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Efecto de la contaminación sobre las comunidades de gorgonáceos al Oeste de la Bahía de la Habana
... Many of these cnidarians produce organic compounds with antiviral (Cimino et al. 1984), antibacterial (Jensen et al. 1996, anti-inflammatory (Mayer et al. 1998), and antitumor (Rodríguez and Martínez 1993) activities. In addition, gorgonians provide a key environmental bioindicator based on the structure of their communities (Alcolado 1981;Herrera and Alcolado 1983;Fabricius and McCorry 2006;Rey-Villiers et al. 2020a, b) and stable nitrogen isotopes (Risk et al. 2009;Rey-Villiers et al. 2021). ...
... Research on octocoral communities in Cuba began in the 1980s (Alcolado 1981;Herrera and Alcolado 1983). The first studies focused on the distribution of species in relation to wave turbulence (Alcolado 1981) and organic pollution near the city of La Habana (Herrera and Alcolado 1983;Herrera and Alcolado 1986a, b). ...
... Research on octocoral communities in Cuba began in the 1980s (Alcolado 1981;Herrera and Alcolado 1983). The first studies focused on the distribution of species in relation to wave turbulence (Alcolado 1981) and organic pollution near the city of La Habana (Herrera and Alcolado 1983;Herrera and Alcolado 1986a, b). Subsequently, several studies were conducted on the responses of octocoral communities to organic pollution in the northwestern region of Cuba (Herrera Fig. 9.2 Polyps of Plexaurella nutans (a and b). ...
Octocorals provide multiple ecosystem services in coral reefs. Currently, in tropical western Atlantic reefs, the ecological condition of stony coral communities continues to decline; however, octocoral abundance is increasing at several locations throughout the region. The structure of octocoral communities was evaluated in Cuban reefs and was compared with that in the western Atlantic. We used 1 m2 quadrats to count colony numbers by species between 2001–2005 and 2008–2017 at 189 sampling sites. With 55 species, the octocoral richness in Cuban reefs constitutes one of the highest in this region. Among areas sampled during 2001–2005, the best ecological conditions for octocoral communities were found in Gardens of the Queen and Coco Key; here, octocorals had the greatest richness, diversity, and density. Among areas sampled during 2008–2017, the best ecological conditions for octocoral communities were in Colorados, Sabana-Camagüey, Canarreos, Artemisa, Mayabeque, and Havana (except in four highly polluted sites), where they showed the greatest richness and density. Antillogorgia americana and Eunicea flexuosa had wide distributions in Cuban reefs, except at some sites under the chronic influence of discharges from polluted watersheds in Havana. At those sites, the richness, diversity, and density of octocorals decreased, and their species composition changed toward more tolerant taxa to pollution and sedimentation.
... Specifically, E. flexuosa is sensitive to organic pollution, while P. kükenthali is more tolerant since the density of the latter did not show significant differences between reefs under the influence of polluted river basins versus reference sites [12,26]. In addition to the response of these species, a decrease in the richness, diversity of species, density of colonies and changes in the composition of the octocoral communities toward more tolerant species have been reported in this same gradient [12,[26][27][28]. ...
... Some species of Caribbean octocorals have been classified as tolerant to organic pollution, while others are considered sensitive, based on their relative abundances in sites influenced by polluted river basins compared to reference sites. Species considered tolerant are P. kükenthali, Pseudoplexaura flagellosa, Eunicea tourneforti, Eunicea calyculata forma calyculata, Eunicea calyculata forma coronata [27], Eunicea mammosa [39] and Pterogorgia citrina [40]. Furthermore, the octocorals E. tourneforti and Pseudoplexaura porosa have shown tolerance to ammonium enrichment [15]. ...
... Furthermore, the octocorals E. tourneforti and Pseudoplexaura porosa have shown tolerance to ammonium enrichment [15]. Sensitive species to organic pollution are G. ventalina, Gorgonia mariae, Antillogorgia elisabethae, Antillogorgia rigida, A. americana and Muriceopsis flavida [27,39]. The tolerance of octocorals to organic pollution and their vertical growth, are life strategies that may contribute to the abundance of these species. ...
