ballast water

Invasive species – including plants, animals and fish – cause heavy damage to crops, wildlife and human health worldwide. Some prey on native species; other out-compete them for space and food or spread disease. A new United Nations report estimates the losses generated by invasives at more than US$423 billion yearly and shows that these damages have at least quadrupled in every decade since 1970. Humans regularly move animals, plants and other living species from their home areas to new locations, either accidentally or on purpose. For example, they may import plants from faraway locations to raise as crops or bring in a nonnative animal to prey on a local pest. Other invasives hitch rides in cargo or ships’ ballast water. When a species that is not native to a particular area becomes established there, reproducing quickly and causing harm, it has become invasive. These recent articles from The Conversation describe how several invasive species are causing eco...