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Abstract Introduction: The sea urchin Diadema mexicanum, due to its bioerosion activity, is considered of ecological importance. This phenomenon could negatively or positively affect coral reef ecosystems. The bioerosion process varies according to the abundance and size of the sea urchin. Objective: Juvenile organisms possess different metabolic needs compared to adults, so knowing their stomach content according to size allows us to quantify the selection of substrate bioeroded. Methods: To determine this, D. mexicanum individuals were collected in 12 sites from January 2009 to September 2010 along the Eastern Tropical Pacific coast. The stomach content was categorized in Carbonated Fraction (CF), Non-Carbonated Fraction (NCF), and Organic Matter (OM). Stomach content was analyzed according to a) juvenile (< 2.5 cm) or adult (> 2.5 cm) stage and b) locality. Results: Juveniles presented the following stomach content average percentages: 20.7 % OM, 12 % NCF and 67.9 % CF; and adults: 11.4 % OM, 14.8 % NCF and 73.8 % CF. Based on a Wilcoxon test and a Kendall linear regression, the following results were obtained. The carbonated fraction in the stomach increased by 0.47 units on average for every cm of growth (p < 0.05). OM consumed by D. mexicanum increases only 0.05 units for every cm of growth (p < 0.05). We found a difference of stomach content depending on the site (p < 0.05) and life stage (p < 0.05). Localities like Huatulco and Coco presented significant differences that could be related to local oceanographic conditions. Conclusions: We relate these changes of the stomach fractions to the necessity of the juvenile sea urchins for nutrients to maintain their growth. The amount of OM is crucial for the development of early stages, meaning that there is a difference in substrate selection associated with growth.
Resumen Introducción: El erizo de mar Diadema mexicanum, por su actividad de bioerosión, es considerado de importancia ecológica. Este fenómeno podría afectar negativa o positivamente a los ecosistemas de arrecifes de coral. El proceso de bioerosión varía según la abundancia y el tamaño del erizo de mar. Objetivo: Los organismos juveniles poseen diferentes necesidades metabólicas en comparación con los adultos, por lo que conocer el contenido estomacal según el tamaño, nos permite cuantificar la selección de sustrato bioerosionado. Métodos: Para determinar esto, se recolectaron individuos de D. mexicanum en 12 sitios desde enero de 2009 hasta septiembre de 2010 a lo largo de la costa del Pacífico Tropical Oriental. El contenido estomacal se clasificó en Fracción Carbonatada (FC), Fracción No Carbonatada (NCF) y Materia Orgánica (MO). El contenido estomacal se analizó según a) estadio juvenil (< 3 cm) o adulto (> 3 cm) y b) localidad. Resultados: Los juveniles presentaron los siguientes porcentajes promedio del contenido estomacal: 20.7 % OM, 12 % NCF y 67.9 % CF; y adultos: 11.4 % OM, 14.8 % NCF y 73.8 % CF. Con base en una prueba de Wilcoxon y una regresión lineal de Kendall, se obtuvieron los siguientes resultados. La fracción carbonatada en el estómago aumentó en promedio 0.47 unidades por cada cm de crecimiento (p < 0.05). La MO consumida por D. mexicanum aumenta solo 0.05 unidades por cada cm de crecimiento (p < 0.05). Encontramos una diferencia en el contenido estomacal según el sitio (p < 0.05) y el estadio de vida (P < 0.05). Localidades como Huatulco y Coco presentaron diferencias significativas que podrían estar relacionadas con las condiciones oceanográficas locales. Conclusiones: Relacionamos estos cambios de la composición porcentual del contenido estomacal con la necesidad de los erizos de mar juveniles de nutrientes para mantener su crecimiento. La cantidad de MO es crucial para el desarrollo de las primeras etapas, lo que significa que existe una diferencia en la selección de sustrato asociada con el crecimiento.
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Animales , Erizos de Mar/crecimiento & desarrollo , Erosión de Playas , Arrecifes de Coral , DietaRESUMEN
Introducción: Los estudios de coral negro en Centroamérica son escasos. No se ha publicado nada sobre las especies, hábitats, distribución e importancia del coral negro de El Salvador. A pesar de que Antipathes ha sido reportado como uno de los géneros de coral que ha sucumbido a la presión antrópica. Objetivos: Identificar las especies de corales negros en Los Cóbanos, El Salvador, y caracterizar cualitativamente la abundancia y el tamaño de las colonias; e identificar las especies epibiontes más conspicuas en las colonias. Métodos: Se realizó censo visual con buceo para la caracterización cualitativa y fotografías submarinas para el registro de especies epibiontes en seis puntos de Los Cóbanos, entre diciembre de 2021 y febrero de 2022, asimismo para caracterizar tamaño de las colonias y abundancia. Resultados: Se realizo el primer informe de bosques de coral negro en El Salvador, construidos por dos especies: Myriopathes panamensis y Antipathes galapagensis. También, reportamos por primera vez la presencia de M. panamensis, Pacifigorgia senta, Heterogorgia verrucosa, Eugorgia mutabilis, Nemathus californicus y Amphiodia sp. Encontramos afectaciones de origen antrópico, como desechos marinos y daños a las colonias por anclas. Conclusiones: Es necesario establecer esfuerzos para conocer la fauna de la zona mesofótica, principalmente en ecosistemas marinos vulnerables de bosques de coral negro y jardines de gorgonias. Existe un potencial importante, y los datos ayudarán a superar las brechas de información en la región, permitiendo mejores medidas de conservación.
Introduction: Black coral studies in Central America are scarce. Even though Antipathes has been reported as one of the coral genera that has succumbed to anthropic pressure, publications haven't been made on El Salvador black coral species, habitats, distribution, and importance. Objective: To identify the species of black corals in Los Cóbanos, El Salvador, and qualitatively characterize the abundance and size of the colonies; and to identify the most conspicuous epibiont species in the colonies. Methods: Visual census with SCUBA diving for qualitative characterization and underwater photographs were taken for the registration of epibiont species in six points of Los Cóbanos, between December 2021 to February 2022 and six to characterize size of the colonies and abundance. Results: The first report of black coral forests in El Salvador was made, constructed by two species: Myriopathes panamensis and Antipathes galapagensis. We also reported, for first time, the occurrence of M. panamensis, Pacifigorgia senta, Heterogorgia verrucosa, Eugorgia mutabilis, Nemathus californicus and Amphiodia sp. We found disturbances of anthropic origin, such as marine debris and damage to the colonies by anchors. Conclusions: It is necessary to establish efforts towards the knowledge of the fauna of mesophotic zones, mainly in vulnerable marine ecosystems of black coral forests and gorgonian gardens. There is an important potential, and data will help overcome information gaps in the region, allowing for better conservation measures.
