Rosanna Heaslett Jon Gerrish, Muji, Ellen Chung
As the investigation into the mysterious deaths of a family of three and their dog continues, a portion of a river located near to where they were found in a remote area of the Sierra National Forest has been closed due to toxic algae.
On Friday, officials announced that all public areas along the Merced River between the towns of Briceburg and Bagby would be closed until at least Sept. 17 “in response to the presence of toxic algal blooms.” The area is located downstream from where the family was found last month, per the Associated Press.
“These algal blooms can produce toxins that can make people and pets extremely sick,” Elizabeth Meyer-Shields, a Bureau of Land Management field manager, said in a statement. “We will continue to monitor for the algae’s presence and look forward to when the public can safely recreate in the Merced River.”
The news was shared days after officials with the Sierra National Forest announced that several trails and campgrounds around the Merced River Recreation Site were closed “due to unknown hazards.”
RELATED: Relatives of Calif. Family Who Mysteriously Died on Hiking Trail Don’t Believe They Were Murdered
The closures came two weeks after John Gerrish and Ellen Chung were found dead alongside their 1-year-old daughter, Miju, and the family dog, Oski, in the Devil’s Gulch section of the Hites Cove Trail on Aug. 17.
Courtesy Steven Jeffe John Gerrish, Ellen Chung
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An initial autopsy yielded little information about how the family died, although authorities have been able to rule out two causes of death: exposure to chemicals along the trail and use of a gun or another deadly weapon.
“We know the family and friends of John and Ellen are desperate for answers, our team of detectives are working round the clock,” Sheriff Jeremy Briese said in a previous statement to PEOPLE.
RELATED VIDEO: Family and Dog Mysteriously All Found Dead, Prompting Officials to Declare a ‘Hazmat Situation’
Authorities are currently waiting on the results of a pending toxicology report for more clues. A necropsy is also being conducted on the dog.
“As of the date of this update cause of death remains a question,” the sheriff’s office said. “Detectives continue conducting interviews and investigating all potential possible explanations.”