Unfortunately, unwanted organisms that have been unintentionally introduced with stock movements can reduce production. An accidentally introduced exotic species may remain unnoticed until such time as it either becomes abundant or causes harmful effects, whereas larger organisms are normally recognized sooner. Little is known about the movement of the smallest organisms, yet these must be in transit in great numbers every day.
Volunteer at your local park, refuge, or other wildlife area to help remove invasive species. Other invasive species descended from pets that escaped or were released into the wild. Many people have released pet Burmese pythons into the Everglades, a swampy area of south Florida. Pythons, native to the jungles of southeast Asia, have few natural predators in the Everglades.
Climate change, specifically, the anthropogenic warming trend presently underway, is recognized as a major extinction threat, particularly when combined with other threats such as habitat loss. Scientists disagree about the probable magnitude of the effects, with extinction rate estimates ranging from 15 percent to 40 percent of species by 2050. Of plants and animals may reach new localities through deliberate introduction by humans or accidental introduction during transport. The rate of introductions both between and within continents is rising rapidly. The most obvious introductions into freshwater systems have been plants, both aquatic (e.g., water hyacinth) and riparian (e.g., salt cedar), and fish (e.g., carp). Invasive alien species have devastating impacts on native biota causing decline or even extinctions of native species and negatively affecting ecosystems.
Invasive carp are swiftly spreading northward up the Illinois River, and are now on the verge of invading the Great Lakes. Once established in an ecosystem they are virtually impossible to eradicate. Adult invasive carp have no natural predators in North America and females lay approximately half a million eggs each time they spawn. Invasive carp are fast-growing, aggressive, and adaptable fish that are outcompeting native fish species for food and habitat in much of the mid-section of the United States. The huge, hard-headed silver carp also pose a threat to boaters, as the fish can leap out of the water when startled by boat engines, often colliding with people and causing injuries. “Invasive carp” is a catchall name for species of silver, bighead, grass, and black carp from Southeast Asia.
Scientists do agree, however, that climate change will alter regional climates, including rainfall and snowfall patterns, making habitats less hospitable to the species living in them. The warming trend will shift colder climates toward the north and south poles, forcing species to move with gentry finance yankton sd their adapted climate norms while facing habitat gaps along the way. Changing climates also throw off species’ delicate timing adaptations to seasonal food resources and breeding times. Many contemporary mismatches to shifts in resource availability and timing have already been documented.
Introduced aquatic plants, such as water hyacinth and alligator weed, may blanket the surfaces of lakes and rivers. Such blanketing may reduce water quality by causing deoxygenation or by reducing photosynthesis of native plankton and aquatic plants. Introduced riparian plants, such as tamarisk or salt cedar, may cause the loss of habitat for native invertebrates by dominating the stream banks and often by reducing water levels in the channel. Other introduced plants, such as eucalypts in Spain and Portugal, may produce dead plant material that is not readily consumed by stream invertebrates, thereby causing them to starve. Can have severe effects on vulnerable freshwater communities, in particular lakes and isolated stream systems.
For example, Kudzu , which is native to Japan, was introduced in the United States in 1876. Problematically, it grows too well in the southeastern United States—up to a foot a day. It is now a pest species and covers over 7 million acres in the southeastern United States. If an introduced species is able to survive in its new habitat, that introduction is now reflected in the observed range of the species.
The neighboring island of Borneo, home to the other sub-species of orangutan, has lost a similar area of forest, and forest loss continues in protected areas. The forests are being removed for their timber, and to clear space for plantations of palm oil, an oil used in Europe for many items including food products, cosmetics, and biodiesel. One of the most alarming recent invasions in North America was arrival of the Eurasian zebra mussel in the Great Lakes in 1988. Within two years, zebra mussels had reached densities of 700,000 individuals per square meter in parts of Lake Erie, choking out native mussel species. They have subsequently been found in the Detroit, Cumberland, and Tennessee Rivers.