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Animales , Ecosistema , Arrecifes de Coral , El SalvadorRESUMEN
RESUMEN Un total de 326 helmintos parásitos fueron recuperados de 94 especímenes de Halichoeres bivittatus (Pisces: Labridae) en dos sitios de la zona arrecifal en los límites del Parque Nacional Sistema Arrecifal Veracruzano, Veracruz, México, el suroeste del Golfo de México: Punta Gorda (n = 51) y Mata de Uva (n = 43). Los peces fueron capturados entre mayo y septiembre de 2001. Cada muestra se analizó a nivel de comunidad componente e infracomunidad. Tres especies de helmintos se localizaron en intestino: Nicolla halichoeri (Digenea) considerándose nuevo registro de localidad, Procamallanus (Spirocamallanus) garnotus (Nematoda) es nuevo registro de hospedero, y las larvas de Tetraphyllidea gen. sp. (Cestoda) fueron los parásitos con mayor prevalencia e intensidad promedio para cada sitio. La riqueza de especies para ambos sitios fue de S = 3 y el índice de diversidad de Shannon-Wiener (Punta Gorda, H'= 0,42; Mata de Uva, H'= 0,49) fueron inferiores a los registrados para las comunidades hospedero-parásito de lábridos y de hospederos de la localidad. No hubo correlación entre el número total de especies o el número total de helmintos con respecto a la longitud total o el peso del hospedero. El análisis de las curvas de especies acumuladas para la comunidad componente sugirió, que el inventario de especies de helmintos estaba casi completo para ambos sitios. La abundancia de larvas del céstodo ubica a H. bivittatus como hospedero intermediario del parásito.
ABSTRACT A total of 326 parasitic helminths were obtained from 94 specimens of Halichoeres bivittatus (Pisces: Labridae) at two sites in the reef zone at the limits of the Veracruz Reef System National Park, Veracruz, Mexico, southwestern Gulf of Mexico: Punta Gorda (n = 51) and Mata de Uva (n = 43). Fish were caught from May to September 2001. Each sample was examined at the levels of the component community and infracommunity. Three parasitic helminth species were found in intestines: Nicolla halichoeri (Digenea: Plagiorchiida: Opecoelidae) is a new geographic record, Procamallanus (Spirocamallanus) garnotus (Nematoda) is a new host record, and larvae of Tetraphyllidea gen. sp. (Cestoda) were the parasites with the highest prevalence and the average intensity at both sites. Species richness (S = 3) and the Shannon-Wiener diversity index (H'= 0,42; 0,49) were lower than those previously estimated for the labrid host-parasite community in the study area. No correlations between the total number of species or the total number of helminths and the total length or weight of the host were observed. An analysis of the accumulated curve for the component community suggested that the inventory of helminth species was almost complete for both sites. The abundance of cestode larvae infers H. bivittatus is an intermediate host of the parasite.
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Introduction: Coral reef structures in Zihuatanejo, Guerrero are well-preserved. The coverage of living corals, near 60 % at several locations, makes them comparable to other coral reefs in the states of Oaxaca, Jalisco, and Nayarit and with high potential to promote their conservation. Objective: To present the outcome of 12 years of research in coral communities from Zihuatanejo, Guerrero, as a justifying argument for the current conservation efforts in the area. Methods: We developed a baseline on the conservation status of the reef structures, bioerosion processes and the source of major natural and anthropogenic impacts. We assessed the genetic diversity of the coral zooxanthellae symbionts, the outcome of a technique of coral transplantation to recover the coverage of living corals and the local ecological knowledge to involve local inhabitants to promote conservation. Results: At least five coral reefs remain exposed to a medium-low level of impact by bioerosion and anthropization. Coral transplantation experiments made in the area showed records of transplant survival nearing 90 %. Although the warming of the sea surface temperature that occurred during the El Niño of 2015-2016 caused coral bleaching and mortality in several coral populations in this area, there were no affectations attributed to this phenomenon in other locations. This response was not related to the level of exposure to anthropogenic impacts, and the presence of thermal resistant zooxanthellae was assessed using molecular tools, confirming the existence of zooxanthellae of the genus Durusdinium. The analysis of local ecological knowledge of the inhabitants of Zihuatanejo showed that they keep elaborate knowledge on the ecology of coral reefs. This is complemented with scientific knowledge that will encourage community participation in conservation strategies. Conclusions: A long-term multidisciplinary strategy is required for coral reef conservation that encompasses: 1) assessing the role of the overall holobiont in the thermal resistance of corals from this area and 2) establishing restoration strategies of coral reefs that include the local knowledge about marine ecology, for the establishment of coral reef protection and management schemes put in place by local inhabitants.
Introducción: Los arrecifes coralinos de Zihuatanejo Guerrero están bien conservados. La cobertura de corales vivos, cerca del 60 %, los hace comparables a otras comunidades coralinas presentes en Oaxaca, Jalisco y Nayarit y con un alto potencial para promover su conservación. Objetivo: Presentar los resultados de 12 años de investigación en las comunidades coralinas de Zihuatanejo, Guerrero, como un argumento que justifica los esfuerzos actuales de conservación en el área. Métodos: Desarrollamos una línea base del estado de conservación de la estructura arrecifal, los procesos de bioerosión y las fuentes principales de impactos naturales y antropogénicos. Evaluamos la diversidad genética de los simbiontes zooxantelados de los corales, el resultado de una técnica de trasplante de corales para recuperar la cobertura de corales vivos y el conocimiento ecológico local para desarrollar estrategias de conservación con participación local. Resultados: Cinco de esas comunidades coralinas permanecen expuestas a un nivel de impacto medio a bajo por bioerosión y antropización. Los experimentos de trasplante de corales en el área mostraron una supervivencia cercana al 90 %. Aunque el calentamiento de la temperatura superficial del mar ocurrido durante el evento El Niño 2015-16 causó blanqueamiento y mortalidad coralina en algunas poblaciones de corales del área, no hubo afectaciones atribuidas a este fenómeno en otras. Esta respuesta no se relacionó con el nivel de exposición a impactos antropogénicos y la presencia de poblaciones de zooxantelas fue examinada usando herramientas moleculares, confirmando la existencia de una población del género Durusdinium. El análisis del conocimiento ecológico local de los habitantes de Zihuatanejo mostró que estos resguardan conocimientos complejos sobre la ecología de las comunidades coralinas. Este conocimiento es complementario al conocimiento científico y servirá para promover estrategias de participación ciudadana en la conservación de las comunidades coralinas. Conclusiones: Se requiere una estrategia multidisciplinaria de largo plazo para la conservación de las comunidades coralinas que incluya: 1) examinar el papel del holobionte completo en la resistencia térmica de los corales de esta área y 2) establecer estrategias de restauración en arrecifes coralinos que incluyan el conocimiento ecológico local para el establecimiento de esquemas de protección y manejo de los arrecifes coralinos a cargo de los habitantes locales.
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Crustose coralline algae (Corallinophycideae) are red algae that produced calcium carbonate and are well recognized as foundation species in the epipelagic zone of the marine ecosystem. These algae induced settlement juvenile of coral by released chemical cues from bacterial communities on the surface of their colonies. Their extracellular calcium carbonate also can stabilize reef structure that influencing many invertebrate attaches and growth in the seabed. Crustose coralline algae (CCA) have obtained attention because of their distribution and health compromise to increasing seawater temperature, ocean acidification, and pollutant. As a cryptic species in the ecosystem, the presence of CCA recruit sometimes doesnt have attention, especially on their capability to occupy the empty space. This study aimed to document coverage and number of CCA recruit in two different recruitment tiles material. The highest CCA percentage of the cover was showed inside surface than others surface in all stations. Light intensity and low sedimentation were suggested as a key factor of success of high coverage. Overall, station higher CCA recruits have shown from Tiga Warna. Low sedimentation and protection from aerial exposure became the main reason for it. No significant difference number of CCA recruits between marble and sandstone in this study. Successful CCA recruitment in this study can give a wide picture that natural recruitment of coral and other reef biodiversity in Southern Malang might be will succeed because of the abundance of coralline algae that support their life history stage.
