Gray whale feeding at the surface and showing it's baleen. (Photo by Christopher Swann/Biosphoto)

Behaviour: Mammals category. Giant Gathering by Tony Wu, USA. Dozens of sperm whales mingled noisily off Sri Lanka’s northeast coast, stacked as far down as Tony could see. This was a congregation of dozens of social units, like a gathering of the clans. Aggregations like this could be a critical part of the whales’ rich social lives but are rarely reported. Some two thirds of the population was wiped out before commercial whaling was banned in 1986. This kind of major gathering could be “a sign that populations are recovering”, says Tony. (Photo by Tony Wu/Wildlife Photographer of the Year 2017)

A woman takes selfie as municipal workers use cranes to lift carcass of Bryde whale at the Juhu beach, in Mumbai, India, Friday, January 29, 2016. Marine biologists in India were conducting an autopsy on the carcass of 35-foot long Bryde whale that washed ashore on a popular beach in the western city of Mumbai. The beached mammal which appeared to have died at sea two or three days ago was spotted on the beach Thursday by late evening walkers, who informed police. (Photo by Rajanish Kakade/AP Photo)

Hideki Tokoro, president of whaling company Kyodo Senpaku, boards Japan's new whaling mothership, the Kangei Maru, following the ship's launch ceremony at a port in Shimonoseki city, Yamaguchi prefecture on May 21, 2024. The nearly 9,300-tonne ship set sail on its maiden hunting voyage on May 21, heralding a new era for the controversial practice defended by the government as an integral part of national culture. (Photo by Yuichi Yamazaki/AFP Photo)

Marine biologist Simon Pierce, who studies whale sharks, happened to be in the right place at the right time to capture amazing photo off Cancun, Mexico. (Photo by Simon Pierce/Mercury Press/Caters News)

Human Connection Award: People and Planet Ocean – Winner – Steve Woods. A free diver interacts with a sperm whale among a cloud of sargassum weed, Dominica. (Photo by Steve Woods/Ocean Photographer of the Year 2022)

A seal playfully tries to bite the camera, taken on February 2016 in Plettenberg Bay, South Africa. A group of friendly seals get up close and personal with the camera. The pod of brown fur seals, also known as “cape fur seals”, were shot in Plettenberg Bay in South Africa by dive tour operator Rainer Schimpf. The playful creatures prove they are not camera shy in the slightest as they they swim upside down, grin widely and attempt to bite the camera lens. (Photo by Rainer Schimpf/Barcroft Media)