Foundations for the largest restoration oyster reef in the Solent have been laid

This five-year partnership, funded by the Endangered Landscapes Project, aims to restore a wealth of diverse marine species and habitats back to the Solent.

Working closely with the River Hamble Harbour Authority and local contractors Jenkins Marine, ocean conservation charity Blue Marine Foundation laid a thin veneer of shingle mixed with cockleshells, known as ‘cultch,’ covering 2,500 metres square onto the seabed.

Oysters sourced from south Wales will be transferred to the site to seed the area at the Swanwick bend in the River Hamble in a few weeks.

The Solent was once the largest and most important oyster fishery in Europe, but over the last

decade oysters have significantly dwindled in numbers as a result of poor water quality, competition from invasive species, disease and fishing pressure.

The loss of the native European oyster not only negatively impacts the livelihoods of local fishermen, but also removes the many ecosystem services that a healthy oyster population provides.

Adult oysters can filter as much as 200 litres of seawater each day, improving water clarity and removing excess nutrients.

Oysters also stabilise marine sediments and dramatically increase biodiversity, including commercially important fish species.

Louise MacCallum, Solent Project Manager for Blue Marine, said: ‘This new restoration reef has taken more than a year to plan - the River Hamble is one of the busiest waterways in the UK.

‘As well as creating a perfect home for 30,000 oysters, it has also been critically important to ensure that our operations do not affect navigational safety for the many people who enjoy boating and water sports on the river.’

In the coming months and years, scientists from Blue Marine, University of Portsmouth and University of Southampton will monitor the new reef.

Oyster survivorship and biodiversity gains will be measured and compared to another part of the river where no restoration activity is to take place.

This will be the second restored oyster reef in the Solent, the first having been built in Langstone Harbour at the end of 2021 - a 1,000 square metre reef.

The Langstone reef has already attracted a wealth of marine fauna including cuttlefish, catsharks and even seahorses.

Joanne Preston, Reader in Marine Ecology and Evolution at the University of Portsmouth, said: ‘This reef deployment is another significant step forward in recreating the subtidal oyster reef habitat that has been all but lost in the Solent and across Europe.

‘We hope this reef creates a tipping point, kick-starting a population of native oysters that builds over several generations and provides offspring that will spill over and populate other areas.

‘We also predict strong biodiversity gains and water quality improvements, which we will be monitoring over the next five years.’