A boy reacts as dogs play along the riverbank of Pasig river, in Manila, Philippines, June 10, 2021. (Photo by Lisa Marie David/Reuters)

A brown bear cub by the Khailyulya River in north-east Kamchatka, Russia on July 24, 2021. (Photo by Yuri Smityuk/TASS)

Labourers carry a log above their head near the Buriganga River in Dhaka on May 6, 2020. (Photo by Munir Uz Zaman/AFP Photo)

A girl swings on a rope swing over the Volga River in Zavolzhsk, Ivanovo Region, Russia on June 9, 2020. (Photo by Vladimir Smirnov/TASS)

In this photograph taken on August 20, 2022 a woman dances with a child alongside the Garonne river in Toulouse, southern France. (Photo by Charly Triballeau/AFP Photo)

In this July 29, 2021 file photo, the pillars of the massive Rosario-Victoria Bridge are exposed during a drought affecting the Parana River near Rosario, Argentina. At the port city of Santa Fe the river registered a level of 22 centimeters, the lowest in 50 years. (Photo by Victor Caivano/AP Photo/File)

The NASA Extreme Environment Mission Operations (NEEMO) 21 mission began on July 21 as an international crew of aquanauts splashed down to the undersea Aquarius Reef Base, located 62 feet below the surface of the Atlantic Ocean in the Florida Keys National Marine Sanctuary. The NEEMO 21 crew will perform research both inside and outside the habitat during a 16-day simulated space mission. During simulated spacewalks carried out underwater, they will evaluate tools and mission operation techniques that could be used in future space missions, including journeys to Mars. (Photo by Karl Shreeves/NASA)

Shooting star by Tony Wu, US/Japan. Winner, underwater. The electrifying reproductive dance of a giant sea star. As the surrounding water filled with sperm and eggs from spawning sea stars, Wu faced several challenges. Stuck in a small, enclosed bay with only a macro lens for photographing small subjects, he backed up to squeeze the undulating sea star into his field of view. The dancing posture of spawning sea stars rising and swaying may help release eggs and sperm, or may help sweep the eggs and sperm into the currents where they fertilise together in the water. Kinko Bay, Japan. (Photo by Tony Wu/Wildlife Photographer of the Year)