Searching the shore

11th January 2021

I am no biologist, and I don’t really know very much about shore life. Before retiring and moving to be near the sea I worked in physics and engineering. The attractions of the sea were for me, like most people I would think, a mixture of fresh air, the simple pleasures of sun, sand and sea on skin and the novelty of a different environment. But the coast has also always inspired. I used to walk along the shore and use the sea and sand to spark thoughts about physics. Actual physics, such as wondering how sand ripples form or more esoteric metaphysical thoughts, inspired by the sea, about the universe or time and space. Biology was never my thing, a bit too squishy and potentially messy for my liking and, I thought, less fundamental and therefore intrinsically less interesting than the big questions of physics.

Bird watching was the nearest I came to an interest in life sciences. I had often thought that once retired and settled in, I would look for some ornithologically themed volunteer work. I imagined myself monitoring bird numbers along some stretch of wild Pembrokeshire coast. Motivation for a regular walk and a chance to feel like I was doing something useful in the face of the constant soul-destroying news of climate change, pollution, habitat loss and declining wildlife.

It was my son who noticed the online advert for volunteers for Living Seas Wales (https://livingseas.wales/ ) and passed it to me. Not birds, but the life of the seashore. Recording what is present, but also looking for invasive species or species indicative of climate change.

The novelty intuitively appealed. The chance to learn something new. Not just new, but quite different. The sea, an unknown alien world to most of us, is particularly good at firing our imaginations and I enjoyed the thought of immersing myself in this new subject. I made contact and after a pleasantly small amount of admin and some online training, was ready to go.

Since discovering it a few years ago I have greatly enjoyed the area around Dinas Island on the north Pembrokeshire coast. The walk around the head itself is beautiful and dramatic with views out into Cardigan bay and across to North Wales. There is even a small sea stack which, in the spring and summer, hosts colonies of beautiful, raucous seabirds including razorbills and guillemots.

Razorbills and guillemots on Needle Rock, Dinas Island

It was maybe natural then that I would choose a bay near the Head for my first shore search.

Picking a pleasant day, I arrived a little before low tide. It was easy this first time. I knew nothing and so everything was new. I thought the easiest thing might be just to take photographs and identify what I found back at home with books and the internet to hand. I walked over the sand, heading to the rocks that form one side of the bay, photographing the different seaweeds that were either growing on rocks or cast up on the sand as I went.

I like the early stages of getting into a new subject. It reminds me of looking out onto a field of newly fallen snow. You have no preconceptions or mental clutter and are free to wander where you will, think what you like and ask whatever questions come to mind. I remember wondering whether seashore life is as seasonal as life on the land and whether the types of rocks, or how exposed a shore is, has much effect on what will be found there. I also had more specific questions such as whether those little fish you sometimes find in rock pools choose to live there or just get stranded as the tide goes out and if a rock pool is simply a visible bit of the undersea habitat that lies all around or a fundamentally different and unique eco-system.

Arriving at the east end of the bay I chose a moderately sized, attractive looking rock pool and knelt for a closer look.

Rockpool

It is a cliché I know, but rock pools do look like gardens. Some look like flower gardens, full of life and colour, others are more like Japanese Zen gardens, austere arrangements of rock and light and shade. This one was of the first type, a play of weeds of different shapes and colours; greens and reddy-browns, flat, and feathery, with the rock basin below the water line covered in that pale pink growth you sometimes see; a type of under-water lichen perhaps?

There were a number of those sea anemones that look, when they are closed, like blobs of red jelly, as well as shells of various sorts, some I recognised as limpets but others I was not sure about. I took photos of all these before spotting something more unusual; a broad piece of brown seaweed covered in a fine geometric pattern. I had no idea what this was. More photographs.

I was just about to move on when I became aware of a small patch of pale star-like growth, partially hidden among the weed on the bottom of the pool. As my eyes tuned in, I realized there was quite a lot of it, perhaps it was another type of anemone.

A quick look around, followed by a cup of coffee sat on a rock and a short, shouted conversation about the pleasantness of the morning with a fisherman setting out to pick up lobster pots and it was time to go. It had been good. There is something about going to a place with a sense of purpose rather than just strolling along looking at the view. You engage with things more deeply, people come up and talk to you, interested in what you are doing.

My lasting impression was just how much life there had been. Fifteen species¹ within a few square yards, some of which I had never seen before and had not known existed. Seashore life is not cosy or cute, but it is beautiful and wonderfully alien. You might as well be exploring life on other planets, Star Trek style, as delving into rock pools. Getting to know the shore is bringing home to me that Life is at least as great a mystery as the abstract questions of physics and of course, you only have to look up and the birds are there as well.

A few of the species described above (tentative ID):