Habitat distinctness doesn't influence on the abundance and relative growth of the juveniles Atherinella brasiliensis (Quoy & Gaimard, 1824) in a subtropical estuarine ecosystem

Abstract

Shallow coastal habitats with and without vegetation may perform nursery function from distinct way for many species, raising questions about the role of vegetation on structuring nursery ground. Unfortunately, degradation and inappropriate human use of these areas associated with the lack of ecological data about fish populations can limit appropriate strategies to protect both species and habitats. In this paper we examine the nursery value of different estuarine habitats by comparing the abundance and relative growth of juveniles Atherinella brasiliensis. Fish were sampled once a month from November 2018 to October 2019 in five habitats: no vegetation close to the ocean, no vegetation close to the river, no vegetation and distant from other sampling points (control), mangrove and saltmarsh. Juveniles are present and abundant in all habitats and specimens had similar relative growth in the salt marsh, mangrove habitats and non vegetated habitats. The results indicate that estuarine habitats offers suitable conditions to A. brasiliensis in early stages of life, indicating that these sites have nursery value for juveniles of this species. Conservation and/or preservation of estuarine shallows habitats along the coast is important for A. brasiliensis and probably for other species, and the identification of priority areas could help to provide subsidies to management policies on conservation of coastal marine environments.