Today is , a good time to reflect on the damage that humankind has done to the blue part of the planet.
The health of the seas hangs in the balance. The bleaching of coral reefs as amid global warming has reached record levels in some areas.
Drilling for oil has spread to the deep seas. New forms of plastic pollution are widespread and are harming fish, and the oceans face rising acidification – a phenomenon that we now know in Earth’s past. Overfishing continues in many places.
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The upshot is that life in the oceans remains under great pressure.
Aside from curbing carbon emissions and pollution, banning whaling and preserving fish stocks, can we do anything else to tip the balance the right way? Yes, we can use rewilding to restore some of what has been destroyed, just like we do with the reintroduction of iconic land species such as the wolf and lynx.
And there are few better candidates than the humble oyster. The ranks alongside some of the biggest changes the oceans have seen.
It is not just New York Harbor and Chesapeake Bay that once had oysters in profusion. They were commonly found in deep seabeds in the English Channel and the eastern North Sea in the 19th century – locations where none exist today, chiefly because of overexploitation and habitat destruction by bottom trawling.
Bringing oysters back
The idea of rewilding lost oyster beds has many attractions. They were ecosystems in their own right, providing habitats for other marine life. The effects of restoration would go far beyond increasing the population of molluscs.
Oysters create a good environment for spawning fish, prey fish and food for fish to eat, such as worms and young crabs. They filter seawater, encouraging seagrass to grow that provides cover for breeding fish. Oyster reefs also slow waves, protecting coastlines.
There are many restoration projects for North American oyster species, such as the . All of these have strong community engagement, particularly in the and around New York Harbor and Long Island.
It is time for the UK to have its own such grand project. The charity I head, the , has chosen the Solent, a sea strait off the country’s south coast, for this. Until 2006, these waters supported – largest, that is, since the last oyster was dredged from the eastern North Sea in the early 1930s.
Previous restoration attempts have been small and largely unsuccessful, amid the onslaught of disease and predation. A study concluded that it would be possible to restore oysters to the Solent, but it is a numbers game.
The plan, for which the foundation is seeking funding, is to lay 10 million hatchery-bred oysters in places that fishermen have agreed to avoid or that are inaccessible in other ways, to ensure protection from the overexploitation that drove the decline in the first place.
A combination of methods will be used – including suspending caged wild oysters under pontoons in marinas – to maximise survival chances.
This will be the first milestone on the way to restoring an ecosystem that was once of enormous economic and ecological importance – and which could be again.
If we are to turn the tide in favour of life in the oceans by making good decades of neglect, rewilding with the unspectacular oyster is a good start.
