This consists of the narrow, low, NW coastal strip from Tourgis Point to Clonque Island and the steep upward sweep of the west facing hillside above. (Fig.3 Click here). The shore line, below a vertical cliff about 5-8m high, comprises a pebble beach and, at low tide, a large area of tidal, mainly granodiorite, reefs, stretching far out into The Swinge, from Clonque island to the south and the Nannels rocks to the North, with the sandstone islands of Burhou and Little Burhou beyond.
This area is the haunt, at most states of the tide and for much of the year, of a colony of Oyster Catchers Haematopus ostralegus and several species of Gull Larus spp. Large numbers of Crows feed on the reef area when the tide is down and in the thick belts of seaweed washed up after a storm. Grey Heron Ardea cinerea, are frequently seen, as well as occasional visits from one or more of the Little Egrets Egretta garzetta, which appear to have taken up residence in the island and a few Curlew Numenias arquata. In the autumn and winter up to 60 Mallard Anas platyrhynchos, are regularly seen at the southern end of this area near Vau Pommier.
Evidence of a raised beach is clear in several places at the base of the low cliff. (Fig. 4 Click here). Some of the island's few clay patches are also found along the base of this cliff where fresh water seepage occurs. Water-cress Rorippa nasturtium-aquatilis is to be found along here and some of the few patches of Common Scurvy-grass Cochlearia officinalis in the island. (Fig. 5 Click here).
The lower caponnière of Fort Tourgis, by the car park, supports a range of ferns in the mortar crevices, Hart's-tongue Phyllitis scolopendrium, Sea, Lanceolate and Maidenhair Spleenworts Asplenium marinum, A. obovatum & A. trichomanes respectively. A few yards away, the top of the German gun emplacement is covered with Hottentot Fig Carpobrotus edulis and a number of other aliens, probably planted by former "tenants" of the gun site, including Russian Vine Fallopia baldschuanica, Globe Artichoke Cynara scolymus, Red-hot Poker Kniphofia spp., Greater Periwinkle Vinca major and Century Plant Agave americana, may be found nearby. The slopes down from Fort Tourgis are covered with a dense carpet of Bracken Pteridium aquilinum with a few scattered Hawthorn Cratægus monogyna and Elder Sambucus nigra bushes. Masses of Common Dog Violets Viola riviniana, Celandine Ranunculus ficaria and the occasional Pyramidal Orchid Anacamptis pyramidalis are to be found in the small bracken-free grassy patches along here in season, with Autumn Squill Scilla autumnalis in bare patches at the top of the slope in late summer. Beyond the two cottages a small damp quarry supports a range of interesting plants, two of them; Least Duckweed Lemna minuta and Greater Spearwort Ranunculus lingua, quite rare. Also to be found here in the quarry, which generally has about 10-30cms water below the vegetation, are some well-established, aliens, Montbretia Crocosmia x crocosmiflora and Tutsan Hypericum androsæmum flourish in company with one of only three colonies of Galingale Cyperus longus in the island, known in the local patois as Han and common in the larger islands. Here too are Ragged Robin Lychnis flos-cuculi and Lesser Spearwort Ranunculus flammula in some quantity and a few plants of the tall, elegant, Marsh Thistle Cirsium palustre, also found scattered singly, or in small groups, in a number of damp places along this route. The short grassy area in front of this quarry is home to a number of minute plants requiring a hands-and-knees examination. Lesser Parsley-piert Aphanes inexspectata and a number of clover species; including Western Clover Trifolium occidentale, flowering up to a month earlier than the ordinary White Clover T. repens, from which it has only been separated as a distinct species, in the last 10 years or so. Suffocated Clover T. suffocatum, Bird's-foot Clover T. ornithopodioides often wrongly called Fenugreek, and Subterranean or Burrowing Clover T. subterraneum.
The slopes along this part are thickly covered with Ivy Hedera helix subsp. hibernica, noisy with bees collecting wax from the leaves in the Spring and nectar from the yellow flowers in late September and October and a large patch of Rose-bay Willowherb Chamærion angustifolium well known to wartime Londoners as Fire-weed on bomb sites and surprisingly rare in Alderney.
There are two converging valleys, now unhappily so overgrown as to be impassable at their lower end, with streamlets running down from the top and joining to form Vau Pommier which passes under the trackway in a Victorian brick-lined tunnel, known locally as The Blue Bridge, from its lovely blue-grey diorite arches, to discharge on the beach at the bottom of an old, d erelict, vraic road, the cobbles, of the remaining small sections on the beach, raked to give the horse hooves a good grip when pulling their laden carts of seaweed up the slope. Probably planted many years ago, a very large spread of pink Dorothy Perkins Rose grows on top of the bank above the stream, with a large bush of the Hedge Fuchsia Fuchsia magellanica, well naturalised all over the island and in flower for much of the year, below it. Just beyond the stream, in a cutting through the rock made for access to the Victorian Fort Clonque some of Alderney's infrequent Primroses Primula vulgaris are to be found in Spring.
Figure 6. Blue Bridge, with much older stone drain below and remains of vraic road between.