As algas coralinas crustosas (Corallinophycideae) são algas vermelhas que produzem carbonato de cálcio e são bem reconhecidas como espécies de base na zona epipelágica do ecossistema marinho. Essas algas induziram o assentamento juvenil de coral por meio de estímulos químicos liberados por comunidades bacterianas na superfície de suas colônias. Seu carbonato de cálcio extracelular também pode estabilizar a estrutura do recife que influencia muitos invertebrados anexados e crescimento no fundo do mar. As algas coralinas crustosas (CCA) têm obtido atenção devido à sua distribuição e comprometimento da saúde com o aumento da temperatura da água do mar, acidificação dos oceanos e poluentes. Como uma espécie enigmática no ecossistema, a presença de recrutamento CCA às vezes não recebe atenção, especialmente em sua capacidade de ocupar o espaço vazio. Este estudo teve como objetivo documentar a cobertura e o número de recrutamento de CCA em dois materiais de recrutamento diferentes. A maior porcentagem de CCA da cobertura foi mostrada na superfície interna do que nas outras superfícies em todas as estações. A intensidade da luz e a baixa sedimentação foram sugeridas como um fator-chave para o sucesso da alta cobertura. De modo geral, recrutas de CCA mais graduados mostraram-se em Tiga Warna. A baixa sedimentação e a proteção contra a exposição aérea se tornaram a principal razão para isso. Não houve diferença significativa no número de recrutas CCA entre mármore e arenito neste estudo. O recrutamento bem-sucedido de CCA neste estudo pode dar uma imagem ampla de que o recrutamento natural de corais e outros recifes da biodiversidade no sul de Malang será bem-sucedido por causa da abundância de algas coralinas que sustentam seu estágio de história de vida.
Asunto(s)
Animales , Arrecifes de Coral , Rhodophyta/crecimiento & desarrolloRESUMEN
Abstract Crustose coralline algae (Corallinophycideae) are red algae that produced calcium carbonate and are well recognized as foundation species in the epipelagic zone of the marine ecosystem. These algae induced settlement juvenile of coral by released chemical cues from bacterial communities on the surface of their colonies. Their extracellular calcium carbonate also can stabilize reef structure that influencing many invertebrate attaches and growth in the seabed. Crustose coralline algae (CCA) have obtained attention because of their distribution and health compromise to increasing seawater temperature, ocean acidification, and pollutant. As a cryptic species in the ecosystem, the presence of CCA recruit sometimes doesnt have attention, especially on their capability to occupy the empty space. This study aimed to document coverage and number of CCA recruit in two different recruitment tiles material. The highest CCA percentage of the cover was showed inside surface than others surface in all stations. Light intensity and low sedimentation were suggested as a key factor of success of high coverage. Overall, station higher CCA recruits have shown from Tiga Warna. Low sedimentation and protection from aerial exposure became the main reason for it. No significant difference number of CCA recruits between marble and sandstone in this study. Successful CCA recruitment in this study can give a wide picture that natural recruitment of coral and other reef biodiversity in Southern Malang might be will succeed because of the abundance of coralline algae that support their life history stage.
Resumo As algas coralinas crustosas (Corallinophycideae) são algas vermelhas que produzem carbonato de cálcio e são bem reconhecidas como espécies de base na zona epipelágica do ecossistema marinho. Essas algas induziram o assentamento juvenil de coral por meio de estímulos químicos liberados por comunidades bacterianas na superfície de suas colônias. Seu carbonato de cálcio extracelular também pode estabilizar a estrutura do recife que influencia muitos invertebrados anexados e crescimento no fundo do mar. As algas coralinas crustosas (CCA) têm obtido atenção devido à sua distribuição e comprometimento da saúde com o aumento da temperatura da água do mar, acidificação dos oceanos e poluentes. Como uma espécie enigmática no ecossistema, a presença de recrutamento CCA às vezes não recebe atenção, especialmente em sua capacidade de ocupar o espaço vazio. Este estudo teve como objetivo documentar a cobertura e o número de recrutamento de CCA em dois materiais de recrutamento diferentes. A maior porcentagem de CCA da cobertura foi mostrada na superfície interna do que nas outras superfícies em todas as estações. A intensidade da luz e a baixa sedimentação foram sugeridas como um fator-chave para o sucesso da alta cobertura. De modo geral, recrutas de CCA mais graduados mostraram-se em Tiga Warna. A baixa sedimentação e a proteção contra a exposição aérea se tornaram a principal razão para isso. Não houve diferença significativa no número de recrutas CCA entre mármore e arenito neste estudo. O recrutamento bem-sucedido de CCA neste estudo pode dar uma imagem ampla de que o recrutamento natural de corais e outros recifes da biodiversidade no sul de Malang será bem-sucedido por causa da abundância de algas coralinas que sustentam seu estágio de história de vida.
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Abstract Introduction: Video techniques are used worldwide to study marine communities. As elsewhere, the use of remote underwater videos has recently increased in Brazil and there is a need for information about their advantages, disadvantages, and reliability in tropical habitats. Objective: To evaluate the use of baited remote underwater video stations (BRUVS) in fish diversity research in a tropical habitat. Methods: We used baited video stations to record the fishes and their relationship with habitat type, underwater visibility and depth, in 79 random sites in the Metropolitan Region of Recife, Northeastern Brazil (11 days in November 2017). Results: We recorded 3 286 individuals (65 taxa, 29 families) along a 25 km section of the shoreline, 10.2 to 28.6 m depth. The Clupeidae dominated numerically, followed by Haemulidae, Carangidae, and Lutjanidae; by species, Haemulon aurolineatum, Opisthonema oglinum, Haemulon steindachneri, Lutjanus synagris and Caranx crysos. The highest mean number of species was detected over sediment close to shipwrecks, but we found no differences among the mean number of individuals between habitat types. More species and individuals were observed at a depth of 20-25 m depth. The highest mean number of species was in 2-3 m of visibility, and the highest number of individuals within 4-5 m. Conclusions: Video recording seemed to be a valid method, and indicated that -besides being relatively diverse- the local fish community is dominated by a few species of small and medium-sized mesopredators, and a few top predators.
Resumen Introducción: Las técnicas de video se utilizan en todo el mundo para estudiar las comunidades marinas. Como en otros lugares, el uso de videos submarinos remotos ha aumentado recientemente en Brasil y existe la necesidad de información sobre sus ventajas, desventajas y confiabilidad en los hábitats tropicales. Objetivo: Evaluar el uso de estaciones de video subacuáticas remotas cebadas en la investigación de la diversidad de peces en un hábitat tropical. Métodos: Utilizamos estaciones de video cebadas para registrar los peces y su relación con el tipo de hábitat, la visibilidad submarina y la profundidad, en 79 sitios aleatorios en la Región Metropolitana de Recife, noreste de Brasil (11 días en noviembre de 2017). Resultados: Registramos 3 286 individuos (65 taxones, 29 familias) a lo largo de una sección de 25 km de la costa, de 10.2 a 28.6 m de profundidad. Los Clupeidae dominaron numéricamente, seguidos de Haemulidae, Carangidae y Lutjanidae; por especies, Haemulon aurolineatum, Opisthonema oglinum, Haemulon steindachneri, Lutjanus synagris y Caranx crysos. El mayor número medio de especies se detectó sobre sedimentos cerca de naufragios, pero no encontramos diferencias entre el número medio de individuos entre tipos de hábitat. Se observaron más especies e individuos a una profundidad de 20-25 m. El mayor número medio de especies se registró en 2-3 m de visibilidad, y el mayor número de individuos en 4-5 m. Conclusiones: La grabación en video pareció ser un método válido e indicó que, además de ser relativamente diversa, la comunidad local de peces está dominada por unas pocas especies de mesodepredadores de tamaño pequeño y mediano, y pocos depredadores superiores.
