ABSTRACT
Abstract Wave exposure can influence community structure and distribution of shallow coral reefs, by affecting organisms both directly and indirectly. To assess the current stony coral community condition under different degrees of wave exposure at a marine protected area of the Gulf of Cazones (SW Cuba), two expeditions were carried out in May 2010 and June 2012. Four sampling sites were sampled at reef crests (1.5 m deep), and twelve at fore-reefs, at 10, 15 and 20 m deep in four geographic locations. Live coral cover, species richness and composition, colony density, and maximum diameter were assessed using the AGRRA 2001 methodology. Multivariate and non-parametric statistics were applied to compare sites. The coral community structure within reef crests was not homogenous. The observed variability of indicators apparently was determined by great coral mortality events resulting from natural disturbances that occurred in the past (hurricanes, bleaching and diseases). Forereef coral communities displayed better condition and lower coral mortality than reef crests. Species richness and coral composition varied, while multivariate and statistical methods did not reveal site grouping with regard to wave exposure. The remaining biological condition indicators were similar among sites, except in the most exposed one, where coral cover and coral size were slightly lower. Wave exposure in the gulf of Cazones seemed not to have a significant influence on differences in condition and structure of the assessed coral communities. Rev. Biol. Trop. 64 (1): 78-93. Epub 2016 March 01.
ResumenEl oleaje es una perturbación natural que puede inferir en la estructura y condición de los arrecifes de coral someros, afectando los organismos directa e indirectamente. Para evaluar la condición de comunidades de corales con diferente exposición al oleaje, se realizaron dos expediciones al Área Marina Protegida del Golfo de Cazones durante mayo 2010 y junio 2012. Se escogieron cuatro arrecifes (localidades) ubicados en posiciones diferentes del golfo. Se ubicaron cuatro sitios en la zona de cresta (1.5 m de profundidad) y 12 en la zona de arrecife frontal (en cuatro localidades a 10, 15 y 20 m de profundidad) donde se replicaron transectos lineales (10 m de largo) de muestreo. Se evaluó la cobertura de coral vivo, riqueza y composición por especies, densidad y diámetro máximo de las colonias mediante la metodología AGRRA 2001. Para la comparación entre sitios se aplicaron métodos evaluativos multivariados y análisis estadísticos no paramétricos. La estructura y condición de la comunidad de corales en las crestas fue distinta pero la variabilidad observada parece responder a grandes eventos de mortalidad producto de huracanes, blanqueamientos y enfermedades del pasado. La condición de los arrecifes frontales fue más favorable observándose menor mortalidad coralina. La riqueza y composición por especies fue variable y los métodos estadísticos y multivariados no definieron grupos de sitios con similitud respecto a la exposición al oleaje. Los demás indicadores biológicos de condición fueron parecidos entre sitios, excepto en el más expuesto al oleaje, donde la cobertura y la talla de los corales fueron ligeramente inferiores. En general, la diferente influencia del oleaje dentro del golfo de Cazones, parece no afectar significativamente la estructura y condición de las comunidades coralinas.
Subject(s)
Animals , Anthozoa , Biodiversity , Coral Reefs , Environmental Monitoring , Population Density , CubaABSTRACT
Wave exposure can influence community structure and distribution of shallow coral reefs, by affecting organisms both directly and indirectly. To assess the current stony coral community condition under different degrees of wave exposure at a marine protected area of the Gulf of Cazones (SW Cuba), two expeditions were carried out in May 2010 and June 2012. Four sampling sites were sampled at reef crests (1.5 m deep), and twelve at fore-reefs, at 10, 15 and 20 m deep in four geographic locations. Live coral cover, species richness and composition, colony density, and maximum diameter were assessed using the AGRRA 2001 methodology. Multivariate and non-parametric statistics were applied to compare sites. The coral community structure within reef crests was not homogenous. The observed variability of indicators apparently was determined by great coral mortality events resulting from natural disturbances that occurred in the past (hurricanes, bleaching and diseases). Forereef coral communities displayed better condition and lower coral mortality than reef crests. Species richness and coral composition varied, while multivariate and statistical methods did not reveal site grouping with regard to wave exposure. The remaining biological condition indicators were similar among sites, except in the most exposed one, where coral cover and coral size were slightly lower. Wave exposure in the gulf of Cazones seemed not to have a significant influence on differences in condition and structure of the assessed coral communities.
