Cetacean observation in Minch Strait

A remarkable concentration of sea mammals

As early as in spring, whales begin their migration from Arctic regions where they restocked their supplies of krill throughout the previous season. Located on their migration path, the islands around Scotland offer sea mammal observation opportunities during this period.

Thanks to the protection enjoyed by most cetaceans and the waning of the Scottish fishing industry, increasing numbers of whales are passing in Scottish waters. Their presence represents a significant source of income for local communities and offers tourists a fascinating experience.

The waters of the Hebrides are among the most important marine habitats in Europe, with nearly 70% of whale, dolphin and porpoise species. Despite this diversity and the accessibility of cetaceans in the Minch Strait, whale-watching is not yet well developed.

Cetacean watching, a growing sector

There are relatively few local operators who rarely focus only on cetaceans, whale watching being restricted to summer months and being less predictable than that of seals and seabirds. Sea outings related to cetacean watching range from 2-hour excursions to one-week cruises around the Hebrides Islands, in addition to sailboat rental which is proving to be among the best options after a slow start. The latter activity, however, requires a larger budget and the ability to navigate in this region where the weather can be difficult.

Minke whales, the stars of the Minch

Scientific research on marine mammals has been undertaken in Scottish territorial waters, particularly North Atlantic Minke whales (Balaenoptera acutorostrata) to identify areas for future marine protected areas. Some data shows that Minke whales are particularly present in two broad areas: along the west coast of Scotland in the Minch, the Little Minch and the sea off the Hebrides (Weir and al., 2001; Evans. and al, 2003; Reid and al, 2003; HWDT) as well as off the coast of Scotland between Fraserburgh and the southern border with England (Hammond et al., 1995, 2002; Northridge et al., 1995; Reid et al., 2003). The relative abundance of Minke whales in these two major areas seems to be greater than elsewhere in the UK or northwestern Europe (Reid et al., 2003).

Seasonal residents in the region

While Minke whales migrate to warmer waters in winter, they return each summer to the waters of the Hebrides, particularly in the Minch Strait where stocks of fish are particularly abundant at that time. Scientific studies have demonstrated that many whales return specifically to the Minch Strait each year and therefore seem to be seasonal residents in the region. Hence the importance of protecting this particularly frequented area.

During our stay in the Gairloc’h region, we had the opportunity of observing 4 specimens off the coast of the Isle of Skye and a few miles from the Bay of Gairloc’h. According to the locals, these places are often visited by cetaceans coming to feed on sand eels, which are particularly plentiful there in summer. We were able to see 4 fin whales enjoying their feast. It is truly an exceptional moment to be able to observe these cetaceans measuring between 7 m and 9 m long moving according to the movement of the shoal of fish and to imagine them swallowing them up in their oversized throat with over 50 grooves! Minke whales have small dorsal and pectoral fins and a very thin head, and they are not as spectacular as their cousins the humpback whales or killer whales. But it is just as magical to see them blowing and sounding.

Remarkable encounter with killer whales

While killer whales move within in a vast area stretching to the sea off the Hebrides, their passage is expected from the month of June each year in the Minch Strait. The passage between Gairloc’h and the south of the Isle of Skye is renowned for regular sightings of sea mammals and less often, of killer whales. While navigating in the area, we had a remarkable opportunity of coming across a group of 6 killer whale (Orcinus orca) feasting on a shoal of sand eels. We first spotted the dorsal fin of a male rising almost 2 m above the surface, like a submarine periscope! According to local scientific observations, a small population of killer whales was spotted in the Hebrides. The group is constantly on the move and circulate around the region over a relatively long distance.

A fascinating sea predator

We were able to clearly identify three pairs through the shape of their dorsal fins and the marks and scratches that are visible when they are on the surface. Among the group, we immediately spotted a dominant male distinguished by its massive and powerful appearance, accompanied by a female with a significantly shorter dorsal fin. Measuring nearly 9 m and boasting a beautiful black coat with white spots behind and above the eyes, the male approached the sailboat two or three times. We then realised the incredible power and intelligence of this extraordinary predator of the seas which was curious about our boat. The group was preying on a shoal of fish, thus facilitating observation. While we were manoeuvring the boat to cause the least possible disturbance, we, however, had ample opportunity to observe the three pairs emerge and sounding from time to time over a fairly small hunting area, as if they were working together using a well-oiled strategy. Killer whales are formidable hunters; according to observations in Scotland it mainly eats fish, seals, and porpoises.

Killer whales are the last mammals in the food chain and have no natural predators, but they are particularly threatened by pollution from toxic chemical residues. Studies in the UK have revealed high levels of flame retardant chemicals in killer whales.

Killer whales are protected by European Community and British law, mainly by Schedule 5 of the Wildlife and Countryside Act 1981, by the Nature Conservation (Scotland) Act 2004 and the EU Habitats and Species Directive of 1992.

The effective involvement of the Hebridean Whale and Dolphin Trust

The Hebridean Whale and Dolphin Trust (HWDT) conduct long-term monitoring of the habitat, numbers and distribution range of cetaceans in the waters of the Hebrides. The purpose of this research is to provide information on marine wildlife to tourism operators in order to ensure effective conservation of the region’s remarkable biodiversity. A community observation site set up by the HWDT encourages residents, tourism operators and visitors to the region to report on their observations of cetaceans. Furthermore, the WISE system aims to minimise disruptions through training and certification programme targeting passenger transport operators and chartered vessels offering marine fauna observation trips as well as through support for vessels involved in interaction with the marine fauna and finally through communication aimed at helping the general public choose sustainable operators that are respectful of the marine environment via the list of service providers endorsed by WISE.