Chinstrap penguins are decreasing in numbers due to a lack of krill, their only food source.

This 1-centimenter-long frogfish is one of the many subjects of marine photographer Richard Smith.

Researchers plan an oceanographic expedition to understand why a phytoplankton bloom developed as molten lava flowed into the sea east of Hawaii's Big Island.

Researchers’ simulations suggest that small population sizes and inbreeding made Neanderthal populations vulnerable to chance fluctuations in population size.

Carbon dioxide and temperature need to increase in a constant ratio for plants to keep up with climate change.

The concentration of the greenhouse gas is now one-and-a-half times what it was before the Industrial Revolution, the World Meteorological Association says.

Slowing to just two beats per minute, the animals’ heart rate shows how they survive plunging far below the ocean’s surface to eat.

Warming temperatures threaten reindeer herding and the preservation of cultural artifacts in Mongolia.

Plants use two different strategies to photosynthesize underwater.