Subject(s)
Anthozoa , Biodiversity , Coral Reefs , Animals , Cuba , Environmental Monitoring , Population DensityABSTRACT
The effect of pollution on coral recruitment has been insufficiently studied. This research deals with coral recruitment in coastal areas and aimed to determine the variations of density and dominant species of corals recruits in sites at different distances from pollution sources. The composition and structure of stony coral (scleractinian and milleporids) recruit associations were characterized in the fringing reef of Western Havana, Cuba. This reef is influenced by urban pollution from the Almendares River and a sewage outlet located at its mouth. Four sites were sampled on the upper fore reef escarpment at 10m deep every three months between July 2007 and May 2008. A 25cm side quadrat was used to determine the density and taxonomic composition of recruits smaller than 3cm in diameter. Sampling units were placed following a random-systematic pattern. The mean density of recruits was determined both at assemble and species level. Bifactoral ANOVA tests were applied to compare mean densities at both sampling sites and dates. Student-Newman-Keuls test was applied to compare pairs of means. Cluster and nMDS analyses were applied to evaluate between site similarities. The predominant species was Siderastrea siderea followed by S. radians and Porites astreoides. Recruit densities were similar among La Puntilla, Calle 16 and Acuario sites. Lower densities were always found in Malec6n. Significant differences in mean stony recruit densities were found both between sites and sampling dates. The statistic analysis did not show significant spatial-temporal interactions. Malec6n, the most polluted site, showed the lowest recruit density and the greater presence of species considered as indicators of organic pollution, sedimentation and abrasion. The density of recruit species was higher in October 2007 and lower in May 2008, and it was apparently influenced by reproduction and cold front seasons, respectively. The higher dominance and abundance of S. siderea, S. radians and P. astreoides recruits were apparently due to their high reproductive potential and resistance to disturbances. The identity of dominant species was apparently related to distance from major pollution sources. We highly recommended the replication of this research in other areas of the greater Caribbean region to test the generality of present results and to compare among areas. Future research should take into account the influence of other environmental factors, along with an appraisal of recruit species tolerance to these factors, to better ponder the effect of urban pollution on recruitment. Areas with well assessed pollution regimes are recommended for research.
Subject(s)
Anthozoa/physiology , Coral Reefs , Environmental Monitoring , Water Pollutants , Animals , Cuba , Population Density , Population Dynamics , SeasonsABSTRACT
The composition and structure of octocoral communities on coral reefs close to a submarine outfall were studied at Reparto Flores, west of Havana City, Cuba. Octocoral community changes after the deployment of the submarine outfall in 2000 were monitored from June 2002 to September 2005, taking as baseline the data existing before its construction. The area also receives the influence of the polluted river Quibú that passes through a great part of the west side of the City. Sampling was done by means of SCUBA diving, counting and identifying colonies in situ within a 1 m2 frame that was randomly placed as many times as to warrant stabilized values of Shannon and Weaver's heterogeneity index H'. In agreement with the available hydrochemical information, changes in the diversity indexes (Shannon and Weaver's heterogeneity index H', Pielou's equitability index J', and Margalef's species richness index R1), the Herrera-Moreno's comparative pollution index (ICC), and density of some octocoral species at a depth of 10 m suggest a decrease in the influence of polluters from 1989 to 2005. Nevertheless, these indicators were affected in 2004 by a sudden intense but brief colonization of Briareum asbestinum, a species that is not typical of polluted places. At a depth of 20 m, a co-dominance of Plexaura kuekenthali and Eunicea clavigera (resistant and non resistant to pollution, respectively) and an increase of the comparative pollution index (ICC) was observed. The increase of P. kuekenthali, a pollution indicator, suggests a rise in the pollution effect 20 m in depth, because of the recent impact caused by the greater closeness of the outfall mouth 50 m deep. Results corroborate the hypothesis about the pollution indicator character of P. kuekenthali. However, this could not be explored for Eunicea flexuosa (also considered a pollution-indicator) due to an intensive illegal selective extraction for lucrative handicraft purposes, which led to a remarkable decrease in its density. B. asbestinum and E. clavigera were outlined as poorly resistant to pollution.
