County Clare's late-summer waters have become the stage for one of the more puzzling wildlife spectacles in European seas. Dozens of basking sharks — the second-largest fish in the ocean, with Irish specimens recorded at over nine metres — are gathering in large groups off Loop Head and up towards the Aran Islands each August and September, lining up nose to tail in slow circular spirals and occasionally launching their five-tonne bodies clean out of the water.
Photographer Nigel Motyer, who has dived Irish waters since the 1980s, documents the phenomenon in his new book Beneath Irish Seas (Merrion Press, £24.99). He first photographed the gatherings in August 2016, southwest of the Aran Islands, while out looking for blue sharks, and says both the frequency and the numbers have grown every year since.
The bigger story here is recovery. Hunting basking sharks was only banned in Ireland in 1984 — their oil once fuelled London's streetlamps — and sightings were rare for decades afterwards. Now the sharks arrive each April as plankton blooms begin, often feeding at the surface with mouths flared open. The late-summer Clare gatherings are something different: since the sharks appear to be drifting south from Scotland and Donegal, and since the spiralling groups — known as toruses — are made up of large, likely sexually mature animals, researchers suspect it's mating behaviour. Pale colouring and pectoral fin abrasions on some females support the theory, though actual mating has never been observed in this species. The breaching, meanwhile, could be dominance display, a way of summoning others via the sound of the splash, or simply a means of shaking off parasitic lampreys.
For travellers, this puts Ireland firmly on the map for world-class marine wildlife. Boat operators out of west Clare offer the chance to see these giants up close, and October 2022 protections under Ireland's Wildlife Act come with a code of conduct: anyone entering the water must stay at least four metres away. Even if you stay dry, spotting the splash of a breaching shark from a cliff or boat at Loop Head is hard to beat — a ten-metre animal makes quite an entrance.
