Visitors to Delaware beaches might be able to earn a $100 reward while helping shark researchers at the same time.

Researchers are asking beachgoers to keep an eye out for satellite tags that are used to track the movement of sharks off the Delaware coast. The satellite tags get attached to the base of the shark's dorsal fin and are about 12 inches long. 

Sometimes the tags fall off and wash ashore. They could be found floating in the water or may have washed up on beaches or marshes. 

The researchers from the University of Delaware and Delaware State University are very interested in getting the tags back. That's why they're offering the reward money for their return. 

If you find a tag, contact researchers Daneille Haulsee at (717) 451-7636, Matt Oliver at (302) 645-4075 or Dewayne Fox at (302) 857-6436. The researchers need to know the date you found the tag, the location where the tag was found, the identification number on the tag and your contact information so they can send you the reward money.

The Delaware research team has tagged and released more than 500 sharks since 2006. They've seen evidence that the sand tiger shark population is down as much as 75 percent compared to 30 years ago. Their research effort is designed to determine if the population is starting to rebound or is still in decline.