(CNN) -- Oil spill cleanup is under way at many beaches along the Gulf Coast, and beach-bound travelers are keeping a close eye on coastal conditions.
Here are some of the latest updates from destinations affected by the oil spill:
Grand Isle, Louisiana
Oil is affecting more than 45 miles of Louisiana coast, according to a state emergency website.
The site includes a roundup of oil sightings along the coast, including this report Monday from Grand Isle: "Oil sheen filled with 10 foot wide tar balls extending from 50 yards off of the southwest tip of Grand Isle south into the gulf."
iReporter Natasha Combs visited Grand Isle on Sunday to observe cleanup efforts.
"The beach was empty with the exception of the workers and the military. All of the cleanup crew were wearing HAZMAT suits. Bags of oil were gathered in piles along the beach, and workers were rinsing oil off of themselves in small plastic kid pools," Combs said.
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 Mississippi State Department of Health urges people to avoid swimming or boating in "any waters visibly affected by oil."
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 waters off Gulf Shores, Orange Beach and Fort Morgan 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.
State Gulf waters and some inshore waters have been closed to fishing by the Alabama Department of Conservation and Natural Resources.
Pensacola and Perdido Key, Florida
The waters in Pensacola and Perdido Key are open Tuesday 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.
iReporter Mike McHugh shot video over the weekend at Johnson's Beach on Perdido Key. "I came back to Johnson's Beach to see how the cleanup was progressing and to see what high tide brought in. At 4:30 p.m., the cleanup crews were gone. There were less tar balls, but still [they] are easy to find," he wrote.
iReporter James Amerson has been tracking the oil in Pensacola, Florida. Tar balls were found late last week on Pensacola Beach, ranging in size from 2 to 3 inches up to 18 inches, Amerson said.
"Strange to think this stuff, millions of years old, came from several thousand feet underground and floated over a 100 miles until it came to rest our sugar white sands," Amerson wrote on iReport.com.
The visitors bureau urges beachgoers to take precautions. "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.