Octocoral abundance is increasing on Caribbean reefs, and one of the possible causes is their vertical morphological plasticity that allows them to grow above the substrate to reduce the effect of processes that occur in it (e.g., scour by sediments) as well as adapt to environmental gradients. The aim of this study was to determine the morphometric response of two octocorals species (Eunicea flexuosa and Plexaura kükenthali) with different life strategies in a water quality gradient. The research was carried out between 2008 and 2016 on eight forereefs of northwest Cuba. Different morphometric indicators were measured in the colonies of both species found within a belt transect (100 x 2 m) randomly located at each site. The lowest means in height, diameter, number of terminal branches/colony, cover index, and least arborescent colonies of E. flexuosa were detected at the sites with the greatest anthropogenic pollution. The water quality gradient did not explain the variability of the five morphometric indicators of P. kükenthali. However, hydrodynamic stress was the factor that most negatively affected the morphometry of this species. The chronic effect of poor water quality over time resulted in more small sized colonies of E. flexuosa at the polluted site, probably due to higher mortality. The size distribution of P. kükenthali also showed the same trend but at the sites with greater hydrodynamic stress. These results show that the morphometric response of octocorals along a water quality gradient is species-specific. This study suggests that poor water quality decreases the size and thus availability of habitat provided by octocorals sensitive to that factor (e.g., E. flexuosa) while other tolerant species (e.g., P. kükenthali) could provide the habitat of several organisms in a scenario of increasing anthropogenic pollution.
... The variations in the octocoral species distributions corresponded with the distances between the reefs and the polluted river basins in the littoral zone of this study (Herrera and Alcolado, 1983;Herrera, 1990;Guardia and González-Sansón, 2000b) and in Hong Kong (Yeung et al., 2014). This finding coincides with the results obtained in this research, where the structure of the octocoral assemblages varied due to fecal organic pollution (FC and FE bacteria) between the reefs at different distances from the polluted river basins. ...
... For these reasons, we considered these five species to be sensitive to water quality degradation, specifically organic pollution and nitrogen enrichment, sediment accumulation on the bottom, and low Vis. Three of these species coincided with those reported by Herrera and Alcolado (1983) and Herrera (1990), who considered that the following octocorals were sensitive to pollution: G. ventalina, G. mariae, A. elisabethae, A. rigida, A. americana and M. flavida. Both authors considered the following species to be tolerant: E. flexuosa, P. kuekenthali, E. tourneforti, P. flagellosa, E. calyculata form coronata, E. calyculata form typica and E. mammosa. ...
... However, regarding E. flexuosa, we do not agree with the results reported by Herrera and Alcolado (1983) and Herrera (1990), since the density of E. flexuosa decreased at the sites closer to Havana Bay (PAM) and the Almendares (Pu) and Cojímar (Co) Rivers, and its density was significantly negatively correlated with the FC and FE bacteria and sediment accumulation on the bottom. For these reasons, we consider this species to be sensitive to water quality degradation, despite having the second highest relative abundance at the reefs near the Almendares (10.7%) and Cojímar (11.2%) ...
Rivers are the main sources of nutrients to coastal zones. Therefore, the effects of water quality degradation on octocoral assemblages and their relationship with microbiological and physical-chemical variables were determined in reefs close to river basins in the northwestern region of Cuba. The evaluations were carried out in 1 m 2 frames at a depth of 10 m in 13 fore reefs. The highest concentrations of the microbiological variables and hydrochemicals and the lowest horizontal visibility in the water column were detected in the reefs near the river basins. The lowest richness, diversity and octocoral density were related to higher concentrations of fecal co-liform, total coliform and fecal streptococcal bacteria, sediment accumulation on the bottom and lower visibility. The structure of the octocoral assemblages varied significantly between reefs due to fecal organic pollution. Water quality deterioration in the reefs near the river basins has negatively affected the octocoral assemblages.
