You do if you live anywhere in Connecticut, southwestern Rhode Island, or any other area shaded on the map. A watershed is land that collects rainwater, sediments and dissolved materials that flow to rivers, their tributaries and estuaries. The three rivers shown are (1) the Connecticut, (2) the Housatonic and (3) the Thames.
The Sound’s watershed extends into Canada, covering an area of 15,820 square miles inhabited by 32+ million people. Any pollutants entering the water in this vast area can ultimately harm the Sound. Other areas such as New York are also a big part of the watershed of Long Island Sound.
Here's a list of streams in New York that directly impact Long Island Sound. (Remember that you might live in the watershed of one of these streams as well as within the larger watershed of Long Island Sound. If you feel that taking action to help the Long Island Sound watershed is too large of a task, then focus on helping the watershed of your local stream listed here! Ultimately, that will help the Sound too.)
Watch Long Island Sound develop in geologic time in this cool animation. This animation is part of an interactive exhibit at the Aquarium in Newman's Own Hall: