Habitat selectivity of substrate-spawning fish: modelling requirements for the Eurasian perch Perca fluviatilis

Abstract

Substrate spawning fish are believed to be selective in their choice of spawning habitat, yet few studies have shown the relative importance of different characteristics in terms of habitat quality. We used an extensive and detailed dataset to identify the factors that govern both large-scale (10 3 to 10 5 m) and local-scale (10 1 to 10 2 m) selection by a substrate-spawning fish, the Eurasian perch Perca fluviatilis L. Distribution of spawning habitat was strongly dependent on habitat characteristics defined by substrate, wave exposure, temperature and depth. The most important predictor was the type of spawning substrate, which generally consisted of different types of vegetation. Substrates providing rigidity and structural complexity were preferred, despite abundant presence of other substrate types. Shallow depth and sheltered areas were also selected habitat characteristics. The response to temperature was scale-dependent, with a stronger selection expressed at the local scale. The specific selectivity suggests that spawning patterns can be successfully modelled with sufficient detail using only a few fundamental environmental variables. Wave exposure and depth are readily available for large-scale spatial predictions, while temperature and substrate require further development in most coastal areas. The high specificity of the characteristics determining habitat quality suggests that it should be possible to apply this modelling approach for identification and conservation of spawning habitats of Eurasian perch and other substrate-spawning fishes in coastal waters.

Extremely shallow spawning of perch (Perca fluviatilisL.) : the roles of sheltered bays, dense semi-terrestrial vegetation and low visibility in deeper water

“…However, the reproducing perch used only bays with dense stands of submerged semi-terrestrial vegetation (grass bays) and completely avoided bays where this spawning substrate was absent (rocky bays). This finding corresponds to the previous observations of Jones (1982), Treasurer (1983), Urho (1996) and Snickars et al (2010) that appropriate spawning substrate, especially in shallow water, is another crucial factor affecting spawning site selection by perch. As has been shown in the present study, even in the same water body, the presence or absence of shallow water vegetation can strongly influence the depth distribution of perch egg strands.…”

“…an appropriate spawning site or spawning depth, is essential for the development and survival of the new generation since immobile eggs are vulnerable both to unfavorable biotic and mainly abiotic conditions (Wootton, 1998). In perch [Perca fluviatilis L. in Eurasia and P. flavescens (Mitchill) in North America], the ability to react to different environmental conditions is well known and has been documented in their selection of appropriate spawning sites (Holčík, 1969;Jones, 1982;Treasurer, 1983;Probst et al, 2009;Snickars et al, 2010;Čech et al, 2011;, spawning depth (Gillet and Dubois, 1995;Newsome and Aalto, 1987;Williamson et al, 1997;Huff et al, 2004;Čech et al, 2009, as well as in selection of an appropriate spawning substrate (Čech et al, 2009, 2012) or temperature for incubation of their egg strands Dubois, 1995, 2007;Cech et al, 2011Cech et al, , 2012. It should be taken into account that many factors responsible for the success of perch reproduction may interact with each other, particularly spawning site and spawning substrate (Jones, 1982;Treasurer, 1983), spawning depth and spawning substrate (Čech et al, 2009, 2010) or spawning depth and temperature of incubation (Gillet and Dubois, 1995;.…”

Shoreline development and degradation of coastal fish reproduction habitats

“…Pike, perch, and roach reproduction habitats had previously been mapped using predictive species distribution (Snickars et al 2010), and sampling of YOY pike and roach was conducted in late summer -2006(Sundblad et al 2011). The models used to predict the distribution of reproduction habitats were evaluated by their cross-validated discriminatory ability, i.e., the ability to correctly separate suitable from non-suitable habitats, using ROC-values (Sundblad et al 2011).…”

“…Recent decades have, however, seen a rapid development of species distribution modeling methods, allowing researchers and managers to produce predictive maps of the underwater environment and its associated biota (Elith and Leathwick 2009). In the Baltic Sea, several recent research programs have significantly benefited our understanding and knowledge of habitat distributions in general (Al-Hamdani and Reker 2007;Bučas et al 2013;Lindegarth et al 2014) and coastal fish habitats in particular (Härmä et al 2008;Kallasvuo et al 2009;Sundblad et al 2009Sundblad et al , 2011Sundblad et al , 2013Snickars et al 2010;Bergström et al 2013). For instance, using statistical non-linear relationships between life-stage specific occurrence and environmental descriptors, Sundblad et al (2011) used predictive distribution models to map key reproduction habitats of three of the most common species in the Baltic Sea coastal fish community, northern pike (Esox lucius), Eurasian perch (Perca fluviatilis) and roach (Rutilus rutilus).…”

“…Pike and perch are large piscivores important both for ecosystem functioning and for commercial and recreational fisheries, while roach is an important benthivore and prey species for large predators. During their first year of life, all three species utilize shallow, sheltered near-shore habitats with suitable vegetation and temperature development during spring and summer (Gillet and Dubois 1995;Sandström et al 2005;Snickars et al 2009Snickars et al , 2010Sundblad et al 2011Sundblad et al , 2013. These species are all sensitive to disturbances related to boating activities, either directly or indirectly.…”