Anadón, Verónica, Carlos Delannoy, Adrianne Tossas, José Cancel, Hector Ríos, Emanuel Sánchez, Gustavo González, Michelle Marti, Edward Pérez, Jeiger Medina, Rolando Saavedra, Marisel Sánchez, Mariela Valle, Amaralis Cuevas, Daniel Domínguez, Zoraida



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Anadón, Verónica, Carlos Delannoy, Adrianne Tossas, José Cancel, Hector Ríos, Emanuel Sánchez, Gustavo González, Michelle Marti, Edward Pérez, Jeiger Medina, Rolando Saavedra, Marisel Sánchez, Mariela Valle, Amaralis Cuevas, Daniel Domínguez, Zoraida Sotomayor, Sindiali Acosta e Ixia Avilés.

Universidad de Puerto Rico, Recinto de Mayagüez, Departamento de Biología, P.O. Box 9012, Mayagüez, Puerto Rico 00681-9012. veroanadon1@hotmail.com



DISTRIBUCIÓN, DENSIDAD Y HÁBITATS DE LA REINITA DE BOSQUE ENANO (Dendroica angelae) EN PUERTO RICO

Endémica a Puerto Rico, la Reinita de Bosque Enano (RBE) es considerada amenazada y se encuentra en los bosques montañosos. Descubierta en el Bosque Nacional del Caribe en el 1971 y posteriormente en Maricao, Carite y Toro Negro, desde entonces, no se había hecho ningún estudio sobre su distribución ni el estado actual de las poblaciones. Este proyecto determinó la distribución geográfica actual, hábitats y densidad de las poblaciones. Además se hicieron recomendaciones sobre su estatus para su protección y conservación. El estudio se realizó de marzo a noviembre de 2003 en la Cordillera Central (Maricao, Toro Negro, Guilarte y Bosque del Pueblo), Bosque de Carite y en el Bosque Nacional del Caribe. Se utilizó el método de conteo de puntos, en donde cada estación estaba separada por 200 m, colocadas en diferentes hábitats. Nuestros resultados indican que la RBE está restringida a dos poblaciones, en Maricao en el oeste y el Bosque Experimental de Luquillo en el este de la isla. Encontramos RBE en bosques de Arboleda Expuesta, de Pendientes Secas y de Podocarpus en Maricao. En Luquillo la encontramos en Bosque Enano, Palo Colorado y Bosque de Tabonuco. Los estimados poblacionales de la RBE fueron: 1142 en el Bosque de Maricao y 688 en el Bosque de Luquillo. En conclusión la RBE tiene una muy limitada distribución en Puerto Rico, restricta a un número reducido de hábitats y en densidades bajas. Dado estos resultados recomendamos que la especie debe ser clasificada en peligro de extinción y protegida por el Acta de Especies en Peligro de Extinción.


Burrowes, Patricia A. and Rafael L. Joglar

Department of Biology, University of Puerto Rico, P.O. Box 23360, San Juan, P.R. 00931-3360



THE ROLE OF CLIMATE CHANGE AND DISEASE AS POTENTIAL STRESSORS ASSOCIATED WITH AMPHIBIAN DECLINES IN PUERTO RICO

We monitored 11 populations of eight species of Eleutherodactylus in Puerto


Rico from 1989 through 2001. We determined densities of active frogs along
transects established in the Caribbean National Forest (El Yunque), Carite
Forest, and San Lorenzo, as well as in the vicinity of San Juan. Three
species (Eleutherodactylus karlschmidti, E. jasperi and E. eneidae) are
presumed to be extinct and eight populations of six different species of
endemic Eleutherodactylus are significantly declining at elevations above
400 m. Of the many suspected causes of amphibian declines around the world,
we focused on climate change and disease. Temperature and precipitation data
from 1970-2000 were analyzed to determine the general pattern of
oscillations, and deviations that could be correlated with amphibian
declines. We examined a total of 106 tissues taken from museum specimens
collected between 1961 and 1978, and from live frogs in 2000, and found
chytrid fungi in two species collected at El Yunque as early as 1976. This
is the first report of chytrid fungus in the Caribbean. Analysis of weather
data indicates a significant warming trend, and an association between years
with extended periods of drought and the decline of amphibians in Puerto
Rico. The 1970s and 1990s which represent the periods of amphibian
extirpations and declines, were significantly drier than average. We suggest
a possible synergistic interaction between drought and the pathological
effect of the chytrid fungus on amphibian populations.

Cabarcas, Alexis and Dallas E. Alston

Department of Marine Sciences, PO Box 9013, University of Puerto Rico, Mayagüez Campus, Mayagüez, PR 00681-9013 USA


