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

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).

A comparative analysis of habitat quality between artificial and natural creeks in the Mediterranean killifish Aphanius fasciatus: Implications for conservation

“…For the Adriatic Sea, during the 20 th century, the sea level rose at a rate of 1.3 mm year −1 , and by 2100 it could rise by 14–49 cm (Scarascia & Lionello, 2013). Artificial creeks can host a diverse fish community (Cavraro et al, 2017; Facca et al, 2020), containing species of both commercial and conservation interest (e.g. the lagoon goby Knipowitschia panizzae ).…”

“…Most studies dealing with the anthropogenic effects on coloured traits have focused on birds and freshwater fish, while less attention has been dedicated to fish in transitional water ecosystems (TWE). Fish fauna is a key component of TWE, mainly for its important ecological role in aquatic food webs, its significant lifespan, which integrates the effects of environmental pressures on a relative long timescale, and for its economic value as a food resource (Whitfield & Elliott, 2002; Van der Oost, Beyer & Vermeulen, 2003; Harrison & Whitfield, 2004; Cabral et al, 2012; Zucchetta et al, 2016; Facca et al, 2020). Estuaries and coastal lagoons are widely known to be elective habitats for abundant and diversified fish populations (Franco et al, 2008; Potter et al, 2015) as are salt marsh creeks.…”

“…Recent attention paid to the quality of lagoons and estuaries (Gilliers et al, 2004), which are subjected to high anthropogenic pressures (Kennish, 2002; Airoldi & Beck, 2007), has raised the potential of evaluating and quantifying environmental quality using the health status of fish populations. Fish species belonging to the estuarine resident guild spend their whole life in transitional waters Integrating all the stimuli coming from this environment into their life cycle (Bortone, Dunson & Greenawalt, 2005; Fiorin et al, 2007; Zucchetta et al, 2012; Facca et al, 2020) and can be used to assess the quality of these ecosystems (Cavraro et al, 2019).…”

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

“…Fish have been widely used to assess habitat alterations and describe the characteristic of the aquatic ecosystem [29] based on a number of reasons (e.g., sensitivity to stressors, longevity, complex habitat requirements) [30][31][32][33]. The long-standing tradition of ecological, physiological, and ecotoxicological research on a large number of fish species [34][35][36] has allowed to provide insight into environmental degradation at different levels. Since the issuing of the Water Framework Directive (WFD, 2000/06/EC) [37], the interest has shifted towards a global evaluation of the ecological status of aquatic ecosystems.…”

“…Information from single fish populations addressing health, condition status or contamination might be used as complementary information on habitat environmental conditions. Particularly for transitional water bodies, especially wetlands and coastal lagoons, resident fish are considered the most suitable [43] indicator species of lagoon environmental conditions [36,43,44]. They spend their entire life cycle within the water basin [1], and they can integrate the effects of natural environmental stress of the ecosystem [20] and those of pressures deriving from human activities [18,45], with responses at the different levels of the biological organization [46].…”