Wrack (seaweed)

Fucus serratus2

Pelvetia canaliculata

West Beach wrack

Wrack from Hurricane Matthew in Brunswick, GA, US

Wrack is a common name for several species of brown seaweed belonging to the order Fucales. These seaweeds are typically found in the intertidal zones of rocky seashores and are known for their ability to withstand harsh environmental conditions such as desiccation, high salinity, and strong wave action.

Species

Several species of wrack are commonly found along coastlines worldwide. Some of the most notable species include:

• Ascophyllum nodosum - Also known as rockweed, this species is characterized by its long, leathery fronds with air bladders.
• Fucus vesiculosus - Commonly known as bladder wrack, it has distinctive paired air bladders along its fronds.
• Fucus serratus - Known as serrated wrack, it has a saw-toothed edge along its fronds.
• Pelvetia canaliculata - Known as channelled wrack, it has narrow, channelled fronds.

Habitat

Wrack species are typically found in the intertidal zone, where they attach to rocks and other hard substrates. They are well-adapted to the fluctuating conditions of this zone, including changes in water levels, temperature, and salinity. Wrack seaweeds play a crucial role in the ecosystem by providing habitat and food for various marine organisms.

Ecological Importance

Wrack seaweeds are important primary producers in coastal ecosystems. They contribute to the food web by providing nutrients and habitat for a variety of marine life, including invertebrates, fish, and birds. Additionally, wrack seaweeds help stabilize the shoreline by reducing erosion and trapping sediments.

Uses

Wrack seaweeds have been used for various purposes throughout history. They are harvested for their alginate content, which is used in the food, pharmaceutical, and cosmetic industries. Additionally, wrack seaweeds are used as fertilizer and animal feed due to their high nutrient content.

Conservation

The harvesting of wrack seaweeds must be managed sustainably to prevent overexploitation and ensure the health of coastal ecosystems. Conservation efforts include monitoring populations, regulating harvests, and protecting critical habitats.

Related Pages

• Seaweed
• Intertidal zone
• Marine ecosystem
• Primary production
• Alginate
• Fertilizer
• Animal feed