothesis is plausible for green turtles but not for leatherbacks. Some plasma biochemistry studies indicate dehydration in sea turtles during the nesting season, although this is not a universal finding and these data have rarely been collected during the internesting interval itself. There is mixed support for a trade-off between clutch size and the length of the interval. We conclude that the ‘water-limitation’ hypothesis is plausible for most sea turtle species, but requires direct experimentation.

Characterizing benthic habitats in two Marine Protected Areas on the West Florida Shelf

2020 ◽  
pp. 605-618
Author(s):  
Jennifer L. Brizzolara ◽  
Sarah E. Grasty ◽  
Alex R. Ilich ◽  
John W. Gray ◽  
David F. Naar ◽  
...  
Keyword(s):  
Protected Areas ◽  
Marine Protected Areas ◽  
West Florida Shelf ◽  
The West ◽  
Benthic Habitats ◽  
Florida Shelf

scholarly journals Incidental capture of sea turtles by industrial bottom trawl fishery in the Tropical South-western Atlantic

2017 ◽  
Vol 98 (6) ◽  
pp. 1525-1531 ◽  
Author(s):  
Suzana Machado Guimarães ◽  
Davi Castro Tavares ◽  
Cassiano Monteiro-Neto
Keyword(s):  
Sea Turtles ◽  
Action Plan ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Bottom Trawl ◽  
Conservation Strategies ◽  
Future Research ◽  
Olive Ridley ◽  
Western Atlantic ◽  
Turtle Species

The five sea turtle species occurring in Brazilian waters are susceptible to threats, including incidental catches by fisheries. Studies on incidental captures in fishing gears are the main focus of several conservation actions due to high sea turtle fishery mortality worldwide. This study provides the first evaluation of incidental sea turtle catches by industrial bottom trawl fisheries operating in Brazilian waters. Four twin-trawler vessels were monitored between July 2010 and December 2011 by captains who voluntarily completed logbooks. Forty-four turtles were captured during the 1996 tows (8313 fishing hours), resulting in a catch of 5.3 ± 0.8 turtles per 1000 h per unit effort. Captured species included the loggerhead turtle (Caretta caretta, 22 individuals), olive ridley turtles (Lepidochelys olivacea, 21 individuals) and one green turtle (Chelonia mydas). Water depth was the only variable that significantly affected sea turtle captures according to Generalized Linear Models. The capture rates reported in this study ranked sixth in relation to other published studies of similar fisheries occurring worldwide. Considering the importance of this region for sea turtles, the increasing evidence of sea turtle mortality and the goals of the National Action Plan for Conservation of Sea Turtles in Brazil, it is essential to identify the main threats towards these animals and propose mitigating solutions to reduce sea turtle mortality induced by fishing activities. This study provides results that may guide future research and goals in meeting sea turtle conservation strategies.

Detection of Karenia brevis blooms on the west Florida shelf using in situ backscattering and fluorescence data

Harmful Algae ◽  
2009 ◽  
Vol 8 (6) ◽  
pp. 898-909 ◽  
Author(s):  
Jennifer P. Cannizzaro ◽  
Chuanmin Hu ◽  
David C. English ◽  
Kendall L. Carder ◽  
Cynthia A. Heil ◽  
...  
Keyword(s):  
Karenia Brevis ◽  
West Florida Shelf ◽  
The West ◽  
Florida Shelf

scholarly journals BATHYMETRY EXTRACTION FROM SPOT 7 SATELLITE IMAGERY USING RANDOM FOREST METHODS

2019 ◽  
Vol 16 (1) ◽  
pp. 23
Author(s):  
Kuncoro Teguh Setiawan ◽  
Nana Suwargana ◽  
Devica Natalia Br. Ginting ◽  
Masita Dwi Mandini Manessa ◽  
Nanin Anggraini ◽  
...  
Keyword(s):  
Random Forest ◽  
Satellite Imagery ◽  
Coefficient Of Determination ◽  
Shallow Waters ◽  
Benthic Habitat ◽  
Benthic Habitats ◽  
Depth Data ◽  
Marine Habitats ◽  
Random Forest Method

The scope of this research is the application of the random forest method to SPOT 7 data to produce bathymetry information for shallow waters in Indonesia. The study aimed to analyze the effect of base objects in shallow marine habitats on estimating bathymetry from SPOT 7 satellite imagery. SPOT 7 satellite imagery of the shallow sea waters of Gili Matra, West Nusa Tenggara Province was used in this research. The estimation of bathymetry was carried out using two in-situ depth-data modifications, in the form of a random forest algorithm used both without and with benthic habitats (coral reefs, seagrass, macroalgae, and substrates). For bathymetry estimation from SPOT 7 data, the first modification (without benthic habitats) resulted in a 90.2% coefficient of determination (R2) and 1.57 RMSE, while the second modification (with benthic habitats) resulted in an 85.3% coefficient of determination (R2) and 2.48 RMSE. This research showed that the first modification achieved slightly better results than the second modification; thus, the benthic habitat did not significantly influence bathymetry estimation from SPOT 7 imagery.

scholarly journals Satellite tracking of rehabilitated sea turtles suggests a high rate of short-term survival following release

