(CNN) -- Beach-bound travelers are keeping a close eye on the spread of oil along the Gulf Coast and weighing vacation decisions.
Oil has come ashore in Louisiana, Mississippi, Alabama and Florida, and cleanup is under way in some areas. Here are some of the latest updates from coastal destinations affected by the oil spill:
Gulf Islands National Seashore
All of the Gulf Islands National Seashore sites are open, according to the National Park Service website. The park service reports that crews found "very light occurrences of oil" on Horn and Petit Bois islands in Mississippi. Petit Bois island was cleaned up and has been free of oil as of Sunday, the site said.
The spill also has affected parts of the Gulf Islands National Seashore in Florida. Cleanup crews have been working on medium and heavier oil coverage at Perdido Key, Fort Pickens and Santa Rosa.
Gulf Shores and Orange Beach, Alabama
In Alabama, the Department of Public Health has issued an advisory against swimming in Gulf waters or in bay waters close to Fort Morgan. The beaches remain open. The pier at Gulf State Park in Gulf Shores is closed to fishing but open for sightseeing, according to the Alabama Gulf Coast Convention and Visitors Bureau.
Oil has been reported on shore at Dauphin Island, Fort Morgan and Gulf Shores.
Pensacola and Perdido Key, Florida
The waters in Pensacola and Perdido Key are open Monday for swimming and fishing, according to the Pensacola Bay Area Convention and Visitors Bureau. Officials have not issued closures or health advisories for the area, the bureau's website said.
Several tar balls were spotted in the area over the weekend. "According to [the National Oceanic and Atmospheric Administration], tarballs do not pose a health risk to the average person, but visitors are advised not to pick them up," the website said.