Natural reefs are one of the most varied ecosystems on the Earth, and they are quickly disappearing due to a combination of factors such as overfishing, pollution and pathogenic diseases. However, stricter government regulations could take years to implement. The deployment of artificial reefs may be the short term answer.
Marine scientists in the Faculty of Science & Technology have been awarded a multidisciplinary EU Interreg project to design artificial reefs optimised for Atlantic waters.
The 3DPARE project is working to deploy and monitor artificial reef blocks in the Atlantic ocean which have been designed and fabricated using innovative 3D printing technology and sustainable, low-impact bio-receptive materials.
Reef blocks have the potential to mitigate for loss of natural reef habitats and enhance food production, coastal infrastructure and recreational amenity. 3D printing technology offers considerable scope to increase the complexity of textures and voids to create block structures that may be more effective than concrete blocks which are currently being submerged.
The project is led by the University of Cantabria Department of Civil Engineering (Santander, Spain) who specialise in 3D Printing. The other main partners include Bournemouth University (Faculty of Science & Technology), CIIMAR (Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Portugal), IPMA (Portuguese Institute of Sea and Atmosphere), ESITC Caen Institute for Civil Engineering and Construction (Caen, France).
BU expertise includes the monitoring of ecosystems on natural and artificial reefs that will provide data for mapping, design of varying materials, and the deployment of large reef blocks across the transnational partnership.
During the summer of 2018, the research team studied natural and artificial habitats within Poole Bay, UK. Scuba diving surveys and baited remote underwater video surveys were conducted to capture ecological data.
BU developed protocols to monitor the submerged reef blocks and identify the animal and plant life using them. This involves regular surveys including the use of SCUBA dives and drop-down cameras. SCUBA underwater visual census (UVC) and remote underwater video (RUV) surveys have been undertaken between 2020 and 2023. Data has been continually analysed and presented through dissemination events and publications.
The story so far
After they were 3D-printed at the University of Catabria, Spain, nine artificial reef blocks were shipped to the UK. They were deployed in Poole Bay by crane from a large barge in March 2020, with similar blocks also deployed at study sites in France, Spain and Portugal.
Within days, many crabs had moved into the holes and tunnels, and by the end of the year over 40 species had been recorded, including many seaweed species, filter feeding organisms, crabs and fish. The site is popular with juveniles of many fish species, so the artificial reef blocks may be acting as a nursery habitat.
New species are recorded every time the reef units are surveyed, and after two years underwater, the artificial reef was supporting over 100 species, including rare native oysters, whose populations have declined by over 95% since the mid-19th century. In addition, the varied design features of the artificial reef units, such as holes, tunnels, overhangs and flat surfaces support a higher diversity of marine life than nearby natural rocky reefs in Poole Bay.
The research has focused on several areas, such as exploring different concrete formulations and artificial reef designs. Much of the work undertaken has concerned ascertaining whether certain species of marine life have preferences for the type of habitat features included within the artificial reef units, for example crabs prefer the holes, whereas fish prefer the tunnels.
As part of our project extension, in September 2022 we also released over 200 juvenile lobsters at the 3D-printed artifical reef, to see whether they will provide a good habitat to support them in their early life stages, when they are very vulnerable to predation. We’ll be looking to see how they are doing when we monitor the reef units again in the spring of 2023, 6 months after releasing them.
The project will continue until June 2023, when the artificial reef blocks will have been immersed for over 3 years. Scientists at BU hope to continue to monitor them to assess longer term changes in the community of marine life that they support.