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Animales , Recursos Audiovisuales , Biodiversidad , Peces , Brasil , Arrecifes de CoralRESUMEN
Introducción: Los hábitats costeros de todo el mundo están experimentando una presión cada vez mayor debido a la contaminación, el desarrollo costero, la pesca y el cambio climático. Identificar y registrar la biodiversidad costera es esencial para evaluar la salud, los cambios y el alcance de la pérdida de biodiversidad de los ecosistemas. Los hábitats costeros tropicales como los arrecifes de coral y los lechos de pastos marinos han sido el foco de investigación de los científicos durante las últimas décadas; sin embargo, se han descuidado otros ecosistemas, como los bosques de macroalgas, los fondos de sedimentos submareales (20-30 m de profundidad) y los arrecifes rocosos. Objetivo: Este trabajo reporta la biodiversidad marina asociada con arrecifes rocosos, arrecifes de coral, bosques de Sargazo y fondos submareales sedimentarios (20-30 m de profundidad), en un área tropical de afloramiento estacional (Península de Santa Elena, Bahía de Santa Elena e Islas Murciélago, Costa Rica). Métodos: Durante la Expedición Santa Elena (21 de abril-2 de mayo de 2018), se visitaron un total de 28 sitios para registrar la biodiversidad en cuatro hábitats diferentes (arrecifes rocosos y de coral, bosques de sargazo y fondos de sedimentos submareales), utilizando SCUBA, en muestreos sistemáticos, evaluaciones visuales y en algunos fondos de sedimentos se utilizó una draga de arrastre por 20 minutos. Resultados: Se identificaron un total de 254 taxones, siendo los peces óseos el grupo más diverso con 91 especies, seguido de los gasterópodos (25 spp.), las algas rojas (21 spp.) y los antozoos (19 spp.). Se reportan cuatro nuevos registros para el Pacífico continental de Costa Rica, incluida la subclase de una anémona tubícola (Ceriantharia). Conclusiones: Los resultados muestran que la península de Santa Elena, la bahía de Santa Elena y las islas Murciélago albergan hábitats poco comunes y no estudiados, como bosques del alga parda Sargassum, fondos de sedimentos, arrecifes construidos por el coral masivo Pavona gigantea, que es muy inusual, y comunidades de arrecifes rocosos dominadas por colonias calcáreas de poliquetos (Salmacina tribranchiata).
Introduction: Worldwide, coastal habitats are experiencing increasing pressure from pollution, coastal development, fisheries, and climate change. Identifying and recording coastal biodiversity is essential to assess ecosystem health, changes and the extent of biodiversity loss. Coastal tropical habitats such as coral reefs and seagrass beds have been the research focus for scientists during the last decades; however, other ecosystems have been neglected, such as macroalgae forests, subtidal (20-30 m deep) sedimentary bottoms, and rocky reefs. Objective: Our study reports the marine biodiversity associated with rocky reefs, coral reefs, Sargassum forests and sedimentary subtidal bottoms (20-30 m deep), in a tropical seasonal upwelling area (Santa Elena Peninsula, Santa Elena Bay, and Murciélago Islands, Costa Rica). Methods: During the 'Santa Elena Expedition' (April 21-May 2 2018), a total of 28 sites were visited in order to record the biodiversity across four different habitats (rocky and coral reefs, Sargassum forests, subtidal sedimentary bottoms), using SCUBA and both systematic surveys and visual assessments; in some sedimentary bottoms a 20-minute dredge tows were done. Results: A total of 254 taxa were identified, being bony fishes the most diverse group (91 species), followed by gastropods (25 spp.), red algae (21 spp.) and anthozoans (19 spp.). We report four new records for the Pacific mainland of Costa Rica, including the subclass of tube-dwelling sea anemone (Ceriantharia). Conclusions: Our results show that Santa Elena Peninsula, Santa Elena Bay, and Murciélago Islands harbor uncommon and unstudied habitats, such as Sargassum forests, sedimentary bottoms, reefs constructed by the stony coral Pavona gigantea -which is very unusual- and rocky reef communities dominated by calcareous colonies of polychaetes (Salmacina tribranchiata).
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Fondo Oceánico , Biodiversidad , Arrecifes de Coral , Ambiente Marino , Costa RicaRESUMEN
Introducción: Es poco lo que se conoce sobre aspectos biológicos y poblacionales de Acanthaster planci en México. Su tamaño se ha relacionado con la cantidad de alimento que consume, por lo que es relevante conocer esta variable. Objetivo: Describir la variabilidad en el diámetro del disco de la especie y de su alimentación en cuatro sitios al sur del Golfo de California. Métodos: De febrero 2008 a marzo 2009 se visitaron mensualmente los sitios. Se registró el diámetro del disco de un total de 389 individuos observados. El diámetro del disco se midió con una cinta métrica flexible colocada de lado a lado, en el borde donde comienzan los brazos. Para facilitar la descripción, el diámetro del disco se clasificó en tres grupos: pequeños ( 26 cm). Del total, 298 organismos se encontraron alimentándose. Se clasificaron los tipos de organismos consumidos en corales duros, otros invertebrados y algas. Para calcular la probabilidad de que individuos del mismo tamaño se alimenten de diferente variedad de organismos, se aplicó el índice de Diversidad de Simpson. Con el fin de detectar diferencias del diámetro del disco entre los meses de estudio y los sitios de muestreo, se aplicó un análisis permutacional de varianza. Resultados: Acanthaster planci tuvo un promedio de diámetro del disco de 18.23 ± 0.21 cm, con un mínimo de 7 cm y un máximo de 36 cm. La estructura de tallas fue unimodal y se caracterizó por la predominancia de individuos medianos, seguida por los pequeños y en baja proporción por los grandes. El diámetro del disco fue estadísticamente más grande en febrero y más pequeño en los últimos meses del año. En San Rafaelito se encontraron los ejemplares más grandes y en Ensenada de Muertos los más pequeños. Los individuos de tamaño mediano fueron más frecuentes a lo largo del año y en todos los sitios. Los individuos pequeños se alimentaron significativamente más de Porites panamensis, seguido de algas coralinas y tapetes. Los más grandes tuvieron los valores de diversidad más bajos, más del 90 % de los individuos en este grupo se alimentaron de Pocillopora spp. y algunos de macroalgas. Los medianos presentaron los valores más altos de diversidad y consumieron todos los tipos de alimento encontrados, sin embargo, como era de esperarse, muchos fueron selectivos hacia Pocillopora spp. Conclusiones: Acanthaster planci se considera un individuo de tamaño mediano en el área de estudio. Se detectó una evidente relación entre el diámetro del disco y la diversidad del tipo de alimento. Los tres grupos de tallas fueron positivamente selectivos hacia corales duros; los más pequeños se alimentaron preferentemente de Porites panamensis y en conjunto con los grandes, presentaron valores bajos de diversidad en el tipo de alimento, mientras que los medianos fueron los que consumieron una mayor diversidad de presas.
