This dolphin sighting up the James River in Richmond is unusual due to the freshwater found there. Photo: Bill Draper Photography

VIDEO: Dolphins Spotted Further Up Bay Tributaries this Summer

Since the rise of capable camera phones and the creation of the crowd-sourced DolphinWatch app, we know about more Chesapeake Bay dolphin sightings than ever before. And this summer season, dolphins are turning up in more unusual locations. In recent weeks the popular marine mammals have been spotted way up the James River in Richmond and in the Pamunkey River, a tributary of the York.

In Richmond, one lucky photographer was in the right place at the right time. Cheryl Costello talks with dolphin researchers about what could be behind these surprise visits. Watch below:

The moving animation in this interview was created by Lauren Rodriguez who is a graduate research assistant for the Chesapeake DolphinWatch research program. You can view the animation here: