HEBRIDEAN SEA LIFE

Robert Arnold

(Extracts from a dummy book compiled in the 1980s from prints made from Kodachrome slides taken underwater)

book

inside

The pleasures of diving are many; most people appreciate the attractions of swimming, but when diving with scuba gear you are able to swim in three dimensions and experience weightlessness like an astronaut. Some have called the sub sea "inner space". If you couple the extraordinary physical sensations with the entry into a separate calm green and silent world hidden from view, it is possible to begin to feel the excitement of diving.

kelp

The restriction of carrying one's own air supply limits the time available for a dive to about an hour, which forces a diver to plan his time carefully. The shallow sea which is accessible with scuba, that is down to fifty metres, is the most prolific and fertile area of the sea.

If your interest lies in naturalism it is the ideal place for a nature ramble. Many people enjoy looking in rock pools on the shore and diving apparatus enables this study to extend beyond the beach and onto the sea bed.

By visiting sites throughout the year it is possible to begin to appreciate the complex changes that take place just as the land based naturalist learns which birds or plants are to be found at each season.

In the nineteenth century Philip Henry Gosse popularised the collection of sea shore creatures to such an extent that some beaches were said to be totally barren after a season of visits by earnest naturalists. After the amazing technological advances brought about by the work of Jacques Cousteau on diving apparatus and also Japanese camera developments in the last thirty years it is now possible to see the animals that Gosse saw only in a dredge, living in their own habitat and moreover the wonder of this can be shared in part at least by recording the sights on film. This is in accord with modern ideas of conservation and we can rekindle the old style naturalist's enthusiasm for the exotic without any damage to the animals themselves and thereby increase our simple joy in observation.

shallows

With the opening up of this sub-littoral zone to free-swimming observers, it has become clear that there is a lot more to be learnt even about such basic matters as the distribution of animals and plants around the coast. There is also the study of behaviour in the natural environment which is a possibility now. There are many fascinating problems to unravel and solve concerning the ecology of the sea and coastal areas.

Marine scientists are working on such things all over the world. There is a danger that the generally interested person will get left behind by all this research. TV and films always show underwater footage from distant places and the learned work is largely inaccessible and not for the ordinary naturalist.

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N W Skye and the Minch

My intention in this book is to illustrate some of the sights that can be seen on one small part of the British coastline; to show that the exotic and astoundingly beautiful creatures of the sea are not confined to far-off countries. I would like to supplement the many excellent books about shore creatures by extending their range below the low water mark and by using photographs of animals in their natural habitats. I am not able to provide an exhaustive guide to the underwater environment and it is definitely not my aim to do this; rather I would like to share pleasure at the sight of animals that I have found and photographed here on the North West coast of the Isle of Skye.

Every dive is a crossing of the barrier of the sea's surface into a mysterious world. Every time I have done this I have seen something new or unexpected. It would be the end of my interest in diving these northern waters if I could say that I had seen every animal that lives here. This is the delight of natural history.

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I have often been asked after a dive if I saw anything; an impossible question to answer without some common ground. The silent green or the seaweed floating upright forming undersea forests are a total experience and are hard to describe to someone only seeing the shining surface of the sea. If this book can communicate a little of the answer I will be satisfied and I hope that it can add to the enjoyment of the sea and the Hebrides by others.

It is possible in many parts of Skye to dive from the shore and reach depths of up to fifty metres, the limit for air diving. This type of dive takes you across the various zones   of the shore and sub-littoral to the sand and silt of the sea floor. In fact the observer can find more to interest him in the shallow areas to a depth of about fifteen metres.

kelp

Diving involves getting kitted up in an uncomfortable and restricting suit and then hanging lead weights and heavy air cylinders around one's body to struggle towards the sea and find weightless ease and three-dimensional movement; the silence underwater contrasts with the time spent pumping up air bottles, attending an astoundingly noisy air compressor. The paradox that all this elaborate technology is   needed to enjoy the truly wild and remote underwater world is one of the attractive aspects of diving.

pump

The visibility is always important, but when it is spectacular, for instance ten or twenty metres, on land this would be considered severe fog and very limited. The whole experience is so different to being on land; creatures hover and glide, plants are buoyant with no rigid structure needed to hold them upright; even the cold seems to affect one differently, and often on winter dives the first indication of how chilled you become is in the hot bath afterwards when the water seems to get cold immediately  as the core of your body absorbs the heat.

