Two species of sea slugs usually found in warmer waters and a critically endangered tope shark are among the ‘climate change indicators’ surveyed in the Wildlife Trusts’ annual Marine Review for 2024, a detailed assessment of the health of the UK’s marine life which suggested that, overall, wildlife has started to make somewhat of a comeback over the last 12 months.

Among the species recorded were a number of pleasant surprises, including the discovery of a spiny lobster in Wembury Bay, which was sighted “for the first time in living memory” following excessive fishing in the 1960s and ‘70s, giant mussel beds, a tope shark, and a European eel.

Last month, the Wildlife Trusts revealed how it was innovation, research, and a “mammoth volunteering effort” in which seaside volunteers clocked over 46,000 hours of surveying shorelines and recorded wildlife, to bring The Wildlife Trusts’ 2024 marine review to life.

Discoveries made during the survey included ‘climate-indicator’ sea slugs and seaweeds, as well as sightings of conger eels and humpback whales.

Not only does the review highlight conservation projects to reconnect land and ocean habitats and restore oyster beds, but details a number of the efforts made to bring people closer to nature, including the development of a network of snorkelling trails in Scotland’s seas.

Last year saw the UK become the first country to map its ‘blue carbon’ – the carbon stored in seabed mud and coastal habitats such as salt marshes – thanks to a project by a number of charities, including the Wildlife Trusts. 

The survey was released with a call to action to ban bottom trawling in protected areas – a stance that has, according to the Wildlife Trusts, received the backing of 80% of the British public – as well as taking measures to ensure that offshore developments are “nature positive”. The charities say that strengthening protection of the UK’s blue carbon can help to achieve climate and biodiversity goals.

“People are central to nature recovery and made huge contributions to our knowledge of UK seas this year. Wildlife surveys and monitoring have led to incredible discoveries, including new species on UK shores,” said Ruth Williams, head of marine conservation at The Wildlife Trusts.

“Success stories demonstrate the enormous value of marine conservation and why robust protection is critical for nature recovery.”

Such examples would be the recording of giant mussel beds, greater diversity of fish, and an increased number of lobster reported in Sussex where – three years after a byelaw was passed to protect 300-square-kilometres of seabed from trawling – marine life is making a comeback.

In fact, it was in the waters around Sussex that a tope shark and European eel were among the 81 different marine species recorded.

Meanwhile, monitoring in the Medway – the largest no-take zone in the UK – found huge numbers of juvenile bass, while shore crabs were found “in abundance”. Along the south coast, St Piran’s hermit crabs were recorded in great numbers, providing a particular win for the species that had been all but wiped out by the Torrey Canyon oil spill of 1967.

Humpback whales were seen off Lancashire, Pembrokeshire, and North Wales; a rarely seen sea mouse was seen in Sussex moving through the sands at high tide; and the discovery of small-headed clingfish on the Isle of Man was confirmed as a new species for the island. 

The survey highlighted a number of conservation projects across Cornwall and Essex, which included the first UK trial of remote setting to reintroduce native oysters in the Humber estuary, the measurement of a snakelock anemone and coral weed bed the size of five Olympic swimming pools in Kimmeridge Bay in Dorset, and the collection of over 3,000kg of rubbish from beaches through clean-up operations organised by Wildlife Trusts.

As the first country in the world to map all its blue carbon habitats, it’s a held belief that the UK has a “unique position” to champion better protection for seabed habitats, environments acknowledged by Wildlife Trusts as the “unsung heroes” in our fight against climate change.

The effects of climate change are now on our very doorstep. The warty dorid sea slug found in Sussex and the rainbow sea slug found in Devon – far from the warmer waters they typically frequent – aren’t the only indicators of changing ocean habitats around the UK. The Wildlife Trusts also highlighted the first records of devil’s tongue weed and the non-native kelp seaweed, wakame on a Kent shore. 

Meanwhile, pom-pom weed – a seaweed native to Asia that forms red tangled ‘pompoms’ was found across Devon bringing with it concerns that it could displace UK macro-invertebrates like barnacles. Further climate indicators included the “very dense” aggregation of invasive pacific oyster at Hope Cove in Devon and a loggerhead sea turtle which was found in Cumbria and released in the Azores.

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