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246241
Author(s):  
David P. Robinson ◽  
Kevin Hyland ◽  
Gerhard Beukes ◽  
Abdulkareem Vettan ◽  
Aneeshkumar Mabadikate ◽  
...  
Keyword(s):  
Sea Turtles ◽  
Sea Turtle ◽  
Satellite Tracking ◽  
Anthropogenic Factors ◽  
Gulf Region ◽  
Term Survival ◽  
Turtle Species ◽  
Movement Characteristics ◽  
Loggerhead Turtles ◽  
Hawksbill Turtles

The rehabilitation of wildlife can contribute directly to the conservation of threatened species by helping to maintain wild populations. This study focused on determining the post-rehabilitation survival and spatial ecology of sea turtles and on comparing the movements of individuals with flipper amputations (amputees) to non-amputee animals. Our aims were to assess whether rehabilitated sea turtles survive after release, to compare and contrast the movement characteristics of the different species of sea turtles we tracked, and to examine whether amputees and non-amputees within species behaved similarly post-release. Twenty-six rehabilitated sea turtles from four species, including hawksbill Eretmochelys imbricata (n = 12), loggerhead Caretta caretta (n = 11), green Chelonia mydas (n = 2), and olive ridley Lepidochelys olivacea (n = 1) sea turtles from the United Arab Emirates were fitted with satellite tags before release. Rehabilitation times ranged from 89 to 817 days (mean 353 ± 237 days). Post-release movements and survival were monitored for 8 to 387 days (mean 155 ± 95 days) through satellite tracking. Tag data suggested that three tracked sea turtles died within four days of release, one after 27 days, and one after 192 days from what are thought to be anthropogenic factors unrelated to their pre-rehabilitation ailments. We then compared habitat use and movement characteristics among the different sea turtle species. Although half of all turtles crossed one or more international boundaries, dispersal varied among species. Loggerhead turtles had a high dispersal, with 80% crossing an international boundary, while hawksbill turtles displayed higher post-release residency, with 66% remaining within UAE territorial waters. Amputee turtles moved similarly to non-amputee animals of the same species. Loggerhead turtles travelled faster (mean ± sd = 15.3 ± 8 km/day) than hawksbill turtles (9 ± 7 km/day). Both amputee and non-amputee sea turtles within a species moved similarly. Our tracking results highlight that rehabilitated sea turtles, including amputees, can successfully survive in the wild following release for up to our ~one-year monitoring time therefore supporting the suitability for release of sea turtles that have recovered from major injuries such as amputations. However, more broadly, the high mortality from anthropogenic factors in the Arabian Gulf region is clearly a serious issue and conservation challenge.

scholarly journals Variation in Species Composition, Size and Fitness of Two Multi-Species Sea Turtle Assemblages Using Different Neritic Habitats

2021 ◽  
Vol 7 ◽  
Author(s):  
Margaret M. Lamont ◽  
Darren Johnson
Keyword(s):  
Gulf Of Mexico ◽  
Species Composition ◽  
Body Condition ◽  
Sea Turtles ◽  
Condition Index ◽  
Sea Turtle ◽  
Body Condition Index ◽  
Turtle Species ◽  
Green Turtles ◽  
Sand Bottom

The neritic environment is rich in resources and as such plays a crucial role as foraging habitat for multi-species marine assemblages, including sea turtles. However, this habitat also experiences a wide array of anthropogenic threats. To prioritize conservation funds, targeting areas that support multi-species assemblages is ideal. This is particularly important in the Gulf of Mexico where restoration actions are currently ongoing following the Deepwater Horizon oil spill. To better understand these areas in the Gulf of Mexico, we characterized two multi-species aggregations of sea turtles captured in different neritic habitats. We described species composition and size classes of turtles, and calculated body condition index for 642 individuals of three species captured from 2011 to 2019: 13.6% loggerheads (Caretta caretta), 44.9% Kemp’s ridleys (Lepidochelys kempii) and 41.4% green turtles (Chelonia mydas). Species composition differed between the two sites with more loggerheads captured in seagrass and a greater proportion of green turtles captured in sand bottom. Turtles in sand bottom were smaller and weighed less than those captured in seagrass. Although small and large turtles were captured at both sites, the proportions differed between sites. Body condition index of green turtles was lower in sand habitat than seagrass habitat; there was no difference for Kemp’s ridleys or loggerheads. In general, smaller green turtles had a higher body condition index than larger green turtles. We have identified another habitat type used by juvenile sea turtle species in the northern Gulf of Mexico. In addition, we highlight the importance of habitat selection by immature turtles recruiting from the oceanic to the neritic environment, particularly for green turtles.

scholarly journals Guide to Nesting Sea Turtles in Florida

EDIS ◽  
2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Analisa Duran ◽  
Ruth Francis-Floyd ◽  
Maia Patterson Mcguire ◽  
Iskande Larkin
Keyword(s):  
Sea Turtles ◽  
Sea Turtle ◽  
The State ◽  
Critical Habitat ◽  
Turtle Species ◽  
The World ◽  
The Common ◽  
Leatherback Sea Turtles

Florida’s coastline provides critical habitat for sea turtle nesting, as it has for millions of years. Throughout the state, three of the seven species of sea turtles in the world have significant nesting populations. Loggerhead, green, and leatherback sea turtles use Florida’s beaches to lay nests each year. This publication provides information on the identification, nesting characteristics, and abundance of each of the common sea turtle species who nest in Florida.

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