Knotted Wrack

Knotted Wrack (Ascophyllum nodosum), also known as egg wrack, is a dominant and incredibly resilient brown seaweed that drapes the rocky shores of the North Atlantic. Growing in slow, majestic sweeps, it forms dense underwater forests during high tide and blankets the intertidal rocks like a heavy, golden-brown carpet when the tide recedes. This long-lived species is not just a plant-like organism; it is a foundational ecosystem engineer, providing critical shelter, moisture, and protection for hundreds of marine invertebrates, small fish, and other algae. Its remarkable ability to withstand extreme shifts in temperature, salinity, and wave action makes it a true survival specialist of the coast. For centuries, coastal communities have harvested Knotted Wrack for use as organic fertilizer, livestock feed, and more recently, in biotechnology and cosmetics.

Habitat: Found on sheltered rocky shores in the middle intertidal zone, where it attaches firmly to rocks and boulders.