Following the causeway, rebuilt and raised above HWM by the Germans during the Second World War, across to the Fort, on the right as it meets the former island, another part of the 8m. raised beach can be clearly seen beneath the overlying sandy head, (Fig. 7 below). A pair of Cormorant Phalocrocorax carbo nest in some years on the 10m high, rocky outcrop, close by. More clovers, including the delightful Hare's-foot Clover Trifolium arvense are to be found on the grassy area in front of the fort and the much rarer Rock Sea-lavender Limonium binervosum and Golden Samphire Inula crithmoides may be found on the beach below and high up at the base of its walls, at various places around the outside of the fort. Clonque Island, was broken into two by a storm in the late 1960s eroding a narrow isthmus, thus separating the Victorian fort into two parts.
The whole length of this coastal strip is also a good place to find the Glanville Fritillary butterfly Melitea cinxia, (Fig. 8 below), virtually unknown in England except for a small area of the Isle of Wight and probably more frequent in Alderney than in the other islands.
This region has suffered little direct damage from the hands of man this century, but coastal erosion of the low cliff area is gradually moving this further inland. Old photographs, from the end of the last century, show grazing animals and a haystack on the former meadows between the track and the cliff top near the cottages, (Figs. 9 & 10 below).
Sprays, mainly of Garlon, have been used by States Agricultural teams in the last 3-4 years in an attempt to control the Mauvaises Herbes, (see Appendix 1), here principally Hogweed. This has resulted in some loss of Clovers, Celandine, Violets and Pyramidal Orchids. However, as in many other parts of the island, particularly the cliff areas, the virtual cessation of former agricultural practices on the Blayes and the cutting of Gorse Ulex europeus for winter fuel and heating ovens, as well as Bracken for bedding, including the old cottage joncquières (the Alderney patois name for Green or Day beds), has led to large areas of gorse, bracken and bramble scrub developing, unchecked by cultivation or mowing. This has had a profound effect on the herbaceous plant ground flora in many places, suppressing (or in some cases only hiding) it beneath the overgrowth. The scrub clearing occasionally carried out (on either States or private land) around the cliffs, often sees the return (or re-emergence) of Violets, Primroses, Celandines and other small plants in the following years.
Figure 7. Raised beach on Clonque Island
Figure 8. Glanville Fritillary Butterfly
Figure 9. Clonque Bay and cottage about 1890-1900
Figure 10. Same view in 2000
with Fort Clonque on the tidal island top right.
Note erosion of the cliff beyond the haystack in Figure 9.
The intertidal area of rock and pools shown in Figure 10 is interesting from a number of points of view.
Geologically the granodiorite base rock is crossed by a considerable number of narrow, parallel, veins of porphyritic felsite running roughly NE-SW. These are themselves crossed, more or less at right angles, by several similarly narrow, parallel, veins of the younger rock lamprophyre. There is a much broader band of aplogranite approximately at the extreme right of the picture and another outcrop of this rock forming the pointed cone-shaped rock at the top right edge of the photo. At either end, just off the picture to the right (i.e. behind the camera position) and just beyond the causeway to the fort at the top of the picture are two veins of the intrusive black volcanic rock, dolerite.
Above the beach, straddling the roadway along virtually the whole length of the photo, is a narrow band of head mostly about 4-5m thick, a mixture of soil and broken rock, sharp-edged and very variable in size, overlying the granodiorite. As noted above, at the top of the beach and the foot of this low cliff for much of its length, a shallow band of well rounded, water worn pebbles, forming a raised beach from the last ice age, is exposed at several places. At a number of points along this stretch, at the foot of the cliff a 0.7-1m thick, band of clay is exposed, possibly formed by seepage and at several points kept damp by water from small springs in the hillside above. The Vau Pommier stream flows down the fold between the hills on the top left and emerges through Blue Bridge (Figure 7 above) to the beach, roughly vertically below the 'I' printed just above Figure 10. (The arrow originally inserted won't print in html).
In the tidal pools created in this bay, a fine collection of (mostly common) seaweeds are to be found attached to the rocks. The following applies to all bays and beaches.
The development of the seaweeds usually found in a given area depends on six main factors;
(i) the average water temperature and its variation throughout the year, (which affects their geographical distribution). Over the period 1980-94, the mean warmest sea temperature (measured in Guernsey) was 16.5º, reached in week 36 (beginning of September), and the coldest 8.25º in weeks 8 & 9, (the last two weeks in February). Alderney seas are usually about 1º colder, due to its more exposed position;
(ii) whether the substrate is sandy or rocky and the presence or absence of tidal pools. In the summer, pools, particularly those on the upper shore, can heat up considerably and their salinity increase through evaporation;
(iii) the degree of desiccation and the temperatures they can withstand whilst exposed between tides, (the actual duration of exposure at any given point of course varies greatly between spring and neap tides);
(iv) their ability to withstand wave action, (i.e. whether the coast is exposed or sheltered);
(v) the light intensity and daily duration they need to grow and reproduce, (which largely affects the depth of water in which they can survive and the latitudes in which they grow; and;
(vi) the salinity of the water at their place of growth, (this can also vary considerably where fresh water runs across a cliff or beach).
In more recent years sea pollution has also become an important factor in the development and distribution of a number of species of marine organisms, including the algae. Swift tides of 8-9 knots run through 'The Swinge' here, between Alderney and Burhou.
A brief list of the more common seaweed species to be found round the island is given here, in the sequence of their usual zonation from the upper shore downwards to shallow wading depth below the lowest water mark of spring tides. Many do not have 'common' names. The actual species found on any shore around the island will depend on the degree of exposure to wave action, the steepness of the shore and the relative proportions of rock/sand/shingle. Seaweeds are collectively called 'Vraic' throughout the Channel Islands.
