Amateur and professional photographers are being asked to capture one of Britain’s national treasures most of us will only have seen on a dinner plate – the native oyster.

It is hoped underwater images of the oyster (Ostrea edulis) might restore Britain’s 'cultural memory' for a species perilously close to being lost forever.

We have lost our cultural memory of the native oyster reef habitat in Europe.

Dr Joanne Preston, Marine biologist and co-founder of the Native Oyster Network

Native oysters have suffered a 95 per cent decline in population over the past 200 years due to a devastating cocktail of overfishing, habitat loss, pollution and the introduction of diseases.

Oyster expert Dr Joanne Preston, a marine biologist at the University of Portsmouth, and conservationists at ZSL (Zoological Society of London), which is running the photography competition, launched the Native Oyster Network in 2017 to help restore the native oyster in Europe.

A five-year-old native oyster with a juvenile oyster growing on it (c) ZSL

Dr Preston said: “Oysters are the engineers of the sea, providing the right conditions for a wide range of marine life to thrive, but we are losing them at an alarming rate.

“We have lost our cultural memory of the native oyster reef habitat in Europe.

“This competition is a fantastic opportunity to find, document and celebrate the remnant oyster reefs in our temperate coastal waters.”

A single oyster will filter more than 140 litres of water a day consuming microscopic algae and remove pollutants and excess nutrients such nitrogen. They’re also able to sequester carbon from the water as they grow and build calcium carbonate shells.

When in sufficient densities to form reefs, oysters improve water clarity and prevent erosion of other valuable seagrass and saltmarsh ecosystems, both of which are powerful carbon dioxide sinks that can help tackle climate change.

Native oysters (c) ZSL

Alison Debney, a senior conservationist at ZSL, said: “Throughout our restoration work, one of the barriers we’ve come up against is not having images of native oysters in the wild. Trying to explain the importance of a species to people when they’re only ever framed it as a seafood dish can be a struggle.

“Oysters provide enormous benefits in the form of ecosystem services; nurseries for wildlife, clean water and removal of carbon from our environment into their shell to name a few. Whether you’re a diver, photographer, fisher or simply live near a coast, we need your help. The native oyster is a forgotten British treasure that needs the public’s support during this long road to recovery.”

All photographs entered into the competition – open until September 30 – will shed light on the species’ health and welfare.

Many oysters found in British waters are the Pacific oyster, introduced in 1965 and now thriving. These non-native species are purple-pink, have an elongated shell with sharp curved edges, and are mostly found in the zone between high and low tides and in muddy estuaries..

Native oysters are brown-green, have a rounded, brown-green flaky shell and although they can sometimes be seen on the shoreline at low tide, are generally found in deeper water, beyond the lowest tide.

Pacific oysters (c) ZSL

Celine Gamble, ZSL’s native oyster network coordinator said: “Oysters are an essential part of coastal communities around the UK, helping to sustain them through means of a livelihood. Our work would be halfway done if everyone could tell the difference between the Pacific non-native oyster and our native oyster. We can’t simply let another vital British native species slip away.”

The photography competition will be judged by professional wildlife photographers and the winners will be announced on December 1.

Prizes include an advanced photography workshop with photographer and National Geographic explorer Dave Stevenson.

A maximum of three photographs and/or videos per entrant can be emailed to Entrants must include their full name, contact details and location the photograph and/or video was taken. More information can be found here.

The oyster restoration work is part of ZSL’s Mother Thames campaign, celebrating the variety of life in The Thames, which will culminate in the publication of the first state of the Thames report this summer.