Análise comparativa da biota críptica incrustante em ilhas costeiras de São Paulo, Brasil

Le résumé fourni par la source

Coralline environments are important, complex and valuable systems of coastal marine life.They are highly relevant biologically and socioeconomically, harboring an infinite number of organisms, most of which have never been named or described.Local benthic communities are diverse and one of its components is the cryptic fauna, usually composed by invertebrates that inhabit crevices within the reef matrix.Many of them encrust to surfaces and their study is hampered by the limited access to this component and troublesome taxonomic identification.To deal with such issues, the Autonomous Reef Monitoring Structures (ARMS) were conceived as a standardized reef biodiversity sampling method, aimed at reproducing the reef matrix and attract the colonization of the cryptic biota.Therefore, the goal of this study is to analyze and compare cryptic encrusting biota from installed ARMS structures in coastal islands of the São Paulo estate, Brazil, through high-definition image capture and traditional taxonomy.Four ARMS sets were deployed between March and April of 2019, two in Alcatrazes isle and two in Ubatuba, in Palmas and Cabras isles and, one year later, retrieved for processing.The structures were disassembled and all 216 face plates were photographed in high definition.All images were processed using the CoralNet platform and organisms were identified to the lowest possible taxonomic level.Resulting data was analyzed regarding richness, diversity and benthic coverage for different spatial scales.A great abundance of bryozoans, tunicates, sponges, polychaetes and mollusks were identified.ARMS from the Alcatrazes island showed higher richness, while Ubatuba showed higher diversity according to both Simpson and Shannon indexes.Interspersed patterns of diversity and richness were observed inside the ARMS structure, which can be a result caused by the ARMS own design and the addition of micro-habitats in the structures themselves.Beta diversity analyses showed higher component turnover rather than their nestedness, thus vouching for a big complexity in the cryptic component.The ARMS were very efficient to assess the cryptic biota, being a non-destructive method that generates knowledge for the conservation of these environments with satisfactory cost-benefit.

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