Splash Zone; exposed for most of the time; (Click underlined names for photo.)
Channelled Wrack or Pelvetia canaliculata; found in a narrow zone at normal HWM or in the splash zone on exposed shores, often in a very much reduced moss-like form. Very frequent either side of the Clonque causeway. Do not confuse these patches with the similar appearing growth of the tufted lichen Lichina pygmaea, which is sometimes seen from just below the Pelvetia, down to mid-tide level. This lichen harbours a rich fauna of small, even minute, crustaceans, insects and molluscs. Look particularly for the red bivalve, Lassea rubra, 1.5-2mm long.
Upper shore; exposed for up to eight hours in each tide; this and the next zone, combined, are sometimes called the Fucus zone.
Next comes Spiral Wrack (Fucus spiralis); with Laver (Porphyra umbilicalis), forming a thin dark red/purplish coating over exposed rocks in some areas and frequently coating the Raz causeway in summer. A type of bread can be made with this. The bright green flat fronds of Sea Lettuce (Ulva lactuca), also a species formerly frequently used for food; and thin bright green hollow tubes of Enteromorpha intestinalis are found on rocks and in shallow pools in this area, especially where there is fresh water seepage. They occur on most beaches;
Middle shore; exposed for four to six hours at each tide;
Bladder Wrack (F. vesiculosus), with, a little further down, Toothed Wrack (F. serratus), and Knotted Wrack (Ascophyllum nodosum) both these frequently having bright red tufts of Polysiphonia lanosa attached to them.
The pools in this zone hold a wide variety of green, red and brown algae. Most easily recognised are the pinky-white calcareous clumps of Corallina, of which there are several species, encrusting the edges of the pools. These provide homes amongst their branches for more minute animal species. Pink or violet chalky, somewhat knobbly encrustations on the rock sides are Lithothamnion and Lithophyllum species. Irish Moss or Carrageen (Chondrus crispus) and the similar looking Gigartina stellata, often gathered with it, are common in these pools particularly towards LWM. Their flat, reddish-purple, dichotomously branched cartilaginous fronds are edible, either cooked or raw, and make a nutritious pudding, frequently made in Guernsey during 1940-45 Occupation. Gelatin can be extracted from them. Pointed red, round, dichotomously branched stems of Furcellaria lubricalis and the fairly similar round-ended stems of Polyides rotundus will be also be found here.
Easily identified are the dull, dark-green fronds of Codium tomentosum, similar in shape but larger than the previous two species. Soft much-branched, fine-stemmed clumps of several green Spongomorpha, and Cladophora species and the olive-green Enteromorpha species are not always easy to distinguish from each other.
The reader should refer to one of the specialised guides to help sort out the many dozens of beautiful seaweeds found in these pools and those on the lower shore.
Lower shore; exposed for one to four hours each tide;
Brown seaweeds here include; Sea Oak, (Phycodrys rubens) common in pools in this region with its pod-like float bladders; the continuously forked Bifurcaria bifurcata; brightly green/blue iridescent (when submerged), much branched, bushy plants of the Bladder Weed (Cystoceria tamariscifolia); and flat, dark spotted, olive green, leaf-like fronds of Punctaria plantaginea, are all easy to spot
Sub-littoral zone; not generally exposed at all;
Oarweed (Laminaria digitata), this lies flat on the rock or water surfaces at extreme low tide; Sea Belt, or Poor Man's Weather Glass, which gets its Latin name Laminaria saccharina, from the white sugary powder, mannitol, which appears on its surface as it dries. Dabberlocks (Alaria esculenta), a thin ribbon-like Laminarian with a thickened midrib, is eaten as a salad in some coastal areas. It is more frequently found on exposed coasts. Sea Bootlace (Chorda filum), with a thin, tough, unbranched, hollow stem up to 4-5m long and Thongweed (Himanthalia elongata), its dichotomously branched flattened stems growing afresh each year up to 2-3m. long, from a small round perennial, button-like holdfast, (note this on photo). These and the flat, soft, olive-green fronds of Dictyota dichotoma are the principal brown seaweeds found in this zone, often with epiphtic red seaweeds growing on them. Dulse (Palmaria palmata), another of the seaweeds used as food and the pink fronds, like chains of beads, of Lomentaria articulata being the most frequent on the Fucoids and Laminarians. Look particularly in this area for the beautiful fan-like fronds of the Peacock's Tail (Padina pavonia). Up to 10cm long these are curved and have a lime-green inner surface and are brown with green stripes on the outer side of the curve.
Another brown seaweed found entangled with the kelps, and often cast up on the shore is Desmarestia aculeata, with soft spines looking a bit like a Hawthorn twig, it frequently bears epiphytic, small balloon-like, soft spongy, brown masses of Leathesia difformis.
At greater depths, the huge palmate fronds, up to 3.5m. long of Laminaria hyperborea with several red epiphytes occur. These have a much branched holdfast and a rough round stipe and remain erect at extreme low spring tides, often standing up out of the water, whilst of a similar general appearance and even larger size, up to 4.5m., Saccharina polyschides has a large (up to 10cm.), thick, round, hollow, knobbly holdfast and a flattened wavy-edged stipe. They are often washed up after a storm.
