Would you prefer a side of chips or steamed veggies with your lionfish? Maybe some onion rings with your rainbow trout?
The International Union for the Conservation of Nature says rainbow trout and lionfish are among the world’s 100 worst invasive alien species.
What are invasive species though?
The National Ocean Service, part of the US National Oceanic and Atmospheric Administration defines invasive species as species which “can harm both the natural resources in an ecosystem as well as threaten human use of these resources”.
Read the latest Simply Green digital magazine below
“An invasive species can be introduced to a marine area via the ballast water of ocean-going ships, intentional and accidental releases of aquaculture species, aquarium specimens or bait, and other means.
“Invasive species are capable of causing extinctions of native plants and animals, reducing biodiversity, competing with native organisms for limited resources, and altering habitats. This can result in huge economic impacts and fundamental disruptions of coastal and Great Lakes ecosystems.”
Invasive Species South Africa says: “Research conducted in South Africa has conclusively found that trout eat indigenous fish, amphibians and invertebrates.
Trout live in self-sustaining populations in cool waters and they have to eat to stay alive. These eating habits have a devastating impact on biodiversity.”
South Africa's National Environmental Management Biodiversity Act (Nemba) seeks to protect biodiversity, and says: “If the spread of a species may result in environmental harm, the species is declared invasive.”
North America’s Florida Fish and Wildlife Conservation Commission (FWC) has declared lionfish to be an invasive species with a potential negative impact on native wildlife and habitat.
The commission encourages divers, anglers and commercial harvesters to remove lionfish in Florida waters to limit their negative impacts.
Edible Invaders, a bespoke small business in Florida, specialises in creating delicious meals using invasive species such as the lionfish. It is widely believed that aquarium owners introduced lionfish or their eggs to the Gulf of Mexico.
These could have been dumped in the ocean by owners who no longer wanted them or brought to the gulf within the ballast water of cargo ships.
A key issue that makes invasive species such a huge problem is that many lacks natural predators within their adopted habitats – and lionfish are no exception.
Naturally found in Indo-Pacific waters, the lionfish has no natural predators in the The Gulf of Mexico, which has allowed the population to explode to levels that are now causing massive damage to native ecosystems.
Clara Proctor, Edible Invader’s operations manager, says by getting people to order lionfish, they become part of the problem’s solution. She says lionfish have white, flaky meat that “tastes a little bit sweet, buttery and mild”.
Each year, South Africa loses about R6.5 billion to invasive alien species, according to a 2018 government report. OR Tambo International Airport is the only official port in the country – out of a total of 72 including marine ports – where the Department of Environmental Affairs has a permanent biosafety office.
There are a number of non-native species which are not considered invasive simply because they do not pose a significant threat to indigenous fauna and flora. Nemba, the biodiversity management act, divides invasive species into four categories:
Category 1a: Invasive species which must be combatted and eradicated. Any form of trade or planting is prohibited.
Category 1b: Invasive species which must be controlled and wherever possible, removed and destroyed. Any form of trade or planting is prohibited. Plants in river areas fall into this category.
Category 2: Invasive species, or species deemed to be potentially invasive, and a permit is needed for restricted activities. Category 2 species include commercially important species such as pine, wattle and gum trees.
Category 3: Invasive species which may remain in prescribed areas or provinces.
Further planting, propagation or trade, is however prohibited.
Visit your local nature reserve to join the invasive plant eradication programme. Do not release exotic pets such as non-native birds or fish into local habitats and try to plant only indigenous plants in your garden.