... El arrecife coralino del RG constituye un recurso importante en el manejo del Paisaje Natural Protegido del mismo nombre, ubicado en Las Playas del Este al Norte de la Ciudad de La Habana, el cual sirve como sustento a pobladores locales y externos, y se utiliza con fines recreativos y turísticos. Estudios previos, realizados en la década de los 80 por Herrera y Alcolado (1983), Martínez-Estalella y Herrera (1989) y Alcolado (1989), demuestran que han ocurrido transformaciones en el arrecife que ameritan tomar medidas para garantizar su protección. Este estudio tiene como objetivos caracterizar el estado del arrecife y detectar los efectos de posibles impactos humanos con vistas a generar información básica para la confección de planes de manejo sobre bases sólidas. ...
RESUMEN Se presentan los resultados del monitoreo Reef Check realizado en los arrecifes coralinos del área protegida del Rincón de Guanabo en los años 2000, 2001 y 2002. El muestreo se realizó con el fin de evaluar el estado de salud del arrecife, obtener información científica básica para establecer planes de manejo e involucrar a voluntarios de la comunidades en las actividades de conservación. Se establecieron estaciones fijas en 3 y 10 m de profundidad. Como complemento de Reef Check, en el 2002 se evaluó la composición por especies de corales y la abundancia de gorgonias y esponjas mediante el método del marco de 1m². El cubrimiento del sustrato por corales vivos fue superior al 20% tanto en la cresta como en el arrecife frontal y no mostró variaciones entre los 3 años. Se identificaron 25 especies de corales pétreos, las más abundantes fueron Agaricia agaricites, Porites astreoides, Siderastraea siderea y Montastraea annularis. La densidad de corales fue de 13.8 col./m² y mayor que la de gorgonias y esponjas. Fue significativa la baja densidad de erizos del género Diadema y la casi total ausencia de peces comerciales. Los resultados indican que el arrecife se encuentra en buen estado de salud, sin embargo, se detectan serias afectaciones por sobrepesca que pueden llevar a futuros trastornos ecológicos. De aquí la necesidad de continuar la aplicación del monitoreo Reef Check, el cual permitirá obtener información científica confiable para prevenir la destrucción del arrecife y vincular la comunidad local al proceso de conservación. ABSTRACT The results of the monitoring Reef Check in the coral reef of Rincón de Guanabo protected area during 2000, 2001, 2002 are presented. This survey was carried out to evaluate the coral reef´s health, to obtain the basic scientific information for establishing the management plans and to involve the community volunteers in the conservation activities. Fixed stations in 3 and 10 m deep were settled down. Besides the Reef Check monitoring, in the 2002 a 1 m 2 frame was used so as to analyze the coral species composition and the abundance of sponges and gorgonians. Alive coral cover was superior to 20% in the crest and in the front reef but didn´t show variations in the 3 years. Twenty five species of scleractinian corals were identified, and the most abundant were Agaricia agaricites, Porites astreoides, Siderastraea siderea y Montastraea annularis. Coral density was 13.8 col./m², and higher than gorgonians and sponges density. The low density of Diadema urchin and the almost total absence of commercial fish was significant. The results indicated that the coral reef of Rincón de Guanabo is in good health condition, however, there are serious impacts by over fishing that can bear future ecological dysfunctions. Because of this, it is necessary to continue with Reef Check monitoring that will give reliable scientific information to prevent coral reef destruction and will involve local community to the conservation process.
... Aumentó el porcentaje de 6 especies resistentes a la contaminación. Grupo formado por: P. kuekenthali, E. flexuosa, E. calyculata forma coronata, E. calyculata forma typica, E. tourneforti y P. flagellosa Herrera (1984) Tabla 1. Continuación. Disminuye la densidad y la riqueza de octocorales: ...
