Light shining into the depths of the lagoon of Bassas da India, a remote atoll in the Mozambique Channel, reveals a gathering of juvenile Galapagos sharks. The light is from a spotlight on a research boat above, which is being used to illuminate the reef so that the divers can see what's going on. Thomas was part of the expedition to census the population of this vulnerable species. 'Not having to use underwater strobes or a flash,' he says, 'meant it was possible to convey a sense of the nocturnal scene.' This lagoon is one of the few places where the Galapagos shark is found beyond the Pacific and is the only known ocean nursery for it, with schools of 50 or more occurring.
Nikon D700 + 16mm f2.8 lens; 1/125 sec at f6.3; ISO 1250; Subal housing.
Bassa da India, Mozambique Channel