Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-23T03:56:19.321Z Has data issue: false hasContentIssue false
  • English
  • Français

Aerial and snorkelling census techniques for estimating green turtle abundance on foraging areas: A pilot study in Mayotte Island (Indian Ocean)

Published online by Cambridge University Press:  15 July 2005

David Roos ,
Dominique Pelletier ,
Stéphane Ciccione ,
Marc Taquet  and
George Hughes
David Roos
Affiliation:
Laboratoire Ressources Halieutiques, Ifremer, BP 60, 97822 Le Port Cedex, France
Dominique Pelletier
Affiliation:
Laboratoire MAERHA, IFREMER, BP 21105, 44311 Nantes Cedex 3, France
Stéphane Ciccione
Affiliation:
Centre d'Étude et de Découverte des Tortues Marines de La Réunion, BP 40, 97898 St-Leu Cedex, France
Marc Taquet
Affiliation:
Laboratoire Ressources Halieutiques, Ifremer, BP 60, 97822 Le Port Cedex, France
George Hughes
Affiliation:
4 Thorngate Road Pietermaritzburg 3201, South Africa
Get access

Abstract

Monitoring the abundance of green turtles (Chelonia mydas) is necessary to assess population trends and risks of collapse. This note presents a study aimed at comparing three techniques for the direct estimation of green turtle numbers in their foraging habitats (seagrass beds and reef flats). The experiment was carried out at Mayotte Island, Western Indian Ocean. The techniques involved were surveys by snorkel, and aerial surveys using a microlight aircraft and a paramotor. Each technique had shortcomings and advantages. While each technique provided estimations of turtle numbers only surveys by snorkel permitted identification of species and sex, whenever visibility and turtle behaviour permitted. Along the shorelines, and over foraging areas, the paramotor was found to be most suitable for direct estimations of turtle numbers. The major advantage of this technique lied in its capability to obtain a synoptic snapshot of turtle distribution over foraging areas. Linear surveys from a microlight aircraft are better suited to monitor foraging areas located further away from the shore.

