A "red tide" algae bloom in the Gulf of Mexico has led to the closing of Mississippi beaches, shutdown of oyster harvesting areas in Mississippi and Louisiana, and warnings of potential fish kills and human health problems in Alabama. Health officials say red tides release toxins that can contaminate shellfish and kill finfish. They also can cause human respiratory problems, along with irritation of the nose, throat or eyes. Mississippi officials closed all beaches and oyster reefs Friday. In Louisiana, officials closed oyster harvesting areas 1 through 7 along the state's southeastern coast. In Alabama, health officials warned that anyone with respiratory problems should avoid mists from the affected waters - meaning people may want to avoid the beach despite unseasonably warm temperatures.