Los octocorales son cnidarios bentónicos que tienen una importancia estructural y funcional en los arrecifes coralinos, y por ser sésiles, no pueden emigrar de los arrecifes eutrofizados, por lo que reflejan las condiciones ambientales que han existido durante su desarrollo. Este trabajo sintetiza las respuestas de los octocorales en el nivel de comunidad, población e individuo ante la eutrofización de las zonas marino-costeras. Las descargas de cuencas fluviales contaminadas deterioran la calidad del agua y provocan eutrofización en muchos arrecifes, lo que disminuye la abundancia, cobertura, riqueza y diversidad de octocorales, y cambia la composición cuantitativa (%) de sus asociaciones. En arrecifes cercanos a cuencas fluviales contaminadas aumenta la abundancia relativa (%) de octocorales tolerantes a la contaminación, mientras que en arrecifes alejados se incrementa el de otras especies que no toleran ese factor. En el nivel de población, la eutrofización disminuye la densidad y cobertura de diferentes especies, y también tiene un efecto negativo en distintos indicadores morfométricos. Sin embargo, los resultados de varias investigaciones evidencian que la tasa de crecimiento de los octocorales aumenta con un mayor aporte de materia orgánica, microorganismos y nutrientes proporcionados por las descargas de cuencas fluviales, difusores submarinos y escurrimientos terrestres. En el nivel de individuo, se afecta la fisiología de las colonias, ya que adquieren una pigmentación parda muy oscura por el incremento en la densidad de las zooxantelas, y aumenta el δ15N en el tejido y eje de varios octocorales como consecuencia del aporte de aguas residuales.
... The E. flexuosa and P. kuekenthali species were selected for being one of the most abundant in the study area and in the fore reefs near the polluted river basins (Rey-Villiers et al. 2020). In addition, Herrera and Alcolado (1983) considered both species tolerant to organic pollution, while Rey-Villiers et al. (2020) only considered P. kuekenthali tolerant to this factor. These octocorals were collected in 13 coastal reefs at 10-m depth (Fig. 1, Table 1). ...
Eutrophication is one of the causes of the degradation of reefs worldwide. The aim of this research is to determine if sewage discharge reaches the fore reefs at northwest of Cuba using δ15N in tissues of the octocorals Eunicea flexuosa and Plexaura kuekenthali and the concentration of microbiological and physical-chemical variables. Thirteen reefs at 10-m depth were selected near river basins and far from the urban and industrial development of Havana City. Branch tips of both species were collected, the concentrations of nutrient and microorganisms in water samples were quantified, and horizontal visibility in the water (Vis) was determined. Overall, δ15N of E. flexuosa ranged from 1.5 to 6.3‰ and P. kuekenthali from 1.7 to 6.7‰. The tissue of both species was significantly enriched in 15N in reefs near polluted watersheds compared with reefs far from pollution by anthropogenic activities. The δ15N of both species showed a positive and significant correlation with the concentration of fecal and total coliform bacteria, heterotrophic bacteria, and NH4+ and a negative and significant correlation with the Vis. The δ15N of the two species and microbiological and physical-chemical variables evidenced water quality decline by sewage discharge that reached reefs near polluted watersheds.
... ). Otras causas serian que los juveniles se encontraran inmersos mas profundamente en el sedimento y que la draga no hubiera podido capturarlos(Green, 1979), o que la frecuencia de muestreo no haya coincidido con los periodos de reclutamiento.IV.4 DETERMINACION DEL ESTRES AMBIENTAL.Los diferentes métodos utilizados para determinar el estrés ambiental mostraron que durante el periodo de muestreo se presentaron condiciones de estrés en la bahia debido a la serie de fluctuaciones fisicoquimicas detectadas durante las condiciones "El Nifio", las surgencias y la operacién de la CT.Lostres indicadores sintéticos del estrés ambiental arrojaron resultados similares, y permitieron definir periodos de estrés relacionables con los eventos fisicoquimicos detectados, independientemente dela intensidad de estos.En general, las curvas de rarefaccién mostraron los resultados mas interpretables.Este método es el que cuenta con mas antecedentes en estudios de impacto ambiental (Herrera Moreno yAlcolado, 1983). Las curvas cortas definidas en las fechas de 1992 reafirmaronla hipdtesis de la ocurrencia de un evento "El Nifio", ya que mostraron un bajo numero de individuos y de especies, correspondiente a un alto estrés ambiental. ...
