B. wrote: “Any idea what they might be building on the old pier at Watts and Canal? They are drilling and placing large piles. They’ve been there for several weeks.”

Well, yes, I do! The construction there is condos for oysters — part of a project started last summer to restore the nature’s filters in the river by the Hudson River Park Trust and funded by the state. The structures sunk between Piers 26 and 34 hold 11 million junvenile oysters, and the goal is to support marine life and strengthen the overall health of the river.

There are four different habitat structures: reef balls, gabions, pile wraps and textured piles that will create a reef system for other wildlife — mussels, barnacles — and the reef in turn supports migrating fish. The oysters also clean pollutants from the water and can mitigate flood impacts.

The installation is part of the Billion Oyster Project, which started at the Harbor School on Governors Island and has the goal to restore 100 million oysters to New York Harbor in the next five years. This was their largest project in 2021.