PONTE VEDRA BEACH, Fla. – Usually, it's seaweed that washes ashore, but a weed of another kind did Thursday morning, triggering a response by the St. Johns County Sheriff's Office.

After a package of marijuana washed ashore on Ponte Vedra Beach, the Sheriff's Office marine unit kept an eye on the water as deputies reminded beachgoers to report any suspicious packages along the surf.

The man who discovered the illegal weed told News4Jax he was on his routine morning walk along the beach near the Ponte Vedra Inn when he stopped and discovered a package that washed up on the shore.

IMAGES: Package of marijuana washes ashore on Ponte Vedra Beach

He took photos of the suspicious package and called the Sheriff's Office. When deputies arrived, they cut open the package and tested what was inside. Turns out, deputies said, it was marijuana -- about 30 pounds of it.

Sheriff's Office spokesman Chuck Mulligan said it's not unusual to find packages of drugs wash up along the beach.

"Many times we find that these are dropped by either airplanes or boats. Sometimes during the transfer process in the ocean, a package gets lost and finds its way to shore," Mulligan said. "All of these packages would generally be heavily wrapped in a packaging tape and that helps to water seal the package from saltwater."

In 2013, deputies collected 25 bricks of cocaine, worth more than $7 million, that washed up along St. Johns County beaches. The beaches were closed while deputies searched for evidence.

In this case, only one package was found. Depending on the grade and potency, Mulligan said, the bundle of weed could have a street value of up to $5,000.

Mulligan said it's possible more packages could wash ashore.

"Sometimes we will see a day or so later other packages wash ashore and, sometimes, it's a single package," he said. "Our deputies working and the marine unit will continue to keep an eye on the beaches."

Many times, drug smugglers remain a mystery because there is no return address and no identifying characteristics or markings on the package. Anyone caught smuggling drugs face more than 15 years in prison.

If anyone spots a sealed or suspicious package along the beach, Mulligan said, do not tamper with it and immediately call law enforcement officers so they can deal with it.