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The Role of Coral Gardens as habitat providers for associated species
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O mar profundo representa 95% do volume do oceano, mas ainda se sabe muito pouco sobre ele. As comunidades bentónicas presentes podem criar habitats biogénicos que desempenham um papel ecológico importante, fornecendo microhabitats, fontes de alimento e áreas de reprodução a uma grande variedade de espécies. Isto é ainda mais importante em ambientes onde o alimento e a complexidade do substrato geológico diminuem. A região dos Açores alberga uma grande diversidade geomorfológica que permite o desenvolvimento de comunidades bentónicas diversas no mar profundo, como os corais de água fria e agregações de esponjas. Estes hotspots são importantes para a fauna associada, melhorando a biodiversidade do mar profundo. Com base em duas metodologias diferentes (análise de vídeo e base de dados COLETA), este trabalho teve como objetivo descrever a composição de espécies, abundância e diversidade da fauna associada de cinco espécies de corais comuns no mar profundo dos Açores: Leiopathes cf. expansa, Callogorgia verticillata, Paracalyptrophora josephinae, Viminella flagellum e Dentomuricea aff. meteor. Foram encontrados 136 taxa (2.208 organismos) associados às espécies de coral, dos quais 56 taxa (843 organismos) foram identificados nas imagens de vídeo e 95 taxa (1.365 organismos) na COLETA. Os resultados da análise de vídeo mostraram que a espécie de coral com mais fauna associada foi L. cf. expansa, que através da sua morfologia arborescente e tridimensional cria habitats para uma grande variedade de espécies. Este resultado foi ainda apoiado por curvas de rarefação construídas com base em dados de riqueza e diversidade de espécies. Os espécimes físicos da COLETA apresentaram resultados diferentes, com a espécie D. aff. meteor a albergar o maior número de organismos associados e C. verticillata o maior número de taxa. A espécie P. josephinae apresentou o menor número de taxa e organismos entre todos os corais. Independentemente da metodologia utilizada, Cnidaria foi o filo mais representativo de todos. A maioria das espécies de corais apresentou maior riqueza e abundância de espécies associadas em colónias grandes, o que indica a importância de preservar estas comunidades dos impactos de actividades de pesca como o palangre, que tendem a selecionar positivamente colónias maiores (e muito mais velhas) em detrimento das mais pequenas.
ABSTRACT: The deep sea represents 95% of the ocean volume, but yet very little is known about it. Benthic communities present in the deep sea can create biogenic habitats that play an important ecological role in the ecosystem, providing microhabitats, food sources, and reproduction areas to a wide variety of motile and sessile species that live associated to them. This is even more important in environments where food supply and the complexity of the geological substrate decreases. The Azores region hosts a wide variety of geomorphological features enabling diverse benthic communities such as cold-water corals (CWC) and sponge grounds to develop. These are important hotspots for associated fauna, improving deep-sea biodiversity. Based on two different methodologies (video analysis and COLETA database), this work had the objective of describing the species composition, abundance, and diversity of associated fauna of five CWC species common in the deep sea of the Azores: Leiopathes cf. expansa, Callogorgia verticillata, Paracalyptrophora josephinae, Viminella flagellum and Dentomuricea aff. meteor. A total of 136 taxa (2,208 organisms) were found associated with the coral species selected, of which 56 taxa (843 organisms) were identified on the video images and 95 taxa (1,365 organisms) in COLETA. The results of the video analysis showed that the coral species with the most associated fauna was L. cf. expansa, which through its arborescent and three-dimensional morphology creates habitats for a wide variety of associated species. This result was further supported by rarefaction curves built on species richness and diversity data. The physical specimens from COLETA analysed showed contrasting results, with the species D. aff. meteor hosting the highest number of associated organisms and C. verticillata the highest number of taxa. The species P. josephinae hosted the lowest number of taxa and organisms among all corals. Regardless of the methodology used, Cnidaria was the most representative phylum of all. Most coral species showed higher numbers of associated species richness and abundance on large and very large colonies, indicating the importance of preserving those communities from the impacts of fishing activities such as longlining, which tend to positively select larger (and much older) colonies against smaller ones.
ABSTRACT: The deep sea represents 95% of the ocean volume, but yet very little is known about it. Benthic communities present in the deep sea can create biogenic habitats that play an important ecological role in the ecosystem, providing microhabitats, food sources, and reproduction areas to a wide variety of motile and sessile species that live associated to them. This is even more important in environments where food supply and the complexity of the geological substrate decreases. The Azores region hosts a wide variety of geomorphological features enabling diverse benthic communities such as cold-water corals (CWC) and sponge grounds to develop. These are important hotspots for associated fauna, improving deep-sea biodiversity. Based on two different methodologies (video analysis and COLETA database), this work had the objective of describing the species composition, abundance, and diversity of associated fauna of five CWC species common in the deep sea of the Azores: Leiopathes cf. expansa, Callogorgia verticillata, Paracalyptrophora josephinae, Viminella flagellum and Dentomuricea aff. meteor. A total of 136 taxa (2,208 organisms) were found associated with the coral species selected, of which 56 taxa (843 organisms) were identified on the video images and 95 taxa (1,365 organisms) in COLETA. The results of the video analysis showed that the coral species with the most associated fauna was L. cf. expansa, which through its arborescent and three-dimensional morphology creates habitats for a wide variety of associated species. This result was further supported by rarefaction curves built on species richness and diversity data. The physical specimens from COLETA analysed showed contrasting results, with the species D. aff. meteor hosting the highest number of associated organisms and C. verticillata the highest number of taxa. The species P. josephinae hosted the lowest number of taxa and organisms among all corals. Regardless of the methodology used, Cnidaria was the most representative phylum of all. Most coral species showed higher numbers of associated species richness and abundance on large and very large colonies, indicating the importance of preserving those communities from the impacts of fishing activities such as longlining, which tend to positively select larger (and much older) colonies against smaller ones.
Descrição
Dissertação de Mestrado, Estudos Integrados dos Oceanos, 26 de abril de 2024, Universidade dos Açores.
Palavras-chave
deep-sea cold-water corals associated fauna video analysis community structure
Contexto Educativo
Citação
BRUNO, Inês Correia. (2023). "The Role of Coral Gardens as habitat providers for associated species". Horta: Universidade dos Açores, 2023, 71 p. Dissertação de Mestrado em Estudos Integrados dos Oceanos. Disponível em http://hdl.handle.net/10400.3/8914