Analysis of ecologic changes on benthic polychaetes related to the start of operation of a coastal power plant in the South Mexican Pacific Ocean.
Octocorals are showing resilience to local and global stressors, while the decline in zooxanthellate corals continues. One of the processes that helps explain this ecological succession is the vertical growth of octocorals, which allows colonies to avoid stressors occurring at the substrate level. However, the growth and survival of octocorals could be affected by eutrophication, similar to what has happened with zooxanthellate corals. For this
reason, the growth rate, mortality and survival of two octocoral species were determined along a eutrophication gradient in Cuba. A permanent band transect (250 × 2 m) was established on seven frontal reefs, and marked colonies were monitored for one year. The growth rates in height, width and colony area of Eunicea flexuosa and Plexaura kükenthali were significantly greater in the reefs near the polluted river basins. The eutrophication gradient, water visibility, and sediment accumulation on the bottom explained 36–78% of the variability in the growth of both species. The positive and significant correlations between the growth rate and stable nitrogen isotopes in both species and the microbiological variables, suggest that the contributions of dissolved inorganic nitrogen and organic matter from sewage discharge favor the growth of colonies. The eutrophication gradient did not explain the variability in mortality of either species in the short term, while hydrodynamic stress did. The
results of this research highlight the resilience of both species and their ability to grow more rapidly in areas with eutrophic conditions, low water visibility, and greater sediment accumulation on the bottom, which may help explain the abundance of octocorals in the western tropical Atlantic.
In recent decades, there has been an accelerated deterioration of coral reefs due to the synergistic effect of natural and anthropogenic stressors. Thus, the objective of this chapter is to evaluate the cumulative effects produced by multiple stressors that impact coral reefs of the northwestern region of Cuba. To this end, ecological indicators were estimated at community level (i.e., coral species; density of corals, gorgonians, sponges, and fish) and population level (i.e., sizes and health of Siderastrea siderea and Montastraea cavernosa). The results show structural changes in communities driven by existing anthropogenic impacts, which vary in intensity (low, medium, and high impact area) along the northwestern coast of Cuba, decreasing from the east-west. In addition, these impacts and changes decrease in the east-west direction. The ecological indicators show differences between the sites with different levels of impact. Corals and gorgonians were more abundant in sites with medium impact, while sponges were more abundant in the area with high impact. The density of herbivorous fish was higher in sites with low and high impact and lower in sites with medium impact. The indicators assessing the health of the corals better reflect the effect of impacts such as the increase in sea surface temperature and extreme meteorological events. In sites where eutrophication and sedimentation prevail, bleaching processes are not as critical.
This chapter summarizes the history of the scientific knowledge regarding Cuban coral reefs. The work of Antonio Parra, published in 1787, is the first book to refer to species of reef life in Cuba. In the nineteenth century, the works of Alexander von Humboldt, Charles Darwin, Ramón de la Sagra, Felipe Poey, and Rafael Arango are the most prominent, along with the debates on the origins of reefs by William O. Crosby and Alexander Agassiz. During the twentieth century, William M. Davis and William Smith considered the reefs on the southern coasts of Cuba to be the longest in the West Indies. Also in this century, multiple institutions devoted to marine studies emerged and research grew exponentially. The monograph by Zlatarski and Martínez Estalella, published in 1980, demonstrated the variety of the Cuban scleractinian and the presence of intermediate phenotypes of acknowledged species. Information is presented concerning “true” coral barrier reefs in Cuba, the contribution of projects such as AGRRA, the early warning voluntary monitoring in coral reefs, the studies of the mesophotic coral ecosystems, and the economic value of the Cuban coral reefs, with references to the most notable publications in the last 30 years.
