Using innovative coastal restoration practices – the role of biopolymers in ecological restoration

As global efforts intensify to restore our rapidly declining coastal ecosystems, the search for innovative, sustainable solutions becomes paramount. Coastal wetlands, such as mangrove forests and saltmarshes, provide various benefits including protection from storm surges and climate change mitigation. While coastal wetlands are degrading and being lost around the world, new innovative approaches are being explored to help restore some of these areas. One approach is the application of artificial habitats made of biodegradable materials.  

What are biopolymers and why are they important?

Biopolymers are biodegradable materials and can either be directly extracted from natural biomass, such as plant or animal waste, or generated through bacterial fermentation. Because they are biodegradable, they hold a great potential for making materials that can be used in coastal restoration work, where minimal impact on the natural environment is required. The production of biodegradable biopolymers from under utilised waste biomass, such as agricultural by-products or forestry residues supports sustainability and economic benefits and contributes to circular economy practices.  

In our recent review “Using waste biomass to produce 3D-printed artificial biodegradable structures for coastal ecosystem restoration”, we highlight the range of factors involved in developing biopolymer-based artificial structures for coastal restoration end-uses. These factors include biomass selection and diversity, bioprocessing procedures and requirements, characteristics of biopolymers for 3D-printing and mold casting, designing structures that are fit for purpose, testing biodegradability and environmental impacts, and cost-benefits and commercial viability. Each of these factors significantly influences whether the biodegradable structures will function as intended in marine environments. The specific design will affect their ability to support species growth and protection, while the biopolymer material will influence how long the structures will persist in and interact with the environment.

Conceptual design of the process of developing biodegradable habitats for coastal restoration using biopolymers derived from waste biomass. Modified from Talekar et al. 2024, Science of the Total Environment.

The Regenerating Our Coasts Program

The Blue Carbon Lab and the Centre for Sustainable Bioproducts at Deakin University are at the forefront of this interdisciplinary effort. A key initiative under this collaboration is exploring the use of biopolymers such as starch, cellulose, and lignocellulose derived from potato peels, apple and grape pomace, and seaweed waste, to create structures that support coastal wetland restoration. Due to the different properties of each of these biopolymers, a key aspect of exploring their potential is to develop the right blend that is suitable for either 3D printing or moulding. When the biodegradable material can be turned into a structure that is customisable to a specific ecosystem, it offers a wide range of applications. 

In previous studies, BESE-Elements, a biodegradable structure from potato starch, has shown success in revegetating seagrass and saltmarshes. These biodegradable structures are developed to slow the movement of water, allowing for soil accumulation as well as promoting soil stabilisation and seed and seedling establishment. The Regenerating Our Coasts program is now further exploring how BESE-Elements can be used to enhance coastal wetland restoration in Australian saltmarsh, seagrass and mangrove ecosystems. Preliminary results from this work have indicated that there is a need for structures to be customised to each blue carbon ecosystem. See more of our early field results in our interactive Story Map.