The Laminarians define the limits of the sub-littoral zone.
Japanese Oarweed, (Sargassum muticum), an invasive newcomer, the long branched fronds of which, floating in patches, can cause considerable problems by wrapping themselves round the propeller shafts of ships and motor cruisers, is gradually appearing round our coasts especially near the harbours.
The lists above represent only a small part of the littoral zone algae to be found by the careful observer, who can spend many happy hours studying them in the rock pools which abound in some part of all of the islands' bays. See the page opposite for some illustrations.
The zonation on primarily sandy shores or on shingle is somewhat different and although there is usually a rich fauna, the intertidal area is often pretty barren of algae, apart from driftweed along the strand line. This will be dealt with in Region 6 and is equally relevant to the sandy beaches in Regions 3,7 and 8.
Below HWM the wide spreading, black, tarry-looking, encrustation over many of the rocks is Verrucaria maura, found right across the world. Above this the bright orange patches are usually Caloplaca marina. Higher up the rock and cliff faces, the greenish white branched (foliose) lichens are probably Ramalina siliquosa and the grey patches are Lecanora species, with Parmelia and Umbilicaria species on rocks in the splash zone and above.
1. COLONIAL ANIMALS
Many of the animals in this group are so small as to form part of the free floating or swimming plankton and are only readily identified by using a microscope. However, a wide range of sponges, ascidians, sea squirts, hydroids, sea anemones and jellyfish etc. will be found on, or under, rocks; as epiphytes on various algae, especially the laminarians; or occasionally free-floating. The reader is again referred to the specialist guide books on this subject. Those most commonly seen are;
White, orange, green, yellow, red or brown Breadcrumb Sponges, Halichondria panicea, in colonies usually less than 20cm across and up to 2cm thick. These encrust seaweeds, stones and rocks, especially on their underhanging surfaces from the middle shore down into deep water.
a. Sea Squirts; several different types may be noted, solitary or in small groups. They are usually found near LWM or below, attached to rocks or large seaweeds. They have upright bodies with smooth swellings and two body openings, a 'mouth' at the top and an exhalant opening in the side about half way up. Pale, almost translucent and up to 10cm high is Ascidia mentula; brown; rougher looking and up to 6cm high is probably Ascidiella aspersa. Neither have common names. Look also for the almost transparent 'vases' up to 3cm of Clavelina lepadiformis, with the two siphons close together at the top and the spiral, orange, body contents showing through the tunic. More easily spotted and beautiful in a variety of colours are the;
b. Star Ascidians; although members of the same class, these are flat, colonial and the colonies are embedded in a transparent cellulose sheath. The colonies of 3-12 groups of individuals may all be yellow, brown, green or red star-shaped, each colony arranged in a circle or oval round a common exhalant cavity, Botryllus schlosseri, or with the groups either side of an elongated exhalation cavity and coloured orange, yellow or blue-grey, Botrylloides leachi. Look for them on smooth rock surfaces and some of the larger fucoids.
These, such as Obelia are generally almost transparent, have soft, sac-like bodies and live in flower-like colonies, attached at the base to rocks and seaweeds. They are amongst the commonest and most varied groups of marine animals but are usually overlooked. One of the generations in their life cycle is a minute free-swimming medusa, a jellyfish-like larva. The reader is again referred to specialist books for their identification.
Of the free-floating or swimming jellyfish, all of which can sting, the Portuguese Man-of-War has a body 30 x 10cm, silver, blue and red with, attached to it, large numbers of very long mauve/blue tentacles with a dangerous sting. It has been seen floating on occasions in several bays. The Octopus Jellyfish up to 60cm across and massive, whose sting does not usually trouble humans and the Compass Jellyfish which does, are sometimes found washed up, particularly after a violent storm at sea in the summer. The Common Jellyfish, almost transparent white, with four conspicuous purply, horse-shoe shaped reproductive organs (when seen from above), is sometimes seen swimming in groups close inshore in the summer and autumn. Although it can grow up to 25cm across, those most frequently seen are rarely more than about 10cm. Its sting, although painful at the time, is not usually troublesome to humans.
The 5-10cm high, pink/red, Stalked Jellyfish, is found attached to seaweeds in pools or on the lower shore. It is trumpet-shaped and has eight clusters of red tentacles arranged round the open end.
Of the many types of Sea Anemone to be found, those most commonly seen are; the Beadlet Anemone, Actinia equina, in red, strawberry and green forms, up to about 7cm, but usually nearer 3-4cm. It retracts into an almost closed ball as the tide recedes and is able to stand several hours exposure at each tide. It is very common on rocks in the middle shore, whilst the larger 10-12cm Snakelocks Anemone, in both green and grey forms cannot retract its tentacles and is only to be found in permanent pools or from just below LWM down to about 20m.
The Trumpet Anemone, Aiptasia couchi, at a maximum of about 6cm high, has up to 80 tapering golden-brown tentacles, whilst the slightly smaller but not too different-looking Anthopleura thallia, has about 60 translucent ones.
Several kinds of the beautiful little so-called Jewel Anemones, Corynactis viridis, can be found, but these are actually true Corals. Their tentacles are arranged in three circles and have coloured blobs on the ends. Soft Corals also occur, the one most likely to be encountered, under overhanging rocks in deeper water at very low tides, is Dead Man's Fingers, the colonies often looking rather like a ghostly white or pale yellow glove. The many individual polyps give it a rough appearance with their retractable tentacles, up to 1cm long.
