As I walk down the concrete steps to the bay the sea smell is stronger than usual. Autumn has arrived. Piles of red seaweed and brown laminaria lie along the beach, torn from the rocks by the first rough weather.
It is a grey day and the bay strikes me as looking a little tired, but I set off anyway towards the cliffs and the rockpool I have been monitoring for the last year or so. But something is wrong. I get roughly to where the rockpool should be but it’s not there! The rocks as well! Nothing is in its right place! I stand, momentarily confused and disorientated, but then realise, it is just that the sea is so much further out than usual, due to the exceptionally low spring tide, and so the landscape is changed. I pause, re-establish my bearings and after a few minutes find my objective.
In contrast to the bay, the pool’s appearance is improved by the recent heavy wave action, it is much cleaner and brighter than the last time I saw it1.
It is fresh and clear and its distinctive pink colour plain to see. This colouration, which is shared by many pools in the area, is due to a soft-pink encrusting coral that covers the pool basin below the waterline and a sturdy red seaweed known as Corallina officianalis which grows in tufts within the pool itself2. There are, in these pools, often also a few delicate twists of a bright green algae known as Sea lettuce, as well as a scattering of limpets and periwinkles on the rockpool floor. Some pools also sport Snakelocks anemones, with their striking purple-tipped green tentacles; a simultaneously startling, but subtle play of complementary colours. There also often signs of apparent whimsy; limpets sporting delicate weed fascinators, or with periwinkles riding on their backs. Often these various elements appear arranged with such fussy, delicate artistry as to bring to mind a plate of Michelin starred food from a fancy London restaurant.
I have been observing these pools regularly for not quite a year, and have noticed they are most attractive in the spring. Throughout the summer months, presumably due to the higher light levels and warmer water, some of them, including the one I monitor, grow an epiphytic algae that gradually obscures both colour and form3. At the same time silt and detritus, including excreta from the grazing shellfish built up on the bottom, hiding the coral floor and filling seams and cracks in the rock.
But now, with the bigger seas, all is refreshed. Wave-gales have blown though, scouring the pool, and removing all that was not strong or well anchored.
Peering in, one of the first things I see are the pale, blue-banded tentacles, of daisy anemones. I feel a perhaps unreasonably strong sense of relief. They had been missing all summer and, in my habitual assumption of the worse, I had thought them gone. But no, all is well, they were merely obscured by the silt. But such is the relentless reporting of loss and change in nature these days that any sign, such as this, of resilience or even normal natural routine, is frequently accompanied by an motional release. Given the transformation wrought by the recent waves I wonder if this scouring is a necessary part of these rockpool habitats, in the same way that fire is a necessary part of some grass or woodland ecosystems.
I find a place to stand where my reflection in the water is least and take a series of fifty or so overlapping photographs covering the rockpool from barnacled shore to barnacled shore. These will be stitched together into a single highly detailed image when I get home – a method of recording the pool and something new I am trying.
While taking the photographs I notice that the sea has deposited some of the same red seaweed, or macro algae as it is properly called, in the pool as lay along the beach. Here, as there, a lot of it is covered in a pale encrustation called sea mat. It looks nothing from a distance but looking closely reveals a very fine lacy mesh of perfectly rectangular cells, each less than a millimetre in size. This is a Bryzoan4 or ‘moss animal’, a colony of tiny flower-like filter feeders. I have never seen the creatures, only these dead remains, but still there is something arresting about this geometric precision amongst the organic forms of the seaweed.
- This sounds like a totally anthropocentric judgement – perhaps the inhabitants prefer a rich, murky soup of nutrients, but then according to ‘3’ below this instinctive judgement may be correct.
- This type of rockpool is given a special designation by the Joint Nature Conservancy Council (JNCC), you can read more about it here.
- I have read that this growth of epiphytes actually stunts or kills the red Corallina officinalis sea weed.
- Rockpools and the life within them have inspired and continue to inspire great interest from evolutionary biologists, from Charles Darwin down. Bryzoans, are heavily researched for a number of reasons, including that their calciferous cells mean they are well preserved in the fossil record, enabling close tracking of evolutionary changes.