Introduction: Little is known about the biology and population dynamics of Acanthaster planci in Mexico. Its size is considered relevant because it is related to consumption rate. Objective: To describe the variability of the disk diameter and food type of the species in four sampling sites in the southern Gulf of California. Methods: Each site was visited on a monthly basis from February 2008 to March 2009. Disk diameter was registered from a total of 389 observed specimens. Measurements included only the main disk from side to side where the arms begin. A flexible tape was used to measure disk diameter. Three size groups were created for easier explanations: small ( 26 cm). From the total, only 298 asteroids were feeding. Preyed organisms were classified in hard corals, other invertebrates, and algae. The Simpson's Diversity Index was used to calculate the probability that any specimen would be feeding on different types of organisms. A permutational analysis of variance was used to detect differences of disk diameter amongst months and study sites. Results: This population of Acanthaster planci had an average disk diameter = 18.23 ± 0.21 cm, with a minimum of 7 cm and maximum of 36 cm. Size structure was unimodal and largely dominated by medium sized specimens, followed by small ones. The larger were less frequent. Disk diameter was statistically higher in February and lower in the last months of the year. San Rafaelito was the site with the largest and Ensenada de Muertos with the smallest organisms. Medium sized individuals were dominant throughout the year and sampling sites. The small sized fed significantly more on Porites panamensis and coralline algae and turf. Larger specimens had the lowest diversity values, more than 90 % of this size group fed on Pocillopora spp. and very few on macroalgae. Medium sized specimens showed the highest diversity, feeding on all the food types, although as expected, many of them were selective to Pocillopora spp. Conclusions: Acanthaster planci can be considered a medium sized species in the study area. There is an evident food selectivity regarding disk diameter size. The three size groups were positively selective to hard corals, but only the small favored Porites panamensis; and together with large individuals, they had the lowest diversity on food types, whereas medium sized asteroids fed on a high diversity of prey.
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Animales , Estrellas de Mar/crecimiento & desarrollo , Equinodermos/crecimiento & desarrollo , MéxicoRESUMEN
Abstract Coral reefs harbor one of the largest fish biodiversity on earth; yet information on reef fishes is still absent for many regions. We analyzed reef fish richness, distribution, and conservation on the largest Brazilian multiple use coastal MPA; which cover a large extent of coral reefs at the SWA. A total of 325 fish species have been listed for MPA Costa dos Corais, including Chondrichthyes (28 species) and Actinopterygii (297). Fish species were represented by 81 families and the most representative families were Carangidae (23 species), Labridae (21) and Gobiidae (15). The MPA fish richness represented 44% of all recorded fish species of the Southwestern Atlantic Ocean (SWA) highlighting the large-scale importance of this MPA. A total of 40 species (12%) are registered at Near Threatened (NT), Vulnerable (VU), Endangered (EN) or Critically Endangered (CR). This study reinforces the importance of MPA Costa dos Corais on reef fish biodiversity and conservation and emphasize the urgent need of conservation strategies.
Resumo Os recifes de coral abrigam uma das maiores biodiversidades de peixes do planeta; no entanto, as informações sobre peixes de recife ainda estão ausentes em muitas regiões. Analisamos a riqueza, distribuição e a conservação de peixes recifais na maior Área de Proteção Ambiental (APA) costeira de uso múltiplo do Brasil; área que possui grande extensão de recifes de corais no SWA. Um total de 325 espécies de peixes foram listadas para APA Costa dos Corais, incluindo Chondrichthyes (28 espécies) e Actinopterygii (297). As espécies de peixes foram representadas por 81 famílias e as famílias mais representativas foram Carangidae (23 espécies), Labridae (21) e Gobiidae (15). A riqueza de peixes da APA representou 44% de todas as espécies de peixes registradas no Oceano Atlântico Sudoeste (SWA), destacando a importância em grande escala desta APA. Um total de 40 espécies (12%) estão registradas como Quase Ameaçada (NT), Vulnerável (VU), Em Perigo (EN) ou Criticamente Em Perigo (CR). Este estudo reforça a importância da APA Costa dos Corais na biodiversidade e conservação dos peixes recifais e enfatiza a necessidade urgente de estratégias de conservação.
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Abstract: Threatened by global warming and extreme climatic events, such as El Niño Southern Oscillation (ENSO) and Marine Heatwaves (MHW), coral reefs worldwide faced the worst bleaching and mortality event between 2014 and 2017, induced by the 2015/2016 ENSO. We evaluated the impacts of ENSO and MHW episodes on bleaching and mortality frequencies of Siderastrea stellata at Rocas Atoll, Southwestern Atlantic, using visual censuses conducted in 2016, 2017 and 2019. Bleaching rate varied significantly along the sampling period (11.71% in 2016, 1.52% in 2017, and 88% in 2019), but mortality was always less than 4%. Bleaching events in Atlantic reefs have been constantly associated with ENSO, until these recent events of the last two years. We suggest that MHW were probably the primary driver of the observed bleaching, especially in 2019, when much higher bleaching rates were observed than in ENSO periods. Although Southwestern Atlantic massive corals are considered more resistant to thermal stress than reefs corals worldwide, the strong events registered since 2019 highlight the need for continuous monitoring to better understand coral bleaching dynamics and improve predictions on the effects of global change in the region.
Resumo: Ameaçados pelo aquecimento global e eventos climáticos extremos, como El Niño Oscilação Sul (ENSO) e Ondas de Calor Marinhas (MHW), os recifes de coral em todo o mundo enfrentaram o pior evento de branqueamento e mortalidade entre 2014 e 2017, induzido pelo ENSO 2015/2016. Nesse estudo, avaliamos os impactos dos episódios de ENSO e MHW nas frequências de branqueamento e mortalidade de Siderastrea stellata no Atol de Rocas, Atlântico Sudoeste, a partir de censos visuais realizados em 2016, 2017 e 2019. O branqueamento variou significativamente ao longo do período de amostragem (11,71% em 2016, 1,52% em 2017, e 88% em 2019), mas a mortalidade não, sendo sempre inferior a 4%. Eventos de branqueamento em recifes do Atlântico têm sido constantemente associados ao ENSO, até os eventos recentes dos últimos dois anos. Nós sugerimos que as MHW foram provavelmente o principal impulsionador do branqueamento observado, especialmente em 2019, quando as taxas de branqueamento observadas foram maiores do que nos períodos de ENSO. Embora os corais massivos do Atlântico Sudoeste sejam considerados mais resistentes ao estresse térmico quando comparados com corais recifais de outros oceanos, os fortes eventos registrados desde 2019 destacam a necessidade de monitoramento contínuo para entender melhor a dinâmica do branqueamento de corais e melhorar as previsões sobre os efeitos das mudanças globais na região.