Various species, most commonly Membranipora membranacea, (photo on Laminaria at Longis), are frequently found encrusting the larger algae from the middle shore zone down to just below LWM. These will be particularly noted on the larger algae in patches of driftweed washed up by the tide, looking like a covering of white snakeskin.
2. VARIOUS WORMS
A rare flatworm, Convoluta roscoffensis may be found in the fine gravel at Clonque in the area some way behind the camera in Figure 10. Small (0.5-1cm) like a lanceolate leaf, its green colour is due to a symbiotic single-celled green alga. Walking on the gravel nearby causes them to disappear below the surface.
The Sea Mouse is a large scaly worm 10-20cm, its oval body is covered in green/grey/brown hairs along it dorsal surface. It prefers to live in a soft substrate in shallow water.
A bristle worm, the Green Leaf Worm, Eulalia viridis 5-15cm. with up to 200 segments has a vivid green colour. It lives in rock crevices on the lower shore. Free swimming, it lives on barnacles. In the spring look for its eggs, small green spots in little bags of translucent jelly. The Rock Worm, Eunice harassii 15-20cm, brown with reddish gills on the lower 2/3rds and a greenish stripe along its back also lives in rock crevices on the lower shore. King Rag Worm, Nereis virens (30-60cm), pale green purple and yellow lives in mucus lined burrows on the lower shore. Lugworm, Arenicola marina 20-30cm, much dug for bait, burrows in the sand on the middle shore.
Tubeworms found, which form a calcareous shell attached to rocks or on fronds of Laminaria and Fucus, are usually species of one of the following. Spirorbis, (the most common), the abundant small white shells of S. spirorbis, which are coiled almost into a circle on the seaweeds, or the ridged, only slightly curved shells of S. tridentatus, found on rocks. Pomatoceros triqueter, which is triangular in section, and variable in colour, is found under stones or on dead shells on the lower shore or in shallow water. Hydroides norvegica, the twisted and interlaced, 3cm., brownish-white shells of which may be seen also on stones and shells. These are all attached to the substrate all along their length. Serpula vermicularis is attached only at the base, it exhibits circular growth rings up its shell and is found on rocks and old shells at the bottom of the tide. The tube of this last is pinky or greenish-brown with red gills, trumpet shaped, tapering to a point at the base and about 5-8cm long.
3. STARFISH & SEA URCHINS
Large starfish are not commonly found alive in the littoral zone, but small specimens of the Common Starfish occur. The more usual and quite common species seen is the green Cushion Star. The Goose-foot Star, whitish, with the margin and five divisions on top of the shell marked out in red, is occasional and various Brittle-stars are quite frequent. The many colour varieties of Opiothrix fragilis, often red and white or yellow, will be found under stones and seaweeds on the lower shore. Amphipholis squamata, smaller and grey/blue/white uses the same habitats, but is especially found amongst Corallina. The red-brown Feather Star may be found under rock overhangs or in crevices in rock pools and on the lower shore.
The Green Sea Urchin, grows to about 3-4cm and is found on and under stones, on the lower shore. The dark purple Rock Urchin, is about the same size, but generally lives in groups in hollows it has ground out of the rocks. Small specimens of the pinky red with white spines, Edible or Common Sea Urchin, which grows to about 10-12cm. may be found in this zone, but larger specimens are usually only found offshore. It grazes on rocks and Laminarians. Sand coloured Sea Potatoes Echinocardium cordatum, 6-9cm. across are quite common in the lower intertidal zone, burrowing into the sand and leaving a hole to mark their presence.
In this same class are the Sea Cucumbers; the Cotton Spinner, at about 20cm is the largest. Black/brown above and green/yellow below, it moves slowly on three rows of suckered tube-feet, usually amongst Zostera from the lowest shore level down to about 70m. Much smaller (4cm), and pinky coloured, the Sea Cucumber, is occasionally found.
On the upper shore look out for;
Various Sand-hoppers amongst stones and rotting seaweed. Often present in large numbers, on a warm day the bites of these can be troublesome. The two most common species are Talitrus saltator, about 2.5cm,. on the upper shore amongst the weed, with Orchestria gammarella, slightly longer and slimmer, amongst rocks and weed lower down the beach.
The Sea Slater, at 2.5cm long, looking like a large woodlouse with two forked tails will frequently be found on larger rocks at the top of the tidal zone. Usually hiding in crevices during the day, it moves very rapidly over the rocks in the evening. Be careful to distinguish these from the smaller Bristle-tail, which has three single bristles at its tail end, the longer central one equal to the body length. This animal is actually an insect, not a crustacean.
On rocks, exposed at some state of the tide;
The Barnacle Chthamalus stellatus, is generally found in the splash zone, often forming a complete encrustation across some rocks, as does the Acorn Barnacle, Semibalanus balanoides, (photo with Dog-whelk on rock at Corblets bay), a little further down the shore in the intertidal zone, differing from the other barnacle in the slightly different arrangement of its five shell plates. The first is almost at the northern limit of its range and is not found in the eastern English Channel or the North Sea, whilst the second species is nearly at the southern limit of its range and does not occur in the Bay of Biscay.
