Species profile
Devil weed
Sargassum horneri
At a glance
Devil weed (Sargassum horneri) is a marine alga with specific harvest rules tracked in 1 of 66 jurisdictions covered by CatchRules.
Confirmed by 450 research-grade iNaturalist observations, concentrated in California.
Notable details
- Native to Japan and China, it was first recorded in Southern California around 2003.
- It can grow several meters tall, rapidly smothering native kelp and algae.
- Unlike most seaweeds, it completes its entire life cycle in under one year.
- Dense stands degrade habitat for native invertebrates and fish that depend on kelp forests.
Where Devil weed are seen
Jurisdictions with rules for Devil weed
Background
Sargassum horneri is a species of brown macroalgae that is common along the coast of Japan and Korea. It is an annual algae which has a varying fertile season along the coast. In Wakasa Bay, Japan it begins to grow in early autumn through winter and matures in spring, when the sea water temperature is around 11.6–15.2 °C (53–59 °F). Also called "devil weed", S. horneri has invaded the Eastern…
Background excerpt adapted from Wikipedia's Devil weed 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.