Project Coastbusters Biogenic reefs concept

Summary

The public-private Coastbusters consortium aims to study and translate desired coastal protection functionality into designs that make use of the capability of ecosystem engineering species. In other words, it looks at whether ecosystem creation and the technical design of nature-based solutions provide a more sustainable and cost-effective management approach to conventional coastal engineering.

To answer this question, two Coastbusters research projects have been executed, funded by the Flemish agency for Innovation and Entrepreneurship (VLAIO) and co-funded by the industry (Dredging International part of the DEME-group, Jan de Nul group and Sioen industries):

1. In the first – proof-of-concept – Coastbusters project (2017-2020), three ecosystem engineering species were tested: subtidal seaweeds (Saccharina latissima), intertidal tube building sand mason worms (Lanice conchilega), and subtidal blue mussels bivalves (Mytilus edulis). An initial assessment of the biogenic reef potential of each of the selected species revealed some basic insights on (tidal) boundary conditions, and into the efficiency of their facilitating structures.
2. The sequel Coastbusters 2.0 project (2020-2023), concentrates on further in-depth investigation and optimization of the setup for one of ecosystem engineering species: the bivalve reef. The project focusses on developing new tunable marine biodegradable and sustainable (bio)materials, and optimizing the reef setup design to facilitate the reef development in a more efficient, sustainable, and resilient way. Advanced environmental monitoring techniques are then applied to research the effects and boundary conditions of the reef, while developing the optimal sampling techniques and strategy.

Learn more about how we can protect our coasts from erosion and storms in this video!

Area characterisation

The Belgian Part of the North Sea (BPNS) is a shallow and irregular sea that encompasses the southwestern region of the North Sea. Coastbusters 2.0 experiment setup was installed in the western coastal area of the BPNS (in front of the coastal municipality of De Panne), whereby two distinct hydrodynamic conditions were examined. Sheltered site (51° 07’19.2” N, 2°35’16.8” E) and exposed site (51°07’22.2″N 2°33’28.5″E) are situated at distances of 2 km and 5 km from the shoreline, respectively. 

Outcomes and Impacts

The pioneering work of Coastbusters has demonstrated that both the chosen ecosystem engineer and the boundary conditions at deployment location are crucial to the success of nature-based solutions (NbS) projects.

Coastbusters advocates for an Ecosystem-Based Coastal Management solution, with a longer lifetime, higher resilience to changing environmental conditions, and reduced maintenance cost compared to conventional coastal protection systems – heading for a more sustainable coastal management.

Potential impacts and benefits: 

The implementation of the NbS-concept in the marine environment necessitates in-depth knowledge of the driving parameters and local natural processes. This expertise is needed to integrate the stochastic nature of ecosystem development with the traditional technical engineering of coastal management tools (i.e. design, installation, operational management and maintenance). The result is a ground-breaking new coastal management approach: a nature-based engineering project which identifies coastal habitats and determines their viability, function and possible contribution to coastal protection.

Successful biogenic reefs of sand mason worms and blue mussels were formed in the intertidal and subtidal foreshore, respectively. The feasibility of the basic concept is clearly demonstrated, but several questions and operational challenges still remain. The acquired insights have led to a competitive valorisation of sustainable nature inspired design and business opportunities for all industrial partners and will generate exceptional knowledge for the research institutes, putting the Flemish marine knowledge community at the forefront in this innovation field. Dynamic resilience, storm survivability, ecosystem household or biodiversity preservation are just a few topics to be managed and engineered in a further development towards nature inclusive coastal management.

In order to ensure an effective valorisation, it is of the utmost importance that scientific substantiation is used as the starting point for further steps. The pioneering work of Coastbusters demonstrated that each ecosystem engineer and boundary conditions at deployment location are crucial to the success of NbS projects. In addition, extreme events such as storm surges will impact ecological systems to such an extent that returning to a state valuable for coastal protection can fluctuate. Nonetheless, incorporating these ecosystems engineers on the foreshore of sandy coastlines will locally stabilize sediments, reduce erosion and yield beneficial ecosystem services.

Hence, Coastbusters advocate for a hybrid coastal management solution, where the functional life is extended, flexibility to adapt to changing environmental conditions is increased and maintenance cost is reduced compared to conventional coastal protection systems.

Lessons Learnt

An ecosystem-based coastal NbS can only be brought into large-scale practice as a regional solution, on condition that: 

• sufficient space is present to accommodate the creation and development of (additional) ecosystems;
• key engineering species and their habitats naturally occur;
• and local stakeholders support development of ecosystem services. 

Once these conditions are met, solutions can be designed to translate the desired ecosystem engineering functionality into coastal management measures. On the one hand, such development requires a generic framework to select the appropriate measures based on the spatial and temporal scale of coastal protection. On the other, it requires knowledge (and broad dissemination thereof) on the ecology, engineering and ecosystem services delivered by the reef-forming ecosystem.

The pioneering public-private Coastbusters consortium embraces the ecosystem approach and since 2017 has deployed multiple proof-of-concept pilots at the Belgian North Sea coast. Coastbusters’ scientifically underpinned research lines provide a first solid knowledge on the technical requirements for biofacilitating infrastructures’ modularity, optimal design configuration, selection of bio-based materials, innovative environmental monitoring techniques, and delivered ecosystem services. In the near future, the consortium will implement novel spin-off projects within a broader multiple-use of space framework to push sustainable coastal management forward.

Further Resources

Suggested Citation:

For the Coastbusters poster: Semeraro A. & Langedock L., Boone W., Delbare D., Fordeyn J., Geldhof R., Groenendaal B., Huygens M., Mascart T., Moulaert I., Stratigaki V., Van Hoey G. & Sterckx T. (2020). Nature based solutions for coastal zone management: biogenic mussel reef concept.