Survey work
Fifty years later, and with the shark by now a highly protected species in Scotland’s waters, the country’s wildlife trusts set up a basking shark project to survey the same waters that the hunters had found so productive.Would the sharks be found in significant numbers, and would there still be key sites focused on the areas where the hunters pursued the big shoals? Statistics for the northeast Atlantic recorded that 81,639 sharks had been taken throughout the area between 1952 and 2004 – a severe onslaught on a scarce creature. Five years of surveys along set routes, totalling some 956
hours of actual survey time, yielded a variety of results. In the historically important area of the Clyde Sea, we saw very few sharks at the surface. It was disappointing to find that only one small area, around Ardlamont Point, produced anything more than random sightings. But the Sea of the Hebrides was a different matter entirely.We saw sharks throughout the area, and at two sites we recorded remarkably high numbers of sharks on a regular basis. Interestingly, the first of these sites was around Canna,
where the hunting story began. Between Canna and the Hyskeir lighthouse to the south, we recorded nearly three sharks per hour of survey, which was a remarkably high
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success rate. At the second site, around the island of Coll, we recorded nearly two sharks per hour. At both sites, the sharks were consistently engaged in what’s believed to be courtship behaviour, where groups of animals swim closely together, often touching each other. They were also breaching – leaping clear of the water – which is also thought to be connected to courtship. Moreover, we recorded big shoals at both sites – 50 at Hyskeir and a shoal of 73 at Coll. As a result, we classed both of these sites as basking shark ‘hotspots’. Now that the shark is protected, the days of hunting are
over. But that doesn’t mean that these gentle giants are out of harm’s way, as incidents from other sites around the UK have shown. This is especially true when the sharks are at their most vulnerable to human impact – swimming at or near the surface. Sharks can become tangled up in fishing nets or creel ropes, for example, or run the risk of being hit or disturbed by boats. Fortunately, there was little evidence of the former during the survey, but a number of sharks did show fresh evidence of colliding with boats, all of them close to the Coll hotspot.
1 54 The Nature of Scotland
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