Beach wrack or marine wrack is organic material (e.g. kelp, seagrass, driftwood) and other debris deposited at high tide on beaches and other coastal areas, and may form a wrack line. This material acts as a natural input of marine resources into a terrestrial system, providing food and habitat for a variety of coastal organisms.
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Beach wrack in the context of Driftwood
Driftwood is a wood that has been washed onto a shore or beach of a sea, lake, or river by the action of winds, tides or waves. It is part of beach wrack.
In some waterfront areas, driftwood is a major nuisance. However, the driftwood provides shelter and food for birds, fish and other aquatic species as it floats in the ocean. Gribbles, shipworms and bacteria decompose the wood and gradually turn it into nutrients that are reintroduced to the food web. Sometimes, the partially decomposed wood washes ashore, where it also shelters birds, plants, and other species. Driftwood can become the foundation for sand dunes.
View the full Wikipedia page for Driftwood