The Global Dispersal of the Non-Endemic Invasive Red Alga Gracilaria vermiculophylla in the Ecosystems of the Euro-Asia Coastal Waters Including the Wadden Sea Unesco World Heritage Coastal Area: Awful or Awesome

Gracilaria vermiculophylla (Ohmi) Papenfu ß 1967 (Rhodophyta, Gracilariaceae) is a red alga and was originally described in Japan in 1956 as Gracilariopsis vermiculophylla. It is thought to be native and widespread throughout the Northwest Pacific Ocean. G. vermiculophylla is primarily used as a precursor for agar, which is widely used in the pharmaceutical and food industries. It has been introduced to the East Pacific, the West Atlantic and the East Atlantic, where it rapidly colonizes new environments. It is highly tolerant of stresses (nutrient, salinity, temperature) and can grow in an extremely wide variety of conditions; factors which contribute to its invasiveness. It invades estuarine areas where it out-competes native algae species and modifies environments. The following European coastal and brackish water seas are already invaded: Atlantic, North Sea, Mediterranean and Baltic Sea. The Euro-Asian brackish Black-Sea have not yet been invaded but are very vulnerable to intense invasion with G. vermiculophylla because they are isolated from direct marine influences and have a harsh environment with large salinity, nutrient and temperature fluctuations.