Casco Bay National Estuary

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Casco Bay is both a working port and a vital estuary. An estuary is a place where rivers and tides converge and marine life thrives in this ecosystem. Casco Bay is a National Estuary under the Clean Water Act which is overseen by the Environmental Protection Agency.


Perhaps not the most scenic waterfront I’ve ever seen, there is a lot of natural beauty here mixed with gritty fishing industry and oil tankers. The Eastern promenade, which winds along the bay, is nice for a stroll. There are plenty of walkers, joggers and bicyclists enjoying the outdoors here.

The relative calm and quiet in Casco Bay makes it ideal for kayaking and paddle boarding. We really enjoyed our sunset tour with Portland Paddle Company and our guide Kalla. It was hard work, but not so tough that we couldn’t manage.

There are over 700 small islands, called the Calendar Islands, in Casco Bay. First we paddled over to an old railroad bridge and saw some nesting ospreys. Next we went out to an island in the bay where we saw some seals and lots of sea birds. Then we coasted back to shore to enjoy the glorious sunset.

Location: Portland, Maine
Designation: National Estuary
Date designated/established: 1987
Date of my visit: August 18, 2015