Keywords

Green turtleChelonia mydasAbundance estimationAerial surveySnorkelling surveyForaging habitats
Type
Research Article
Information
Aquatic Living Resources , Volume 18 , Issue 2 , April 2005 , pp. 193 - 198
Copyright
© EDP Sciences, IFREMER, IRD, 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bjorndal K.A., Bolten A.B., 2000, Proceedings of a workshop on assessing abundance and trends for in-water sea turtle populations. NOAA Technical Memorandum NMFS-SEFSC-445.
Braun, J., Epperly, S.P., 1996, Aerial surveys for sea turtles in Southern Georgia waters, June, 1991. Gulf Mexico Sci. 14, 39-44.
Crouse, D.T., 1984, Loggerhead sea turtle nesting in North Carolina: Applications of an aerial survey. Biol. Conserv. 29, 143-155. CrossRef
Epperly, S.P., Braun, J., Chester, A.J., 1995a, Aerial surveys for sea turtles in north Carolina inshore waters. Fish. Bull. 93, 254-261.
Epperly, S.P., Braun, J., Chester, A.J., Cross, F.A., Merriner, J.V., Tester, P.A., 1995b, Winter distribution of sea turtles in the vicinity of Cape Hatteras and their interactions with the summer flounder trawl fishery. Bull. Mar. Sci. 56, 547-568.
Frazier J., 1985, Marine turtles in the Comoros Archipelago. Amsterdam, North Holland.
Fritts, T.H., Hoffman, W., McGehee, M.A., 1983, The distribution and abundance of marine turtles in the Gulf of Mexico and nearby Atlantic waters. J. Herpetol. 17, 327–344. CrossRef
Fritz, T.H., Stinsin, M.L., Marquez, M.R., 1982, Status of sea turtle nesting in southern Baja California, Mexico. Bull. South. Calif. Acad. Sci. 81, 51-60.
Gerrodette T., Taylor B.L., 1999, Estimating population size. In: Eckert K.L., Bjorndal K.A., Abreu Grobois F.A., Donnelly M. (Eds.). Research and management techniques for the conservation of sea turtles, pp. 67-71. IUCN/SSC Marine Turtle Specialist Group Publication.
Gibson J., Smith G., 1999, Reducing threats to foraging Habitats. Research and management techniques for the conservation of sea turtles. In: Eckert K.L., Bjorndal K.A., Abreu Grobois F.A., Donnelly M. (Eds.). Research and management techniques for conservation of sea turtles, pp. 184-188. IUCN/SSC Marine Turtle Specialist Group Publication.
Henwood T.A., Epperly S.P., 1999, Aerial surveys in foraging habitats. In: Eckert K.L., Bjorndal K.A., Abreu Grobois F.A., Donnelly M. (Eds.). Research and management techniques for conservation of sea turtles, pp. 65-66. IUCN/SSC Marine Turtle Specialist Group Publication.
Heppell, S.S., Limpus, C.J., Crouse, D.T., Frazer, N.B., Crowder, L.B., 1996, Population model analysis for the loggerhead sea turtle, Caretta caretta, in Queensland. Wildl. Res. 23, 143-159. CrossRef
Hykle D., 1999, International conservation treaties. In: Eckert K.L., Bjorndal K.A., Abreu Grobois F.A., Donnelly M. (Eds). Research and management techniques for conservation of sea turtles, pp. 228-231. IUCN/SSC Marine Turtle Specialist Group Publication.
Le Gall, J.Y., Bosc, P., Chateau, D., Taquet, M., 1986, An estimation of the number of adult females of green turtles Chelonia mydas per nesting season at Tromelin and Europa (Indian Ocean) (1973-1985). Oceanogr. Trop. 21, 3-22.
Meylan, A., Meylan, P., Ruiz, A., 1985, Nesting of Dermochelys coriacea in Caribbean Panama. J. Herpetol. 19, 293-297. CrossRef
Mortimer, J.A., 1988, Green turtle nesting at Aldabra atoll - Population estimates and trends. Biol. Soc. Wash. 8, 116-128.
Oravetz C.A., 1999, Reducing Incidental catch in fisheries. Research and management techniques for the conservation of sea turtles. In: Eckert K.L., Bjorndal K.A., Abreu Grobois F.A., Donnelly M. (Eds.). Research and management techniques for the conservation of sea turtles, pp. 189-193. IUCN/SSC Marine Turtle Specialist Group Publication.
Reese, D.A., Welsh, H.H Jr., 1998, Comparative demography of Clemmys marmorata populations in the Trimity river of California in the context of Dam-induced alterations. J. Herpetol. 32, 505-515. CrossRef
Sale P.F., 2002, Coral reef fishes, Elsevier Science.
Sauvignet, H., Pavitrin, A., Cicionne, S., Roos, D., 2000, Premiers résultats des campagnes de dénombrements aériens des tortues marines sur la côte ouest de La Réunion. Bull. Phaeton. 11, 8-18.
Shoop, C.R., Kenney, R.D., 1992, Seasonal distributions and abundances of loggerhead and leatherback sea turtles in waters of the northeastern United States. Herpetol. Monogr. 6, 43–67. CrossRef
Schroeder, B.A., Thompson N.B., 1987, Distribution of the loggerhead turtle, Caretta caretta, and the leatherback turtle, Dermochelys coriacea, in the Cape Canaveral, Florida area: results of aerial surveys. In: W.N. Witzell (Eds.), Ecology of East Florida sea turtles: Proceedings of the Cape Canaveral, Florida, sea turtle workshop, pp. 45-53. US Dep. Commer., NOAA Tech. Rep. NMFS 53.
Schroeder B., Murphy S., 1999, Population surveys (ground and aerial) on nesting beaches. In: Eckert K.L., Bjorndal K.A., Abreu Grobois F.A., Donnelly M. (Eds.). Research and management techniques for the conservation of sea turtles, pp. 45-55. IUCN/SSC Marine Turtle Specialist Group Publication.
Wibbels, T., 1999, Diagnosing the sex of sea turtles in foraging habitats. In: Eckert K.L., Bjorndal K.A., Abreu Grobois F.A., Donnelly M. (Eds.). Research and management techniques for the conservation of sea turtles, pp. 139-143. IUCN/SSC Marine Turtle Specialist Group Publication.