The state Health Department has issued an advisory warning of a high bacteria count for waters at Laniakea Beach on Oahu’s North Shore.

Officials from the Clean Water Branch say the levels of enterococci at Laniakea, popularly known as “Turtle Beach,” exceed the threshold at more than 2,005 enterococci per 100 milliliters. The acceptable threshold is 150 enterococci per 100 milliliters.

Enterococci are used as indicators of the presence of fecal material in water, and therefore, the presence of disease-causing bacteria, viruses, and protozea which can sicken swimmers.

“Swimming at beaches with pollution in the water may make you ill,” said the advisory. “Children, the elderly, and people with weakened immune systems are the most likely populations to develop illnesses or infections after coming into contact with polluted water, usually while swimming.”

While swimming-related illnesses can be unpleasant, the advisory said, they are usually not very serious and require little or no treatment or get better quickly upon treatment, with no long-term health effects.

Gastroenteritis, the most common illness associated with swimming in water polluted by fecal pathogens, can have one or more of the following symptoms: nausea, vomiting, stomachache, diarrhea, headache or fever.

Other minor illnesses associated with swimming include ear, eye, nose and throat infections.

The advisory will remain in effect, officials said, until water sample results no longer exceed the threshold.