Dodging New York traffic: hundreds of humpback whaless on a collision course with ships

Humpbacks are thriving in the warm waters off the coast of Manhattan but maritime restrictions have not kept pace

It is the beginning of August and a crowd is gathered on the deck of the American Princess cruise boat waiting for one thing - and they are not disappointed. Suddenly, a juvenile humpback whale, known as NYC0318 in local records, bursts through the surface of the water, engulfing thousands of small, oily fish.

For those onboard the 29-metre (95ft) vessel, the scene is a thrill to watch, in part because it is taking place not far out at sea but just off the coast of Manhattan, New York. Among the tourists watching is Chris St Lawrence, a naturalist and the communications director of Gotham Whale, a volunteer-run marine research organisation in the city. He is not just looking out for the whales, he is watching for danger around them.