Gary Braasch, an award-winning nature photographer who chronicled climate change, died on March 7 while snorkeling off Australia’s Great Barrier Reef.

The 70-year-old, Portland, Oregon-based photographer was documenting the effect of climate change on the reef near the the Australian Museum’s Lizard Island Research Station, according to a Reuters report.

Braasch was found by his snorkeling buddy face down in the water and not breathing, according to a Brisbane Times report.

No news yet on the cause of death, but the Museum said in a statement that the Queensland police were investigating.

Braasch was a Nikon “Legend Behind the Lens” photographer and a climate change campaigner.