Due to their isolation from the mainland, islands often harbor a high proportion of specialized native plants and animals that contribute to the world’s biodiversity. Introduced invasive species, such as rats and feral cats, pose a serious threat to fragile island ecosystems and wildlife, especially birds. It has been estimated that over the past 500 years, invasive alien species have contributed to nearly half of global bird extinctions.
Genetic biocontrol methods are under consideration for certain vertebrate pests that present particularly difficult ecological and economic challenges on islands. For example, removal of invasive rodents from islands has proven to be a highly impactful conservation intervention. However, currently effective methods for doing so are limited largely to use of rodenticides, which have other ethical, ecological, social, and financial constraints. Genetic biocontrol methods that could suppress the island rodent population by reducing reproductive capacity have been proposed as a possible alternative that would be more humane and sustainable. Research on genetic biocontrol of rodents and other island pest vertebrates is underway but still at an early stage.
Introduced pathogens also present a well-recognized risk to island biodiversity. Avian malaria is an introduced disease known to threaten native birdlife in Hawaii. Since this pathogen is transmitted by mosquitoes, it may be susceptible to similar genetic biocontrol methods being developed for vector-borne human diseases.
For more information: https://www.cbd.int/island/invasive.shtml; https://www.aphis.usda.gov/aphis/maps/sa_wildlife_services/ws-managing-invasive-species; https://www.geneticbiocontrol.org/; https://portals.iucn.org/library/efiles/documents/2019-012-En.pdf; https://royalsociety.org.nz/assets/Uploads/Gene-editing-in-pest-control-technical-paper.pdf; https://www.frontiersin.org/articles/10.3389/fagro.2021.806569/full