Hebridean Seas
Life Below the Waves
Hebrides: Islands on the Edge - Ewan McGregor
Storms and tides in mid-September are some of the biggest of the year. Beneath the waves the ferocious tidal flows are good news! Here, beyond the curtains of kelp is a remarkable world of creatures who depend upon the movement of the tide to keep them alive. A squat lobster can search for food. But, most creatures here are firmly anchored to the rock.
dead-man’s fingers
These are dead-man’s fingers a type of soft coral. Each colony is made up of hundreds of tiny animals called polyps.
The movements of the tides are critical to these animals as they filter plankton from the water streaming past. But corals have enemies; a sea slug. This miniature predator eats soft coral polyps. The dead-man’s fingers, however, have a neat trick!
All they polyps are connected by a primitive network of nerves and they retract as one. The tide has turned. It’s picking up pace. Soon the beaches here, on the Isle of Oronsay will be completely submerged by the highest tide of the year.
The grey seal pupping season has started. There are new babies everywhere. Suckling on some of the richest milk anywhere in the world. This is a dangerous place to be born. The seals are packed close together on the beach. Mothers will attack pups that don’t smell like their own and fight viciously.
New-born pups don’t know how to swim. Usually, they won’t enter the water until they are three weeks old. But, today the tide will reach so far up the beach they will need to learn very quickly. Some mothers are already showing their pups how to swim, but they are too young to cope.
A fight breaks out in the water, between two females and both pups are at risk of being caught in the crossfire. One mother and pup struggle back to the beach but, the other baby is exhausted by being in the water. It’s just two days old and must rest.
Today’s tide will be the highest of the year and the pup is completely unprepared for what is to come. The water is still rising. Rocks which are usually safe resting places will soon be underwater. The mother seal has made a serious mistake.
The rising tide is now funnelling a huge volume of water through the narrow gap between the islands of Jura and Scarba. This is the legendary Corryvreckan, the Hag’s Cauldron. A place reserved for the most dedicated thrill-seekers. As the tidal flow is squeezed between the two islands the sea-bed suddenly plunges into a cavernous hole - 300 m down. The water then surges up and hammers into a rock pinnacle just below the surface.
The turbulent water, supercharged by the highest tide of the year is now on a direct course to Oronsay and the seal family. They have no choice but to sit it out. The mother rolls on one side, trying to shield her pup but it mistakes the cue and moves in to suckle. The pup is just hanging on, if it’s swept away it could drown. There is nothing the mother can do to help her baby now. It’s only hope is to swim back to the beach alone. The pup is safe at last. And now it can enjoy the most satisfying feed of its life.
Life below the Hebridean Seas will continue as it has for many millennia.
