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6 resultados encontrados para: AUTOR: Perera Valderrama, Susana
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Resumen en: Inglés |
Resumen en inglés

Marine protected areas (MPAs) conserve diversity and abundance of fish communities. According to the biotic resistance hypothesis, communities with higher diversity and abundance should resist invasions better. To test this idea, the presence of lionfish in two Caribbean MPAs was studied: Parque Nacional Guanahacabibes (PNG) in Cuba and Parque Nacional Arrecifes de Xcalak (PNAX) in Mexico. Selection of these MPAs was based on both their different levels of success with enforcement and different abundances of native fish, with a more abundant native fish fauna at PNG. Underwater visual censuses were used to evaluate both the native fish structure and composition and at the same time distribution and abundance of lionfish. The abundance of potential predators on lionfish was also measured to determine possible effects of lionfish on both the abundance and the size of its prey and competitors. Lionfish showed higher abundance and larger size in PNG compared to PNAX, even though its probable competitors and predators were also more abundant and larger in PNG. Prey abundance and size decreased after the invasion. No correlation was detected between potential predators and lionfish, which might indicate natural predation is not substantial. In PNAX, lower abundance of prey, potential competitors and predators can also be attributed to historical overfishing, but this did not provide an advantage to lionfish. Lionfish were less abundant and reached smaller sizes in PNAX compared to PNG. This work confirms the effectiveness of lionfish culling at PNAX, but does not support the biotic resistence hypothesis that native fish might have controlled this invasive species.


2.
- Artículo con arbitraje
Resumen en español

El pez león (Pterois volitans) invadió la región del Caribe y tiene el potencial de alterar la composición y estructura de las comunidades de peces en los arrecifes coralinos. El objetivo de este estudio fue analizar los índices de diversidad en las comunidades de peces nativos en sitios invadidos por el pez león en dos áreas marinas protegidas (AMP) del Caribe y compararlos con datos previos a la invasión. En ambas AMP, Parque Nacional Guanahacabibes (PNG) en el occidente de Cuba y Parque Nacional Arrecifes de Xcalak (PNAX) en el S de Quintana Roo, se realizaron censos visuales de las especies de peces en hábitats durante las épocas de seca y lluvia del 2013-2015. Se evaluaron nueve sitios, mediante conteos estacionarios. Se registró mayor riqueza de especies en el PNG (43.47±5.14) que en el PNAX (40.22±4.96). No se observaron diferencias entre épocas en ninguna de las AMP. El pez león se ubicó entre las especies más abundantes del PNG. La abundancia media en el PNG (0.76 ± 1.25) fue mayor a la registrada en el PNAX (0.19±0.46). La diversidad disminuyó después de la llegada del pez león en un solo sitio del PNG y en dos sitios del PNAX, pero al parecer estos resultados están más asociados al efecto de la pesca que a la presencia del pez león. A partir de los resultados y asumiendo que los cambios en las comunidades de peces por el pez león podrían no detectarse aún, recomendamos seguir los monitoreos de los descriptores comunitarios para detectar cambios futuros en las comunidades de peces.

Resumen en inglés

Lionfish (Pterois volitans) invaded the Caribbean region with the potential to alter the composition and structure of native coral reef fish communities. The objective of this study was to analyze the diversity indices of these fish communities potentially affected by lionfish predation and to compare with pre-invasion data. The study was undertaken in two Caribbean marine protected areas (MPAs): Guanahacabibes National Park (PNG) in W Cuba and Xcalak Reefs National Park (PNAX) in S Quintana Roo. We carried out visual censuses of fish species in reef habitats during the dry and rainy seasons of the period 2013-2015. For this, nine sites were defined and evaluated using stationary counts. Our results showed higher species richness (43.47 ± 5.14) and mean abundance (0.76 ± 1.25) in PNG than in PNAX (40.22 ± 4.96, 0.19 ± 0.46, respectively). Diversity decreased after the arrival of lionfish in a single site of PNG and in two sites of the PNAX, but apparently, these results are more related to the fishing activity effect than to the lionfish presence. Based on the results and assuming that changes in the native fish communities by lionfish may not yet be detected, we recommend to continue the monitoring community descriptions in order to detect future changes in native fish communities.


3.
- Artículo con arbitraje
Resumen en: Inglés |
Resumen en inglés

This study assessed the coral reef condition of two marine protected areas in the Caribbean: Guanahacabibes National Park, Cuba, and Costa Occidental de Isla Mujeres-Punta Cancun-Punta Nizuc National Park, Mexico, in a two-year period. The analyzed indicators for corals were live coral cover, diameter and height of the colonies, ancient and recent mortalities and abundance of recruits, which were evaluated in quadrats of 1 m² . In addition, it was estimated the coverage by morphofunctional groups of macroalgae in 25 × 25 cm quadrats and the density of the Diadema antillarum urchin in 1 m² quadrats. The results showed differences between countries at broad spatial scales (hundreds of kilometers). Reefs of both MPAs seem to be in different stages of changes, which have been associated with deterioration of Caribbean reefs, toward the dominance of more resistant, non-tridimensional coral species, causing a decrease of the reef complexity that may leads to the reefs to collapse. At scales of kilometers (within MPAs), a similar pattern was found in reefs of GNP-Cuba and different trends were observed in reefs of CNP-Mexico. The observed differences between CNP-Mexico sites appear to be associated with the current tourism use patterns.


