Wrack (seaweed)

Wrack is a common term used to refer to several species of seaweed that are often found washed up on the shores of oceans and seas. The term is derived from the Old Norse word 'vrak', which means 'wreckage', and is used to describe the mass of seaweed and other marine debris that is often left on the beach after high tide.

Species

There are several species of seaweed that are commonly referred to as wrack. These include:

• Fucus vesiculosus, also known as bladder wrack, is a brown seaweed that is commonly found on the coasts of the North Sea, the western Baltic Sea, and the Atlantic and Pacific Oceans.

• Ascophyllum nodosum, known as egg wrack or knotted wrack, is a large, common brown alga that is found on the rocky shores of the Atlantic coasts of Europe and North America.

• Pelvetia canaliculata, or channelled wrack, is a brown seaweed that is found on the upper shores of exposed coasts in the North Atlantic.

Ecology

Wrack plays a crucial role in the ecosystem of coastal areas. It provides food and habitat for a variety of marine organisms, including crustaceans, mollusks, and fish. When it washes ashore, it also provides nutrients for coastal vegetation and food for beach-dwelling organisms.

Uses

Historically, wrack has been used for a variety of purposes. It has been used as a source of iodine and other minerals, as a fertilizer, and as a source of alginate, a substance used in food processing and other industries. Today, it is also used in the production of biofuel.

See also

• Seaweed
• Algae
• Marine debris