Urbanisation of coastal areas is considerable and set to increase worldwide as a consequence of the ongoing demographic expansion and tendency for humans to migrate there. This results in considerable changes to the ecology of coastal habitats as substantial proportions of the coast are being destroyed and replaced by artificial structures. Urban structures act as artificial habitats for organisms, supporting epibiotic assemblages that differ from those on natural reefs. Investigating processes that influence associations between species and their habitats is key to understanding their patterns of abundance and distribution. The quality, size and spatial arrangement of habitats as major determinants of the diversity and abundance of species has received little attention. This knowledge, however, is relevant in the context of the management of coastal systems and the prediction of the consequences of urban developments, particularly those related to the deployment of hard artificial structures such as port installations and coastal defences. Further research, involving experimental work, is necessary in order to reach a more comprehensive understanding of how changes in coastal habitats influence local and regional patterns of biodiversity.
The proposed project focuses on the identification of factors that cause taxa to differ in composition and abundance between urban structures and the natural habitat. We start with a small pilot survey to gather information on the location and characterization of urban structures and their associated biota. We then move to an experimental approach that will allow us to distinguish between the effects of coastal urbanisation at various scales. We will test hypotheses that are of direct relevance to our understanding of how habitat alterations of anthropogenic origin are expected to affect the structure and functioning of natural communities. The specific tasks in this project will evaluate: (i) the effects of habitat loss due to coastal urbanisation at both small (<1m) and large scales, by comparing the relative magnitudes of the effects of substratum microtopography (small scale) and the matrix composition (large scale); (ii) the role of habitat slope and orientation (north versus south facing) in structuring rocky intertidal assemblages on both natural and artificial structures; and (iii) the factors that limit the successful establishment of canopy forming algae on artificial structures. By using the field-based experiments outlined we will not only contribute to bridging current theoretical and applied knowledge, but also provide a new perspective on how habitat alterations caused by urbanisation influence local and regional patterns of species diversity and community structure. This knowledge will aid programmes of restoration or rehabilitation of damaged habitats and contribute to the ecological criteria that should be considered in the design and management of artificial structures.
The Portuguese Science and Technology Foundation (FCT- PTDC/MAR-EST/2160/2012).
Participants from other Institutions: Richard Charles Thompson (University of Plymouth, UK).