Island ponds are a connection to cultural heritage and a livelihood for fishermen. But housing booms and land-use changes threaten to undo a delicate balance.

Cribbing a famous line from an infamous late U.S. president, it is public enemy number one in Southeastern Massachusetts, although this time the enemy is not drugs but nitrogen. Nitrogen poses a serious threat to the health of our coastal ponds and saltwater embayments that were once pristine and are now in alarming states of decline. Eelgrass beds are gone or disappearing, and along with them the clean shellfish that both provide a rich source of food and form a key cog in the local economy.