Composição meiofaunística da praia de Ponta Negra, Natal – RN: primeiros registros.

Abstract

Beaches are dynamic and sensitive coastal systems that act as buffer zones, protecting the coastline against the direct action of the ocean. These areas are in constant transformation, undergoing natural and anthropogenic influences. Meiofauna have a short life cycle, high abundance and diversity, and act as environmental bioindicators. The objective of this study was to evaluate the stock of the meiofaunal community before the execution of a sedimentary deposition engineering project (hydraulic landfill) on Ponta Negra Beach, Natal - RN. The present study was carried out on Ponta Negra Beach, located in the municipality of Natal, capital of the state of Rio Grande do Norte, Brazil. The study area was divided into four distinct points along the sand strip, with three replicates at each point. Collections were carried out during low tide, in the months of December 2023, March 2024 and August 2024. To evaluate the abiotic data, sediment samples were collected for analysis of organic matter and granulometry. The organic matter varied between the points, with point 1 of the second collection presenting the highest index (0.32 g). Twelve meiofaunal groups were identified: Nematoda, Copepoda, Tardigrada, Turbellaria, Gastrotricha, Oligochaeta, Polychaeta, Ostracoda, Acari, Naupliu, Kinorhyncha and Rotifera. The first collection had the Nematoda as the dominant group. In the second, a significant increase in the relative abundance of tardigrades was observed. In the third collection, there was a more balanced distribution between Nematoda, Tardigrade and Copepod. The results suggest that the qualitative and quantitative composition of the meiofauna on Ponta Negra Beach is strongly related to sedimentation processes, possibly intensified by erosion or by the contribution of sediments from Morro do Careca. The spatial and temporal variations identified in the meiofaunal communities provide an important baseline for future comparative studies, especially after the implementation of the hydraulic landfill, allowing the evaluation of possible impacts of the intervention on the local ecological structure.