Habitat structure shaping megabenthic communities inhabiting subtidal soft bottoms along the Algarve coast (Portugal)

Bivalve sanctuaries to enhance stocks along the Algarve coast of southern Portugal: A spatio‐temporal approach

“…This area clearly corresponds to a geological sector where the sediment supply is ensured by the adjacent shelf through soft cliff erosion (sector Olhos d'Água–Garrão; Rosa et al, ), and is characterized by an increased percentage of gravel sediments towards the west. The distribution patterns observed in the current work corroborate the megabenthic community patterns for the area, where C. gallina was an indicator species of the community assemblage closer to the Guadiana River, and where D. trunculus and S. solida were indicator species of the assemblages characteristic of longitudes below −7.9 °W, with moderate energy (Rufino et al, ).…”

“…The spatial component of the variogram model indicated that the population of D. trunculus formed smaller patches (~8 km in diameter) compared with C. gallina (~9 km in diameter) and S. solida (~11 km in diameter). This change in patch size corresponds to the bathymetric distribution of these species in the study area, with D. trunculus occurring at shallower depths, whereas C. gallina and S. solida inhabit comparatively deeper waters (Dolbeth, Viegas, Martinho, Marques, & Pardal, 2006;Martins, Sampaio, Quintino, & Rodrigues, 2014;Rufino et al, 2009Rufino et al, , 2017. On the other hand, the spatial patterns of C. gallina and S. solida in deeper waters may differ from the current one, as the importance of spatial structure may vary with changes in the environment (Michel & Knouft, 2014).…”

“…On the other hand, the spatial patterns of C. gallina and S. solida in deeper waters may differ from the current one, as the importance of spatial structure may vary with changes in the environment (Michel & Knouft, ). Similarly, the smaller patches formed by D. trunculus may be a consequence of its shallower distribution, as the communities at lower depths are mainly shaped by local environmental drivers, namely hydrodynamics induced by wave exposure (Delgado et al, ), whereas deeper sublittoral communities are subject to environmental conditions that are typically more stable (Rufino et al, ). Although with recruitment events occurring at the same time of year in a nearby area, D. trunculus size–frequency distributions differed markedly between beaches across a gradient, highlighting the importance of local factors for this species (Dolbeth et al, ).…”

“…The present study was undertaken along the Algarve coast of southern Portugal (Figure 1). An environmental characterization (abiotic conditions) of the study area and details of the megabenthic communities can be found in Rufino et al (2008Rufino et al ( , 2017, the characterization of the superficial sediments can be found in Rosa et al (2013), whereas the description of the main oceanographic features, namely an analysis of the upwelling system in Sagres and the circulation in the Gulf of Cadiz, can be found elsewhere (Garel, Laiz, Drago, & Relvas, 2016;Relvas, 2002;Relvas et al, 2007;Sánchez, Mason, Relvas, da Silva, & Peliz, 2006;Santos et al, 2007).…”

Hydrodynamic Conditions Effects on Soft-Bottom Subtidal Nearshore Benthic Community Structure and Distribution

“…In these nearshore areas, rocky substrates are indeed more documented than so -substratum [55]. Regarding the high level of anthropogenic threats and disturbance within these ecotonal zones, and the requirements of EU directives, studies such as the current one are essential to provide baseline knowledge that can be enhanced for sustainable management of these areas [56]. Indeed, the major constrains to implement conservation strategies in marine ecosystems are the general lack of baseline data prior to impacts and the substantial gaps in the current knowledge of natural patterns of variability of their assemblages, which are intrinsically variable [20,57,58].…”