Frogs in peril, bug zapper mayhem, and the artificial reef debate.
I remember hearing that the world's frogs were in peril. How are they doing today?--Omar Khan, Columbus, IN
According to Harvard biology professor Jim Hanken, "Overall, the status of frogs has definitely gotten worse. The problem is more serious than we originally thought." Scientists are particularly concerned because frogs are considered a "sentinel species," meaning they serve as an indication of environmental quality.
According to the Declining Amphibian amphibian, in zoology
amphibian, in zoology, cold-blooded vertebrate animal of the class Amphibia. There are three living orders of amphibians: the frogs and toads (order Anura, or Salientia), the salamanders and newts (order Urodela, or Caudata), and the Populations Task Force (DAPTF DAPTF Declining Amphibian Populations Task Force ), formed by the World Conservation Union, many species of amphibians amphibians
members of the animal class Amphibia. Includes frogs, toads, newts, salamanders and cecilians all capable of living on land or in water. (frogs, toads, salamanders and newts) throughout the world have experienced population declines or extinction over the last 50 years. Causes may include deforestation deforestation
Process of clearing forests. Rates of deforestation are particularly high in the tropics, where the poor quality of the soil has led to the practice of routine clear-cutting to make new soil available for agricultural use. , draining of wetlands, ozone depletion and pollution (which may also increase rates of disease). In a few cases, as with the Costa Rican golden toad, entire species have disappeared almost overnight.
In addition to population declines is the phenomenon of amphibian deformities, such as extra eyes and legs and misshapen mis·shape
tr.v. mis·shaped, mis·shaped or mis·shap·en , mis·shap·ing, mis·shapes
To shape badly; deform.
mis·shap limbs. In the U.S., amphibian malformations have been reported in 44 states since 1996. High rates of deformities, in some cases up to 60 percent of a species, exceed what scientists generally consider natural. Research is investigating several potential causes, including parasites, contaminants and UV-B UV-B or UVB
ultraviolet radiation with a range of 280-320 nanometres radiation. CONTACT: Amphibian Conservation Alliance, c/o Ashoka Foundation, (703)807-5588, www.frogs.org.
Are electric bug zappers effective at killing mosquitoes?--Cari Mariani, Charleston, SC
Summer evenings have long been accompanied by the anticipated frying frenzy of insects trapped in an electric mosquito zapper. But it may be the mosquitoes that are having the last laugh. According to a Dateline NBC investigation team, out of 10,000 carcasses recovered--one night's haul--only eight were mosquitoes.
Insect biologist Phil Pellitteri says bug zappers emit ultraviolet light Ultraviolet light
A portion of the light spectrum not visible to the eye. Two bands of the UV spectrum, UVA and UVB, are used to treat psoriasis and other skin diseases. to entice pests, even though mosquitoes aren't attracted to the rays, since they hone in on carbon dioxide carbon dioxide, chemical compound, CO2, a colorless, odorless, tasteless gas that is about one and one-half times as dense as air under ordinary conditions of temperature and pressure. from our breath and heat from our bodies. Approximately four million zappers are at work in the U.S. toasting nearly 71 billion innocent insects each month. The most common bugs slaughtered are beetles, moths, flies, bees, ants and wasps, many of which are beneficial for pollination pollination, transfer of pollen from the male reproductive organ (stamen or staminate cone) to the female reproductive organ (pistil or pistillate cone) of the same or of another flower or cone. and insect control.
Garden Web suggests that the death toll can be reduced by wrapping a fine mesh screen around a bug zapper with holes that are big enough for mosquitoes to pass through but too small for larger bugs. Another option is The Mosquito Magnet, which mimics a large mammal by emitting a plume of carbon dioxide, heat and moisture. This is irresistible to the biting insects, but at $295 to $495 it's pricey. CONTACT: Entomological Society of America The Entomological Society of America (ESA) was founded in 1889 and today has more than 6,000 members, including educators, extension personnel, consultants, students, researchers, and scientists from agricultural departments, health agencies, private industries, colleges and , (301)731-4535, www. entsoc.org; Garden Web, www.gardenweb.com.
Is it a good idea to sink man-made materials, such as old cars, into the sea for use as artificial reefs?--Lahdan Al-Mohanadi, Doha, Qatar
Artificial reefs have been used in one form or another by fishermen to attract their quarry for some 200 years. In 1953, 250 car bodies were submerged off Alabama for use as artificial reefs. Over time, thousands of man-made materials have been tried, including bridges, pipes, boats, docks, airplanes, ballistic missiles and even specially engineered "reef balls," which are made from concrete casts. But Jack Sobel, a spokesperson for the Ocean Conservancy, says, "Artificial reefs can do as much harm as good. They are no replacement for natural reefs or for proper fisheries management, and we don't want people to view the oceans as a dumping ground for our wastes."
Advocates of man-made reefs, including many fishermen and divers, argue that reef communities can be established in areas convenient for people, such as off major cities, and some point to studies showing artificial reefs can attract as many fish as natural ones. But critics such as research biologist James Bohnsack of the University of Miami This article is about the university in Coral Gables, Florida. For the university in Oxford, Ohio, see Miami University.
The University of Miami (also known as Miami of Florida, UM, or just The U argue that artificial reefs merely concentrate fish--putting them at risk of overharvesting--instead of stimulating higher populations.
The Alabama Department of Conservation and Natural Resources This article or section needs sources or references that appear in reliable, third-party publications. Alone, primary sources and sources affiliated with the subject of this article are not sufficient for an accurate encyclopedia article. , which sunk 100 obsolete combat tanks in 1994, estimates that most artificial reefs will last no longer than 50 years, meaning they could threaten fragile marine life as they break up. "There are better ways to recycle cars," concludes Sobel. "There is also no cost-effective way to remove all the hazardous materials." CONTACT: The Ocean Conservancy, (202)429-5609, www.oceanconservancy.org.
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