Ecological traits do not predict the uptake of microplastics by fishes in a Neotropical River.

Pollution by synthetic polymers is even more problematic to the environment when this material is fragmented into small portions, forming microplastics (MPs). We analyzed the contamination of ichthyofauna by MPs in an important river of the Atlantic Rainforest in regard to abundance, diversity of morphotypes, polymers, colors, and sizes of the synthetic particles in 20 species of fish. Fish were collected in November 2019 and in March 2020 in five sites along the Pomba River. Of the 101 fish analyzed, 49 (49%) presented MPs in at least one organ. Of the 20 species of fish collected 13 included individuals with at least one MP in their analyzed organs. The organs, trophic categories and feeding areas did not affect the general abundance of MPs types. Blue MPs were predominant, followed by the colors black, red, and white. MP fibers represented 91% of total MPs. Most MPs were between 2 and 3 mm in size. Polyethylene terephthalate (PET), polypropylene (PP), polyamide (PA), polyvinylidene chloride "Nylon" (PVDC), and high-density polyethylene (HDPE) were detected in the fishes. The exposure of the fish species to MPs was associated mainly with individual size and species-specific aspects, regardless of ecological traits. Considering that 55% of the fish species studied are consumed by humans, it is necessary to study the potential impact of MP ingestion on human health and to understand to what extent we may be consuming both plastic particles and contaminants that are adsorbed to MPs.

Fish assemblage of the Mamanguape Environmental Protection Area, NE Brazil: abundance, composition and microhabitat availability along the mangrove-reef gradient

Reefs, mangroves and seagrass biotopes often occur in close association, forming a complex and highly productive ecosystem that provide significant ecologic and economic goods and services. Different anthropogenic disturbances are increasingly affecting these tropical coastal habitats leading to growing conservation concern. In this field-based study, we used a visual census technique (belt transects 50 m x 2 m) to investigate the interactions between fishes and microhabitats at the Mamanguape Mangrove-Reef system, NE Brazil. Overall, 144 belt transects were performed from October 2007 to September 2008 to assess the structure of the fish assemblage. Fish trophic groups and life stage (juveniles and adults) were recorded according to literature, the percent cover of the substrate was estimated using the point contact method. Our results revealed that fish composition gradually changed from the Estuarine to the Reef zone, and that fish assemblage was strongly related to the microhabitat availability, as suggested by the predominance of carnivores at the Estuarine zone and presence of herbivores at the Reef zone. Fish abundance and diversity were higher in the Reef zone and estuary margins, highlighting the importance of structural complexity. A pattern of nursery area utilization, with larger specimens at the Transition and Reef Zone and smaller individuals at the Estuarine zone, was recorded for Abudefduf saxatilis, Anisotremus surinamensis, Lutjanus alexandrei, and Lutjanus jocu. Our findings clearly suggests ecosystem connectivity between mangrove, seagrass and reef biotopes, and highlighted the importance of Mamanguape Mangrove-Reef System as a priority area for conservation and research, whose habitat mosaics should be further studied and protected.

Recifes, manguezais e bancos de fanerógamas marinhas são biótopos frequentemente associados, formando um ecossistema complexo e altamente produtivo que proporciona significativos bens e serviços ecológicos e econômicos. Diferentes impactos antrópicos estão crescentemente afetando esses habitats costeiros tropicais, trazendo preocupações acerca de sua conservação. Neste estudo de campo, utilizamos uma técnica de censo visual subaquático (transecções de 50 x 2 m) para investigar as interações entre os peixes e microhabitats no complexo estuarino-recifal de Mamanguape, no Nordeste do Brasil. Entre outubro de 2007 e setembro de 2008 foram realizadas 144 transecções para avaliar a estrutura da assembleia de peixes. Grupos tróficos e estágios de vida dos peixes (jovens e adultos) foram registrados segundo a literatura, enquanto a porcentagem de cobertura do substrato foi estimada através do método de pontos de contato. Nossos resultados mostraram que a composição da ictiofauna mudou gradualmente da Zona Estuarina para a Zona Recifal, e que a assembleia de peixes esteve fortemente relacionada com a disponibilidade de microhabitats - como sugerido pela predominância de carnívoros na zona estuarina e presença de herbívoros na zona recifal. A abundância e diversidade de peixes foram maiores na zona recifal e nas margens do estuário, destacando a importância da complexidade estrutural. O padrão de uso da área como berçário, com indivíduos maiores nas zonas de transição e recifal, e os menores na zona estuarina, foi registrado para Abudefduf saxatilis, Anisotremus surinamensis, Hippocampus reidi, Lutjanus alexandrei e Lutjanus jocu. Nossos resultados sugerem que há conectividade entre os biótopos de manguezal, bancos de fanerógamas e recifes, e destacam a importância do Sistema Manguezal-Recife de Mamanguape como uma área prioritária para conservação e pesquisa, cujos mosaicos de habitats devem ser ainda estudados e protegidos.