Sea Turtle Nesting Habitat Assessment: A Rapid, Integrated, Technological Approach (original) (raw)
Related papers
ISPRS International Journal of Geo-Information
Numerous environmental conditions may influence when a female Loggerhead sea turtle (Caretta caretta) selects a nesting site. Limited research has used Geographic Information Systems (GIS) and statistical analysis to study sea turtle spatial patterns and temporal trends. Therefore, the goals of this research were to identify areas that were most prevalent for nesting and to test social and environmental variables to create a nesting suitability predictive model. Data were analyzed at all barrier island beaches in North Carolina, USA (515 km) and several variables were statistically significant: distance to hardened structures, beach nourishment, house density, distance to inlets, and beach elevation, slope, and width. Interestingly, variables that were not significant were population density, proximity to the Gulf Stream, and beach aspect. Several statistical techniques were tested and Negative Binomial Distribution produced good regional results while Geographically Weighted Regres...
In México, nest relocation is the most commonly accepted methodology of sea turtle conservation. However, due to the heightened level of manipulation, lack of proper training for volunteer monitoring groups, and limited regulation, the shift is for more in-situ nest monitoring. Especially is the case for olive Ridley species (Lepidochelys olivacea) which is the least endangered of all marine turtle species. Yet in-situ nest monitoring is complicated by (1) poaching, (2) dynamic Pacific coastline, (3) extreme seasonal erosion from tropical storms, (4) an onslaught of unregulated coastal developments and (5) high-impact beach activities such as ATV tours.
Handbook for Sea Turtle Interns,; Especially those on St. Catherine's Island
Handbook for Sea Turtle Interns,; Particularly those on St. Catherine's Island, 2007
Edition 3 © 2007 was rewritten once again by Gale A. Bishop Professor Emeritus Department of Geology and Geography Georgia Southern University Statesboro, Georgia 30460 for the original authoring group Gale A. Bishop, Nancy B. Marsh, Royce H. Hayes, Mike Harris, Jeff Carter, and Charles Maley PROGRAM BACKGROUND "Loggerhead sea turtles [Caretta caretta Linneaus 1758] constitute one of seven species of marine turtles, all endangered and protected by international, national, and state statutes. Loggerhead sea turtles nest on the Southeastern Atlantic coast including sandy beaches of Georgia’s Sea Islands. Since 1990 the authors have assisted St. Catherines Island and Georgia Department of Natural Resources Sea Turtle Index Monitoring Program with loggerhead nesting on St. Catherines Island, Georgia, mapping distribution of nest sites for the last eleven years after initiating the St. Catherines Island Sea Turtle Conservation Program in 1992. Georgia Southern University joined Georgia’s Department of Natural Resources and The St. Catherines Island Foundation, Inc. to run the sea turtle nesting program on St. Catherines Island (Fig. 1). This provided a unique opportunity for the integration of service to our region and state, the teaching of scientific methodology to GSU students and state school teachers sponsored by The Improving Teacher Quality Higher Education Program (50%), and the initiation of a significant basic and applied scientific research program which will possibly allow better management of sea turtle nesting on Georgia’s urbanizing barrier islands."
Endangered Species Research, 2017
Satellite tracking studies can reveal much about turtles' spatial use of breeding areas, migration zones, and foraging sites. We assessed spatial habitat-use patterns of 10 adult female green turtles Chelonia mydas nesting at Buck Island Reef National Monument (BIRNM), US Virgin Islands (USVI; 17°47.4' N, 64°37.2' W) from 2011 to 2014. Turtles ranged in size from 89.0 to 115.9 cm curved carapace length (CCL) (x − ± SD: 106.8 ± 7.7 cm). The inter-nesting period for all turtles ranged from 31 July to 4 November, and sizes of the 50% core-use areas ranged from 4.2 to 19.0 km 2. We observed consistency of inter-nesting habitat-use patterns, with all turtles using near-shore (<1.5 km), shallow waters (<-20 m depth) within approximately 10 km of Buck Island. Seven of the 10 turtles remained locally resident after the nesting season; 5 turtles (50%) established resident foraging areas around Buck Island, 2 established resident foraging areas around the island of St. Croix, and the other 3 (30%) made longer-distance migrations to Antigua, St. Kitts & Nevis, and Venezuela. This is the first empirical dataset showing limited migration and use of 'local' resources after the nesting season in the USVI by this unique management unit of green turtles. Five of the turtles had resident foraging area centroids within protected areas; thus, inter-nesting and foraging areas at BIRNM that overlap with human use zones present an important management concern. Delineating spatial areas and identifying temporal periods of nearshore habitat use can be useful for natural resource managers with responsibility for overseeing vulnerable habitats and protecting marine turtle populations.
