Envrionmental experts say new evidence could help protect North West Wales' most important marine habitats.

The sponge communities in the Menai Strait and Conwy Bay - and the horse mussel reefs off the Llŷn Peninsula - are all designated as special areas of conservation (SACs).

According to Natural Resources Wales (NRW), detailed research has provided new insight into the pressures affecting marine wildlife as well as identified what could be done to improve conditions for recovery.

The sponge investigation in the Menai Strait and Conwy Bay offered new insight into the impact of enviromental changes, helping to inform future monitoring and management.

In Pen Llŷn a'r Sarnau, researchers looked into the combined efforts of historic physical disturbance, changing envrionmental conditions and climate-related pressures on the horse mussel reefs.

Studies were also carried out in Milford Haven, home of the only known living maeri bed in Wales.

NRW said it found no single pressure explained the changes to marine habitats and while pressures varied between sites - such as nutrient pollution, sedimentation and invasive species - it also identified new ways of helping target conservation action and support recovery.

Andrea Winterton, NRW marine services manager, said: "We've known for some time that these habitats are facing a range of pressures, and monitoring has helped us understand how their condition is changing."

"These investigations take that a step further by improving our understanding of what's driving those changes and where action can have the greatest impact."

"The studies form part of NRW's wider work to improve the condition and resilience of Wales' marine protected areas and support action to address the nature and climate emergencies."

"By identifying the pressures that are holding these habitats back, we have a better opportunity to support their recovery and safeguard the rich marine life they support."

"They form part of the natural heritage that makes Wales unique, and the findings will help us work with partners to protect these special places and build their resilience for the future."

The investigations were carried out following last year's assessment of marine protected areas, which highlighted several protected habitats and species were more investigation was needed to better understand declining conditions.