Lagoon Resident Fish Species of Conservation Interest According to the Habitat Directive (92/43/CEE): A Review on Their Potential Use as Ecological Indicator Species

Chiara Facca,Piero Franzoi,Stefano Malavasi,Francesco Cavraro

doi:10.3390/w12072059

Abstract

Transitional waters are fragile ecosystems with high ecological, social and economic values, that undergo numerous threats. According to the information provided by European Member States in the framework of the European Directive 92/43/EEC (Habitat Directive), the main threat to these ecosystems is represented by morphological and hydrological changes. The present work focuses on six lagoon fish species included in the Habitat Directive annex II (species requiring conservation measures: Aphanius fasciatus, A. iberus, Knipowitschia panizzae, Ninnigobius canestrinii, Valencia hispanica and V. letourneuxi) that spend their entire life cycle in the Mediterranean priority habitat 1150* “Coastal lagoons”. The overview of the current scientific literature allowed us to highlight how the presence and abundance of these species may provide important indications on the conservation status of coastal lagoon habitats. In fact, their occurrence, distribution and biology depend on the presence of peculiar structures, such as salt marshes, small channels, isolated pools and oligohaline areas. Coastal lagoon fragmentation and habitat loss have led to a significant reduction in genetic diversity or local population extinction. Although Aphanius and gobies have been shown to survive in eutrophic environments, it is clear that they cannot complete their life cycle without salt marshes (mainly Aphanius) and wetland areas (mainly gobies).

Highlights

In 1992, the Directive 92/43/EEC, known as the Habitat Directive (HD), was issued to promote the “conservation of natural habitats and of wild fauna and flora” by ensuring bio-diversity (HD art. 2 par. 1) in the territory of European Member States
In Annex I, the Habitat Directive lists the sites of community interest, “whose conservation requires the designation of special areas of conservation”
As the morphological alteration is one of the main threats for coastal lagoons (Table 2, [4]), the present paper describes the biology, habitat preference, distribution and conservation status of those fish species that are more strictly related to salt marshes and wetlands, in order to propose them as early warning signal of habitat loss

Summary

Introduction

In 1992, the Directive 92/43/EEC, known as the Habitat Directive (HD), was issued to promote the “conservation of natural habitats and of wild fauna and flora” by ensuring bio-diversity (HD art. 2 par. 1) in the territory of European Member States. In Annex I, the Habitat Directive lists the sites of community interest, “whose conservation requires the designation of special areas of conservation” Among these sites, some are considered of “priority interest” because they are in danger of disappearance, such as the priority habitat 1150* “Coastal lagoons”, defined as follows:. Salinity may vary from brackish water to hypersalinity depending on rainfall, evaporation and through the addition of fresh seawater from storms, temporary flooding of the sea in winter or tidal exchange” [1]. These habitats are found along all European coasts and their extent in the Mediterranean Sea varies widely, from 2 ha of Chalikiopoulou Greek lagoon [2] to 57,000 ha of Italian lagoon of Venice.

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Discussion

Conclusion