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Introducción: La variación morfológica intraespecífica puede ser el resultado del desarrollo ontogénico, la variación genética o la heterogeneidad ambiental. En el último caso, los organismos están expuestos a diversas condiciones ambientales, lo que puede influir en el comportamiento y las adaptaciones morfológicas de las especies. Precisamente, el Corredor Arrecifal del Suroeste del Golfo de México (CASGM) está compuesto por arrecifes separados geográficamente que están expuestos a diferentes factores oceanográficos, así como atributos propios con múltiples variables ambientales. Por lo tanto, es posible encontrar diferencias morfológicas de las poblaciones de especies que se distribuyen en el corredor. Objetivo: Determinar la variación morfológica de la linterna de Aristóteles del erizo de mar Eucidaris tribuloides a lo largo del CASGM. Métodos: Se analizó la relación alométrica entre la altura de la linterna versus diámetro de la testa en 104 especímenes, también realizamos un análisis de covarianza para detectar diferencias alométricas entre grupos. Se analizó la variación de la forma de una rótula y una semipirámide de cada erizo de mar mediante morfometría geométrica. Resultados: Existen diferencias alométricas entre sistemas arrecifales. La forma de la rótula y semipirámide de los erizos de mar del norte son diferentes a los erizos del centro y el sur; sin embargo, no hubo diferencias de forma entre el centro y el sur. El tamaño centroide de la rótula y semipirámide de los erizos de mar del norte son significativamente más grandes que los del centro y el sur. Conclusiones: A lo largo del Corredor Arrecifal del Suroeste del Golfo de México, los individuos de E. tribuloides mostraron variación morfológica en sus estructuras analizadas, dichos resultados, pueden ser explicados por los gradientes latitudinales y ambientales del CASGM, además de los hábitos alimenticios de la especie y la disponibilidad del recurso alimenticio en el ambiente donde se establecen.
Introduction: Intraspecific morphological variation can be attributed to the result of genetic variation or influence of environmental heterogeneity. In the latter case, organisms are exposed to diverse environmental conditions which have an influence on their biological processes and can be seen reflected in the morphological adaptations of species. Indeed, Reef Corridor in the Southwest Gulf of Mexico (CASGM, in its Spanish acronym) is constituted of geographically separated reefs that are exposed to different large-scale oceanographic factors and show their own attributes with multiple environmental variables. Therefore, this can stimulate morphological variations of species populations that are distributed in this corridor. Objective: The aim of this study was to determine the morphological variation of the Aristotle's lantern of the sea urchin Eucidaris tribuloides along CASGM. Methods: The allometric relation between height of the Aristotle's lantern and diameter of the test of 104 specimens was analyzed, and we also used a covariance analysis to detect allometric differences between groups. Apart from that, the variation of the shape of a rotule and a demi-pyramid for each sea urchin were analyzed using geometric morphometry. Results: There are allometric differences among reef systems in the north, center and south of Veracruz. The shape of rotula and demi-pyramid of sea urchins of the north zone are different from the central and south area. However, there were no differences in shape between the center and the South area. The centroid size of rotula and demi-pyramid of the sea urchins of the North are larger than those in the center and the South. Conclusions: Along the Corridor of the Southwest of the Gulf of Mexico, specimens of E. tribuloides showed a morphological variation in their analyzed structures, these results can be explained by the geographical and environmental gradients of the CASGM, in addition to the feeding habits of E. tribuloides and the availability of the food resource in the habitat where they are established. As a stimulus to the morphological variation found in this research, the distance among the reef systems and the marine currents patterns are also considered.
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ObjectiveTo study the psychological quality of the soldiers stationed at a reef and their influencing factors, and to analyze the relationship between psychological quality, subjective evaluation of health and social support. MethodsA questionnaire survey was conducted on 100 soldiers stationed at a reef using the military psychology quality scale, self-test health rating scale and comprehension social support scale. The military psychology quality scale includes five dimensions: Intelligence, loyalty, courage, self-confidence and frustration. The self-test health rating scale includes three dimensions: Physical health, mental health, and social health. The comprehension social support scale includes three dimensions: Family support, friend support, and other support. The scores of the military psychological quality scale of the soldiers stationed at the reef were compared with the norm of military mental quality using independent-sample t test. Pearson correlation analysis was used to analyze the correlation between scores of each dimension and total scores for the three scales. Multivariate linear regression was used to analyze the influence between social support, healthy subjective evaluation and the psychological quality of soldiers stationed at the reef. ResultsThe scores of dimension confidence (calm+independent+sociable) of the soldiers were significantly better than the overall norm score (P=0.030), and the difference for the other 4 dimensions was not statistically significant between the soldiers and the norm (all P>0.05). Pearson correlation analysis showed that the scores of all dimensions and total scores were positively correlated between the three scales used in this study (all P<0.01), except for loyalty dimension of military psychology quality scale and social health dimension of self-test health rating scale (P=0.366). Multiple linear regression analysis showed that mental health was the inf luencing factor of the tolerance (P=0.006); family support and physical health were the influencing factors of mental health (P=0.022, P<0.001), and family support was the influencing factor of physical health (P=0.025). Conclusion The psychological quality of soldiers stationed at a reef is vulnerable to the environment of the reef. It is necessary to improve the psychological quality by strengthening social support and improving their own health awareness of the soldiers.
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Abstract The sea anemone Condylactis gigantea is an ecologically important member of the benthic community in coral reefs of the tropical Atlantic, and displays two morphotypes with respect to the color in their tentacular tips: the green tip morphotype and the pink/purple tip morphotype. Although some molecular and ecological differences have been found between these morphotypes, no other morphological distinctions have been reported, and currently both are still considered a single taxonomic species. In the present study, we perform an exploration on the variability in the size of cnidae between these two morphotypes and performed statistical analyses to compare the 10 categories of cnidae from specimens hosted in the Cnidarian Collection of Gulf of Mexico and Mexican Caribbean, of the Universidad Nacional Autónoma de México, which were previously collected in several coral reefs localities of the Yucatán Peninsula. Results reveal no significant variation in cnidae size between the two morphotypes, but significant variations were found within each morphotype. In addition, we update the composition of the cnidom of C. gigantea, and the utility of the size of cnidae to distinguish between morphotypes or closely related species is discussed. Rev. Biol. Trop. 66(3): 1055-1064. Epub 2018 September 01.
Resumen La anémona Condylactis gigantea es un miembro ecológicamente importante de la comunidad bentónica en arrecifes de coral del Atlántico tropical, y exhibe dos morfotipos con respecto al color de las puntas de sus tentáculos: el morfotipo de puntas verdes y el morfotipo de puntas rosadas/púrpuras. Aunque se han encontrado algunas diferencias moleculares y ecológicas entre estos morfotipos, no se han reportado otras distinciones morfológicas, y actualmente ambos siguen siendo considerados una sola especie taxonómica. En el presente estudio, realizamos una exploración sobre la variabilidad en el tamaño de los cnidocistos entre estos dos morfotipos y realizamos un análisis estadístico de 10 categorías de cnidocistos a partir de especímenes albergados en la Colección de cnidarios del Golfo de México y Caribe Mexicano, de la Universidad Nacional Autónoma de México, los cuales fueron previamente recolectados en varias localidades arrecifales de la Península de Yucatán. Los resultados no revelan variación significativa en el tamaño de los cnidocistos entre los dos morfotipos, aunque fueron encontradas variaciones significativas dentro de cada morfotipo. Adicionalmente, actualizamos la composición del cnidoma de C. gigantea, y discutimos sobre la utilidad de la talla de los cnidocistos para distinguir entre morfotipos o entre especies estrechamente relacionadas.
