Draft Guidance for Industry: Postmarketing Safety Reporting for Human Drug and Biological Products Including Vaccines. Biological Invasions: A Growing Threat. An army of invasive plant and animal species is overrunning the United States, causing.
1 Neural Dynamics Research Group, Department of Ophthalmology and Visual Sciences, 828 W. 10th Avenue, Vancouver, British Columbia, Canada V5Z 1L8 2 Program. Health and Safety in Construction pages from the Health and Safety Authority. Biological control options for invasive weeds of New Zealand protected areas SCIENCE FOR CONSERVATION 199 Victoria Ann Froude Published by Department of Conservation. Raman spectroscopy can be used to measure the chemical composition of a sample, which can in turn be used to extract biological information.
Biological Invasions: A Growing Threat. Don C. Schmitz. Daniel Simberloff. Biological Invasions: A Growing Threat. An army of invasive plant and animal species is overrunning the United States, causing incalcuable economic and ecological costs. To the untrained eye, Everglades National Park and nearby protected areas in Florida appear wild and natural. Yet within such public lands, foreign plant and animal species are rapidly degrading these unique ecosystems. Invasive exotic species destroy ecosystems as surely as chemical pollution or human population growth with associated development.
In July 1. 99. 6, the United Nations Conference on Alien Species identified invasive species as a serious global threat to biological diversity. Then in April 1. 99. United States. Already, many states attempt to maintain their biological heritage, and a number of state and federal regulations restrict harmful species.
Unfortunately, for a variety of reasons, such tactics have failed. Without greatly increased awareness and coordinated efforts, the devastating damages will continue. Exotic species have contributed to the decline of 4. U. S. At least 3 of the 2. Endangered Species Act were wholly or partially caused by hybridization between closely related exotic and native species. After habitat destruction, introduced species are the second greatest cause of species endangerment and decline worldwide- far exceeding all forms of harvest.
As Harvard University biologist E. Wilson put it, “Extinction by habitat destruction is like death in an automobile accident: easy to see and assess. Extinction by the invasion of exotic species is like death by disease: gradual, insidious, requiring scientific methods to diagnose.”The cost of inaction. According to a 1. Office of Technology Assessment (OTA), lack of legislative and public concern about the harm these invasions cause costs the United States hundreds of millions, if not billions, of dollars annually. This includes higher agricultural prices, loss of recreational use of public lands and waterways, and even major human health consequences. About a fourth of U.
S. For example, leafy spurge, an unpalatable European plant invading Western rangelands, caused losses of $1. Such losses are likely to increase. Foreign weeds spread on Bureau of Land Management lands at over 2,3. Western public lands at twice that rate. Other effects on private land are more obvious. The spread of fire- adapted exotic plants that burn easily increases the frequency and severity of fires, to the detriment of property, human safety, and native flora and fauna.
In 1. 99. 1, in the hills overlooking Oakland and Berkeley, California, a 1,7. Eucalyptus trees planted early in this century destroyed 3,4. Over the past two centuries, human population growth has substantially altered waterways and what remains of the natural landscape. Once contiguous across the entire United States, wetland and upland ecosystems are often mere remnants that are now being degraded and diminished by nonindigenous species invasions. This exacerbates the problem of conserving what remains of our country’s biological heritage. At the same time, nonindigenous crops and livestock, including soybeans, wheat, and cattle, form the foundation of U.
S. Classifying a species as beneficial or harmful is not always simple; some are both. For example, many imported ornamental plants are used in manicured landscapes around our homes.
On the other hand, about 1. Scientists wake up. Until the past decade or so, conservationists were often complacent about nonindigenous species. Many shared the views of Charles Elton in his 1. The Ecology of Invasions of Plants and Animals, which introduced generations of biologists to invasion problems. He contended that disturbed habitats, because they have fewer or less vigorous species, pose less “biotic resistance” to new arrivals.
Conservationists now realize that nonindigenous invaders threaten even species- rich pristine habitats. The rapidly increasing conservation and economic problems generated by these invasions have resulted in an explosion of interest and concern among scientists. In the United States, invasive plants that constitute new habitats and dramatically alter a landscape or water body have some of the greatest impacts on ecosystems.
