Lake San Antonio to reopen to public after massive fish die-off
Lake San Antonio will reopen to the public on Wednesday after being closed for more than a week due to a massive fish die-off, Monterey County officials said Monday.
New water testing has found the lake is safe for recreation, said Bryan Flores, county chief of parks, at a Monday press conference.
The cause for the die-off, which closed the lake on July 10, hasn't been determined but Flores said it was not due to bacteria, toxins or pollutants, which can be harmful to humans.
Instead, officials believe it might have been caused by a natural algae phenomenon spurred on by high heat.
During the daytime, water plants and natural algae use the sun for the process of photosynthesis and exhale oxygen into the water, which fish breathe in. At night, the plants inhale oxygen. Too much plant life can consume too much oxygen, and the fish can suffocate. This is the phenomenon that researchers believe might have caused the massive fish die off in Lake San Antonio the second week of July.
An extreme heat wave around the Fourth of July weekend saw temperatures near the lake spike to 100 degrees. For almost a week, dead fish washed up on the lake's shores, including small silver shad, trout, carp, crappie, larger bass and catfish.
The county's environmental health bureau asked park officials to close the lake to swimming, boating and fishing, on July 10. The die off appeared to continue through July 12.
"Based on the satellite imagery that we received there was a substantial amount of photosynthesis occurring, which shows that an algae bloom was present during the fish die off event," said Flores. "A fish die-off this large has never happened in the history of Lake San Antonio. Nothing of this multi-species or this large scale."
While the park is reopened, Flores recommends that the public use their best judgment, heed any cautionary signage and stay aware of their surroundings.
"The water that they come in contact with is not necessarily 100% clean, "said Marni Flagg, program coordinator with the County of Monterey Health Department on Monday. She noted that there are healthy fish and wildlife present in and around the lake.
"If anything happens, you can contact your physician and go and seek medical attention. We ran water testing and nearly all the results came back in the normal or the non-detect range. It is safe for humans to go back into the water and have a great time."
"What we can definitively say is that whatever caused it, is over for now," said Monterey County Supervisor Chris Lopez, inviting the public to come back to the park.
Flores estimated that the financial impact was well over $100,000, as campers had to cancel their plans. Before the event, the county had full capacity at South Shore for two weekends. The parks service is anticipating, because of the heat, thousands of people will return to the North Shore.
"We were having $80,000 to $100,000 weekends at Lake San Antonio," said Flores. "So, while the revenue impact stings a little bit, we had to take an abundance of caution to study this event."
The park service is pressure-washing the docks and launch ramps and getting debris and fish carcasses cleaned off the North Shore. Flores said clean-up will continue right up to the point where they open. They also took the opportunity to do some sewer repairs and other maintenance.
"Our biggest help during this whole event was the wildlife," said Flores. "I mean, this was a smorgasbord to them. There was white pelicans and seagulls and crows and ravens and wild pigs and raccoons ... everybody was enjoying the feasts and that helped us out a lot."