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Animales , Anémonas de Mar/crecimiento & desarrollo , Antozoos/anatomía & histología , Nematocisto , Arrecifes de Coral , Región del Caribe , MéxicoRESUMEN
Abstract This paper presents a checklist of the reef fish fauna of the Anchieta Island State Park, a no-take zone in which no extractive activities are allowed, in Ubatuba, Southeastern Brazil. Data was obtained between 2011 and 2013, mainly through underwater observations with snorkelling and SCUBA, and secondarily using scientific fishing (trawling). Published and unpublished data were also verified and compiled. A total of 103 reef fish species, distributed in 78 genus and 50 families was recorded. Haemulidae was the richest family (n=7 species), followed by Epinephelidae (n=6), Pomacentridae, Carangidae and Tetraodontidae (n= 4 each). Haemulon was also the most speciose genera (n=5), followed by Stegastes, Acanthurus and Mycteroperca (n=3 each). Sixty-nine species (67%) are included in global and regional Red Lists. Twenty-five species (24.2%) are within the categories Critically Endangered (CR), Endangered (EN), Vulnerable (VU) and Near-Threathened (NT). The network of Marine Protected Areas in Southeastern Brazil is still incipient, and the considerable number of threatened species in the Anchieta Island State Park clearly indicates the importance of the study area for the conservation of coastal and reef fishes.
Resumo Este artigo apresenta uma lista de espécies de peixes recifais do Parque Estadual da Ilha Anchieta, uma área na qual nenhuma atividade extrativista é permitida, em Ubatuba, Sudeste do Brasil. Os dados foram coletados entre 2011 e 2013, principalmente por observações subaquáticas com o uso de mergulhos livres e autônomos e, secundariamente, através de pescaria científica (arrasto). Dados publicados e não publicados também foram verificados e compilados. Foram registradas 103 espécies de peixes recifais distribuídas em 78 gêneros e 50 famílias. Haemulidae foi a família com maior número de espécies (n=7 espécies), seguida por Epinephelidae (n=6), Pomacentridae, Carangidae e Tetraodontidae (n=4 cada). Os gêneros com maior número de espécies foram Haemulon (n=5) e Stegastes¸ Acanthurus e Mycteroperca (n=3 cada). Sessenta e nove espécies (67%) estão inclusas em listas vermelhas de espécies ameaçadas globais e regionais. Vinte e cinco espécies (24,2%) são classificadas nas categorias Criticamente em Perigo (CR), Em Perigo (EN), Vulnerável (VU) e Quase Ameaçadas (NT). A rede de Áreas Marinhas Protegidas no Sudeste do Brasil ainda é incipiente e o considerável número de espécies ameaçadas no Parque Estadual da Ilha Anchieta indica claramente a importância da área de estudo para a conservação de peixes recifais e costeiros.
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ABSTRACT Coral reefs are one of the most vulnerable ecosystems to ocean warming and acidification, and it is important to determine the role of reef building species in this environment in order to obtain insight into their susceptibility to expected impacts of global changes. Aspects of the life history of a coral population, such as reproduction, growth and size-frequency can contribute to the production of models that are used to estimate impacts and potential recovery of the population, acting as a powerful tool for the conservation and management of those ecosystems. Here, we present the first evidence of Siderastrea stellata planulation, its early growth, population size-frequency distribution and growth rate of adult colonies in Rocas Atoll. Our results, together with the environmental protection policies and the absence of anthropogenic pressures, suggest that S. stellata population may have a good potential in the maintenance and recovery in the atoll. However, our results also indicate an impact on corals' recruitment, probably as a consequence of the positive temperature anomaly that occurred in 2010. Thus, despite the pristine status of Rocas Atoll, the preservation of its coral community seems to be threatened by current global changes, such as more frequent thermal stress events.
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Animales , Cambio Climático , Antozoos/anatomía & histología , Antozoos/crecimiento & desarrollo , Arrecifes de Coral , Factores de Tiempo , Océano Atlántico , Brasil , Monitoreo del Ambiente , Crecimiento Demográfico , Mapeo GeográficoRESUMEN
Abstract:Coral reefs are under intense conditions of stress caused by the anthropogenic activities in coastal areas and the increase of human population. Water effluents from urban and industrial areas carry large amounts of sediments and pollutants affecting corals populations, inducing bioerosion, increasing diseases and promoting the development of algae that compete for space with corals. In the Veracruz Reef System National Park (VRSNP) coral reefs are strongly affected by human activities carried out in the area. Gallega and Galleguilla reefs are among the most affected by wastewater discharges from the industrial (petrochemical and metallurgical) and urban areas in their vicinity. To assess the potential impact of this contamination on corals in the VRSNP, a chemical composition and morphology study of 76 Pseudodiploria colonies collected in reefs Gallega, Galleguilla, Isla Verde and Isla de Enmedio, was performed. Fragments of ~10 cm2 were collected and boric acid at 0.5 % was used to remove tissue from the skeleton; once clean, the morphology of each sample was determined with a scanning electron microscope (SEM). Subsequently, to test the chemical composition, an energy dispersion spectroscopy of X-ray chemical microanalysis (EDSX) was performed in the SEM. We found that corals from Gallega and Galleguilla reefs, located closer to human populations, presented high levels of tungsten and the skeleton exhibited multiple perforations. In contrast, corals from the farthest offshore reefs (Isla Verde and Isla de Enmedio) exhibited lower levels of tungsten and fewer perforations in their skeleton. These results demonstrated that anthropogenic activities in the NPVRS are affecting corals skeleton, highly damaging and promoting their bioerosion. The presence of traces of tungsten in the skeleton of corals is an evidence of the damage that waste discharges are causing to coral reefs. Discharges of large amounts of contaminants promoted the growth of harmful species that grow and develop into the corals skeleton, causing its bioerosion, and making them susceptible to disease and physical damage. This study is the first evidence of the effects of contamination on these species; therefore, further studies are necessary to determine the impact of pollution on their biology and survival. Rev. Biol. Trop. 64 (3): 1077-1089. Epub 2016 September 01.
