Nick Hawkins / Blue shark (Prionace glauca) off Halifax, Nova Scotia, Canada. July.

Nick Hawkins / Overhead view of a blue shark (Prionace glauca) off Halifax, Nova Scotia, Canada. July.

Nick Hawkins / Atlantic bluefin tuna (Thunnus thynnus) off Antigonish, Nova Scotia, Canada. October .

Nick Hawkins / American lobster (Homarus americana) in eelgrass (Zostera marina). Nova Scotia, Canada. July

Nick Hawkins / Long-finned pilot whale (Globicephala melas) off Nova Scotia, Canada. October.

Marie Read / Canada geese (Branta canadensis) two during territorial fight in early spring, Ithaca. New York, USA

Mark Carwardine / Harbour porpoise (Phocoena phocoena) surfacing Bay of Fundy, New Brunswick, Canada

Nick Hawkins / Atlantic salmon (Salmo salar) migrating for spawning in river, Gaspe Peninsula, Quebec, Canada, October.

Nick Hawkins / Two Atlantic salmon (Salmo salar) silhouetted against sky, Gaspe Peninsula, Quebec, Canada, October.

Michel Roggo / Atlantic salmon (Salmo salar) migrating upstream to spawn, Quebec, Canada Photographed for the Freshwater Project.

Ingo Arndt / Harp seal (Phoca groenlandicus) pup on sea ice looking down into icy water, Magdalen Islands, Gulf of St Lawrence, Quebec, Canada, March.

Ingo Arndt / Harp seal (Phoca groenlandicus) pup sleeping on sea ice, Magdalen Islands, Gulf of St Lawrence, Quebec, Canada, March.