In February, the stormy seas and cold water temperatures make it tricky for some marine species to survive and they are often washed up dead on the beach.
There is often a very thick strandline marking the high tide point, made up mostly of kelp, the largest of the seaweeds. Kelp tends to live in fairly shallow water in Britain as it needs a lot of sunlight, however this, and its large size, makes it vulnerable to being torn off the seabed by waves and thrown onto the beach to die.
Kelps therefore tend to have large, strong ‘holdfasts’ the anchor which glues them tightly to the seabed. Even this may not be enough in rough weather, so look out for the big, knobbly holdfasts of Furbellows, our largest kelp. They may look rubbery and man-made but are an important part of the alga and also offer shelter to other marine species such as blue-rayed limpets and marine isopods.
Increasing numbers of grey triggerfish have been making a home in Dorset’s coastal waters over the last 20 years or so, although there is no evidence that they are breeding here. They tend to arrive in late summer when the water is at its warmest, but many die at this time of year as the sea temperature plummets and they can sometimes be found dead on the beach.
They look almost diamond shaped from the side but are flattened from side to side. The name comes from the strong spine on their back which is held upright by a second ‘trigger’ spine in order to wedge them into narrow crevices when threatened. The trigger then releases the spine to fold flat when danger has passed.
Sometimes called ‘Seawash balls’, whelk eggcases often litter the beaches at this time of year. Sailors once used them to wash with, in days gone by, in the same way we use bath sponges today hence their alternative name. However they are the empty eggcases laid by the common whelk or buckie, a large sea snail with the iconic seashell shape children use to listen to the sea. The ‘ball’ is made up of dozens of lens-shaped pockets, each of which contain 10 or more eggs.
Most of these eggs are eaten by the first one to hatch before it emerges from the case. Normally the egg-masses are grey in colour and empty of eggs when they wash onto the beach, but in rough weather they are sometimes thrown up before they are all hatched and are still yellow.
Furbellows by Julie Hatcher
Triggerfish by Julie Hatcher
Whelk eggcases by Julie Hatcher