Wonders of the Wrackline

A view of the wrackline with many birds in front of it on the shore.

The wrackline is the area on the beach where organic material and other debris gets deposited at high tide. Typical debris includes uprooted seagrasses, algae, seeds, mangrove leaves and propagules, along with sponges, soft corals and shells. At Bahia Honda State Park, we have Atlantic and Bayside shorelines, both of which have wracklines. There are two high tides per day, and those tides bring in seagrasses and other debris to form this important part of the ecosystem.

At first glance, one might think the wrackline isn’t very appealing, and it ruins the beach aesthetic to have seagrass on the beach. But understanding how important it is for the island makes it into a welcomed site. The sea grass provides shelter for a variety of animals. Among the wrackline you’ll find small crustaceans called amphipods. As these harmless creatures feed among the seagrass, and then the shorebirds come along and feed on them. All this foraging breaks down the seagrass in the wrackline, and the particles become nutrients for the dunes. The wrackline also helps stabilize the sand which in turn promotes dune life.

In addition to the aforementioned benefits, the wrackline is a treasure trove for those who take time to look. The bits of coral, the sea shells and the drift seeds have all made a journey to the shoreline and tell the story of this wonderful cycle. The wrackline is natural and necessary part of the ecosystem at Bahia Honda State Park, and truly serves as an ecological bridge between land and sea.

A view of the wrack line along the shore.