The Solent Forum, working with partners, is developing this information hub to share knowledge and best practice on building biodiversity into coastal infrastructure as a service for Solent Forum members. It is estimated that nearly half of the UK's coastline has at least one seawall, breakwater, or other construction that in some way modifies the natural coastline. Scientists often refer to this as ocean sprawl.
The Solent has all the key issues that need to be considered in developing ecologically sound coastal infrastructure, and provides a useful pilot for the rest of the country. It has major infrastructure such as roads, rail, airports, ports, water treatment works and energy provision alongside dense centres of population that further increase through the summer tourist season. This is backed by a tight urban boundary with intensive and extensive agriculture, significant competing economic interests, multi-designated sites of environmental protection, and a strong set of academic institutions. Major issues that the Solent has to contend with include: flood defence, water and air quality, developable space, coastal squeeze, loss of biodiversity, economic disparity and fragility and transitions in coastal land use and land management.
This hub is designed to share and promote information on how to retain and increase the biodiversity of the Solent's infrastructure. Building biodiversity as a concept is part of the overall movement towards using nature based solutions to address societal issues. The Forum has also established pages on Habitat Restoration to compliment this hub, this includes information on net gain, natural capital and local nature recovery.
The MARINEFF project has identified the following opportunities for increasing biodiversity in coastal infrastructure:
Coastal infrastructure, such as sea defences (breakwaters, sea walls etc) and boat moorings, present both challenges and opportunities to coastal marine species. Coastal infrastructure built in soft sediment environments can offer an increase in biodiversity by acting as ‘islands’ for marine species that prefer harder substrate to colonise. These ‘islands’ have the capacity to extend the ranges and dispersal of marine species and promote the exchange of genetic diversity by linking up geographically separated populations. However, the usefulness of this benefit is limited by the size of the available habitat and the distance from similar populations that can colonise the coastal infrastructure. It can also provide habitats for fish, which are attracted to structures that occur in soft sediment environments as they present opportunities for shelter, feeding and as nursery habitat for juveniles.
Coastal infrastructure is predominantly finished with smooth, flat surfaces that do not incorporate cracks and crevices to retain water or produce shaded areas. Therefore, they have lower species diversity than natural shores. Eco-engineering aims to disrupt the homogenous surface of coastal defence structures by imitating natural rocky shore habitat, providing habitat complexity and opportunities for colonisation of marine species. This allows more species to survive the periodic exposure to air at low tide and reduces the risk of desiccation and death. When the tide returns, these same cracks and crevices provide refuge from predators and wave energy. Greater habitat complexity also increases surface area, enhancing the island effect.
Funding is a significant issue with incorporating eco-engineering into coastal infrastructure. Often eco-engineering is not incorporated within coastal engineering budgets as funding is not available for it. Eco-engineering needs to be marketed to practitioners in a way that highlights the benefits such as community engagement and bio-protection capabilities.
CIRIA B£ST Tool
CIRIA has developed a free tool and guidance, B£ST (Benefits Estimation Tool – valuing the benefits of blue-green infrastructure) for use on PCs. It makes assessing the benefits of blue-green infrastructure (BGI) easier, without the need for full scale economic inputs. B£ST is used to assess and monetise many of the financial, social and environmental benefits of blue-green infrastructure. The results enable users to understand and quantify the wider value of BGI schemes to support investment decisions and help to identify stakeholders and find potential funding routes.