An ecological classification of rocky shores at a regional scale: a predictive tool for management of conservation values

Abstract

The ecological classification of coastal waters has become an important issue in ecosystem water quality assessment. Previous studies have suggested that abiotic variables seem to be a suitable alternative to biological data for classifying coastal areas at different scales. The study presented here proposes a downscaling methodology for the classification of coastal waters at a regional scale within the NE Atlantic based on standardized data and objective decision rules. Physical variables (temperature, wave exposure, tidal range and radiation) were selected because of their ecological role, availability and statistical decision rules. This information was based on satellite data and mathematical modelling of natural coastal processes. The N and NW Spanish coastline was subdivided into 41 20-km segments that were classified according to physical variables using the self-organizing map and k-means algorithms. To validate the classification with biological data, 21 sites representing the entire range of physical typologies in the study area were simultaneously and consistently sampled. Intertidal macroalgae were identified in each of 10 quadrats of 50 9 50 cm for two to three transects per site, according to a stratified sampling procedure. The coverage of macroalgae was obtained by photographic analysis. The physical classification shows four typologies: Lower Rias, Upper Rias, West Cantabric and East Cantabric. Statistical analyses confirmed the ecological significance of these typologies at the tidal levels where seaweeds were the major structural element (lower and middle intertidal). According to the biological data, the greatest differences were found between the Upper Rias and the rest of the N and NW Iberian Peninsula coast. Thus, the classification methodology has potential application as a management tool.

Consistent patterns of spatial variability between NE Atlantic and Mediterranean rocky shores

“…As anticipated before, processes probably acting at these scales are usually linked to climate, geomorphology and oceanographic features, creating physical gradients that are considered the most important drivers of variation in biodiversity and assemblage structure at the scale of basin (Zacharias & Roff, 2001; Coll et al , 2010; Smale et al , 2011; Ramos et al , 2012; Smale et al , 2013). Both the NE Atlantic and the Mediterranean basins, indeed, exhibit strong gradients in temperature values (Jenkins et al , 2008; Coll et al , 2010; Ramos et al , 2012; Smale et al , 2013; Ramos et al , 2016) and nutrient availability (Bricaud et al , 2002; Jenkins et al , 2008; Lejeusne et al , 2010). In addition, wave exposure and tide amplitude vary greatly along Atlantic European coasts (Jenkins et al , 2008).…”

Using Habitat Classification to Assess Representativity of a Protected Area Network in a Large, Data-Poor Area Targeted for Deep-Sea Mining

“…The scale of classifications varies greatly, from relatively fine-scale classifications focused on national waters (e.g., Roff and Taylor, 2000;Connor et al, 2004;Lombard et al, 2004;Leathwick et al, 2006;Lundblad et al, 2006;Snelder et al, 2006;Verfaillie et al, 2009;Last et al, 2010;Ramos et al, 2015) through regional-scale approaches (e.g., Davies et al, 2004;Grant et al, 2006;Howell, 2010;Ramos et al, 2012;Douglass et al, 2014;Evans et al, 2015), to global biogeographic classifications (e.g., Sherman, 1986;Spalding et al, 2007;Harris and Whiteway, 2009;United Nations Educational, Scientific and Cultural Organization, 2009;Clark et al, 2011;Watling et al, 2013;Sayre et al, 2017;Sutton et al, 2017).…”

Small-scale effects of hydrodynamics on the structure of intertidal macroalgal communities: A novel approach

“…7 days) and by Wave Gauge OSSI-010-003C-03 sensor (Ocean Sensor Systems Inc., Coral Springs, USA). Considering the one-week period used to evaluate wave height exposure, structural differences observed in a given macroalgal community depend on the hydrodynamic forces conditioning it all year long (Levin and Paine, 1974;Ramos et al, 2016b). Thus, the spatial study of community structure, relatively to a condensed set of wave exposure data (here wave heights), may be informative enough about the long-term effect of (2) sampling spots are numerous enough to consider the micro-topography of the shore at the intra-community level (3) the average wave height follows site patterns per community.…”