ResumenLos arrecifes de coral se encuentran bajo condiciones intensas de estrés causado por las actividades antropogénicas y el incremento de las poblaciones humanas en las zonas costeras. Las descargas de aguas de origen urbano e industrial transportan sedimentos y contaminantes que afectan a las poblaciones de corales, induciendo la bioerosion, el aumento de enfermedades en los corales y promueven el desarrollo de algas que compiten por espacio con los corales. En el Parque Nacional Sistema Arrecifal Veracruzano (NPVRS) los arrecifes de coral son afectados fuertemente por las actividades humanas que se llevan a cabo en la zona. Los arrecifes Gallega y Galleguilla son de los más afectados por las descargas de aguas residuales provenientes de la industria (petroquímica y metalúrgica) y de áreas urbanas que desembocan sus aguas en las proximidades de los arrecifes. Para evaluar el posible impacto de las descargas de aguas en los corales del NPVRS, se realizó un estudio de la composición química y morfología de 76 colonias de Pseudodiploria en los arrecifes Gallega, Galleguilla, Isla Verde e Isla de Enmedio. Se recolectaron fragmentos de ~10 cm2, el tejido del esqueleto fue removido utilizando ácido bórico al 0.5 %. Una vez limpia la muestra, la morfología fue analizada con un microscopio electrónico de barrido (SEM), posteriormente, para analizar la composición química de las muestras, realizamos una espectroscopia de dispersión de energía o micro-análisis químico de rayos X (EDSX) en el SEM. Encontramos que los corales de los arrecifes Gallega y Galleguilla que se encuentran ubicados cerca de poblaciones humanas, presentan altos niveles de tungsteno y el esqueleto exhibe múltiples agujeros. En contraste, los corales de los arrecifes más lejanos (Isla Verde e Isla de En medio) mostraron niveles más bajos de tungsteno y un menor número de agujeros en su esqueleto. Nuestros resultados demuestran que las actividades antropogénicas en el NPVRS, están afectando el esqueleto de los corales y promueven la bioerosión. Las descargas de grandes cantidades de contaminantes hacia las zonas costeras, promueven el crecimiento de especies dañinas que crecen y se desarrollan dentro del esqueleto de los corales, causando bioerosión del esqueleto, haciéndolos susceptibles a enfermedades y daños físicos. Debido a que este estudio es la primera evidencia de los efectos de la contaminación sobre esta especie de corales, son necesarios más estudios para determinar el impacto de la contaminación sobre su biología y la supervivencia de los corales.
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Animales , Tungsteno/análisis , Contaminantes Químicos del Agua/química , Antozoos/química , Arrecifes de Coral , Valores de Referencia , Agua de Mar/química , Espectrometría por Rayos X , Microscopía Electrónica de Rastreo , Monitoreo del Ambiente , Antozoos/anatomía & histología , MéxicoRESUMEN
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.
Asunto(s)
Animales , Antozoos , Biodiversidad , Arrecifes de Coral , Monitoreo del Ambiente , Densidad de Población , CubaRESUMEN
When confronted by predators, prey need to make an economic decision between continuing their current activity or flee. Flight Initiation Distance (FID), the distance at which an organism begins to flee an approaching threat, has been used to indicate an animal's fearfulness level and a way to examine factors influencing escape decisions. Here we investigated how the FID of the barber surgeonfish, Acanthurus bahianus, responds to the presence of spearfishers in a fishing site in northeast Brazil. Specifically, we examined whether the FID was influenced by body and group size; by the heterogeneity of species in groups formation; and the distance to shelter. Significant differences in FID were observed with increasing body size. We found no significant relationship of FID with size or group formation, neither with distance to shelter. Preferences in forming groups with A. bahianus were seen among some species, and a higher FID was associated with less sheltered substrates. Results obtained here support theories suggesting that spearfishers do influence fish behavior. We highlight that future research should focus on the indirect impacts of spearfishing on the structure of marine communities, emphasizing the anti-predator behaviour of juvenile and adult target fishes.
Ao serem confrontadas por predadores, as presas precisam tomar decisões econômicas, escolhendo entre continuar com sua atividade atual ou fugir. Distância Inicial de Fuga (DIF), a distância à qual um organismo começa a fugir de uma ameaça que se aproxima, tem sido utilizada para indicar o nível de medo do animal e um modo para se examinar fatores que influenciam nas decisões de fuga. Aqui nós investigamos como a DIF do peixe cirurgião, Acanthurus bahianus , responde à presença de pescadores subaquáticos em uma tradicional área de pesca no nordeste do Brasil. Especificamente, investigamos se a DIF foi influenciada pelo tamanho do corpo e do grupo; pela heterogeneidade das espécies na formação de grupos; e pela distância para refúgio. Diferenças significativas na DIF foram observadas com o aumento no tamanho do corpo. Nós não encontramos nenhuma relação significativa da DIF com o tamanho ou formação do grupo, nem com a distância para refúgio. Preferências na formação de grupos com A. bahianus foram observadas entre algumas espécies,e maiores DIF foram associadas com substratos menos abrigados. Resultados obtidos aqui suportam teorias sugerindo que pescadores subaquáticos influenciam no comportamento dos peixes. Nós destacamos que pesquisas futuras devem focar nos impactos indiretos da pesca subaquática na estrutura das comunidades marinhas, enfatizando o comportamento anti-predador de peixes juvenis e adultos alvo da pesca.
Asunto(s)
Animales , Conducta Predatoria , Peces/crecimiento & desarrollo , Conducta Fugitiva/tendenciasRESUMEN
Resumen Para obtener datos sobre la composición y distribución de los equinodermos presentes en los sistemas arrecifales del norte (Blanquilla, Medio, Lobos y Blake) y sur de Veracruz (La Perla, Zapotitlán, Palo Seco y Tripie) México, se efectuaron 539 muestreos y 770 colectas distribuidos en los diferentes hábitats de cada sistema de marzo a diciembre de 2013 mediante buceo libre y SCUBA. Para valorar las diferencias a cada escala espacial (tipo de arrecife, arrecife y hábitat) se efectuaron análisis de similitud con los índices de Jaccard y EMNM. Se registraron un total de 45 especies pertenecientes a 34 géneros y 26 familias, incluyendo cinco nuevos registros para el estado de Veracruz. El mayor número de especies corresponde a las clases: Ophiuroidea (15 especies) y Echinoidea (13 especies). Los sistemas del norte mostraron una mayor riqueza (40 especies) comparados con los del sur (27 especies). Por localidad, el arrecife Lobos (31 especies) presentó la mayor riqueza y la formación Tripie (7 especies) la menor. El EMNM dividió a los tres tipos de arrecifes, a escala de arrecifes, los marginales se alejan de los arrecifes plataforma y sumergidos. A nivel de hábitats, las zonas someras se separan de las profundas, las praderas de Thalassia y la planicie arrecifal de las pendientes y no se observaron diferencias entre hábitats en los sistema marginales, excepto en el barco hundido. La fauna de equinodermos asociados a los arrecifes de Veracruz está compuesta por 54 especies. El tipo de arrecife así como los atributos del sustrato y la profundidad son muy importantes para definir la riqueza y distribución espacial de los equinodermos.
Abstract Echinoderms are a key element in the structure and function of their ecosystems. To study composition and distribution of echinoderms from northern (Blanquilla, Medio, Lobos and Blake) and southern (La Perla, Zapotitlan, Palo Seco and Tripie) reefs of Veracruz, Mexico, 539 visual censuses and 770 collects distributed in different habitats of each reef were done from March to December 2013 using free and SCUBA diving. To evaluate spatial differences at different scales (type reef, reef and habitat), a similarity analysis was done using Jaccard index and NMDS. 45 species of 34 genera and 26 families were recorded, including five new records for Veracruz. Ophiuroidea (15 species) and Echinoidea (13 species) showed more species. Northern reefs presented more species (40 species) than southern reefs (27 species). By locality, Lobos reef presented the greatest richness (31 species) and Tripie (7 species) the poorest. NMDS at type reef separated the three type reefs, at reef scale fringing reefs were divided from platform and submerged reefs. At habitat scale, shallow zones were separated from deep areas, Thalassia beds and reef flat from slopes and there were not differences between habitats in fringing reefs except in the sunken ship. The fauna of echinoderms associated to reefs of State of Veracruz is composed by 54 species. The type of reef and the characteristics of substrate and depth are very important to define the richness and spatial distribution of echinoderms. Rev. Biol. Trop. 63 (Suppl. 2): 183-193. Epub 2015 June 01.