Facing the future: the importance of substratum features for ecological engineering of artificial habitats in the rocky intertidal

Coastal defences are proliferating in response to climate change, leading to the creation of more vertical substrata. Efforts are being made to mitigate their impacts and create novel habitats to promote biodiversity. Little is known about the effect of aspect (i.e. north–south directionality) and inclination on intertidal biodiversity in artificial habitats. Artificial and natural habitats were compared to assess the role of aspect and substratum inclination in determining patterns of biodiversity at two tidal heights (high and mid). We also compared grazing activity between north- and south-facing surfaces in natural habitats to examine the potential for differential grazing pressure to affect community structure and functioning. Results were variable but some clear patterns emerged. Inclination had no effect on biodiversity or abundance. There was a general trend towards greater taxon richness and abundance on north-facing than south-facing substrata in natural and artificial habitats. On natural shores, the abundance and grazing activity of ‘southern’ limpets (i.e. Patella depressa) was greater on south-facing than north-facing substrata, with possible implications for further range-expansion. These results highlight the importance of incorporating shaded habitats in the construction of artificial habitats. These habitats may represent an important refuge from grazing pressure and thermal and desiccation stress in a warming climate.

Facing the future: the importance of substratum features for ecological engineering of artificial habitats in the rocky intertidal

Coastal defences are proliferating in response to climate change, leading to the creation of more vertical substrata. Efforts are being made to mitigate their impacts and create novel habitats to promote biodiversity. Little is known about the effect of aspect (i.e. north–south directionality) and inclination on intertidal biodiversity in artificial habitats. Artificial and natural habitats were compared to assess the role of aspect and substratum inclination in determining patterns of biodiversity at two tidal heights (high and mid). We also compared grazing activity between north- and south-facing surfaces in natural habitats to examine the potential for differential grazing pressure to affect community structure and functioning. Results were variable but some clear patterns emerged. Inclination had no effect on biodiversity or abundance. There was a general trend towards greater taxon richness and abundance on north-facing than south-facing substrata in natural and artificial habitats. On natural shores, the abundance and grazing activity of ‘southern’ limpets (i.e. Patella depressa) was greater on south-facing than north-facing substrata, with possible implications for further range-expansion. These results highlight the importance of incorporating shaded habitats in the construction of artificial habitats. These habitats may represent an important refuge from grazing pressure and thermal and desiccation stress in a warming climate.

The potential of offshore windfarms to act as marine protected areas – A systematic review of current evidence

As offshore windfarm (OWF) construction in the UK is progressing rapidly, monitoring of the economic and ecological effects of these developments is urgently needed. This is to enable both spatial planning and where necessary mitigation in an increasingly crowded marine environment. One approach to mitigation is co-location of OWFs and marine protected areas (MPAs). This systematic review has the objective to inform this co-location proposal and identify areas requiring further research. A limited number of studies addressing marine renewable energy structures and related artificial structures in coastal waters were found. The results of these studies display a change in species assemblages at artificial structures in comparison to naturally occurring habitats. An increase in hard substrata associated species, especially benthic bivalves, crustaceans and reef associated fish and a decrease in algae abundance were the dominant trends. Assemblages associated with complex concrete structures revealed greater similarity to natural hard substrata compared to those around steel structures. To consider marine renewable energy sites, especially large scale OWFs as MPAs, the dissimilar nature of assemblages on the structures themselves to natural communities should be considered. However positive effects were recorded on the abundance of commercially important crustacean species. This suggests potential for incorporation of OWFs as no fishing, or restricted activity zones within a wider MPA to aid fisheries augmentation. The limited available evidence highlights a requirement for significant further research involving long term monitoring at a variety of sites to better inform management options.

Recovery of a biodiversity action plans species in northwest England: possible role of climate change, artificial habitat and water quality amelioration. Occasional Publication of the Marine Biological Association 16

The honeycomb reef worm Sabellaria alveolata is recognised as being an important component of intertidal communities. It is a priority habitat within the UK Biodiversity Action Plan and as a biogenic reef forming species is covered by Annex 1 of the EC habitats directive. S. alveolata has a lusitanean (southern) distribution, being largely restricted to the south and west coasts of England. A broad-scale survey of S. alveolata distribution along the north-west coasts was undertaken in 2003/2004. These records were then compared with previous distribution records, mainly those collected by Cunningham in 1984. More detailed mapping was carried out at Hilbre Island at the mouth of the River Dee, due to recent reports that S. alveolata had become re-established there after a long absence.