Isla Del Coco National Park Research Articles

Ultraviolet radiation at Isla del Coco (Cocos Island) National Park, Costa Rica.

<p>Incoming solar energy that reaches the land surface is divided mainly in infrared, visible and UV. UV radiation has wave lengths from 100 to 400 nm. The World Health Organization recommends studies and monitoring of UV radiation because of its biological effects in living organisms.<strong> </strong>The use of automatic Davis weather stations, Vantage Pro Plus/Vantage Pro2 Plus type, with a sensor model 6490, allowed UV radiation measurements at Isla del Coco, Costa Rica, located in the Eastern Tropical Pacific. The stations were set near Chatham Bay (5°32’51” N - 87°02’43” W, 142 m.a.s.l) and Wafer Bay (5°32’24” N - 87°03’26” W, 132 m.a.s.l). Measurements were recorded: Apr. 5-11, 2008, Mar. 1-6, 2009, Apr. 22-27, 2010, Jul. 2-8, 2011 and Mar. 15-21, 2012. Data were described for the cloudiest and sunniest days according to the UV index (UVI) as a standardized value that allows easy data interpretation in terms of the hazard exposure for living beings. This is especially important for coral reefs (the island has the largest Pacific reefs in Costa Rica). The maximum UVI average range in Chatham decrease from 14 for sunny days to 3 for cloudy days, and from 16 to 4 for the sunniest and cloudiest days, respectively. In Wafer, these values were 12 to 4 and 14.2 to 3.0, respectively. The average exposure to UV radiation was considered high for sunny days from 9:30 to 14:30hr in Chatham and from 10:00 to 14:30 in Wafer, but these values for the sunniest days increase from 9:00 to 15:00 in Chatham and from 9:00 to 14:30 in Wafer. The equipment used was able to identify events with extremely high UVI values during the expeditions. The generation and use of this information is useful for understanding and modeling the ecosystem dynamics, and it is also valuable for the rangers’ work and for the tourism sector.</p><div> </div>

First record of the genus Paracaristius (Perciformes: Caristiidae) from the Pacific of Central America, with comments on their association with the siphonophore Praya reticulata (Siphonophorae: Prayidae)

Manefish are not very common and there are few observations of associations with other organisms. An adult of the manefish Paracaristius maderensis and a juvenile of Paracaristius sp. are reported for the first time for the Pacific coast of Central America. The adult specimen (215 mm standard length) was captured off Panama, at a depth of 1000 m. The juvenile specimen (17.5 mm standard length) was recorded on video, in association with the siphonophore Praya reticulata at Isla del Coco National Park, Costa Rica, at a depth of 100 m. A brief description of specimens supporting this record as well as comparative morphometric data and distributional information are provided. The fish–siphonophore association is illustrated.

New records of sea anemones (Cnidaria: Anthozoa) from Costa Rica

Despite being important components in coastal marine systems, sea anemones have been poorly studied on both coasts of Costa Rica. In this paper new records of sea anemones are mentioned for the Caribbean and Pacific coasts of Costa Rica and the Isla del Coco National Park. Additionally, the presence of other species previously recorded in Costa Rica based on single observations or photos, is reconfirmed. An updated inventory of these cnidarians is provided, and with the corallimorpharians, comprises of 16 species (10 in the Caribbean and 6 in the Pacific and Coco Island). A comparison with the sea anemone fauna of Panama is added.

Flora marina del Parque Nacional Isla del Coco, Costa Rica, Pacífico Tropical Oriental

Marine flora of Isla del Coco National Park, Eastern Tropical Pacific. A preliminary description of the marine flora around Cocos Island is presented, with base line information on ecological data to evaluate future long-term changes. Data were collected in two expeditions to Cocos Island (September 2006 and January 2007). The macroalgae were removed with a knife and preserved in a solution of buffered 4% formalin. To determine cover percent three 10 m-transects were sampled at two depths (6 and 15 m), at five sites. A total of 42 morphs were found of which 29 were identified to species level. Ten species belong to Chlorophyta (green algae), including genera with wide distribution, such as Ulva, Cladophora and Caulerpa. Six species belong to the Phaeophyta (brown algae), in two families (Sytosiphonaceae and Dictyotaceae). Rhodophyta (red algae) was the most diverse group of macroalgae at Cocos Island, with 13 species. The macroalgae cover average was 50.7 ± 27.4% at 6 m and 47.1 ± 16.1% at 15 m. The algae with greater coverage and greater distribution around the island were Cladophora sp., Dictyota sp., Polysiphonia sp. and the calcareous algae (41% of cover in some sites). Macroalgae represent a large percentage of the benthic reef environments and play important ecological roles. Rev. Biol. Trop. 56 (Suppl. 2): 57-69. Epub 2008 August 29.