Some Brooklyn elementary school students celebrated the first annual "It's My Estuary Day" by cleaning up Coney Island Creek and Kaiser Park Saturday.
A collaboration of environmental groups called Making Waves sponsored the event to raise awareness of waterfront resources in the borough, a spokesman said.
Aside from the cleanup, the group held activities for the children, letting them touch live hermit crabs and other marine life.
Other activists turned out to relocate struggling oysters.
The activists have teamed with educators to raise money for a marine science barge for laboratory and educational purposes, they say.