Scientists estimate that between 5,000 and 10,000 species are traveling around the world in ballast water at any given time. Stellera chamaejasme (Thymelaeaceae) is amongst the worst invasive species of the alpine grasslands on the Qinghai-Tibet Plateau; timely and effective monitoring is critical for its prevention and control. The cost and difficulty of managing invasive non-native species increases substantially once a species has established self-sustaining populations. The hunters moved across the refuge in a massive, coordinated, west-to-east movement. Some examples of the diversity of invasive species include the emerald ash borer, feral swine, zebra and quagga mussels, kudzu vine, cheatgrass, hemlock woolly adelgid, white-nose syndrome fungal pathogen, lionfish, bufflegrass, Asian carp, garlic mustard, leafy spurge, Sirex woodwasp, Burmese python, Japanese knotweed, and many more. Drought and fires are a norm in these grasslands, and only the fittest wild animals get to survive. Ships take on ballast water in their home port. The temperatures are rarely below -20 F (-29 C) or above 90 F (32 C). Often, these species are introduced as a form of pest control. /*-->