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Garcia-Mendez K.,University of Costa Rica | Camacho-Garcia Y.E.,University of Costa Rica | Camacho-Garcia Y.E.,Research Center en Ciencias del Mar y Limnologia
Revista de Biologia Tropical | Year: 2016

The molluscan fauna of Isla del Coco has recently been well documented, but the heterobranch sea slugs, traditionally called “opisthobranchs”, remain poorly known. We report 13 new records, increasing the total to 40 species. Of the 13 newly discovered species, the following species had not been previously recorded along the Pacific Costa Rican mainland: Berthella californica (Dall, 1900), Peltodoris rubra (Bergh, 1905), Dendrodoris albobrunnea Allan, 1933, Doriopsilla cf. spaldingi Valdés & Behrens, 1998, Glaucus cf. marginatus (Reinhardt & Bergh, 1864), and Flabellina sp. Additionally, we report Peltodoris rubra, previously known from the Indo-Pacific, for the first time in the Eastern Tropical Pacific. © 2016, Universidad de Costa Rica. All rights reserved.

Lizano O.G.,Research Center en Ciencias del Mar y Limnologia | Alfaro E.J.,Research Center en Ciencias del Mar y Limnologia | Matarrita A.S.,University of Costa Rica
Revista de Biologia Tropical | Year: 2012

In order to evaluate metal enrichment in sediments, a method is proposed and tested in Bahia Culebra and the Golfo de Nicoya, Costa Rica through the normalization of the elements against aluminum, and by linear regréa Culebra did not satisfy the tests of normalization and linear regression, indicating a nonnatural distribution or enrichment of these elements in this region. In the Golfo de Nicoya the elements copper, zinc, rubidium and the strontium did not satisfy the test of normality or the linear regression with respect to aluminum, indicating a possible enrichment of these elements. The majority of the concentrations of the elements in two sample sites, with the exception of chromium, are within the natural ranges in rocks or clays of marine sediments, and within the concentration ranges of other studies done in these same regions. Chromium has average values beyond the natural concentrations, the values of some samples in the Golfo de Nicoya are up to 10 times greater than the concentration value of a typical bay with high contamination of this element.

Seguro I.,University of Cadiz | Garcia C.M.,University of Cadiz | Papaspyrou S.,University of Cadiz | Galvez J.A.,University of Cadiz | And 9 more authors.
Regional Studies in Marine Science | Year: 2015

Microplankton organisms are an important link in the transfer of matter and energy between the benthic-pelagic microbial food web and higher trophic levels in estuaries. Although tropical estuaries are among the most productive aquatic systems globally, information on the spatial and seasonal dynamics of microplankton in such systems is scarce. In order to identify which variables control microplankton abundance and community structure a number of environmental variables were measured along the tropical Gulf of Nicoya (Costa Rica) during the rainy and dry seasons (2011-2012). The Tempisque River was a major source of nutrients and turbidity and thus imposing a clear gradient along the estuary. Chlorophyll a (chl a) concentration was highest in the middle of the estuary (2.7-20 mg m-3), where turbidity decreased. The microplankton comprised mainly diatoms (88%) and dinoflagellates (8%). Multivariate analysis revealed five different microplankton assemblages associated with a seasonal and riverine-marine gradient, and supporting an ecotone model at the estuary head that shifts to an ecocline model for the rest of the estuary. Our results suggest that primary producers in the estuary were mainly limited by light rather than nutrients. © 2015 Elsevier B.V.

Alfaro E.J.,Research Center en Ciencias del Mar y Limnologia | Alfaro E.J.,University of Costa Rica | Cortes J.,Research Center en Ciencias del Mar y Limnologia | Cortes J.,University of Costa Rica
Revista de Biologia Tropical | Year: 2012

Bahía Culebra, at Gulf of Papagayo on the north Pacific coast of Costa Rica, is an area of seasonal upwelling where more intense cooling events may occur during some boreal winter weeks mainly. To study these extreme cool events, records of nine sea subsurface temperature stations from 1998 to 2010 were analyzed. Five events associated with extremely cool temperatures in this region were identified from these records and taken as study cases. Sea temperatures decreased about 8-9°C during these events and occurred while cold fronts were present in the Caribbean, with strong trade wind conditions over Central America. These strong wind conditions may have favored the offshore displacement of the sea surface water. The axis of Bahía Culebra runs northeastsouthwest, a condition that favors and triggers cool water events, mainly because the displaced water is replaced by water from deeper levels.

Alfaro E.J.,Research Center en Ciencias del Mar y Limnologia | Alfaro E.J.,University of Costa Rica | Cortes J.,Research Center en Ciencias del Mar y Limnologia | Cortes J.,University of Costa Rica | And 8 more authors.
Revista de Biologia Tropical | Year: 2012

Bahía Culebra, Golfo de Papagayo, Costa Rica is a seasonal upwelling area. To determine the relationship of climate and the subsurface temperature variability at Bahía Culebra, we analyzed nine records of sea subsurface temperature from the Bay, continuously recorded from 1998 to 2010. The analysis characterized the annual cycle and explored the influence of different climate variability sources on the subsurface sea temperature and air temperature recorded in Bahía Culebra. Data from an automatic meteorological station in the bay were studied, obtaining the annual and daily cycle for air surface temperature and wind speed. Sea surface temperature (SST) trend from 1854 to 2011 was calculated from reanalysis for the region that coverts 9-11°N, 85-87°W. Because of the positive SST trend identified in this region, results showed that annual and daily cycles in Bahía Culebra should be studied under a warming scenario since 1854, that is coherent with the global warming results and its climate variability is influenced by El Niño-Southern Oscillation (ENSO) in the Equatorial Pacific and by atmospheric forcing triggered by climate variability with Atlantic Ocean origin, because warm (cold) events in Bahía Culebra tend to occur in concordance with positive & negative (negative & positive) anomalies in Niño 3.4 (NAO) index.

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