Monitoring Skeletal Anomalies in Big-Scale Sand Smelt, Atherina boyeri, as a Potential Complementary Tool for Early Detection of Effects of Anthropic Pressure in Coastal Lagoons

Clara Boglione,Chiara Leone,Francesca De Luca,Eleonora Ciccotti,Arianna Martini

doi:10.3390/w13020159

Abstract

Mediterranean coastal lagoons are increasingly affected by several threats, all concurrently leading to habitat degradation and loss. Methods based on fish for the assessment of the ecological status are under implementation for the Water Framework Directive requirements, to assess the overall quality of coastal lagoons. Complementary tools based on the use of single fish species as biological indicators could be useful as early detection methods of anthropogenic impacts. The analysis of skeletal anomalies in the big-scale sand smelt, Atherina boyeri, from nine Mediterranean coastal lagoons in Italy was carried out. Along with the morphological examination of fish, the environmental status of the nine lagoons was evaluated using a method based on expert judgement, by selecting and quantifying several environmental descriptors of direct and indirect human pressures acting on lagoon ecosystems. The average individual anomaly load and the frequency of individuals with severe anomalies allow to discriminate big-scale sand smelt samples on the basis of the site and of its quality status. Furthermore, a relationship between skeletal anomalies and the environmental quality of specific lagoons, driven by the anthropogenic pressures acting on them, was found. These findings support the potentiality of skeletal anomalies monitoring in big-scale sand smelt as a tool for early detection of anthropogenic impacts in coastal lagoons of the Mediterranean region.

Highlights

The big-scale sand smelt Atherina boyeri is a small, short-lived euryhaline fish species, widely distributed throughout the Mediterranean and Black Sea [1] and in the eastern Atlantic Ocean [2]
The overall level of anthropogenic impact observed in the various lagoons is essentially similar, but in the nine lagoons, the types of pressures contributing to the observed impact are different
The skeletal condition of A. boyeri complex was examined in populations from nine Mediterranean coastal lagoons along the coasts of Italy

Summary

Introduction

The big-scale sand smelt Atherina boyeri is a small, short-lived euryhaline fish species, widely distributed throughout the Mediterranean and Black Sea [1] and in the eastern Atlantic Ocean [2]. It usually spends its life cycle in coastal and brackish environments [3] and can dwell in freshwater habitats [4] and hypersaline conditions [5]. Several studies based on morphological [12], biochemical [13], and molecular investigations [14,15] have identified three distinct groups that have been proposed to be elevated to the rank of species [16]: one corresponding to the lagoon type (A. lagunae, [16])

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