Search results for "Rocky shore"
showing 10 items of 34 documents
Habitat Discontinuities Separate Genetically Divergent Populations of a Rocky Shore Marine Fish.
2016
Habitat fragmentation has been suggested to be responsible for major genetic differentiations in a range of marine organisms. In this study, we combined genetic data and environmental information to unravel the relative role of geography and habitat heterogeneity on patterns of genetic population structure of corkwing wrasse (Symphodus melops), a rocky shore species at the northern limit of its distribution range in Scandinavia. Our results revealed a major genetic break separating populations inhabiting the western and southern coasts of Norway. This genetic break coincides with the longest stretch of sand in the whole study area, suggesting habitat fragmentation as a major driver of genet…
Variations in physiological responses to thermal stress in congeneric limpets in the Mediterranean Sea
2014
Cardiac activity (Arrhenius breakpoint temperatures and Q10 relationships) and heat shock response (hsp70 expression) were measured in the congeneric limpets Patella rustica, P. caerulea and P. ulyssiponensis in order to test the relationship between their vertical distribution and physiological thermal tolerance. These species exhibit different vertical distributions along Mediterranean shores and despite the narrow tidal range in the Mediterranean, they experience different environmental conditions and consequently had specific thermal windows. Cardiac activity of the upper zoned P. rustica was maintained at higher temperatures than its mid- or low shore counterparts, P. caerulea and P. u…
Getting into the groove: Opportunities to enhance the ecological value of hard coastal infrastructure using fine-scale surface textures
2015
Concrete flood defences, erosion control structures, port and harbour facilities, and renewable energy infrastructure are increasingly being built in the world’s coastal regions. There is, however, strong evidence to suggest that these structures are poor surrogates for natural rocky shores, often supporting assemblages with lower species abundance and diversity. Ecological engineering opportunities to enhance structures for biodiversity conservation (and other management goals) are therefore being sought, but the majority of work so far has concentrated on structural design features at the centimetre–meter scale.\ud \ud We deployed concrete tiles with four easily-reproducible fine-scale (m…
Status of vulnerable Cystoseira populations along the Italian infralittoral fringe, and relationships with environmental and anthropogenic variables
2018
We analyzed the occurrence and status of infralittoral fringe populations of Cystoseira spp. (Fucales) at thirteen rocky sites around the Italian coastline, and explored the relationships with relevant environmental and anthropogenic variables. We found Cystoseira populations at 11 sites: most were scattered and comprised monospecific stands of C. compressa, and only 6 sites also supported sparse specimens of either C. amentacea var. stricta or C. brachycarpa. Coastal human population density, Chlorophyll a seawater concentrations, sea surface temperature, annual range of sea surface temperature and wave fetch explained most of the variation of the status of C. compressa. We hypothesize a g…
Northern refugia and recent expansion in the North Sea: The case of the wrasse Symphodus melops (Linnaeus, 1758)
2011
Pleistocene climate changes have imposed extreme conditions to intertidal rocky marine communities, forcing many species to significant range shifts in their geographical distributions. Phylogeographic analyses based on both mitochondrial and nuclear genetic markers provide a useful approach to unravel phylogeographic patterns and processes of species after this time period, to gain general knowledge of how climatic changes affect shifts in species distributions. We analyzed these patterns on the corkwing wrasse (Symphodus melops, Labridae), a rocky shore species inhabiting North Sea waters and temperate northeastern Atlantic Ocean from Norway to Morocco including the Azores, using a fragme…
Habitat geometry of benthic substrata: effects on arrival and settlement of mobile epifauna
1996
Abstract The effect of substratum complexity on the early stages of colonization by mobile epifauna was assessed through a comparative study based on the architecture of artificial substrata. We conducted field observations over 4 years, on six types of small plastic substrata placed in the low intertidal zone of an exposed rocky shore, for varied immersion periods (1, 2, 4 and 12 wk). The use of artificial substrata allowed us to manipulate independently structural and spatial features of the habitat, such as total area, amount of folds, intercepting area, total volume, and interstitial volume. The invertebrate fauna colonizing over 300 sample units was recorded, and their densities compar…
Do small marinas drive habitat specific impacts? A case study from Mediterranean Sea.
2011
Many human activities add new structures to the marine landscape. Despite the fact that human structures cause some inevitable impacts, surprisingly little information exists on the effects of marina on natural marine assemblages. The aim of this paper is to assess habitat-specific response of benthic sessile organisms of rocky shores in relation to the presence of a small marina. Sampling was carried out at three coastal habitats (midshore, lowshore and subtidal) by means of visual censuses adopting an after-control-impact (ACI) experimental design. It appears that the marina affects the structure and composition of benthic communities of both the midshore and the lowshore. Little effect w…
Macroalgal assemblage type affects predation pressure on sea urchins by altering adhesion strength.
2010
In the Mediterranean, sea breams are the most effective Paracentrotus lividus and Arbacia lixula predators. Generally, seabreams dislodge adult urchins from the rocky substrate, turn them upside down and crush their tests. Sea urchins may respond to fish attacks clinging tenaciously to the substratum. This study is the first attempt to investigate sea urchin adhesion strength in two alternative algal assemblages of the rocky infralittoral and valuated its possible implication for fish predation. We hypothesized that (1) sea urchin adhesion strength is higher in rocky shores dominated by encrusting macro-algae (ECA) than in erected macro algae (EMA); (2) predation rates upon sea urchins are …
Role of peat organic matter on isotopic composition of most abundant benthic organisms in intertidal habitats of SW Iceland
2008
The transfer of peat organic matter (OM) from tidal pools of upper littoral to downstream rocky shores and its potential incorporation into marine biota were investigated using the stable isotope approach. Samplings were carried out in September 2004 in two SW Icelandic sites (Osar and Hvassahraun), where we selected (1) areas with shores where grass gently declined towards rocks and, on reaching the sea line, formed small tidal peat pools and (2) areas where grass and rocky shores were not contiguous, rather the grass lower limits were several hundreds of meters back from the shore. In both grass and no grass areas, in the intertidal zone, all benthic organisms and all potential OM sources…
Cool barnacles: Do common biogenic structures enhance or retard rates of deterioration of intertidal rocks and concrete?
2017
Sedentary and mobile organisms grow profusely on hard substrates within the coastal zone and contribute to the deterioration of coastal engineering structures and the geomorphic evolution of rocky shores by both enhancing and retarding weathering and erosion. There is a lack of quantitative evidence for the direction and magnitude of these effects. This study assesses the influence of globally-abundant intertidal organisms, barnacles, by measuring the response of limestone, granite and marine-grade concrete colonised with varying percentage covers of Chthamalus spp. under simulated, temperate intertidal conditions. Temperature regimes at 5 and 10 mm below the surface of each material demons…