On land, this could be the production of a forest where none had existed before. For example, sawgrass dominates large regions of Florida Conservation Area marshes, providing habitat for unique Everglades wildlife. Although sawgrass may be more than 9 feet tall, introduced Australian melaleuca trees are typically 7. As melaleuca trees invade and form dense monospecific stands, soil elevations increase because of undecomposed leaf litter that forms tree islands and inhibits normal water flow. Wildlife associated with sawgrass marshes declines. The frequency and intensity of fires change, as do other critical ecosystem processes.
The spread of melaleuca and other invasive exotic plants in southern Florida could undermine the $1. Everglades to a more natural state. Throughout the world, such invasions threaten biodiversity. In Australia, invasion by Scotch broom led to the disappearance of a diverse set of native reptiles and to major alteration of the composition of bird species. On the island of Hawaii, the tall Atlantic shrub Myrica faya has invaded young, nitrogen- poor lava flows and ash deposits on the slopes of Mauna Loa and Mauna Kea. Because it fixes nitrogen, it inhibits colonization by native plants, favoring other exotic species.
Plant communities offering little forage value ultimately lower wildlife abundance or alter species composition. Invading plant species often exclude entire suites of native plants but are themselves unpalatable to native insects and other animals. Two Eurasian plants- spotted knapweed, which infests 7 million acres in nine states and two Canadian provinces; and leafy spurge, which occupies 1. Montana and North Dakota alone- provide poor forage for elk and deer. Likewise in Florida, the prickly tropical soda apple from Brazil and Argentina excludes native palatable species.
Losses to the local cattle industry are over $1. Bird, reptile, and amphibian invasions may also devastate individual native species but generally do not cause as much damage as exotic plants. Herbivorous mammals and insects are often far more troublesome. In the Great Smoky Mountains National Park, feral pigs descended from a few that escaped from hunting enclosures in 1. In parts of the southern Appalachians, two related insects, the hemlock woolly adelgid and the balsam woolly adelgid, defoliate and kill dominant native trees over vast tracts.
Host trees have not evolved genetic resistance, and native predators and parasites of the insects are ineffective at slowing their advance. The zebra mussel from the former Soviet Union has clogged the water pipes of many electric companies and other industries, particularly in midwestern and mid- Atlantic states. It also threatens the existence of many endemic native bivalve molluscs in the Mississippi Basin.
Infestations in the midwest and northeast cost power plants and industrial facilities nearly $7. Death by disease. Introduced animal populations can also harm their native counterparts by competing with them, preying on them, and propagating diseases. For example, a battery of introduced Asian songbirds are host to avian pox and avian malaria in the Hawaiian Islands; native birds are especially susceptible.
Introduced species can also gradually replace native species by mating with them, leading to a sort of genetic extinction. Pathogens are among the most damaging invaders. Plant pathogens can change an entire ecosystem just as an introduced plant can. The chestnut blight fungus, which arrived in New York City in the late 1.
Asia, spread in less than 5. United States, destroying virtually every chestnut tree. Because chestnut had comprised a quarter or more of the canopy of tall trees in many forests, the effects on the entire ecosystem were staggering, although not always obvious. Several insect species restricted to chestnut are now extinct or endangered. After habitat destruction introduced species are the second greatest cause of species endangerment and decline worldwide. We have no precise figures on the enormous costs of introduced pathogens and parasites to the health of humans and of economically important species.
One such invader is the Asian tiger mosquito, introduced from Japan in the mid- 1. It attacks more hosts than any other mosquito, including many mammals, birds, and reptiles. It is a vector for various forms of encephalitis, including the La Crosse variety, which infects chipmunks and squirrels, and the human diseases yellow fever and dengue fever. Almost every ecosystem in the United States contains nonindigenous flora and fauna. Particularly hard hit are Hawaii and Florida because of their geographic location, mild climate, and reliance on tourism and international trade.
In Florida, about 2. In Hawaii, about 4. As a result, all parts of the Hawaiian Islands except the upper slopes of mountains and a few protected tracts of lowland forest are dominated by introduced species. In western states, invasions have harmed native plant diversity and the production capability of grazing lands. Although the percentage of introduced species in California is not as high as in Florida and Hawaii, large portions of the state, including grasslands and many dune systems, are dominated by exotic plants, and exotic fishes threaten many aquatic habitats. All regions of the United States are under assault.
Damage by exotic species is often best documented on public lands and waterways because taxpayers’ dollars are used for management. However, the problem is at least as pronounced on private properties. The Nature Conservancy, which operates the largest private U.