MERR dolphin count drops to historic low of 167

The Dolphin Count held on Saturday, July 28, resulted in the lowest number of Atlantic bottlenose dolphins spotted in the 17-year history of the Marine Education Research & Rehabilitation Institute (MERR) count, with a total of 167 dolphins sighted by volunteers during the two-hour period.

“Visibility was very good that day, which would have enabled volunteers to see any dolphins that were out there,” said MERR Executive Director Suzanne Thurman, who had postponed the count by a week, due to thunderstorms in the area on July 21.

Although she said MERR cannot determine a definitive cause for the low number based on one year of data, there are several factors Thurman said are being considered.

“We are taking into consideration that there was a slack tide during a small portion of the count,” Thurman said. The slack tide could reduce the number of fish in the area, she explained. However, there have been tide changes during previous counts.

Offshore dredging of sand for beach replenishment might be another factor. The sound associated with dredging could deter dolphins from the area, causing them to find alternative migration and feeding routes.

Each year, Thurman said, MERR strives to keep certain variables of the count constant, including the locations. This year, the South Bethany location had to be moved due to the dredging site.

Usually, 70 to 100 dolphins are counted at each site.

“The highest number sighted was at the Point of Cape Henlopen, right near the mouth of the Delaware Bay — they saw 47 dolphins during the two-hour count,” Thurman said.

The second-highest number was at the bathhouse at Cape Henlopen State Park, with 33 dolphins.

Thurman said she would be interested to hear from beachgoers about any dolphin activity sighted. To share any sightings or to learn more about the work of MERR Institute, call (302) 228-5029 or visit

By Ally Lanasa
Point Intern