By Keith Broomfield
A large, mushroom-shaped creature pulsed into view through the briny underwater haze like a mysterious alien from another world. I slowed my breathing through my snorkel tube and watched it glide past, awed by its size and intricate frilled tentacles that trailed behind the bulbous main body.
It was a barrel jellyfish and the first time I had encountered one under water, although I had glimpsed them several times before in Scottish seas from piers and when aboard boats. These cream-coloured monsters really can grow to the size of a barrel, but they are gentle giants, feeding on plankton and their sting is mild and not generally harmful to humans. The biggest specimens can exceed 1.5m in length and 35kg in weight.
I was snorkelling at Ardmair Bay, a sheltered backwater of Loch Broom that lies close to Ullapool in Wester Ross. It is one of my favourite snorkel haunts because of the clarity of the water and the abundance of marine life. As well as the barrel jellyfish, there were scores of lion’s mane jellyfish drifting about, which I carefully steered around because their multitude of long trailing tentacles do give a nasty sting.
I was snorkelling in a sheltered part of the bay, which was home to a host of specialised creatures that prefer a more benign marine environment, including fluted sea squirts, dahlia anemones and burrowing anemones. The white coloured sea squirts were especially abundant, growing in clusters upon seaweeds. Sea squirts have sac-like bodies with two siphons on the top (one inhalant and the other exhalant) through which they draw water and carefully filter out food particles.
A glowing nugget of orange caught my eye on the seabed about 15ft down. I took three deep breaths and dived under to investigate and was rewarded with the remarkable sight of a type of sponge known as a sea orange. It was a fascinating organism – about the size of a cricket ball and with several large pores on the body. Sponges are the simplest of all marine animals, and like the sea squirts, gain nourishment by filtering water through their bodies.
After surfacing and regaining my breath, I drifted over a forest of kelp, and was immediately drawn into the embrace of another bizarre lifeform known as sea mat, which coated fronds of kelp in a dazzling, white crystalline veneer. While sea mats are superficially similar to the encrusting lichens found on rocks on land, they instead belong to a mystical group of colonial animals known as bryozoans. I lifted gently a frond of kelp to examine the coating of sea mats in more detail, enthralled by their intricate, embroidered shawl patterning.
I ventured back into deeper water and in a truly special moment, a harbour seal swirled past me, before taking a wide circle to inspect this strange humanoid that had encroached upon its watery world. Unsure whether I was friend or foe, the seal flashed away into the blue depths, sparking a tingling wave of exhilaration to course through my body.