Resumen en: Inglés |
Resumen en inglés

Knowledge of the current condition of reef communities is essential for the implementation of marine protected areas (MPAs). In 2014, we assessed the conditions of reefs of two MPAs in the Caribbean: Guanahacabibes National Park (Guanahacabibes), Cuba and Costa Occidental de Isla Mujeres - Punta Cancun - Punta Nizuc National Park (Cancun), Mexico. Within each of the two MPAs studied, we examined two reefs. We took data from fifteen 10-m long transect lines. Indicators included coral cover, diameter of coral colonies, old and recent coral mortalities and coral diseases. The abundance of coral recruits and the density of Diadema antillarum were assessed in 1 m2 quadrats. The cover of groups of macroalgae was obtained from 25 25 cm quadrats. Our data illuminated distinct stages in the loss of reef structure similar to what has been seen by other investigators, particularly the change in the dominance of coral species and the deterioration of the three-dimensional structure of reefs. The Cuevones site (in Cancun), which has been closed to tourism for fifteen years, remains dominated by corals, with a high coral cover (33.36%), but with a species dominance (principally Porites astreoides), different from the lead species observed in the Caribbean a few decades ago. The reefs of Guanahacabibes (Laberinto and Yemaya) subject to a low diving intensity appear to be at an earlier stage of changes than the Cancun reefs. The coral indicators remains similar to previous reports, so perhaps this can be slowed or reversed. Meanwhile, Manchones in Cancun showed the lowest coral cover (11.49%) and the lowest recruit density (0.6 recruits/m2), probably due to the joint action of the natural pressures and to the heavy influx of visitors these reefs receive.


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Resumen en: Inglés |
Resumen en inglés

The Indo-Pacific lionfish Pterois volitans is an invasive species that was first recorded in the Guanahacabibes National Park (GNP), a marine protected area in western Cuba, in 2009. In order to determine the invasion progression of this species, we studied lionfish abundance, size, and diet at 6 sites in the GNP between 2010 and 2014. The species’ density, biomass, and length increased over this period, probably due to the abundance of food and shelter in the GNP. Analysis of stomach contents indicated that lionfish fed primarily on fish and crustaceans; main prey were teleosts, predominantly Gobiidae, Pomacentridae, Mullidae, Labridae, Scaridae, and Grammatidae. This example of a rapid increase in an unmanaged population at the onset of invasion provides information that can be used to design a management program targeting lionfish.


6.
Tesis - Doctorado
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Índice | Resumen en: Español |
Resumen en español

El propósito de este trabajo fue evaluar la condición de arrecifes de dos áreas marinas protegidas del Caribe con diferentes escenarios de manejo: Parque Nacional Guanahacabibes (PNG) en Cuba y Parque Nacional Costa Occidental de Isla Mujeres - Punta Cancún - Punta Nizuc (PNC) en México. Se contrastó la condición de comunidades bénticas de dos parches arrecifales con diferente intensidad de uso turístico en el PNC. Se evaluó el efecto de la introducción de fragmentos de colonias de A. cervicornis sobre comunidades bénticas de estos parches del PNC, comparando el área de restauración con una zona de referencia. Los indicadores analizados para los corales fueron cobertura viva, talla, mortalidades antigua y reciente y abundancia de reclutas, los cuales se evaluaron mediante transectos lineales de 10 m y cuadros de 1 m2. Además, se estimó la cobertura por grupos morfofuncionales de macroalgas en cuadros de 25 x 25 cm y la densidad del erizo Diadema antillarum en cuadros de 1 m2. Los indicadores evaluados mostraron un comportamiento diferente entre países. Asimismo, se detectaron tendencias similares en los indicadores analizados, entre los arrecifes del PNG y diferentes entre arrecifes y entre condiciones (Restauración y Referencia) del PNC. Las diferencias observadas entre sitios del PNC parecen estar asociadas a los patrones de uso actual. Los arrecifes estudiados representan la condición actual de deterioro del Caribe, pero se encuentran en etapas diferentes de los cambios descritos, con el PNC en una etapa más adelantada. Los indicadores de cobertura coralina, densidad de colonias, reclutamiento, están mejorando (aumento de cobertura de coral y densidad de colonias, incremento en el reclutamiento) debido a la introducción directa de fragmentos de A. cervicornis, pero al parecer la restauración no está siendo tan efectiva en el sitio Manchones, debido al exceso de visitación.

Índice

Capítulo 1. Introducción general
1.1. Estado actual de los arrecifes coralinos del Caribe
1.2. Dinámica de las comunidades arrecifales
1.3. Estrategias de conservación y restauración arrecifal
1.4. Parque Nacional Guanahacabibes
1.5. Parque Nacional Costa Occidental de Isla Mujeres, Punta Cancún y Punta Nizuc
1.6. Justificación
1.7. Objetivos
1.8. Hipótesis
Capítulo 2. Artículo publicado en la Revista Ocean & Coastal Management. Condition assessment of coral reefs of two marine protected areas under different regimes of use in the north-western Caribbean
Capítulo 3. Artículo sometido a la Revista Journal of Sea Research. Temporal dynamics of benthic coral reef communities in two Caribbean marine protected areas
Capítulo 4. Discusión y síntesis
Conclusiones
Literatura citada