OAKLAND, Calif. -- The East Bay Regional Park District announced Monday it has closed Oakland's Lake Temescal for swimming because of a bloom of toxic blue-green algae.The park district said it will keep the rest of the Temescal Regional Recreational Area open and plans to treat the lake's algae with Pak 27, an organic oxidizing agent, next week.Last year, Lake Temescal was closed for more than two months due to a toxic algae bloom. In that incident, park district officials also used Pak 27 to control the algae bloom, according to the park district.In February, park district officials determined that similar blue-green algae blooms at Lake Chabot in Castro Valley caused the death of three dogs that were exposed to the lake's waters.Additionally, Shinn Pond in Fremont also contains algae bloom and park district officials warn dog owners not to let their dogs swim the pond.In May, park district officials closed Quarry Lakes in Fremont for swimming due to an algae bloom.Because of the drought and warm weather conditions, toxic algae blooms have been occurring more frequently, park district officials said.Park district staff regularly monitor lakes and shorelines and post warnings or closures when appropriate, according to park district officials.The park district is encouraging visitors to visit other popular lakes, beaches and swim lagoons in the area for swimming, such as Lake Anza at Tilden Regional Park in Berkeley, Cull Canyon in Castro Valley, Contra Loma Lagoon in Antioch, Don Castro in Hayward, Del Valle Recreation Area in Livermore and Roberts Pool at Roberts Regional Recreation Area in Oakland.