Simple tasks underwater become complicated and operating a camera effetively is demanding. The 35mm amphibious camera is fortunately extremely simple to use and  can be set up on the shore and only minimal adjustments made in the water. It is particularly simple to set up when shooting close-ups which require the use of a flash gun to provide enough light at any depth below a few feet. The flash is white light much like daylight in air but not at all like daylight filtered through any depth of green sea water. This means that the diver will see red things as brown or black but his photograph will show them as red. This is one of the excitements of taking pictures as well as the ability to study things for longer and more carefully in a photograph than is possible on a dive. The colours are in a real sense not there underwater and this is equally true for tropical coral reefs and all the spectacular fish that live on them. We are more familiar with these scenes lit by powerful white lights on cameras or in aquaria than the blue-green of the sea.

Just as in any attempt to photograph something, there are many occasions when the camera is not with me or the film has run out or the wrong attachment is on the camera for the once only chance. Two things that I would particularly like to have photographed happened on the same stretch of shoreline at shallow depths of five to ten metres in summer. I was swimming up at the end of my dive and saw a shiny creature with a pointed head and very beady eyes racing towards me very aggressively. At about five feet from me it must have seen that I was larger than it expected and it swerved sideways and raced away and surface. It was only then that I realised that it was a shag diving for fish and perhaps had been attracted by my shining bubbles.

The other event was also to do with the power of sunlight on air bubbles to attract animals in the sea. This time I was in the shallows enjoying the sunshine rippling on the rocks and weed around me, when it suddenly became darker. Looking up I saw a huge shoal of mackerel swinmming in formation around the plume of bubbles. Once or twice they darted at the bubbles and then circled again until they streamed away into the distance continuing on their journey along the shore. I was probably too enthralled to have been able to take a reasonable picture but this did not arise as I had no camera anyway.

There are other missed chances that are more technical than accidental. For instance it is not uncommon to meet up with a common seal underwater as t hey are very inquisitive about divers. However they are also very careful and will glide around in a circle at the limit of visibility, maybe ten or twenty feet away. The diver can see their wonderful swimming skills as they roll and swerve about, all the time keeping their large eyes trained on him, but the distance is just enough to be only a ghostly image and quite impossible to capture on film without more than the usual amount of luck.

One of the most densely populated marine environments is the soft mud that lies at the bottom of the lochs. The animals that live here use the mud for shelter and can only be found by digging or dredging. There many worms and molluscs that live hidden in this way and do not allow one to take a naturalistic photograph of them. Similarly there are fish that are common near the shore, such as saithe, but are far too sensitive to the noises that a diver makes to let him approach close enough for photography.

Although Dunvegan Head and the cliffs around Neist Point rise three hundred metres (1000 feet) from the sea, much of the coastline slopes gently down to the shore. The narrow fingers of the sea lochs that are characteristic of the West coast of Scotland are sheltered from the extreme tidal currents of the Minch which funnels through between Skye and the Outer Hebrides. The Outer Isles also provide  a screen against the Atlantic swell so that Skye rarely sees any rollers breaking on the shore. Despite all this shelter there is still exposure force of the wind of the North Atlantic, and short, choppy seas that can arise within a loch can be a considerable hazard to small boats.

Within the sea lochs, some of which are very deep (Loch Dunvegan reaches depths of 100 metres less than half a mile from the shore) there is a build up of sediments washed down by the heavy rainfall from the moorlands above. This forms large areas of soft mud, the ideal habitat for burrowing animals of many kinds; the most commercially important is the Dublin Bay Prawn that is fished by many small boats around Skye.

