Islay Geology, Marine Life and Underwater Nature

In earlier times, many thousands of years ago, Islay's landscape and shoreline looked very different from the island that we see today. Where we wrote on another webpage about the sea's essential influence on Islay's history and geography, on this page we tell you a little about the geology of the island as well as the fascinating wildlife in the sea. Most of this wildlife can be observed from the beaches, from a boat or when diving in Islay's clean life-rich waters. First of all, we start with a short geological introduction, before we give a wee overview and some fascinating images of underwater wildlife.

The booklet 'Islay, A Geological Guide' by Norman S Newton, describes the geology of the island and changes through time to Islay's shape as follows: "The underlying rocks of Islay have been raised and eroded many times in geological history, all of course unseen by the eye of man, but capable of reconstruction through painstaking study. It was two relatively recent geological events which combined to give this part of Scotland the appearance it has today. One was the flooding of the continental margin of Europe, possibly as recently as 10 million years ago, creating the Minch and the islands off the west coast of Scotland, including Islay. The other main event in creating today's landscape were the Ice Ages.

"Related to the retreat of the ice-sheets are marine-cut platforms and raised beaches, forming level areas of well-drained land, as attractive to farmers today as they were to the first settlers (in Islay's Mesolithic period). The most recent post-glacial raised beach stands about 8m above today's strands, but other raised beaches are at 15m and 30m levels. The relative heights of the sea and land changed as the ice melted. When the ice melted, it did so relatively quickly, and sea levels rose rapidly and flooded the land. However, with the weight of ice removed, the land rose out of the sea again, leaving former beaches high and dry. During this period of high sea-level, much of Islay would have been under the sea. The Rinns were separated from the rest of Islay and would itself have been split in two; Loch Gorm is the last remnant of the sea which has now receded. The Mull of Oa would have been cut off at Kilnaughton, and the peat moss between Port Ellen and Bowmore would have been flooded." A more detailed view on the Geology of Islay and a map can be found on the Islay Geology page

Islay's early people and the sea
Soon after glacial ice on Islay's shores melted, about 8,000 years ago, human settlers began to arrive in Islay. Evidence for these Mesolithic (Middle Stone Age) people in Islay is found mostly in the form of hand-knapped flint, both flint tools and chips and cores left from their manufacture. Flint pebbles are found on Islay's beaches.

Archaeologists are not certain where these early peoples came from or how they travelled; whether they arrived by crossing a land-bridge from Europe to England, or by coming along the coasts in hollowed log boats. A post-Ice Age land bridge may have joined Islay with the north coast of Ireland and mainland Argyll, giving Mesolithic people access to Islay by land or shallow sea. Early people would have come to prehistoric Islay and other islands to gather and hunt wildlife for food; plants, birds and animals on land, and fish and animals on the shore and in the sea.

East of Sanaigmore Bay

Life in the seas around Scotland and Islay
According to the Scottish Government (News Release of 30th September 2009), the seas around Scotland support approximately 6,500 species of plants and animals, and a massive 44,000 species if microbial species are included. The RSPB (Royal Society for the Protection of Birds) states; Scotland's seas are truly extraordinary. They are home to half of Scotland's wildlife, and 45% of the EU's breeding seabirds. We have the longest and most diverse coastline, richest marine life, and largest seabird colonies in the UK. Scotland's seas are important for a huge variety of species, from basking sharks to rare cold-water corals. Wildlife watching, fishing and other marine industries bring financial benefits to our coastal communities.

Life in Islay's waters
Below is a short list of some common animals, birds, fish and plants which can be seen in the sea or around the shores of Islay.

Sea Mammals
OtterCommon Otter, Grey Seal, Common Seal, Common Dolphin, Bottlenose Dolphin, Harbour Porpoise. Whales: Fin Whale, Humpback Whale, Minke Whale, Killer Whale (Orca)

Seabirds and Shoreline Birds
Great Northern Diver, Kittiwake, Fulmar, Terns, Gannet, Great Skua, guillemots, razorbills, puffins, fulmars, shags, cormorants, kittiwakes, herring gulls, Lesser Black-backs, Great Black-backs, Eiders, and more..

Sea Fish:
Edible fish: Salmon, Sea Trout, mackerel, flounder, saithe, haddock, halibut
Other common fish: Dogfish, Sand-eel, Wrasse, Sprat, Dab, Ling, Mullet, Tope, and more

Basking Sharks are the second largest fish in UK or Scottish waters, growing to 10 metres in length and weighing up to seven tonnes. They can be seen during the summer months in seas around Islay. Despite the name, this animal is a fish. It is a filter-feeder which lives on plankton, and is harmless to humans. Basking Sharks are protected from capture and disturbance in British waters (up to 12 miles offshore) under the Wildlife and Countryside Act.

Edible: Lobster, Squat Lobster, Prawn, Velvet crab, Edible (red) crab, scallops, oysters (Farmed at Craigens) Common Mussel, Cockles, Winkles
Other common shellfish: Shrimp, Limpet, Sea Urchin, barnacles and many more..

Edible: Dulse, Carragheen(Irish Moss), Sea Lettuce, Sugar kelp, Laver

Islay Marine Life under water gallery

A lobster in its home. Lobsters live in caves under rocks

Prawn walking on the seabed. It's unusual to see a prawn out in the open, as they live in holes in muddy parts of the sea floor.

A very big starfish (over 1m across) pursuing a Sea Urchin. This starfish caught up with the Sea Urchin on the side of an underwater reef. The Urchin pulled in all its tube feet and ROLLED down the rock reef to evade the marauding starfish, when it realised that it could not shake off its pursuit.. When it reached the sandy seabed below, the Urchin stuck its feet back out and made off at high speed (for a urchin!).

The little pink Seastar is trying to eat (and is eating) the much bigger orange starfish. The bigger starfish was positivly galloping over the seabed in an attempt to shake off the unwelcome embrace of the Seastar. Eventually they reached rough ground where the Seastar wedged itself between some stones, and it stripped off the big starfish's arm. There was a big hole left in the arm where the Seastar had been dissolving its dinner with its digestive acid.

Sea Anemones: Plant or animal? (It's an animal; the parts which look like flowers are tentacles for catching food, and can be drawn back into the animal's body)

Sea Anemones on the Sea bed in Islay's waters.

Seaweed: A Kelp forest in the sea near the Jura shore, with Sea Urchins (round shapes) feeding on the kelp stems.

All the underwater photographs on this page are copyright Colin D Campbell, CDCMarine Contracts, Isle of Jura., and only to be reproduced with permission.

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Norman Newton - Islay guide
A small book loaded with gorgeous photo's and practical Information. Lightweight and soft sided makes an ideal companion on Islay.
More Islay books here...