Look particularly for the Darwin Barnacle, Elminius modestus, on rocks in the upper or middle shore. This Australian barnacle is similar in appearance to the above, but only has four plates to its shell. It was first noted near Southampton during the last war and has spread rapidly along the Channel into the Atlantic. It has been found in Guernsey on several occasions now, and was first reported from Alderney in 1977. All three of the above are about 1-1.5cm in diameter.
Further down the shore, two larger barnacles 2-3cm may be noticed, both with six plates The larger, Balanus perforatus occurs first. Its purplish cone has a serrated opening, slightly off centre, making it look like a volcano. Lower down the shore, the slightly smaller B. crenatus, is pale grey-brown and found at the bottom of rocks, just where they meet the sand. The plates on one side are longer than those on the other, making this one appear to be toppling over.
Occasionally large pieces of driftwood will be found encrusted with the Goose Barnacle, Lepas anatifera, (photo on a log washed up at Platte Saline). This large barnacle the shell of which grows to about 5cm, has a 10-20cm long grey or brown stalk, the skin of which is somewhat retractable, shortening it considerably. The 5 plates of the shell are translucent white with bluish/orange edges. The whole animal hangs down underneath the floating timber or from the bottom of boats. In Elizabethan times it was still thought to be a plant and that the shells were the eggs from which Barnacle Geese hatched. A long entry is included in Gerarde's Herbal or History of Plants, published in 1597. This idea was mentioned by Theophrastus as far as back as 350BC.
In tidal pools at varying levels of the beach, usually under stones, or on weed, look for;
Prawns; commonly the almost transparent Palaemon serratus and the smaller Chamaeleon Prawn, Palaemonetes varians, may be found. This may be brilliant green, brown, or a variety of mottled colours taken from the habitat of the moment. The Ghost Shrimp, is frequent in shallow pools and almost transparent, only its black eyes showing clearly.
Crabs; the Chancre or Edible Crab and the Spider Crab, both species are caught and eaten locally, small specimens will often be seen in the permanent pools. Fiddler or Velvet Swimming Crabs, also known locally as Lady Crabs are also eaten and all three species are sold in the Guernsey fish market. The Shore Crab, Porcelain Crabs, usually Porcellana platycheles, the Hairy Crab, and several Hermit Crabs, most commonly Eupagurus bernhardus, can also be found. These last take over the empty shells of a number of molluscs, changing to a larger one as they grow. They will often be seen running across the bottom of a pool or the wet sand, as the tide recedes.
Lobsters; the Squat Lobster, rarely more than 5cm across, will often be found under stones in the tidal zone in the spring when it migrates inshore and small specimens, up to 5cm of the smooth, brownish-blue coloured Edible Lobster, may also be seen on rarer occasions. Larger specimens might be found in deep pools in the summer. Less frequent are small specimens of the Crayfish, generally brown or purplish with pale spines on the shell, it is easily distinguished from the Lobster by the long, whip-like antennae and the lack of the large pincers on the first pair of walking legs.
A wide range of molluscs will be encountered at various levels on the shore, the commoner of which, starting from the top of the beach, are;
(a.) In the splash zone;
An area not widely found on the more accessible parts of Alderney, is the tiny (5mm), smooth, blue-black, Small Periwinkle, Littorina neritoides. Able to withstand long periods of desiccation it hides in the small crevices in the rocks.
(b.) Through most of the intertidal range;
The Rough Periwinkles L. saxatilis and L. rudis may be found in a variety of dull colours, on and under rocks, as may be Chitons, very primitve creatures found as huge fossils in some parts of the world. Ours are generally about 1-1.5cm long, either the brown, Lepidopleurus asellus or the more common, green Lepidochitona cinereus. Able to cling closely to rock surfaces, they graze across the surface of rocks and seaweeds, whilst the smooth Round or Flat Periwinkle, L. littoralis, bright yellow, orange or red-brown grazes mainly on fucoids in the same range. The 2cm. Edible Winkle, L. littorea is quite rare in Alderney and apparently absent from Sark and Herm, its place being taken in local diets by the common Toothed Winkle or Thick Topshell, Monodonta lineata, also 2cm., found in considerable numbers, mostly in the mid-tide range.
Three species of Topshells, Gibbula spp, Grey, (G. cineraria), Purple, (G. umbilicalis) and Large, G. pennanti, (which is not found on the English side of the Channel), are common in the middle-lower zone, and several species of Needle and Spire shells. The Purple or Flat Topshell, can easily be distinguished by the small hole or umbilicus on its lower surface. The beautiful Painted Topshell, (Calliostoma zizyphium), up to 2.5cm high and about as broad, will be found at the bottom of the tide, under seaweeds and overhanging rocks.
Large Common Limpets, Patella vulgata, greenish blue or grey with a rounded outline, up to 7cm across, abound throughout the range on rocks. The comparative height/width ratio of their shells varies markedly according to the direction of exposure to wave motion. The more sheltered specimens tend to be much taller than those on exposed surfaces. About the same size with a more orange top to the shell and short, darker rays around the irregular base is, P. aspera. This species, near the northern limit of its range here, tends to live in pools in the lower shore zone. The smaller Limpet, P. intermedia (P. depressa), about 4cm and darker than the other two, may be found on exposed rocks in the middle tide range. In prehistoric times limpets must have formed a considerable part of the diet of people living in the islands, large quantities of their shells having been found in most of the Neolithic burial chambers. In the same area, the Keyhole Limpet, Diodora apertura, has a greyish-white, 4cm, ribbed shell with an aperture at the top. The Blue-rayed Limpet, Patina pellucida, smooth, oval and about 1.5cm long, will be found on Laminaria at extreme low-tide.
