California researchers have found that oxygen levels and water temperatures play a key role in the health of deep-sea fish populations. San Diego and Monterey Bay scientists studied fish on the floor of the Gulf of California.

“This is an example of some of the video that we are analyzing for this research,” said Natalya Gallo, a post-doctoral researcher at the Scripps Institution of Oceanography.

She pointed to footage taken along the seafloor on the Gulf of California near the Mexican coast. The pictures come from a remotely controlled submarine. Researchers use the underwater tool to gauge the impact of a warming ocean on fish.