A significant recovery in seabird populations has been recorded along the Solent coastline after a devastating outbreak of avian influenza in 2022 sharply reduced breeding numbers. Conservation efforts over the past three years have revived colonies at Pagham Harbour and other key sites, with notable rebounds in several ground-nesting bird species.
In 2022, the colony of sandwich terns at Pagham Harbour, West Sussex, was completely wiped out by highly pathogenic avian influenza (HPAI). However, a combination of targeted conservation measures has seen numbers recover from zero to 756 breeding pairs by 2026. This year, the colony produced 570 fledglings, marking one of the largest nests recorded in the Solent region.
Other species along this stretch of coastline also experienced population increases. Black-headed gull fledglings rose sharply, from 51 in 2025 to 504 in 2026, while little terns climbed from 21 to 34 fledglings in the same period. The ringed plover and oystercatcher populations also reported gains. Avocets have flourished as well, with 18 pairs nesting on new islands created within a saline lagoon at Ferry Pool, offering safer breeding grounds for shoreline birds.
These improvements stem from coordinated efforts led by the Royal Society for the Protection of Birds (RSPB) in partnership with multiple organisations, working across approximately 52,000 hectares of coastal and estuarine habitat spanning from the south coast to the Isle of Wight. Conservation initiatives include the installation of predator-exclusion fencing to deter mammals such as foxes, regular monitoring for rats, on-site patrols to prevent predation, and the selective clearance of vegetation to create optimal nesting conditions.
Wez Smith, senior project manager for the RSPB, noted the severe impact of the 2022 bird flu outbreak on sandwich terns, black-headed gulls, and Mediterranean gulls, which led to the abandonment of breeding colonies at Pagham. He highlighted that years of dedicated conservation work have been pivotal in reversing this decline, with the situation showing clear improvement since last year and encouraging population growth this season.
Volunteers and rangers have also conducted outreach efforts aimed at local residents and visitors to raise awareness about the vulnerability of ground-nesting bird species, establishing dog-friendly zones to reduce disturbance during critical breeding periods.
At RSPB Medmerry near Pagham, floating nesting rafts have provided predator-free platforms for common terns and black-headed gulls, safeguarding them from threats posed by dogs and boats. Similar rafts have been deployed at West Hayling, another coastal reserve in Hampshire, bolstering common tern breeding success.
These initiatives form part of the broader Solent Seascape project, a long-term collaboration led by the Blue Marine Foundation and involving multiple charities and institutions. The project focuses on restoring coastal nesting sites along with enhancing seagrass beds, oyster reefs, and saltmarsh habitats, supporting the overall resilience and biodiversity of the Solent’s marine and avian ecosystems.