Several types of indices distinguished by the sort of information they summarize are discussed and illustrated with examples from the literature. Then an index of eutrophication and pollution that is based upon the relative abundance of oligochaete species differing in their response to organic enrichment is described and the results of a trial in which this index was compared to others which, though commonly used, are deficient in information content are discussed.
Information content may be used as a measure of the diversity of a many-species biological collection. The diversity of small collections, all of whose members can be identified and counted, is defined by Brillouin's measure of information. With larger collections it becomes necessary to estimate diversity; what is estimated is Shannon's measure of information which is a function of the population proportions of the several species. Different methods of estimation are appropriate for different types of collections. If the collection can be randomly sampled and the total number of species is known, Basharin's formula may be used. With a random sample from a population containing an unknown number of species, Good's method is sometimes applicable. With a patchy population of sessile organisms, such as a plant community, random samples are unobtainable since the contents of a randomly placed quadrat are not a random sample of the parent population. To estimate the diversity of such a community a method is proposed whereby the sample size is progressively increased by addition of new quadrats; as this is done the diversity of the pooled sample increases and then levels off. The mean increment in total diversity that results from enlarging the sample still more then provides an estimate of the diversity per individual in the whole population.
Data presented in this paper illustrate how differences in age structure between isolated populations of some longevous benthic invertebrates may be useful in interpreting both the relative suitability and stability of habitats in which they occur. Both measures are species specific. The suitability of a habitat for any species is most easily judged by measures of relative longevity. Habitat stability is defined as the variability between age classes of the population at a single locality. For Muricea californica, this was calculated by fitting several monotonically decreasing functions to the age frequency distributions of populations in different habitats and comparing their standard deviations. The results show that both suitability and stability of the habitat of M. californica are related to features of the substratum, although the most suitable habitats were not necessarily the most stable. The curve-fitting method, while lacking some precision, permits quantitative contrasts between habitats. Also, past changes in a habitat that occurred during the life span of a population may be evident by examining age structure, as in the case of the apparent effect of sewage on the Palos Verdes population of M. californica, an example of environmental hindcasting. If the species selected for study is a dominant member of the community in which it is found, or if it is a keystone or foundation species (Paine 1969; Dayton 1972), then its age structure may also reflect the environmental suitability and stability of many other associated or dependent species. In this sense, the index for such a species is not necessarily species specific but, rather, may be applied more broadly at the community level.
This report summarizes observations of the species composition, distribution, and diurnal activity patterns of gorgonians on a West Indian patch reef under siltation stress. The study was conducted from an undersea habitat operated by the Puerto Rico Inter-National Undersea Laboratory. Fifteen species contribute significantly to the gorgonian fauna. Species diversity and equitability are high (H′ = 3.46 bits/individual; H′/H′max = 0.88), and the cumulative area-diversity curve rises rapidly. The gorgonians appear to interpret their environment as stable, favorable, and spatially uniform in spite of the siltation stress. Gorgonians show a daytime peak in polyp extension at 1000 hours and a nocturnal peak at 2200 hours. The daytime peak is strongly correlated with light intensity and plankton availability. The nocturnal peak is probably associated with feeding on zooplankton. Species specific differences in diurnal activity patterns suggest niche separation and that the degree of dependence on zooxanthellae may vary considerably. Predation on gorgonians appears to be slight but increases maintenance energy requirements and could influence the course of competition.
The mining of china clay in Cornwall is an industry dating from the middle of the eighteenth century, and one which has grown to major prominence in the south-western peninsula, as illustrated by the historical accounts of Barton (1966) and Hudson (1969).
Present-day mining processes give rise to two main types of particulate waste. The coarser waste, or tip-sand, is deposited on land to form the massive white tips which characterize the scenery of the Cornish china clay mining areas, although small amounts may be used locally as a building aggregate. The finer-grained waste, known as micaceous residue, is produced in lesser quantities and is disposed of in a different manner.