Assembleias de peixes recifais em poças de maré tropicais: Elementos estruturadores e mudanças em sua composição (1999 e 2018)

Abstract

Tidepools, ecosystems formed by the damming of ocean salt water during low tide, are a common view observed in tidal areas, exhibiting great biodiversity. They thus provide an unparalleled opportunity for the study of diverse groups of organisms that inhabit them, without demanding a large amount of resources. Fish species that make use of these environments can be classified based on several criteria, such as the life cycle phases in which they remain in these habitats, major feeding habits and phylogenetic relationships. Despite the ease of access to tidepools, until the middle of the nineties little was known about the dynamics of these coastal environments in Ceará, as well as the composition of the resident fish assemblies in this ecosystem. The Iparana beach, located in the municipality of Caucaia-CE, presents an extensive bank of sandstone reefs with about 90,000m², in which dozens of tide pools form during the low tides. These ecosystems eventually attract a large number of people, who exert strong anthropogenic pressure by fishing, local ornamental fish trade, dumping of solid waste and harmful substances to these ecosystems, among other forms. The present study aimed to describe the structure of the fish communities living in tidal pools on Iparana Beach, in order to detect and measure the possible changes in their composition over the last 20 years. Therefore, through the visual census technique in the samplings, the ichthyological data sampled in 2018 were compared with data sampled in the year of 1999. The analysis of the results showed that, between 1999 and 2018, there were statistically significant differences in the structure of the fish assemblages, in addition to revealing that the substrate of the pools studied exerts a greater influence on its composition than the morphometric and physical parameters -chemicals measured.