Boat trips offering passengers a chance to swim with dolphins in the Bay of Islands have been axed amid fears for the future of the local dolphin population. The number of bottlenose dolphins in the Bay has plummeted from 270 in 1999 to a current estimate of 31, a decrease of almost 90 per cent. The new rules for commercial operators also limit dolphin watching tours to afternoons only and cut the interaction time from 30 minutes per cruise to 20.