In Ghana the coastal zone covers 6.5% of the 238,535km2 land area (Armah & Amlalo, 1998). Coastlines worldwide account for about 26 percent of all biological diversity, composed of, but not limited to, seabirds, clams, crabs, starfish, anemones, fish, kelp, and marine mammals, among many others, is a beautiful place, with many different types of natural communities (PewTrust and National geographic)
In Ghana the coastal area is also “home to more than a quarter of the country’s population and contributes as much as 80% of the country’s annual capture fish production” (NDF, Worldbank WACA report, 2013, p.1). However, coastal erosion and flooding resulting from the impacts of human activities, inappropriate systems put in place for managing coastal ecosystems, climate change and sea-level rise remain major threats to coastal dwellers and their livelihoods. Severe erosion rates have been recorded for the eastern coast particularly following the construction of the Akosombo hydroelectric dam (Ly, 1980). Erosion has affected the social and economic life of local populations, threatened cultural heritage and hindered coastal tourism in addition to the destruction of houses and other physical infrastructure. Some of the most affected communities are found in the Keta Municipality, which forms part of the eastern coast (about 149km) stretching from Aflao at the Ghana/Togo border in the East to the Laloi lagoon in Prampram to the west. (NDF, Worldbank WACA report, 2013, p.1).
Ashesi’s bioengineering faculty member, Dr. Rosca and students in her bioengineering class sought out biological solutions to mitigate the coastal erosion problem to contribute to ensuring the conservation, restoration and sustainable use of terrestrial habitation (SDG 15.1). The proof of concept is under discussion with the Environmental Protection Agency, Ghana. It is our hope that it will potentially impact terrestrial and climate related policy.
The goal of the project was to design a living sea defence system (bio-concrete tetrapods) by incorporating organisms capable of removing plastics along the coastline and converting to bio-cementation and bioremediation. It was to “take urgent and significant action to reduce the degradation of natural habitats and halt the loss of biodiversity.” (SDG 15.5)
The method used by Dr. Rosca and her students involved designing and engineering several organisms that have a self-regulation ability to maintain a balanced environment and self-repair mechanisms induced by increased light in the tetrapod due to cracking. The plastic degradation is achieved by introducing genes which have the capability and responsibility of degrading plastics to their constituent monomers (ethylene glycol and terephthalate). The bio-cementation is achieved by adding genes capable of undertaking the hydrolysis of urea -inducing precipitation of the calcium carbonate which results in cementation. The intent is to restore degraded land and soil (SDG 15.3). In addition, the tetrapod contains bioluminescent organisms for a natural illumination of the land and environment.
Consequently, using bio-engineering techniques to reduce coastal erosion through bio-cementation, purging the sea of plastic pollution, and producing smart illumination of the coast, saves and improves the coastal area.