Seagrass Restoration on the River Hamble

Seagrass has returned to the River Hamble for the first time in decades, thanks to a major restoration effort by Hampshire & Isle of Wight Wildlife Trust.
On 10 April 2025, 2,000 seeds were planted directly into the seabed by the Trust’s marine conservation team. This is the first time seagrass has been sown in the Hamble since its once-abundant underwater meadows were lost to disease and degradation nearly a century ago.
Historical records show that eelgrass once stretched from Southampton Water up the Hamble to Bursledon, until a wasting disease outbreak in the 1930s caused widespread loss. Surveys in 2011 and again in 2023 found no remaining beds.
The Trust used an innovative Dispenser Injection Seeding technique, which plants seed directly into the seabed. This technique increases the chances of germination success and reduces disturbance to the marine environment, making it a valuable tool in habitat restoration.
The Zostera seeds used were collected, with the help of dedicated local volunteers, in October 2024 from intertidal beds at Farlington, Portsmouth. After collection, the seeds were safely stored in a cold, dark, high-salinity storage aquarium at the University of Portsmouth’s Institute of Marine Science, which put them in a state of dormancy over the winter months.

Posted 07/05/2025 08:02