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The shore itself is mostly black basalt boulders or sand interspersed with stretches of bedrock. Just below the beach and beyond the dense kelp forest that extends to about ten metres below the surface there is often a band of white sand that can be seen from cliff tops, colouring the sea with greens and blues. This is always a beautiful place to dive along the edge of the sand looking under the stems of kelp at the life on the rocks that make up the boulder slope up to the beach. Visitors to Skye who do not dive miss the white sand beaches that exist on the west of the Outer Hebrides and on parts of the mainland coast. There is one white beach however, where the coarse shell sand and pieces of a common type of coralline alga are washed up between a small island and the headland at Claigan by the longshore drift. The alga that forms the bulk of the beach grows in the shallows in many parts of the coast forming pink encrustations on stones before it is broken off or dies, when it turns white and becomes the substance of the "Coral Beaches".

The geology of North Skye is part of the Tertiary Volcanic area that stretches south to Mull and North Antrim. Forty million years ago this area was made up of basalt lava in flat layers forming plateaus such as those being formed now in parts of Iceland. The eruptions were fed by long cracks in the previous layers of basalt below. The subsequent heavy glacial erosion by the ice sheet spreading from mainland Scotland and later from the Cuillin Hills carved deep sea lochs and exposed the layered nature of the basalt. The flat topped hills are a reminder of the ancient plateau.

hexagon

Hexagonal columns of rock, columnar jointing, like at Staffa and the Giant's Causeway in Ireland are also indications of the volcanic past. They represent the cooling cracks of volumes of lava held beneath the surface forming slow cooling sills. The feeders for the plateaus are now to be found as rock walls cutting through the layers in cliffs and cutting across beaches. These dykes, although mostly covered by peat on land and silt in the sea, are one of the exciting finds of a dive. They rise off the sea floor sometimes ten metres high with vertical sides. This narrow rock wall which may extend for some distance is the perfect environment for soft corals, cup coral, giant anemones and browsing sea urchins.

Skye is at a latitude north of Moscow and level with Hudson Bay in Canada. The weather is remarkably mild considering this. However, the frequent gales and heavy rain conspire to make it feel very bleak much of tN W Skye and the Minchhe year. The occasional brilliantly sunny windless day at any time of the year makes up for a lot and it is easy to forget the worst times. Being so far north means that the days in summer become so long that the twilight of the evening merges with the twilight of the morning and for several weeks around June there is no real darkness. Of course, in mid-winter the days become extremely short and the sun, if it is visible at all, appears to barely rise above the horizon before beginning its descent. Compensation for the darkness of winter comes on clear moonless nights when the Aurora Borealis or northern lights can be seen. On many such nights it is a glow like a huge city to the north, but every so often a spectacular display lasting hours will arise; shafts of white light move and grow, sometimes there are rippling flames of light or ribbons of green glow, and sometimes huge areas of dull red glowing in the night sky. Standing under a sky mysteriously lit by silent moving shapes on a cold night in winter is awe inspiring.

The seasons are also apparent in the sea. The spring is a time of plankton bloom as many animals release their eggs and larvae into the sea. At some time in March the sea can be so densely populated by barnacle larvae that the visibility is down to a few feet. Within weeks the barnacles settle on every available space of stone surface on the shore and become the familiar sedentary creature. By the end of the summer the grey coating they make on the beach has been largely removed, and only the barnacles that had the luck to land on a large rock and escape being smashed by the rolling of small stones by the waves, survive.

clavelina

Clavelina, colonia sea squirt

Shortly after the barnacle larvae appear in the plankton the diver will notice the return of the sessile colonial sea-squirt, Clavelina. It is one of the most magical animals to find and to me represents spring underwater. It grows through the summer only to retract into a jelly like layer on the rock again for the winter. By June the weed has become very thick, and around this time large swarms of jellyfish begin to appear, their early smaller stages having been in the plankton for some months.

In the summer porpoises commonly cruise in the lochs and terns arrive in islands offshore. If you spend any time on the shores of this coast then you must see common seals and more rarely otters. Both can be found throughout the year and seem to take as much pleasure diving and exploring the coast as any naturalist.

The North West coast of Skye is a dramatic place at any time of the year and in any weather. It can feel kind or extremely hostile, but even in its softest mood it has the windswept bleakness of the treeless North, of moorland or tundra. However, under the surface of the sea there is a variety and profusion of animal life that we might more easily associate with tropical waters.


Links to Flickr albums of some of the slides

Isle of Skye diving photos
Isle of Skye Seaslugs 
Isle of Skye Medusae
Isle of Skye Plankton
Marine photo page