A unique floating lab in San Francisco Bay has been invaded — and researchers are learning from it

On an overcast November morning, 15 apprehensive fourth-graders tumbled out of a faded yellow bus at Treasure Island. They came to experience the thrill of sailing on the San Francisco Bay — and to get a lesson on its ecology.

The scene has played out regularly for the past decade at the Treasure Island Sailing Center, a nonprofit that seeks to make sailing accessible to young people around the Bay Area. While the group suspended its operations in December to begin construction on a sizable expansion project...