ENVIRONMENTAL IMPACT OF SUSTAINABLE OFFSHORE CAGE CULTURE IN PUERTO RICAN WATERS

Overexploitation of marine resources and increased population has caused worldwide fisheries depletion, including those of the Caribbean. Fisheries operations in Puerto Rico have exceeded maximum sustainable yield due to coastal ocean pollution, over-fishing, and destruction of suitable essential fish habitat for native species. Local government incentives to fishermen exacerbate the exploitation of over-fished reef-based fisheries. However, the local Puerto Rican fishery supplies less than 5% of the demand for seafood. Thus aquaculture projects are emerging as an alternative to: diminish the pressure on the natural fisheries, increase seafood production, reduce imports of fisheries products, and increase revenues. A private company (Snapperfarm, Inc.) and the University of Puerto Rico are evaluating the environmental and economical feasibility of two submerged open ocean cages at Culebra, Puerto Rico, which are culturing mutton snapper (Lutjanus analis) and cobia (Rachycentron canadum) from August 2002. Both cobia and mutton snapper has exhibited very good potential for commercial aquaculture development in net cages in the Caribbean and tropical waters. Cobia exhibits extraordinary rates of development and growth, growing to an average of 6.0 kg (13.3 lb) in one year, ranging in size from 1.8 - 9.1 kg (4-20 lb). Survival rate was 80%, and feed conversion rate (FCR) was 2:1. The environmental component has evaluated the eutrophication of the water column and the sediment since June, 2002, by monitoring physical, chemical, and environmental variables. Such variables include changes in water and sediments nutrients, chlorophyll-a concentrations, dissolved oxygen, water temperature, turbidity, changes in benthic macroinvertebrates, and impact on the fish fauna. The carrying capacity of the environment to transform and assimilate nitrogen and phosphorus will help to determine the extension of pollution near the cages. The hypothesis was that there will be little net accumulation of contaminants (nitrogen and phosphorus) around the cages and little release of these wastes downstream. The wastes produced by the caged fish will be consumed by fouling organisms attached to the surface of the net, by wild fauna around the cages, and by benthic organisms. Until now, no noticeable environmental impact has been detected in the water and bottom surrounding the cages. There were no overall statistical differences for ammonia-N, nitrite-N, nitrate-N, phosphate concentrations in the water, organic matter or organic nitrogen in the sediments when comparing cages with the control site. Variables in the sampling sites near the cages were similar to background levels. Temporal differences appeared to be seasonal differences affecting both cages and control site equally. There is no evidence of anaerobic sediments beneath the cages as indicated in the results and the appearances of the sediments.



Cantrell, Sharon A.

Universidad del Turabo, Science & Technology, P. O. Box 3030, Gurabo, P. R 00778. scantrel@suagm.edu



A COMPARISON OF TWO SAMPLING METHODS TO ASSESS DISCOMYCETE DIVERSITY IN WET TROPICAL FORESTS.

Most of the diversity studies that incorporated a systematic collecting scheme have not included discomycetes, so optimal sampling methods are not available. I tested two sampling methods in el Yunque, CNF, Puerto Rico and Ebano Verde, Dominican Republic. For a plot-based method, 10 x 10 m plots were established, divided into one-hundred 1 x 1 m subplots. For each sample, 12 subplots were selected at random. For a transect-based method, 60 m long transects were established with twelve 1 x 1 m subplots randomly placed at 5 m intervals at the beginning of the study. The study was conducted from October 2001 to September 2002. For Puerto Rico, 46 and 51 species were identified in transects and plots, respectively. There was a 68% complementarity between sites. The Sorensen Coefficient between sites was 0.50 for both methods, and 0.55-0.63 between methods within sites. For the Dominican Republic, 25 and 26 species were identified in transects and plots, respectively. There was a 69-76% complementarity between sites. The Sørensen Coefficient between sites was 0.40-0.47 for transects and plots, respectively, and 0.40-0.70 between methods within sites. The species accumulation curve indicates that the minimum number of subplots needed is 10 per transect and 60-70 per plot to obtain 70-80% of the species. At least 12 samples distributed throughout a year but with shorter intervals during the rainy season are needed. Based on a Chi-Square analysis using the frequencies of species, transects were better that plots because the distribution of species is more homogeneous.



Caraballo Ortiz, Marcos A. y Eugenio Santiago-Valentín

Departamento de Biología, Universidad de Puerto Rico-Río Piedras, Apartado 23360 San Juan, Puerto Rico 00931-3360 - Herbario, Jardín Botánico, Universidad de Puerto Rico

Apartado 364984 San Juan, Puerto Rico 00936-4984

COMPARACIÓN DE LA EFECTIVIDAD DE POLINIZACIÓN DE UN AVE (Coereba flaveola) Y UNA ABEJA (Apis mellifera) EN Goetzea elegans (SOLANACEAE), UN ÁRBOL EN PELIGRO DE EXTINCIÓN
Muchas plantas en peligro de extinción enfrentan problemas en su biología reproductiva, situación que puede limitar su conservación efectiva. Goetzea elegans es un árbol endémico de Puerto Rico que se encuentra amenazado. Sus flores son visitadas por vertebrados como invertebrados, incluyendo especies nativas como exóticas. En este estudio se compara la efectividad de polinización entre un polinizador exótico (Apis mellifera) uno nativo (Coereba flaveola) en G. elegans. Datos preliminares indican que ambas especies polinizan a G. elegans, pero las mismas difieren en su efectividad de polinización. Esta diferencia puede deberse al comportamiento de cada polinizador al momento de visitar las flores. C. flaveola visita más árboles con menos tiempo de visita por flor, a diferencia de A. mellifera, que visita menos árboles con mayor tiempo de duración por flor. Debido a que G. elegans es mayormente autoincompatible, la diferencia en efectividad de transferencia de polen podría tener relevancia en la preservación de la especie.

Carbery, Kelly; Rivera-Torres, Yaritza and Ernesto Otero-Morales

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