Example Of A Keystone Species example essay topic

Habitat Destruction Overview In this new age of technology and advances in every possible field of study, many people forget about the environment. Some will just throw their trash all over the place with no concern for the possible consequences. Of course, there are many consequences, but only one comes to my mind. That is the demolition of species' homes or habitat destruction. Habitat destruction or habitat loss is the altering or elimination of the conditions that plants and animals need to survive. "The primary threat to the world's biodiversity is habitat destruction" (Okey p. 1).

Prairies have been greatly affected. The "loss of prairie habitat ranges from 20 to 99 percent depending on the region" (Benedict, Freeman, & Geno ways, p. 161). Habitat destruction can be caused by many things. These include: The introduction of alien (exotic) and domesticated species Pest and Predator control The collection of animals for pets and researchPollutionEcological factors Loss of keystone speciesOverexploitationDisease Limited distribution Many of these causes could be prevented fairly easily. If people today would just follow some simple rules, none of these would be as big as they are now. The Introduction of Alien (Exotic) and Domesticated Species Introducing exotic species has been a highly debated issue.

Why should we bring another animal or plant into a region to eradicate another species? That's the question that people have been asking for ages. Of course, there are positives to bringing in another species, but many times, there are just as many negatives. Also, these species can be introduced accidentally or intentionally.

The new organism may cause no obvious problems and eventually, it will be considered "native" to the area. For example, corals are "perhaps the oldest animals on the planet, and these long-lived corals have evolved in one of the Earth's most stable environments" (Eichenberg, p. 2). If a new type of fish were to be put into the ecosystem with the corals, the coral would be affected. First, the fish might eat the coral. Second, they could use the coral for shelter, and possibly damaging it that way. Third, the fish could bring predators that might also eat the coral.

Introducing an exotic species has the "rippling affect" of dropping a stone into a pool of water. Everything outside the epicenter is affected. A study was done at Cornell University, and they estimated that $120 billion per year are spent fixing the problems caused by exotic species" (Chiras, p. 219). Some specific examples of introduced species are the sparrow, barred owl, raccoons, several grasses, the punk tree, the zebra mussel, fis hook water fleas, and the rosy wolf snail.

Pest and Predator Control For many years, humans have tried to control the number of pests by spraying chemicals. One of most infamous of these chemicals is DDT or Dichloro-biphenyl-trichloromethane. This pesticide has had very harmful effects on many birds, like the peregrine falcon. DDT makes the eggs of the birds become more fragile and break very easily. The number of surviving offspring of these birds dropped significantly since the use of DDT has risen.

A major effect of predator and pest control is when the prey populations exceed the carrying capacity of the ecosystem. Since I have done a lot of fishing, I've seen this happen firsthand. When the number of predatory fish plummets, the forage fish reproduce rapidly. Shad do this all the time and often will make a lake useless for fishing. In Cape Cod, Massachusetts, the number of cod has dropped causing many fisherman to find other jobs. Part of this is from the modernization of fishing.

In 1980, many fishers began switching from hooks that caught individual fish to nets that snared cod by the gills, whole schools at a time. At the same time, big trawlers began dragging rollers across the rocky seabed to force the bottom-dwelling fish upward into nets, capturing massive amounts of cod and, some critics claim, destroying its preferred habitat (Glasser, p. 2). Reducing the number of cod allowed the number of forage fish to skyrocket. This in turn, has led to the steady decline of the quality of the fishing. The Collection of Animals for Pets and Research This is not something that most people would think about, but it has a big impact. The number of animals imported into the U.S. is amazingly high.

In 1997, 85 million fish, 920000 live reptiles, 728000 reptile skins, and 11000 live birds were brought into the United States. There is one other fact that is very high. "For each bird that makes it into someone's home, though, 10 to 50 may die along the way" (Chiras, p. 220). Also, scientists collect monkeys and chimpanzees for research on medical problems like AIDS. When they take these animals out of the food chain and ecosystem, it creates a "hole" where they used to live and feed. This will mess up the entire food chain.

Pollution Some examples of pollution that affect habitat are global warming, acid deposition, and ozone depletion. Global warming has contributed to the coral reefs dying out. There is so much pollution in the world today, that several species have become extinct. It's sad that their extinction could have been prevented so easily, and yet we did nothing about it. In prairies or grasslands, the plants use nitrogen.

A study done on the nitrogen uptake by rye grass found out that "the mat of roller-chopped material certainly influences regrowth and consequently atmospheric fixation by legumes. Moreover, the nitrogen contained in this material is partly volatilized in the atmosphere" (Clot uche and Peeters, p. 124). Putting the nitrogen back into the soil helps the plants grow and minimizes the effects of any pollution. Pollution often causes birth defects in animals.

The birth defect depends on the type of pollution and the animal. Pollution has hit whales really hard. Autopsies done on whales have found up to 25 toxic chemicals that shouldn't have been in the whales. Polluting forests can have a negative effect on amphibians in wetlands. "Amphibian richness also showed a positive relationship with forest cover on adjacent lands" (Houlihan & Findlay, p. 1085). If the trees die out, the number of amphibians will probably drop causing many other negative effects.

Ecological Factors and The Loss of Keystone Species Many ecological factors have an effect on whether an organism can survive. Many species are not as adaptable as others, and they can not survive when there is change. Or they can not survive in the human-dominated world. Passenger pigeons and cockroaches are examples of organisms like this. Also, some species have a critical population size. If their numbers drop below that level, they can not reproduce fast enough to survive.

Hunting can contribute to this cause. Unfortunately, scientists do not know a whole lot about critical population size. And an organism's degree of specialization will help it survive when its habitat is destroyed. Keystone species are critical species in an ecosystem whose loss greatly affects a lot of other species.

The gopher tortoise is an example of a keystone species. Thirty-seven species of invertebrates have disappeared in areas where the gopher tortoise has been removed. Other examples are the fig tree of Peru and the sea otter of the Pacific U.S. Overexploitation and Disease Overexploitation is the excessive use of an organism for one reason or another. This could include using the parts of an animal.

The biggest example of this is whaling in the 20th century. This industry brought many species of whales to very low populations. As of today, many treaties and moratoriums have been put into effect to prevent overexploitation. "Due to the trade in animal parts, many species continue to suffer high rates of exploitation" (Kurtis, p. 2). Rhinos and tigers suffer from this a lot because of the demand for rhino horns and tiger bones in Asia.

These are used as "ingredients" in traditional medicines. Disease can wipe out entire species in a matter of days. Partially because it can be spread by introduced organisms that otherwise wouldn't have an effect on a specific species. Today, rabies and canine distemper viruses are devastating carnivore numbers in Africa. Limited Distribution Limited distribution goes along with habitat destruction. If an organism only lives in a certain area, and that area is destroyed, the organism will have to adapt or die out.

Salmon are affected by limited distribution. Since the salmon only spawn in certain areas, destroying their spawning grounds will decrease the population. Along with keeping their spawning grounds intact, "keeping a river intact at its delta end" (Hood, p. 1) is just as important. Another thing I know firsthand is the habitat of the muskie or E sox. I have gone muskie fishing since I was thirteen. I know that they only inhabit certain areas in lakes.

When these areas are altered or destroyed in the lake, the muskie will die out. The muskie, in autumn, likes to live "near rocky, sandy structure" (Best ul, p. 1). This is how I know where to fish for them along with several other factors including water temperature, forage, and water depth. Conclusion With all the causes of habitat destruction and all the technology that we have, couldn't there be a way to reduce some of the causes?

I hope that some day, we will not have to worry about many of the causes. With a little bit of thought and some effort, humans could almost diminish these causes to nothing..