Two types of Cowries, of which the European Cowrie, Trivia monacha, is much the more common will be seen crawling about on the rocks and seaweeds on the lower shore. They feed on the various colonial Ascidia which grow attached to the rocks and larger algae in this area. Look for the round, white, Chinaman's Cap, 3-5cm across, the occasional Sting Winkle or Oyster Drill, Ocenebra erinacea, and the closely related O. aciculata with brilliant red flesh. This species is at the northern limit of its range and does not occur in England.
More commonly Dog-whelks, and the rarer Netted Dog-whelks, will be found. Dog-whelks are good indicators of sea pollution and are particularly sensitive to the TBT anti-fouling paint used on boats. This caused a considerable decline in their population a few years ago, particularly in harbour areas, but they are now recovering since the use of the chemical was prohibited. Unlike in Guernsey, they are not now very common anywhere in Alderney, even on shores well away from any anchorage. In surveys carried out by the authors in 1992 and 1993 for the Marine Conservation Society, few were found at any of eight sites, except in Clonque Bay. This seems to be a variation from the situation in 1970 when a Bailiwick survey was carried out and published in Transactions, (Brehaut, Vol XIX, Pt. 1, pp39-69), when numbers were similar. Large shells of the Whelk, Buccinum undatum, 9-10cm, are found washed up from time to time from deeper water, but they are rarely, if ever, seen alive.
Several types of Sea-slug may be found, some are pinky-coloured animals whose shells are often covered by their mantles; the brown Sea Hare Aphysia punctata, is a member of the same order, but with four 'horns' on its head, which grazes on seaweeds in shallow water and may discharge a purple dye if disturbed.
The yellow, warty, two-horned, Sea Lemon is about 7.5cm long. If you find it without disturbing it, (it too discharges a dye), you may well see the ring of nine retractable plumed gills around the anus. It feeds on the Breadcrumb Sponges. The Common Grey Sea-slug, up to 9cm, with four horns and many hornlike appendages in two rows down its back, feeds on the Snakelocks Anemone. Both are members of the order Nudibranchia.
Others, possibly small Squid, although these are seldom found close to the shore, and the shells of Elephant's Tusk, Razor Shells, (which bury themselves in the sand) and Cuttlefish 'bones' are frequently found, washed up on the beach, but their owners also are rarely seen alive.
(c.) Sub-littoral zone;
The largest mollusc of our shores, the Ormer, Haliotis tuberculata, (photo grazing on red seaweeds at Longis), which grows to about 10-15cm, once abundant, sadly has declined considerably in recent years and is most likely to be found below the lowest tide mark. It browses on red algae, principally Dulse, and rests under rocks and stones to which it attaches itself very firmly. It is now being farmed in Guernsey and shore gatherers in the islands also had better catches in 1993 and 1994. The gathering of Ormers is strictly controlled in the Channel Islands. They can only be gathered from the shore at certain of the lowest spring tides, the dates of which are advertised in the local papers and on radio and TV. Only those larger than a certain size can be collected and diving for them is prohibited. Gatherers usually use a special hook to enable them to detach them from their very firm hold on the rocks.
The Common Octopus, common around Alderney until about 1960 is now rarely found. Both of these animals are at the northern limit of their range and a slight drop in sea temperatures may be one of the reasons for their decline. Over fishing has also contributed.
Bivalves are not common on Alderney shores.
(d.) In deeper water;
Mature specimens of the European Oyster, Scallops and Mussels may be found in certain areas round the coasts and Guernsey fishermen bring in good catches some of which are sold in Alderney. Like the Ormer, Scallops are subject to a minimum size restriction in order to conserve stocks. Large Dog Cockles are sold locally in restaurants as 'Clams', whilst Herm Oysters are famous throughout the islands.
The above lists are by no mean exhaustive. The diligent searcher in pools and under or on the rocks in the intertidal zone will doubtless discover many other species of invertebrate animals not recorded here.
A range of the fish caught by small boats at sea within a few hundred yards from the shore, or by rod and line from the shore or breakwaters is listed here, with only their common English names. The frequency with which the different species are caught is not indicated. Alderney holds the British records for a number of species caught, usually in the annual fishing competitions, organised and sponsored by Aurigny Airlines. Fry of many of these species occur in the intertidal zone and are likely to be found in rockpools, frequently underneath rocks. These are included in the next section. Basking Sharks are occasionally seen all round the islands and rarely, even in Alderney Harbour.
From a list of the Guernsey dialect names of Insects, Birds and Fish published by E.D. Marquand in Transactions in 1908 (p. 512) one may safely assume that these are the species commonly caught in that island since much earlier times. The species mentioned in this list are underlined in the list which follows and varies little from those caught in Alderney today.
Huss, Dogfish, Tope, Thornback Ray, Blond Ray, Sting Ray, Skate, Spratt, Herring, Garfish, Conger Eel, (photo young specimen from a pool at Longis) Cod (generally only up to 2kg), Pouting, Whiting, Pollack, Saithe, Ling, Rockling, Scad, Mackerel, Red Mullet, Bass, Sea Bream, Ballan Wrasse, Cuckoo Wrasse, Weever, Red Gurnard, Sandeels, Grey Mullet, Turbot, Brill, Plaice, Dover Sole, Cornish Sucker, Eel, Bullhead, (photo in a pool at Clonque), John Doree, Topknot, (photo emerging from sand at Longis), Salmon, Monk Fish, Sand Smelt.
