Life in the Pile Fields
Pile fields are a key element of the Park’s estuarine sanctuary. Instead of removing these wooden elements, which once functioned to support piers, Hudson River Park has committed to retaining these piles to provide habitats for invertebrates and fish. Many fish including juvenile Striped Bass take shelter in the piles, and sessile organisms -- those that live in one spot for their entire lives -- are particularly common at these locations. Water birds love to linger around and on top of the piles, finding them to be a great place to search for a meal.
These ever-present crustaceans use feathery feet to filter meals of plankton. Barnacles can be easily spotted when the tide is low and they are exposed to air. Barnacles must stay closed up tight to avoid drying out before the tide returns.
The shipworm Teredo is not actually a worm at all; it is a mollusk. It is related to clams, oysters and snails. These creatures excavate holes in wood and actually eat the sawdust. Over time, this feeding habit results in the deterioration of the piles. Shipworms are increasing in the Hudson River as water quality improves.
The sea grape is a type of animal known as a tunicate. As larvae (young animals), tunicates swim and resemble tadpoles. They then undergo a dramatic metamorphosis into sessile, blob-like organisms. Sea grapes sometimes get caught during the Park's free Big City Fishing programs when enthusiastic anglers accidentally “hook” pilings.