If you have been fortunate enough to visit Kimmeridge for rockpooling, snorkelling or even diving from the shore, you will be well aware of the rich variety of seaweeds to be found there.

Seaweed needs a rocky seabed in order to attach by its holdfast and prevent being washed ashore by strong waves. Few species are found on sandy seabeds where they might attach to pebbles or shells, because these provide a poor anchorage in heavy seas.

Kimmeridge Bay and the surrounding area has been proposed as one of the new Marine Conservation Zones (MCZs) currently being set up to form a network of ‘marine reserves’ around the English coastline.

The individual MCZs are selected for particular species or habitats within them and together as a network will include examples of a range of species and every type of seabed habitat to be found in the country.

Some sites have already been designated but there are gaps in the network that still need to be filled.

Peacock’s Tail seaweed is one of the species for which MCZs are being selected and is a bit of a speciality at Kimmeridge. It is a warm water species more common in the Mediterranean Sea and south of the British Isles, however it is also found at a handful of sites along the south coast of England.

The unusual geology within Kimmeridge Bay means that large areas of rocky seashore are uncovered at low tide and this heats up in the summer so that when the tides returns the seawater is warmed by the rock. The sea temperature in the shallows of the Bay is often 1 or 2 degrees Celsius higher than the ambient sea temperature and this makes it ideal for Peacock’s Tail seaweed.

Despite its colourful name, this seaweed is fairly monochrome, consisting of tough banded fronds, cream in colour and forming the shape of a somewhat torn funnel.

Fine hairs grow from the underside of the frond and can give the plant a fuzzy appearance. It falls within the category of brown seaweeds and is unmistakeable. Peacock’s Tail can grow in extensive patches at the bottom of silty rock pools or as small ‘plants’ amongst other algae in very shallow water. Recently it appears that Peacock’s Tail is spreading at Kimmeridge and is found in more rock pools than previously. 

This may be as a result of warming sea temperatures or because of less disturbance from visitors, or for a completely different reason. 

Whatever the reason it is a good news story for Peacock’s Tail and for the proposed Marine Conservation Zone. Next year there will be a public consultation on which of the proposed MCZs will go forward to complete the network. You can sign up as a Friend of MCZs.

Find out more at wildlifetrusts.org/MCZ/broad-bench-to-kimmeridge-bay.