Apart from fishermen, yachties and the odd boat trip, few of us spend much time beyond our shoreline, let alone wonder what’s beneath. The superb food and drink we are becoming famous for includes excellent shellfish and a seasonal abundance of mackerel and cod yet to be exploited. But only since the Scottish Seabird Centre arrived have we developed understanding for sea mammal friends living out there—seals on the islands and visits from cetaceans: porpoises, dolphins and whales.
Once, our Forth waters were thick with industrial effluents that poured into the Carron. Sea mammals are choosy about their environment and left. But after a decade of exemplary water quality, the seal population is growing again. As they live and feed around the islands and seldom close inshore, they were hard to track and census but marine biologists, BBC documentary teams and our own SSC cameras are giving us a much clearer picture.
Visits by whales are also growing. If not in deeper water, sightings indicate animals in distress—as in the deceased smallish (14m) sperm whale washed up at Portobello early this month. A pod of 14 such whales was snapped from a microlight off Fidra last April. But most sightings are of smaller species: minke (smallest) humpback or fin (largest) whales. In 2003 a 12m humpback spent a month cruising around the Forth before disappearing. A pod of black-and-white mottled killer whales (actually large dolphins as they have teeth) appear occasionally, hunting local seals.
But our most common visitors are bottlenose dolphins identified as from the large Moray Firth pod. They are intelligent creatures who use sound to converse with each other and to echo-locate their prey. Pods act as a pack, herding fish together, some blowing curtains of bubbles as barriers while others strike. But they are often playful, bow-riding large ships, breaching right out of the water, playing games with clumps of seaweed and even bullying their porpoise cousins by flipping them into the air.
In 2013, at least eight were sighted together as close as 300m off Platcock Rocks; some hardy sailors sighted 3-4 there again on New Year’s Day. This season there has been another pod seen several times not far off the Leithies. Look for the triangular pointed fin sticking up from a curved back up to 4m long, usually accompanied by a few friends and all moving in unison. For more information, try http://www.dolphincareuk.org or http://www.seabird.org/wildlife/marine-wildlife/12/27