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

Nick Hawkins / Harbour porpoise, (Phocoena phocoena) Bay of Fundy, New Brunswick, Canada, September

Nick Hawkins / Harbour porpoise, (Phocoena phocoena) porpoising, Bay of Fundy, New Brunswick, Canada, August.

Roland Seitre / Finless Porpoises (Neophocaena phocaenoides) swimming in unison. Captive. Endemic to South East Asia and the Yangtse River.

Todd Pusser / Dall's porpoise at surface {Phocoenoides dalli}, Central Bering Sea, Alaska

Flip Nicklin / Vaquita (Phocoena sinus) by-catch casualty, Baja California, Mexico

Mark Carwardine / Harbour porpoises (Phocoena phocoena) - rare picture of small group Bay of Fundy, New Brunswick, Canada

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

Mark Carwardine / Harbour porpoises (Phocoena phocoena) trapped inside herring weir off the coast of Nancy's Head, Campobello Island, Bay of Fundy, New Brunswick, Canada. September 2018

SCOTLAND: The Big Picture / Harbour porpoise (Phocoena phocoena), wild individual. Shetland, Scotland, UK, October.

SCOTLAND: The Big Picture / Harbour porpoise (Phocoena phocoena), wild individual. Shetland, Scotland, UK, October.

SCOTLAND: The Big Picture / Harbour porpoise (Phocoena phocoena), wild group. Shetland, Scotland, UK, October.