INVASIVE SPECIES and their some examples

Invasive species

1. INVASIVE SPECIES

2. What is an invasive species? Invasive species is an organism that causes ecological or economic harm in a new environment where it is not native. Invasive species are capable of causing extinction of native plants and animals, reducing biodiversity, competing with native organisms for limited resources, altering habitats. Invasive species can be introduced to a new area via the ballast water of oceangoing ships, intentional and accidental releases of acuaculture species, aquarium specimens or bait, and others.

3. Green Carb ( Carcinus maenas )

4. Green Carb ( Carcinus maenas ) Native habitat: North-east Atlantic Ocean, Baltic Sea. Mode of transit: Ships’ hulls, sea planes, packing materials, bivalves moved for aquaculture. Invasive in: Australia, South Africa, South America and both Atlantic and Pacific coasts of North America. Characteristics: Threatens shellfish populations and native crab species, reduces biodiversity, destructs eelgrass beds.

5. Carcinus maenas is first observed on the east coast of North America in Massachusetts in 1817. Then it extended to South America and Australia widely. Appearances of carcinus maenas have been recorded in Brazil, Panama, Hawaii, Madagascar, the Red Sea, Pakistan, Sri Lanka and Myanmar, however these have not resulted in invasions. Once it was found in Lummi Bay, Whatcom County, Washington, USA in 2019, the Nation began trapping and removing carbs in an effort to get rid of them. Then in 2020 hundreds were found in traps, and it became clear that more in tensive trapping will be necessary to keep their numbers down.

6. Approximate distribution of carcinus maenas (blue) native range single sightings which did not result in an invasion (red) introduced or invasive range potential invasive range