ALL AT SEA SEPTEMBER 2021
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THE CHANGING FACE OF MARINAS Over time marina owners have become increasingly aware of the importance of the green credentials of their marinas, and this nature first approach has been shown by the work to increase intertidal biodiversity at a marina in North Essex.
Image: Brightlingsea Harbour Commissioners
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rightlingsea Waterside Marina is located in the picturesque English seaside town of Brightlingsea, in Essex. The marina caters for a wide range of vessels, from traditional sailing boats to modern catamarans and provides access through the Brightlingsea Creek to the River Colne and the wider Blackwater estuary area. Brightlingsea Harbour Commissioners, who manage the marina, have a long history of supporting innovative projects. These include design and development in various natural environments throughout the creek. For example, BHC was a partner in the USAR project (Using Sediment As a Resource), an EU Interreg initiative which led to the beneficial re-use of dredged material from the creek to redevelop and regenerate lost saltmarsh habitats in the St. Osyth and Brightlingsea environment. Building on this ‘nature first approach’, BHC worked with Exo Environmental Ltd to trial two novel piling habitats which could be retrofitted to their sheet piling to help boost intertidal biodiversity.
GeoBlock tech
These units were made from traditional waste streams including quarry waste and dredged sediment, helping to create a product with a significantly lower embodied carbon than traditional concrete products. This approach builds a circular economy of sustainability and is known as GeoBlockTM technology. The piling habitats were designed with small cups to hold water during low tide, providing shelter for organisms such as polychaeta and crustaceans. They also incorporate a heterogenous surface texture, to produce variable environmental conditions and create micro niche habitats to help encourage colonisation from a wide range of marine
organisms, including sessile filter feeders such as barnacles and oysters. The surface textures were designed using specialist 3D software and then printed using 3D printing technology. The 3D printed texture is incorporated into the GeoBlockTM technology to produce ecologically enhanced products. The idea behind placing these units on sheet piling is a simple one: to reduce the impact of coastal squeeze caused by rising sea levels, and construction of hard coastal engineering. Coastal squeeze refers to the decrease in size of the intertidal zone and thus the space for organisms to colonise. By increasing the vertical habitat availability, piling habitats offset this loss. Thus, providing a flexible mitigation approach to climate change and associated biodiversity decline.
Encouraging results
Results so far are very encouraging with a host of different organisms observed. Initial biofilm developed during the first growing season consisted of diatomaceous algae. This was followed by higher trophic organisms such as polychaeta, star ascidians, hydroids, barnacles and much more.
Ascidians, pictured here, have benefitted from the work at the marina
James Thomas, harbourmaster, said: “We see the natural environment as one of our customers, a healthy eco system is part of the harbour’s role in conservancy.” The piling habitats not only improve the marine biodiversity of the marina and boost green credentials, but they are also vital educational tools for young people. Unlike other marine
The piling habitats were designed with cups to hold water during low tide
Brightlingsea Harbour. Jim Pullen Here is a Seabin installed onImage: River Soar
conservation efforts, such as eco reefs or marine protected areas, these units are easily accessible from the shore. They provide opportunities for local schools and youth clubs to visit the marina and learn about the importance of providing habitats for nature; and the vital role these habitats provide through ecosystem services. These piling habitat units demonstrate a marina’s corporate responsibility, green credentials and highlight the positive societal work that ports and marinas are performing in response to the climate and biodiversity crisis. www.watersidemarina.net
