GALVESTON, Texas -

High levels of bacteria found on a Galveston Island beach have caused the Texas Beach Watch to issue a "beach advisory."

The advisory is in the the south Sea Isle area. The Beach Watch runs regular tests on dozens of Galveston's beaches.

The other 51 beaches in the area are safe, according to the county health department.

The cause of the contamination is not fully clear, but it could be as simple as a rain storm.

Here's more info from the Texas Beach Watch website:

"The Galveston County Beach Watch Program, in cooperation with the Texas General Land Office, developed and implemented a program to monitor for bacteria in coastal recreation waters adjacent to beaches that are used by the public and to notify the public if water quality standards for these bacteria are exceeded. The program samples at 52 monitoring stations along Galveston Island, Bolivar Peninsula and one site on the Texas City Dike."