Influence of rock‐pool characteristics on the distribution and abundance of inter‐tidal fishes

Abstract

Rock pools can be found in inter-tidal marine environments worldwide; however, there have been few studies exploring what drives their, fish species composition, especially in Australia. The rock-pool environment is highly dynamic and offers a unique natural laboratory to study the habitat choices, physiological limitations and adaptations of inter-tidal fish species. In this study rock pools of the Sydney region were sampled to determine how the physical (volume, depth, rock cover and vertical position) and biological (algal cover and predator presence) parameters of pools influence fish distribution and abundance. A total of 27 fish species representing 14 families was observed in tide pools at the four study locations. The five most abundant species were Bathygobius cocosensis, Centropogon australis, Enneapterygius atrogulare, Lepidoblennius haplodactylus and Microcanthus strigatus, which together represented 71% of the total number of fish recorded. Larger rock pools containing more algal and rock ledge cover hosted a larger and more diverse population of fish. Furthermore, certain species were only found in pools with specific characteristics, such as the presence of loose shells, a variety algae or rock cover, suggesting a high degree of habitat specificity. By contrast, some species were ubiquitous and thus can likely tolerate a wide variety of physical conditions.

Microhabitat use affects goby (Gobiidae) cue choice in spatial learning task

“…When first released into the test arena under simulated predator attack, the rock‐pool fish's first response was to swim towards a shelter. In the wild, rock‐pool species are only found in tide pools with refuges such as crevasses, algae cover, overhangs and rocks (Griffiths et al ., ; White et al ., in press). Shelter is relatively rare and found in unpredictable locations in sandy shore habitats, thus sand species must also employ alternative avoidance tactics such as quick zig‐zag escape responses often in combination with burying under the sand when shelter is unavailable (Whitely, ; Murdy & Hoese, ).…”

Site fidelity of intertidal fish to rockpools

“…The rocky intertidal zone is often an extremely productive habitat (White, Hose, & Brown, 2015), subject daily to severe changes on its physical, biological and chemical features due to its water/land interface. Within this shifting zone rockpools' temperatures vary widely due to their relative little thermal inertia, in turn, related to the small water volume and prolonged exposure to low-tide conditions (Morris & Taylor, 1983;Vinagre et al, 2013Vinagre et al, , 2016.…”

The use of remote sensing to reveal landscape-scale ecosystem engineering by shellfish reefs

“…Intertidal pools provide an extension of the vertical distribution of many species into areas which normally would be unsuitable for them because of desiccation stress (Metaxas & Scheibling 1993;Firth et al 2013); they provide refuges from predators to a wide variety of intertidal organisms (White et al 2014); they form a temporary shelter for migratory fish during low water, thereby effectively linking marine systems to freshwater systems upstream (Davis et al 2014); they are used by many fish species as nurseries (Chargulaf et al 2011). Different pool characteristics suit different species (White et al 2014), for example, larger pools tend to be more stable in temperature, pH and nutrient levels and are thus more valuable to the widest range of species (White et al 2014). Furthermore, the mosaic of different substrate types created by shellfish at larger spatial scales promotes heterogeneity and provides a habitat for a wide range of species (Eklöf et al 2014).…”

“…For example, given that the maximum reef accretion is dictated by the relative position in the intertidal frame (Rodriguez et al 2014;, the potential for pools to form may be expected to be greater at deeper locations (Chapter 4). Differences in pool characteristics, in turn, influence the function they have for the residing inhabitants (White et al 2014). Intertidal pools are an ideal refuge for animals during low tide and thus allow organisms to expand their distribution to higher parts of the intertidal zone.…”

“…The implications are that although only about 2% of the intertidal area is directly influenced by the local footprint, the extended effects increase the influenced area up to about 11% of the total intertidal. Since many organisms depend on tidal pools to take refuge during low tide, tidal pool creation has important consequences for ecosystem structuring and functioning (White et al 2014;Firth et al 2013), also beyond the local reef edges.…”