Subject(s)
Anthozoa/classification , Anthozoa/physiology , Biodiversity , Environmental Monitoring , Waste Disposal, Fluid , Water Pollution/adverse effects , Animals , Cuba , Population Density , Population Dynamics , SeawaterABSTRACT
The composition and structure of octocoral communities on coral reefs close to a submarineoutfall were studied at Reparto Flores, west of Havana City, Cuba. Octocoral community changes after thedeployment of the submarine outfall in 2000 were monitored from June 2002 to September 2005, taking asbaseline the data existing before its construction. The area also receives the influence of the polluted river Quibúthat passes through a great part of the west side of the City. Sampling was done by means of SCUBA diving,counting and identifying colonies in situ within a 1 m2 frame that was randomly placed as many times as towarrant stabilized values of Shannon and Weavers heterogeneity index H. In agreement with the availablehydrochemical information, changes in the diversity indexes (Shannon and Weaver`s heterogeneity index H,Pielous equitability index J, and Margalefs species richness index R1), the Herrera-Morenos comparative pollutionindex (ICC), and density of some octocoral species at a depth of 10 m suggest a decrease in the influenceof polluters from 1989 to 2005. Nevertheless, these indicators were affected in 2004 by a sudden intense butbrief colonization of Briareum asbestinum, a species that is not typical of polluted places. At a depth of 20 m,a co-dominance of Plexaura kuekenthali and Eunicea clavigera (resistant and non resistant to pollution, respectively)and an increase of the comparative pollution index (ICC) was observed. The increase of P. kuekenthali,a pollution indicator, suggests a rise in the pollution effect 20 m in depth, because of the recent impact causedby the greater closeness of the outfall mouth 50 m deep. Results corroborate the hypothesis about the pollutionindicator character of P. kuekenthali. However, this could not be explored for Eunicea flexuosa (also considereda pollution-indicator) due to an intensive...(AU)
Subject(s)
Animals , Anthozoa/classification , Anthozoa/physiology , Biodiversity , Environmental Monitoring , Waste Disposal, Fluid , Water Pollution/adverse effects , Cuba , Population Density , Population Dynamics , SeawaterABSTRACT
The composition and structure of octocoral communities on coral reefs close to a submarine outfall were studied at Reparto Flores, west of Havana City, Cuba. Octocoral community changes after the deployment of the submarine outfall in 2000 were monitored from June 2002 to September 2005, taking as baseline the data existing before its construction. The area also receives the influence of the polluted river Quibú that passes through a great part of the west side of the City. Sampling was done by means of SCUBA diving, counting and identifying colonies in situ within a 1 m2 frame that was randomly placed as many times as to warrant stabilized values of Shannon and Weaver's heterogeneity index H'. In agreement with the available hydrochemical information, changes in the diversity indexes (Shannon and Weaver's heterogeneity index H', Pielou's equitability index J', and Margalef's species richness index R1), the Herrera-Moreno's comparative pollution index (ICC), and density of some octocoral species at a depth of 10 m suggest a decrease in the influence of polluters from 1989 to 2005. Nevertheless, these indicators were affected in 2004 by a sudden intense but brief colonization of Briareum asbestinum, a species that is not typical of polluted places. At a depth of 20 m, a co-dominance of Plexaura kuekenthali and Eunicea clavigera (resistant and non resistant to pollution, respectively) and an increase of the comparative pollution index (ICC) was observed. The increase of P. kuekenthali, a pollution indicator, suggests a rise in the pollution effect 20 m in depth, because of the recent impact caused by the greater closeness of the outfall mouth 50 m deep. Results corroborate the hypothesis about the pollution indicator character of P. kuekenthali. However, this could not be explored for Eunicea flexuosa (also considered a pollution-indicator) due to an intensive illegal selective extraction for lucrative handicraft purposes, which...
Para profundizar en las respuestas de las comunidades de octocorales a la influencia de residuales urbanos se estudió su composición y estructura en sitios de arrecife cercanos a un emisario submarino urbano en el Reparto Flores, La Habana, Cuba. Desde junio del 2002 hasta septiembre del 2005, se efectuó el monitoreo de los cambios ocurridos en las comunidades después de la puesta en operación del emisario en el año 2000, tomando como línea base datos existentes antes del inicio de su construcción. El muestreo se realizó mediante buceo SCUBA, contando e identificando las colonias in situ dentro de cuadricula de 1 m2 de lado. Diversos índices sugieren una disminución de la influencia de la contaminación en la última década.El incremento de P. kuekenthali (indicadora de contaminación, , sugiere un aumento del efecto de la contaminación a 20 m de profundidad debido al impacto reciente de la mayor cercanía del desagüe del emisario que se encuentra a 50 m de profundidad. B. asbestinum y E. clavigera se perfilaron como poco resistentes a la contaminación.
