The expanded harvest is controversial with many disagreeing with the practise because of the potential impact on larval fish, periwinkles, etc. Air bladders and fruiting bodies are present on the ends or along the blades. Rocks entirely covered with either bladder wrack or knotted wrack provide a cool, moist environment underneath when the tide goes out, protecting such things as crabs, periwinkles and whelks until the tide returns. Bladder wrack may also form mats of floating seaweed when torn from the rocks during storms and come ashore forming tide lines along the beach. The biological breakdown of rockweed tide lines returns nutrients to the intertidal zone.
Bladder wrack is collected in the fall and spread on gardens as a mulch.
It can be tilled into the garden in the spring.