Poblaciones de tiburones en las bahías Chatham y Wafer del Parque Nacional Isla del Coco, Costa Rica

Abstract

Shark populations in Chatham and Wafer bays, Isla del Coco National Park, Costa Rica. At least fourteen species of sharks live in the Marine Protected Area of Isla del Coco National Park (ICNP), some are resident species such as the whitetip reef shark (Triaenodon obesus); others are migratory and visit the National Park throughout the year, e.g. the scalloped hammerhead shark (Sphyrna lewini) and the whale shark (Rhincodon typus). Between March 2010 and August 2012 six expeditions out to the ICNP were carried, during this period 25 night trips (from 18:00 to 22:00 hr) for shark tagging were conducted in the Wafer and Chatham bays. During those trips, 185 sharks were analyzed: 81.1 % were whitetip reef sharks (T. obesus), 16.7 % were blacktip sharks (Carcharhinus limbatus), 1.1 % were blacktip reef sharks (Carcharhinus melanopterus) and 1.1% were silvertip sharks (Carcharhinus albimarginatus). The most common species in Bahía Chatham was T. obesus, while the most common one in Bahía Wafer was C. limbatus, which represented 80.9 % and 80.5 % of the total sharks caught, respectively. Regarding T. obesus, a sex ratio of 1.2 males per female was estimated (X 2 =0.09; p=0.17); in turn a sex ratio of 1.01 males per female was observed (X 2 =0.04; p=0.79) for C. limbatus. The average total length for T. obesus and C. limbatus was 103.66±13.91 cm and 76.58±14.56 cm respectively; suggesting that black tip sharks use those bays during immature stages. The results show an interspecific spatial segregation of the most common resident sharks at ICNP, apparently the clear waters and the coral cover of Chatham Bay are preferred by T. obesus; while the turbid waters of the Genio River mouth are preferred by C. limbatus. Rev. Biol. Trop. 64 (Suppl. 1): S177-S186. Epub 2016 February 01.

Investigación para la toma de decisiones de manejo en áreas marinas protegidas como la Isla del Coco, Costa Rica

“…La Isla del Coco se caracteriza por contar con varias especies pelágicas residentes y migratorias (Sibaja-Cordero, 2008;Friedlander et al, 2012;Fourriére, Alvarado, Ayala-Bocos, & Cortés, 2016), donde los tiburones son uno de los grupos más atractivos en términos de investigación científica (p.ej. Bessudo et al 2011a;Bessudo et al, 2011b;Zanella, López-Garro, Golfín-Duarte, & Saenz, 2012;Arauz & Hearn, 2014;White et al, 2015, Zanella, 2015Zanella, López-Garro, Martínez, Golfín-Duarte, & Morales, 2015). Por facilidad logística, los estudios de tiburones en la región del Pacífico Tropical Oriental se han concentrado principalmente en los alrededores de las islas (Isla del Coco en Costa Rica, Archipiélago de Galápagos en Ecuador, e Isla Malpelo en Colombia).…”

Residencia del tiburón punta blanca de arrecife, Triaenodon obesus, (Carcharhiniformes: Carcharhinidae) en las bahías Chatham y Wafer del Parque Nacional Isla del Coco, Costa Rica

“…Estudios poblaciones previos de marcaje de captura y recaptura, sugieren que T. obesus no realiza grandes movimientos y que prefiere las aguas cristalinas y con cobertura coralinas presentes en Bahía Chatham, con respecto a las aguas turbias de Bahía Wafer (Zanella, López, Martínez, Golfín, & Morales 2016). A pesar de ser una especie abundante en las bahías Chatham y Wafer del PNIC a lo largo del año, la información sobre su residencia y fidelidad resulta escasa.…”