Deadly mystery unfolds as canoeists are found unresponsive after midnight trip

The Marin County Sheriff's Office said the canoeists were found unresponsive Sunday.

Authorities have publicly identified only one of the two victims as San Francisco resident Casey Flynn Melia, 36.

The two individuals had been camping along Tomales Bay before setting out in a canoe shortly before midnight Saturday, according to officials.

"First responders immediately initiated a search-and-rescue operation."

After finding Melia's companion "unresponsive in the water," rescuers later located Melia, who was "unresponsive near Hog Island." 

Both were subsequently pronounced dead.

"A forensic post-mortem examination and routine toxicology testing are scheduled for later this week," the statement said.

"The official cause and manner of death remain pending, awaiting the final findings of a joint investigation conducted by the Marin County Sheriff's Office, the USCG [United States Coast Guard] and the NPS [National Park Service]."

Fox News Digital reached out to the Marin County Sheriff's Office for additional information.

The bay contains bioluminescent plankton that creates a blue-green glow in the water when disturbed. 

But officials warn that kayaking after dark requires extra caution and additional safety measures.

"We strongly recommend the use of a working 360-degree light for all vessels, including kayaks and canoes."

The deaths come amid other recent tragedies involving visitors to national parks and remote wilderness areas.