Species profile
bladder wrack
Fucus vesiculosus
At a glance
bladder wrack (Fucus vesiculosus) is a marine alga with specific harvest rules tracked in 1 of 66 jurisdictions covered by CatchRules.
Confirmed by 2,460 research-grade iNaturalist observations, with Maine, Massachusetts, and Nova Scotia the top jurisdictions by observation count.
Notable details
- Named for the paired air-filled bladders along its fronds that keep photosynthetic tissue near the surface.
- Can grow to about 90 cm (3 feet) in length in the North Atlantic.
- Contains high levels of iodine and was historically harvested as a nutritional supplement and fertilizer.
- Periwinkles and other shore snails graze heavily on it, making it a keystone intertidal food source.
- The air bladders keep fronds upright in the water column, maximizing light exposure for photosynthesis.
Where bladder wrack are seen
Jurisdictions with rules for bladder wrack
Background
Fucus vesiculosus, known by the common name bladder wrack or bladderwrack, is a seaweed found on the coasts of the North Sea, the western Baltic Sea, and the Atlantic and Pacific Oceans, also known by the common names black tang, rockweed, bladder fucus, sea oak, black tany, cut weed, dyers fucus, red fucus, and rock wrack. It was the original source of iodine, discovered in 1811, and was used…
Background excerpt adapted from Wikipedia's bladder wrack article (CC BY-SA). Visit Wikipedia for the full entry.
Other brown algae/kelps on CatchRules
Photo credit: iNaturalist / Wikipedia. Identification reference only — verify regulations with the issuing wildlife agency before retaining a catch.