WASHINGTON — It’s always a thrill to spot dolphins in the Chesapeake Bay, and scientists are hoping you’ll help track them through a new website.

It’s not unusual to see one of these beautiful mammals in the summer. And there is anecdotal evidence that dolphins are making their way into the bay more often than they used to, said Helen Bailey, a scientist at the University of Maryland Center for Environmental Science’s Chesapeake Biological Laboratory.

Bailey and other researchers are trying to find out why dolphins visit the bay, how often they visit, how long they stay and which areas they seem to prefer.

To help them understand, they’re asking people to record their sightings on a website called Chesapeake Dolphin Watch.

“This is really the first time we are systematically recording this,” Bailey said.

The site is free to use, but you have to sign up and create a password before you can report a sighting and view a map of sightings reported so far.

“The more eyes we have on the water, the better to report dolphin sightings,” Bailey said. “We think that citizens can make very good citizen scientists.”

Several underwater microphones, which listen for the dolphins’ unique sounds, have been set up in the Patuxent and Potomac Rivers near the bay.

The information collected through Chesapeake Dolphin Watch will help scientists decide where to place more microphones.