LITTORAL ZONE FISH
Likely to be found in upper tidal pools;
Small specimens of Sole occur frequently, less frequently, Dab and occasionally Plaice fry may be seen in sandy pools;
Rock Gobies may be found in shallow pools, often under rocks and Sand Gobies live in pools with a sandy bottom. Gobies are collectively known in the local patois as cabou.
Usually in mid-tide pools;
Montague's Blenny, up to 8cm. brown with pale blue spots; Shanny, 10-15cm. yellow-brown to green with dark green spots, lives on the lower shore and in shallow water.
Tiny fry, up to 2-3cm, of the Thick-lipped Grey Mullet may be seen in large numbers in many pools. As they get bigger they swim in and out with the tide and larger specimens sometimes come inshore to feed, or adults in shoals to mate.
Small specimens of Sand-eels, (photo dead specimen washed up at Corblets), both the Lesser and Greater, may be seen in rock pools, generally silvery coloured, the Greater is greenish along its dorsal side and has a black spot on the snout. They are sometimes found buried in the sand as the tide goes down and occasionally a thick line of dead ones can be found at the water's edge. Adults are about 20 and 30cm long respectively. they are much used for bait and are also the favourite food of the Puffin. In recent years a considerable decline in numbers may be due to over-fishing, a drop in water temperature, or both, and has probably contributed to the great reduction in Puffin numbers breeding on Burhou.
Three species of the interesting worm-like Pipefish may be found. They have ringed bodies, no ventral fins and usually only a small dorsal fin. The male carries the fertilised eggs in a pouch on his body after the female has placed them there. The Worm Pipefish, about 15cm. long, are dark and frequent in tidal pools with plenty of weed cover. Clonque and Longis Bays are good places to find this species. The Lesser Pipefish, browner, but about the same length is generally found in shallow water. Around the entrance to the Inner Harbour in Alderney is one good spot. The much larger (up to 50cm.) Greater Pipefish may be found in the same area.
Montague's Seasnail, smooth, brown, about 7cm., with a rounded head and tapering body has a long dorsal fin and its two pelvic fins are modified to form a sucker. Look for it under stones in the pools in this part of the shore.
Usually at the bottom of the tidal range;
The Tompot Blenny may grow to as much as 25cm. and lives amongst stones and kelps. The Butterfly Blenny has a brown, spotted body about 15cm with large greenish fins. The first ray of the dosal fin is about twice the height of the remainder and there is a large dark spot about half way along the fin. There are also two branched appendages above the eyes. Butterfish, a long thin fish up to 20cm, brown with a conspicous row of 11 dark spots along the base of its dorsal fin; Garfish, 30-80cm long, green and silvery white with a long jaw, forked tail and green bones lives in shoals near the surface and sometimes comes inshore. It is sold and eaten locally, but has a somewhat earthy flavour.
2-spotted Gobies, growing up to 6cm., live amongst Laminaria and lay their eggs on the holdfasts. Light brown in colour, their two conspicuous dark spots are just below the first dorsal fin and at the base of the tail. The Sand Goby grows to about 8-9cm, brownish, it has four darker vertical bands down its sides.
Sand Smelt, about 15cm. long, green above, silver below with a forked tail, sometimes swim in in small shoals on the incoming tide. The Fifteen-spined Stickleback, the only marine Stickleback may be seen down to about 10m.
Lump Suckers or Sea Hens, a large rounded grey-blue fish up to 50cm, with four rows of conspicuous white bony knobs along the body are sometimes washed up. In the breeding season the lower half of the adult male turns bright pink. At the same time the upper half becomes much brighter blue, making it a very handsome fish. The Cornish Sucker, about 7cm. long, has a reddish flattened body with the dorsal and ventral fins joined to the tail. On top of its head behind the eyes are two large dark blue spots with a whitish ring round them. It clings to rocks in the lower tidal pools. Both have the pelvic fins modified to form a sucker. Other small sucker fish have been recorded from time to time.
Young Wrasse and Conger Eel fry are also common in rock pools. Bright green young of the Ballan Wrasse are also found in the harbours. Several other brightly coloured species of Wrasse have been recorded.
Young Pollack are frequent in the pools alongside the causeway to Fort Clonque.
Shoals of small specimens of Shore Rockling, dark purply-brown with three barbels on the head, 15-20cm when grown and the Five-bearded Rockling, brownish above greeny-silver below with five barbels and reaching 20cm when adult, occasionally swim in.
On rare occasions Common Dolphin, apparently struck and injured by the propellers of passing vessels, have been washed up on this part of the shore. Even rarer, small groups of Bottlenosed Dolphin, Porpoises, one or two Seals and, usually single, Basking Sharks have been seen in the Swinge channel between here and Burhou.
Since about 1998, or possibly earlier, a small colony of Atlantic Grey Seals exists throughout the year on the Renonquet reef islets, beyond Burhou, now in 2004 numbering about 12-15 individuals. Small, young seals (photo below) are occasionally seen, but it is not known if they actually breed on the reef. Tidal conditions and the lack of any sandy shores would seem to make this unlikely.