Since ancient times, human culture has been closely linked with the exploitation and use of the ocean. From the Roman Emperors who ate oysters for aphrodisiacs to the use of algae for bleaching linen. As populations and economies have grown, the ocean has been depleted.

Atlantic Ocean productivity has played a major role in the history of Atlantic Ocean exploitation. According to legend, Atlantic cod stocks were once so abundant that fishermen claimed they could walk across oceans on the backs of fish.

In 1913, 1,2m tonnes of fish had been landed in just the UK. In London alone, 700m European flat oysters are consumed each year. Landings have steadily declined since then. The catch is around 0.4m tons, and the number of employed fishermen has dropped from 50,000 in 2008 to 12,000 today.

The Atlantic Ocean in 2017 is a shadow version of what it used to be. Once productive, the fishery resources were supported and sustained by biodiverse, expansive habitats like seagrass meadows, kelp forests and other habitats. But study after study shows that these habitats are destroyed, and deteriorated by bad water quality, destructive practices of fishing and coastal development.

The Atlantic faces new challenges now, this time due to the rapid growth of renewable energy infrastructure. Ocean rewilding is one solution.

Finding green shoots

Ocean rewilding can be defined as “the restoration at a large scale of ecosystems so that nature can look after itself”. The concept promotes an equilibrium between humans and nature, where both can thrive.

Restoration of terrestrial ecosystems like woodlands, rivers, and marshlands is commonplace. Commercial companies even offer ” ready-made” for certain solutions. Rewilding our oceans is still a long way off. While the reintroduction of beavers, wolves, and Ospreys has been successful, it’s been a slow process. There is growing interest in underwater restoration, especially with the loss of seagrasses and oyster which has been well documented.

The restoration of marine environments has been pioneered by researchers around the world, and our understanding of this is increasing. The marine environment has been transformed by large-scale restorations in places like Chesapeake Bay, an estuary near Virginia’s coast. was used to disperse seeds. Seagrass meadows that have been restored provide habitat for fisheries and are also beginning to sequester large quantities of carbon dioxide from the atmosphere.

Regulations in Europe are leading to cleaner waters along the coast. It is believed that this can lead to major steps being taken to reverse the degradation that has occurred in this ocean.

Renewables and conservation

Divers can collect seagrass seeds as they would blackberries. Credit, Author provided

Our team has been working on underwater gardening in order to improve methods of marine habitat restoration. The underwater rewilding project began in 2014, with laboratory tests. It has now been expanded to the sea. These projects are not about creating rockeries or planting flowers like you might outside your home. They’re trying to take advantage of the renewable energy opportunities offshore and along the coast. Around the world, tidal lagunas are being considered as a reliable and predictable option for power generation. These large, sheltered lagoons offer a great opportunity for environmental renewal.

In collaboration with Tidal Lake Power, we have been examining methods to create new seagrass habitats within these lagoons. It involves growing seedlings, planting them in the lab, using seed bags and transplanting plants. This is similar to terrestrial gardening but done underwater. Trowels and the usual garden shed paraphernalia are used.

Biodegradable frames protect seagrass shoots from disturbance. PR Unsworth provided by the author.

We’ve also been working with partners from the Netherlands on a major test that utilises biodegradable Bio-plastics in order to support these seagrass transplants. This is important because of the huge problems with plastics that are in our oceans and also the possibility of accidentally polluting our oceans by using parts of our experiments.

We hope that with further research, we can take the trials of underwater gardens in tidal lagunas and convert them into habitat creation. This will ultimately help to bolster the rewilding our oceans. As marine energy options grow, they should not be viewed as a threat to the productivity of the oceans. Instead, they should be viewed as an opportunity.