Lots of Barrel Jellyfish, Rhizostoma pulmo, have been spotted along the Dorset coast, both in the water and washed up on beaches. Most records came from around Portland Harbour but they were also spotted at Lyme Regis and Weymouth. This is one of the UK’s largest jellyfish measuring up to 1m across the bell but it has no stinging tentacles and is a plankton-eater. This year the spring plankton bloom is especially good, probably due to an abundance of nutrients in the sea brought in by the flooding rivers and stirred up from the seabed by storms. Another plankton-feeder, the basking shark, also seems to be having a good start to the year with good numbers reported from Cornwall already this year so keep a look out, they may be heading our way!
Jellyfish sometimes host a tiny crustacean called Hyperia galba which lives inside the bell and looks similar to a sandhopper. Not all of them carry this animal but one was found in the bell of a dead barrel jellyfish at Portland. However please do not touch any jellyfish as most sting and they often appear in mixed groups. If you have any photos and records you haven’t sent in yet please email them to
Shark and ray eggcases
Our stand at the Lyme Regis Fossil Festival attracted hundreds of people in early May, keen to find out about our whale baleen and giant Mermaid’s purse as we talked about the close relationship between Dorset’s marine fossils and its living sealife. Visiting school groups hunted for eggcases and found those of four different species on the beach, while green shore urchins, honeycomb worm and a hairy crab with eggs were among the discoveries on the Saturday for our Welly Zone survey.
Seaweed Identification Course
Around 30 volunteers attended our seaweed ID course on 26th April led by local seaweed expert Dr. Lin Baldock at Swanage. As well as learning how to identify a variety of common seaweeds they also witnessed the successful moulting of its shell by a shore crab!
On a seashore survey at Kimmeridge a delightful sighting was of a male 15-spined stickleback guarding its delicate seaweed nest in just inches of water alongside an intertidal rocky ledge. These shallow water marine fish wrap thin silvery threads they produce internally around a small bundle of seaweed and then guard it and the eggs inside from would-be predators. Look at the photo to see the nest tied up in what looks like fishing line.
A local fisherman reported finding a seahorse in a crab pot he had hauled up in Swanage Bay, our first sighting of the year for these charismatic fish . The male short-snouted seahorse was quickly put back in the water and swam away unharmed.
Fossil Festival © Jess Meads
Swanage seaweed course © DWT
15-spined stickleback and nest
© Julie Hatcher
Short snouted seahorse © Tom Greasty