Carlsbad State Beach at Tamarack Avenue and another piece of the shoreline 150 feet north and south of the mouth of the Buena Vista Lagoon at the Oceanside-Carlsbad border were added to San Diego County’s beach advisory list Dec. 31. The advisory means bacteria levels in the water have exceeded health safety levels, and that people should avoid contact with the water in those areas. The cause of the elevated levels was not determined. “There was no spill reported,” said Donna Durckel, a communications officer for the county’s Land Use and Environmental group, on Friday. “It could be run-off from a street or property nearby.” The county tests coastal waters regularly, and the advisory could be lifted in a few days if new tests show the bacteria levels have receded. Both spots tested high for enterococcus, a broad range of bacteria that can cause infections such as meningitis in humans. Elsewhere in the county, an advisory issued Dec. 26 remained in effect at Dog Beach in Ocean Beach for an area extending 300 feet south of the San Diego River mouth. One chronic advisory, for the children’s pool at La Jolla Cove, has been in effect since 1997 because of the sea lion colony there. Two beach closures were in effect Friday. One was at the Tijuana Slough shoreline at the international border with Mexico. That area has been closed since 2021 because of sewage run-off from across the border. The other was the Imperial Beach shoreline from the south end of Seacoast Drive through north of Carnation Avenue, which also is near the international border. That area has been closed since Dec. 29. Advisories are the lowest level of beach postings issued by the county. They can be widespread near the outlets of rivers and creeks after any significant rainfall, which carries surface pollutants such as oil and pet waste into storm drains. Generally, the advisories are lifted after a few days when bacteria levels drop again.