Marine Wildlife Around Britain’s Coasts

A large, curved fin and a clear beak are useful clues in Cardigan Bay. Sea Watch Foundation monitors this resident population from shore and boat. Try a public lookout around New Quay and watch for several fins coming up on the same line. Keep your distance if you watch from the water.

A harbor porpoise surfaces low, rolls, and disappears with little splash. Watch for a small triangular fin from the shore around Tobermory on Mull, especially when the water is calm. Its brief rise through the surface is a better clue than waiting for the jumps you might see from a dolphin.

From a Hebridean headland, a tall dorsal fin edging slowly across calm water may be a basking shark. A tail tip may show behind it as the shark moves near the surface filtering plankton. The Shark Trust lists western Scotland as a good region to look in the warmer months. Give the shark a clear path.

Scan from a headland like Ardnamurchan Point for a long, dark back followed by a small, swept-back fin. The common minke is a regular visitor in the Hebrides. Keep watching the same stretch of water after the first brief roll. A minke often surfaces several times before making a longer dive.

At Donna Nook in Lincolnshire, use the marked viewing area during the colder breeding season. Adult gray seals often show a longer, straighter head profile than common seals. White-coated pups are another clue on the beach. Stay behind the barriers and let resting adults and pups keep their space.

Called the common seal in Britain, it has a rounded head and nostrils that form a V when viewed from the front. Both kinds of seal use Blakeney Point in Norfolk, where local boats can give a view across the water toward the sandbanks. Binoculars make it easier to compare heads without closing in.

Off western Scotland, look for a fast group throwing up white water as it moves across the surface. Catch a side view and you may see the common dolphin’s pale yellow and gray hourglass pattern. The Hebridean Whale and Dolphin Trust records them in its survey waters, with many sightings in summer.

Tiumpan Head on the Isle of Lewis is a documented spot to watch for Risso’s dolphins. Look for a tall fin and, if the dolphin turns, a blunt head and pale scarring. Some older individuals are almost white, so two animals in the same group can look quite different.

Watch the calm surface off Cornwall in the warmer months for an odd, high fin waving from side to side. An ocean sunfish may lie flat near the surface and show its broad, rounded body. That silhouette is a better clue than trying to judge the fin alone.

Watch feeding activity along the Cornish coast in late summer and fall. Atlantic bluefin tuna can strike into shoals of smaller fish near the surface, sending up splashes in quick succession. If a fish breaks clear, look for the heavy body and sharply forked tail.

The barrel jellyfish turns up in the coastal waters of southwest Britain during warmer months. Look for a large, almost clear dome above a frill of thick mouth arms. It can look solid and white from above. A stranded specimen is best observed without touching it.