Unlike many other restoration techniques, this method is cheap and easy to carry out. There's no need for expensive, labor-intensive dive teams to install kelp onto the seabed. Once gravel or shells have been seeded with kelp in aquariums, teams can simply drop them over the side of a boat where they sink, allowing the kelp to attach to the seabed where it grows to maturity. This is as effective as hand-deployment by divers and far more economical. Our team of marine scientists is working with the Fishmongers' Company's Charitable Trust and the Kelp Conservation Initiative to develop this "green gravel" approach. First pioneered in Norway, green gravel techniques have previously been tested on wave-exposed shores along the north-east coast of the UK. Now, in the lab, we are trialing waste scallop shells from the seafood industry and different types of stone from around the UK, easily sourced from hardware stores, as the basis for growing four types of native kelp. Every year, more than 30,000 metric tons of shells go to landfill in the UK, at a cost to the industry. There's huge potential to use shells as a restoration material at scale, either whole or crushed into smaller pieces. From tanks to seabed trials We begin green gravel restoration by identifying a healthy wild population of kelp with adult plants that can be used as donors. Sections of frond filled with spores are cut out and bought back to the lab, then disinfected with a quick dip in iodine solution. Gravel or scallop shells are cleaned and put into tanks of seawater. The fertile kelp material is dried out overnight then rehydrated to initiate the release of hundreds of millions of microscopic kelp spores. Once extracted, spores are added to tanks of seawater where they settle to seed the gravel or shells. Spores develop quickly, so tiny kelp seedlings are visible as a brown fuzz within three to four weeks. We monitor growth for three months, then once... |