Abstract
Mytilus galloprovincialis is an ecosystem engineer that provides habitat and generates environmental heterogeneity, increasing local biodiversity. Moreover, it is an economically important species representing 14% of the global production of marine bivalves. Natural drivers and the increase of anthropogenic pressures, such as sediment stress, influence its populations on rocky shores. The objective of this study was to explore the spatial-temporal patterns of different M. galloprovincialis attributes along the north of Portugal. For that purpose, six rocky shores were selected and sampled six times along the year 2019. The percentage of cover, density, spat density, condition index, clump thickness, size classes and clump sediment content were considered. Results showed the lack of seasonality in M. galloprovincialis along the north coast of Portugal. However, density, spat stage, clump thickness, condition index and size classes showed some variability among dates and shores. The percentage cover and sediment content only significantly differed among shores. Our results indicated an absence of seasonality for all the studied variables, probably because temperature was always within the optimum range for this species and the abundance of food supply in the study area independently of the season. The accumulated sediment on mussel clumps did not show any temporal variability with only significant differences among shores. The accumulated sediment was composed mainly by medium and coarse sand and it was correlated with mussel average size, condition index, but especially with the mussel clump thickness.
Highlights
Mussels are important organisms in intertidal systems (Seed & Suchanek, 1992; Seed, 1996) because they can control biodiversity, sheltering, supporting and enhancing diverse assemblages of invertebrates (Leigh et al, 1987; Seed, 1996)
analyses of variance (ANOVA) results for spat stage showed a similar pattern as total density, but only Aguda showed significant differences in the last two months (Oct, Dec) with lower values (Fig. 6)
Significant differences were shown on the term Sh x Da for density, spat stage, clump thickness, condition index and size classes, demonstrating that drivers shaping these descriptors have effects at spatial and temporal scales
Summary
Mussels are important organisms in intertidal systems (Seed & Suchanek, 1992; Seed, 1996) because they can control biodiversity, sheltering, supporting and enhancing diverse assemblages of invertebrates (Leigh et al, 1987; Seed, 1996). M. galloprovincialis is a widespread invasive species in other regions like South Africa (De Moor & Bruton, 1988). This species competes with native mussels’ species showing greater tolerance to air exposure, faster growth, higher reproductive output (Branch & Steffani, 2004) and higher resistance to parasites and desiccation (Calvo-Ugarteburu & McQuaid, 1998)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
