Introduced and invasive species
9 cases in 8 countries, 1869–2006. Most cases: Australia (3), Türkiye (2), United States (2), MC (1), PF (1).
Invasive seaweed escaped from Monaco museum aquarium and reached Turkey in 2006
An invasive seaweed escaped from the aquarium of the Monaco Oceanographic Museum into the sea and reached Turkish coasts in 2006, according to a Smithsonian record. The cited sources do not give the escape date or the seaweed's species.
Rosy wolfsnail introduction, Moorea (French Polynesia)
A predatory snail was introduced to Moorea to control the giant African snail. A University of Hawaii record states that it ended the island's endemic Partula tree snails in the wild.
Cane toad introduction (Australia)
In 1935 the cane toad was released in Queensland to control a sugar-cane pest. A warning issued the following year did not stop the releases, and the toad is now widespread.
US paid farmers to plant kudzu against erosion; later declared it a weed
The US Soil Erosion Service paid southern farmers to plant kudzu in the 1930s to control soil erosion. The Agriculture Department declared the vine a weed in 1970.
Cactoblastis moth, released against prickly pear in Australia, later reached Florida
A moth introduced to control invasive prickly pear in Queensland later reached Florida, where it now threatens native cacti. The cited sources give few links for the release history.
Lessepsian invasions: pufferfish in Turkey and bounty payments
Since the Suez Canal opened in 1869, hundreds of Red Sea species have entered the Mediterranean. On the Turkish coast, fishers report net damage from pufferfish, and the state pays a bounty for each one removed.
Macquarie Island cat eradication and rabbit boom
Cats were removed from Macquarie Island, and the rabbit population then increased. A 2009 paper recorded that about 40% of the island's vegetation changed and that the extra cost exceeded A$24 million.
Signal crayfish carried crayfish plague in Sweden, a 2006 study reports
A 2006 article in the journal KMAE reported that signal crayfish in Sweden carried crayfish plague. The cited sources do not describe the spread of the disease or its effect on native crayfish.
Madras High Court orders Prosopis uprooted in Tamil Nadu
The Madras High Court ordered the invasive shrub Prosopis juliflora uprooted in Tamil Nadu in March 2026, according to a court digest. The shrub was planted for land reclamation and fuelwood, and the sources say it has invaded pastures and groundwater.