the beauty of mermaid's purses

it's a day of diffused sun filtering through a whitish haze - surprisingly bright as the foghorns have been sounding and the shore in the distance is barely discernible. boats are reduced to cut outs - simple flat shapes collaged against the even paler grey of the coast against the even paler hue of the sky. it is as if the day has been formed from nothing more than card in varying gradations of grey and a pair of scissors.

but down at my feet things are clearer. the equinox spring tide is receding fast and amongst the dark coppery kelp the milky white and palest celadon of the mermaid's purses are breaking the surface of the water. there are large numbers anchored in twos and threes bound tightly to the holdfasts of seaweed. their tendrils are spun round and round in a big tangled spiral suspending them securely against the rushing tides.

freshly laid mermaid's purse - nursehound (scyliorhinus stellaris) - on the red list

visible yolk and embryo of the small-spotted catshark (scyliorhinus canicula)

nursehound case with orange star ascidian colony (botryllus schlosseri)

most of this season's eggs have been laid alongside those whose hatchlings have long gone. empty inside but the tough keratin walls of the exterior are encrusted with a whole host of new life. each old egg case supports a miniature world looking like a tiny abstract painting. intense bursts of colour sing against a dark ground. a particularly beautiful one is bejewelled with star ascidian - two types of  botryllus schlosseri - on one side a translucent yellow with rust-tipped petals and on the other a deep aubergine with pale yellow centres.

i could spend hours here just looking, looking and looking some more. lost in unbroken awe and wonder i haven't noticed the time or anything around me. i feel bewitched, mesmerised and filled with wonder. the water lapping at the top of my wellies has come too soon. the tide has turned. there is so much more i'd like to see but the water is flooding in fast. i will have to wait until another day, to see them properly that will be another month.

i tread a reluctant retreat and carry my feelings of new found wonder higher up the beach. as i trace the high tide line there are many dried mermaid's purses shrunken and wrinkled amongst the heaps of crispy weed. most are old. but i'm alarmed to find a few that are fresh with yolks clearly visible attached to holdfasts broken free.

i gather them together and wrap them in layers of wet seaweed, fill a bag with water and tie them in another bag. i've no idea if they are alive. there are slits in the tendrils which allow water to flow through the egg case but i don't know how frequently this has to happen. one has a large tear across the centre and i fold back the flap and peek inside. i can just make out a tiny embryo attached to the yolk. sadly it has died. i cut it open to have a closer look.

the embryo usually takes 9-11 months to hatch

it hatches when it is 16cm long, can grow up to 1.6 m and lives for at least 19 years

i empty my water bottle, refill it from the sea and head home with a seeping bag which drips persistently down my leg.

i have kept the egg cases in a box of sea water in the garden overnight. the following day i fit the lid firmly in place and head out with strong twine and scissors. today the spring tide is not so low. it has to be a quick trip and although the tide has turned i'm able to take them out a reasonable distance and tie them amongst others. i have to be fast. i position them at the foot of a distinct rock so i can find them again. the wind is chilly and my hands are cold. i see a beautiful stripy case and a ribbon of seaweed covered in star ascidian before i have to leave. the day has clouded over and light rain begins to fall.