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Spatial comparison of the Maputaland leatherback , Dermochelys coriacea and loggerhead , Caretta caretta , turtles ’ internesting movements , and implications for management
| Content Provider | Semantic Scholar |
|---|---|
| Author | Vogt, Natasha Lee Scientiae, Baccalaureus Honores |
| Copyright Year | 2012 |
| Abstract | Sea turtles globally are under great threat, and their population numbers are decreasing. Loggerheads and leatherbacks, which both make use of iSimangaliso Wetland Park (iSimangaliso) as a nesting ground, are considered endangered and critically endangered respectively. Beach protection of nests and individuals has been implemented in the region in order to protect the turtles during the vulnerable nesting period. Despite the efforts being made the leatherback population has remained stable, whereas the loggerhead population has shown an increase in the population trend. It is therefore necessary to determine if the protection supplied by the protected area is sufficient for both species, by determining the distribution, home ranges and habitat and depth selection. It was found that loggerhead home ranges are 100% within the MPA, while leatherback home ranges are 8 % within the MPA, showing a significant difference from parity (X 2 = 86.00, df = 1, p < 2.2 x 10-16). Leatherback distribution is found to occur 25 % within the MPA during the internesting period, while loggerheads are found 99 % within the MPA, showing a significant difference from parity (X 2 = 42.8173, df = 1, p = 6.01 x 10-11). Distances travelled by leatherbacks are significantly further than the distance travelled by loggerheads during the internesting period (F = 16.45, p < 0.5) with a distance travelled of 187.90 ± 52.68 km (mean ± S.E) per nesting event while loggerheads travel a distance of 19.20 ± 4.06 km (mean ± S.E). Time intervals of nesting events were significant different between loggerheads and leatherbacks (F = 10.07, p < 0.5). Loggerhead individual nesting events last a greater time 16.89 ± 1.79 days, compared to leatherback nesting events which last 9.49 ± 0.67 days. Loggerheads select for habitat, with Natal Delagoa Reflective Sandy Coast being the greatest preferred habitat in home and core ranges (PI = 0.63). Leatherbacks having a wide range show no selection for habitat. Loggerheads remain in shallow waters close to shore, within 0-15 m in core and 0-20 m in home range, while leatherbacks show no preference for depth range. Protection offered by the MPA is insufficient to protect leatherbacks during the nesting period, but shows adequate protection for loggerheads. The MPAs and monitoring should be extended further south to offer adequate protection for leatherbacks, even if it is only during the internesting period. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://www.cbd.int/doc/meetings/mar/ebsa-sio-01/other/ebsa-sio-01-southafrica-06-en.pdf |
| Alternate Webpage(s) | http://www.biodiv.org/doc/meetings/mar/ebsa-sio-01/other/ebsa-sio-01-southafrica-06-en.pdf |
| Alternate Webpage(s) | http://www.cbd.int/doc/meetings/mar/ebsa-sio-01/other/ebsa-sio-01-southafrica-06-en.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
