For many people who enjoy Popham Beach in the summer, riding the Morse River is almost as thrilling as riding the waves. Timed right, it is possible to float at a good clip past the western beach in the warmish water of the outgoing tide. It’s the sort of journey that prompts kids of all ages to clamber up the bank at the end and shout, “Let’s do it again!”

However, the long ride that folks have been enjoying for the past 10 or so years, when the river has taken a sharp left turn and run parallel to the Western beach, exiting at Fox Island, has exacted a heavy price on the Popham shoreline.

That price became even heavier this winter when the river, which had already wiped out the first defensive row of dunes and undermined some trees in a rare maritime pitch pine forest, cut even closer into shore and toppled another good chunk of the forest. State marine geologist Stephen Dickson says those trees had been protected for at least 100 years.

Dickson says historical evidence suggests that the natural movement of sand causes the river to change its course approximately every 10 to 15 years. He and Peter Slovinsky have documented changes at Popham since 1953. (see www.maine.gov/doc/nrimc/mgs/explore/marine/sites/nov08.htm).

Dickson and Lindquist observe on the web page