ABSTRACT
Abstract Increasing habitat modification and species loss demand consistent efforts to describe and understand biodiversity patterns. The BIOTA/FAPESP Program was created in this context and it has been a successful initiative to promote studies on biodiversity and conservation in Brazil. The BIOTA/Araçá is an interdisciplinary project that provided a detailed evaluation of the biodiversity of Araçá Bay, a coastal seascape located on the North coast of the state of São Paulo, Southeast Brazil. The bay encompasses multiple habitats, such as beaches, mangroves, rocky shores, and a tidal flat, and provides important ecosystem services. Unfortunately, the bay is the subject of complex social-environmental conflicts that oppose economic, social, and environmental demands (i.e., the expansion of neighboring harbor activities vs. small-scale artisanal fisheries and protection of biodiversity). The present study presents a survey of the benthic species occurring in the different habitats of Araçá Bay, including data obtained during the BIOTA/Araçá project and previous assessments of the area. The benthic species play an important role in marine environments and studying the diversity of these organisms that live associated with the bottom is indispensable for comprehending the environment's functioning. The macrofauna, meiofauna, and microorganisms associated with soft and hard bottom were listed, and additional information, such as the habitat and geographical distribution, were provided for each species. The checklist includes 826 species, almost 70% recorded during the BIOTA/Araçá project. The most speciose taxa were the annelids (225 spp.), mollusks (194 spp.), and crustaceans (177 spp.). Seven benthic species are endemic to Araçá Bay, 14 are considered threatened, and seven are economically exploited. Furthermore, the bay is the type locality of many taxa, and 11 new benthic species were described based on specimens sampled during the project. This project shows the importance of Araçá Bay as a unique biologically rich environment and highlights the need for conservation efforts in light of the current threats.
Resumo O aumento da modificação dos habitats e da perda de espécies demanda esforços consistentes para descrever e compreender os padrões de biodiversidade. O programa BIOTA/FAPESP foi criado nesse contexto e é uma iniciativa de sucesso para promover estudos em biodiversidade e conservação no Brasil. O BIOTA/Araçá é um projeto interdisciplinar que promoveu uma avaliação detalhada da biodiversidade da Baía do Araçá, um ecossistema costeiro localizado ao Norte do estado de São Paulo, Sudeste do Brasil. A baía engloba múltiplos habitats, tais como praias, manguezais, costões rochosos, e uma planície de maré, e também fornece importantes serviços ecossistêmicos. Infelizmente, a baía está sujeita à conflitos sócio-ambientais complexos que contrastam demandas econômicas, sociais e ambientais (i.e. a expansão das atividades do porto vizinho vs. a pesca artesanal de pequena escala e a proteção da biodiversidade). O presente estudo apresenta um levantamento das espécies bentônicas que ocorrem nos diferentes habitats da Baía do Araçá, incluindo dados obtidos durante o projeto BIOTA/Araçá e de investigações realizadas anteriormente na área. As espécies bentônicas desempenham um papel importante no ambiente marinho, e estudar a diversidade desses organismos que vivem associados ao fundo é indispensável para compreender o funcionamento do meio ambiente. A macrofauna, meiofauna, e microorganismos associados aos fundos consolidado e inconsolidado foram listados, e informações adicionais foram fornecidas para cada espécie, tais como a distribuição geográfica e nos habitats. O checklist inclui 826 espécies, quase 70% registradas durante o projeto BIOTA/Araçá. Os taxa mais especiosos foram os anelídeos (225 spp.), moluscos (194 spp.), e crustáceos (177 spp.). Entre as espécies bentônicas listadas, sete são endêmicas da Baía do Araçá, 14 são consideradas ameaçadas de extinção, e sete são exploradas economicamente. A baía é a localidade tipo de vários taxa, e 11 novas espécies bentônicas foram descritas com base em espécimes amostrados durante o projeto. Este projeto mostra a importância da Baía do Araçá como um ambiente de riqueza biológica única e demonstra a necessidade de esforços para a sua conservação considerando as atuais ameaças.
ABSTRACT
Marine meiofauna comprises up to 22 phyla. Its morphological identification requires time and taxonomists' expertise, and molecular tools can make this task faster. We aim to disentangle meiofaunal diversity patterns at Araçá Bay by applying a model selection approach and estimating the effectiveness of metabarcoding (18S rDNA) and morphological methods for estimating the response of meiofauna diversity in small-scale interactions with environmental variables. A rarefaction curve indicated that ten samples were sufficient for estimating the total number of meiofauna OTUs in a tidal flat. In both approaches, richness was predicted by mean sand percentage, sediment sorting, and bacteria concentration. Nematode genera composition differed significantly between approaches, the result of taxonomic mismatch in the genetic database. The similarity between the model selected for diversity descriptors, the richness of nematode genera and meiofauna composition emphasized the utility of predictive models for metabarcoding estimates to detect small-scale interactions of these organisms.
Subject(s)
Aquatic Organisms/classification , Biodiversity , Ecology , Invertebrates/classification , Animals , DNA Barcoding, TaxonomicABSTRACT
We investigated the relationship between the AMBI index and different contamination proxies in an urbanized bay in South America (SE Brazil), and the effect of (a) abundance data transformation and (b) exclusion of low-reliability sites (high SD; low N) on the index' performance. Poor ecological quality and opportunistic species were related to an increase in contaminants concentrations and mud content. Good ecological status and sensitive species (EG I) were mainly related to increased hydrodynamics. Data transformation caused minimal changes to the overall relationships, but exclusion of low-reliability sites improved the relationship between ecological groups and contamination proxies. Our results show that AMBI is robust in detecting effects of different contaminants in the area and reinforce the importance of the index as a tool for coastal management, but local joint efforts are needed to improve and adjust local species classification in ecological groups to improve the index' performance.
Subject(s)
Environmental Monitoring/methods , Animals , Bays , Brazil , Ecosystem , Reproducibility of Results , Urbanization , Water PollutionABSTRACT
Climate change is predicted to lead to more extreme weather events, including changes to storm frequency, intensity and location. Yet the ecological responses to storms are incompletely understood for sandy shorelines, the globe's longest land-ocean interface. Here we document how storms of different magnitude impacted the invertebrate assemblages on a tidal flat in Brazil. We specifically tested the relationships between wave energy and spatial heterogeneity, both for habitat properties (habitat heterogeneity) and fauna (ß-diversity), predicting that larger storms redistribute sediments and hence lead to spatially less variable faunal assemblages. The sediment matrix tended to become less heterogeneous across the flat after high-energy wave events, whereas ß-diversity increased after storms. This higher ß-diversity was primarily driven by species losses. Significantly fewer species at a significantly lower density occurred within days to weeks after storms. Negative density and biomass responses to storm events were most prominent in crustaceans. Invertebrate assemblages appeared to recover within a short time (weeks to months) after storms, highlighting that most species typical of sedimentary shorelines are, to some degree, resilient to short-term changes in wave energy. Given that storm frequency and intensity are predicted to change in the coming decades, identifying properties that determine resilience and recovery of ecosystems constitute a research priority for sedimentary shorelines and beyond.
ABSTRACT
Aiming to analyse the growth pattern, to allow biomass estimates and consequently to subsidize the ecosystem modelling, the length-weight relationships (LWR) of 39 fish species from the Araçá Bay, a subtropical coastal area chosen as model for a holistic study comprising environmental, social and economic aspects have been estimated. The objective of this study was to provide LWR for the fishes from the area itself, accurately based on the life stages of fish populations present there. Particularly for Albula vulpes, Trachinotus carolinus, T. falcatus, Archosargus rhomboidalis and Kyphosus sectatrix these are the first records of LWR in Brazil.
Com o objetivo de analisar o padrão de crescimento e viabilizar estimativas de biomassas e, consequentemente, subsidiar a modelagem ecossistêmica, foram estimadas as relações comprimento-peso (RCP) de 39 espécies de peixes da baía do Araçá, uma área costeira subtropical escolhida como modelo para um estudo holístico compreendendo aspectos ambientais, sociais e econômicos. O objetivo deste estudo foi fornecer RCP para os peixes da própria área, baseadas nas estágios de vida das populações ictiícas ali presentes. Especialmente para Albula vulpes, Trachinotus carolinus, T. falcatus, Archosargus rhomboidalis e Kyphosus sectatrix estas são as primeiras estimativas de RCP no Brasil.