Chelonian Conservation and Biology, 2006
Sea turtle species observed nesting at the US Naval Station at Guantanamo Bay, Cuba (GTMO) include greens (Chelonia mydas) and hawksbills (Eretmochelys imbricata), both of which are classified as endangered by the World Conservation Union (IUCN). As Cuba and its neighbors continue to develop their coasts, all efforts should be made to preserve this important nesting refuge. Habitat suitability index models are one tool with which managers can generate hypotheses and experiment with management options. This study used an observational dataset of nests and measured habitat variables to develop habitat suitability index models in a geographic information system. The first objective was to compare the performance of 3 different habitat model-building approaches in order to determine which technique, if any, provides reliable information on sea turtle nesting habitat preferences. A habitat suitability index score for each beach zone was computed using 1) suitability indices with expert weights, 2) unscaled environmental variables with regression-based weights, and 3) a combination of suitability indices with regression-based weights. The second objective was to use the models to lend insight into important environmental descriptors of suitable sea turtle habitat for GTMO. All models predicted moderately well with 40% prediction rates, even though they assigned different weights to the variables. Moderate model performance may be attributed to low samples sizes and/or nest site fidelity that is unrelated to environmental factors. Overall, differences between empirical and expert model results reflect a shift from a regional (Caribbean) to a local scale of analysis (GTMO). However, in all models, compaction of the substrate was almost twice as influential as the other variables, indicating that the looser the sand, the more suitable the habitat. Conservation implications and suggestions for future research are discussed.
Ocean & Coastal Management, 2015
While tropical and subtropical coastal areas are considered prime areas for a wide range of tourism projects, they also host important sea turtle nesting grounds. Preserving these nesting areas is critical to ensure reproductive success and maintain viable sea turtle populations. The northern coast of the State of Bahia, in northeastern Brazil, is an important sea turtle nesting ground. Sea turtle conservation activities in Brazil began in 1980, focusing initially on reducing harvesting of nesting females and egg collection. Recently, new threats resulting from unplanned coastal development have emerged. In this paper, a geospatial tool, as an initiative of the Brazilian National Sea Turtle Conservation Program (TAMAR) to identify key areas for sea turtle nesting along the coast northern coast of Bahia, is presented. A Sensitivity Map was created, using a detailed GIS map graded by colors representing relevance levels of the coast for sea turtle nesting. From this map, recommendations of management practices that correspond to each sensitivity category can be made. This methodology allows for the identification of critical sea turtle habitats and the subsequent implementation of mitigation measures at nesting beaches, as well support coastal management policies.
The Leatherback turtle (Dermochelys coriacea) is a critically endangered species reliant on sandy beaches for nesting. Consequently, changes in beach morphology are a background factor in embryonic mortality. Grande Riviere beach has the highest density of nesting leatherbacks in the world, supporting a thriving ecotourist industry. The beach undergoes natural seasonal cycles of erosion and accretion, with renewal of sediment of importance to reduce diseases to eggs. Beach morphology surveys were conducted using standard surveying techniques both during and outside the nesting season, from the 2009 nesting season to the end of 2011. A survey was conducted in June 2012 to illustrate changes in the dynamics of the Grande Riviere River, and results reported here focus on a profile adjacent to the river. Relative stability was observed in the profile during the 2009 and 2011 nesting season, with 2010 displaying fluctuations in elevation throughout. In June 2012 there was a drastic decrease in estimated sediment volume of-644 m 3 due to the river changing to a westerly course.Nest loss was greatest when wave-induced erosion of beach sediment greater than 70cms in depth took place, or when river channels shifted, as in the 2012 nesting season. As stable river outlets are essential for both turtle nest preservation and the local fishing industry, the study has implications for the management of this sensitive environment.
Journal of the National Science Foundation of Sri Lanka, 2022
This study assessed marine turtle nesting habitats along the southeastern coastline of Sri Lanka, with the specific objectives of (i) reporting the quality of turtle nesting habitats, turtle nesting abundance, and threats to nesting turtles; (ii) comparing the current results with the results of a study conducted in 2004 and (iii) recommending conservation actions. The current study was carried out from August 2017 to May 2018 to assess the three parameters given in objective (i) above, along a 133 km coastal belt in 531 transects of 250 m each. Direct visual observations were supplemented with data collected from local people and validated using habitat suitability modelling using MaxEnt software. The study demarcated seven turtle nesting hotspots and recommends priority areas for nine turtle conservation activities. Those include the declaration of the Palatupana beach that connects the existing Nimalawa Sanctuary and Yala National Park including its shallow sea as a sanctuary. Its management is recommended through publicprivate partnerships ensuring healthy nesting turtle populations and their monitoring, while promoting turtle-based tourism under strict guidelines. Factors contributing adversely for nesting turtles such as coastal constructions and clearance of beach vegetation should be considered in management actions for the conservation of these globally threatened reptiles. The need for future research is also identified.