ADDRESSING THE PROBLEM OF THREAT TO BIODIVERSITY IN THE ECOSYSTEM THROUGH CONSERVATION OF ENDANGERED SPECIES Ndubuizu, Chinelo L. and Okara, John O. Abstract Endangered species are plant/animal species in numbers or small range, but not a threatened immediate danger of becoming extinct. There species. are four direct consequences of species Many countries have laws offering extinction: loss of species as a biological special protection to these species or their entity, destabilization of an ecosystem, habitats: for 'example, forbidding hunting, endangerment of other species, and loss of restricting land development or creating irreplaceable genetic material. Studies have preserves. Only a few of the many endangered implicated certain human activities in this species actually make it to the lists and obtain ecological malady. These include tropical deforestation, coral loss, other habitat legal protection. Many more species become destruction, overexploitation of species, extinct, or potentially will become extinct, introduction of alien species into ecosystems without gaining public notice and pollution (such as soil contamination and According to Harwell (1997), a declining greenhouse gases). This paper, therefore, species, in the USA, has to be added to the reviews the circumstances threatening official list of endangered species before it biodiversity in the ecosystem, and receives any federal protection. But just getting emphatically highlights some candidate enlisted can be the hardest part. The fish and species officially listed as endangered. It is wildlife service maintains a current list of expected that with the concerted effort of endangered species on line. Any person may government, educators at all levels, as well as other stakeholders, preservation of all species petition the government to list a species as either of wildlife would be possible. endangered or threatened. Unfortunately many species sit on the candidate list for years and Introduction years owing to adverse political pressure or An endangered species is a population of funding constraints. In this regard, this paper organisms (usually a taxonomic species), which reviews the circumstances that threaten because it is either (a) few in number, or (b) biodiversity within the ecosystem, ' while threatened by changing environmental or emphatically highlighting some candidate predation parameters, is at risk of becoming species officially listed as endangered. extinct (Wilcove, 1998). A 'threatened species', on the other hand, is any species which is likely to The Problem of Species Extinction become an endangered species within the Studies indicate that more than one-half foreseeable future; while an 'extinct species' is million species exist on the earth today. one that is no longer living (Molles, 1999). The However, recent estimated state that, at least, 20 passenger pigeon, the dodo, the dinosaur, and the times this number inhabited the planet Stegosaurus are examples of extinct species. (Cunnngham and Saigo, 1997). In the USA, 735 These animals no longer exist on Earth. Flather species of plants and 496 species of animals are (1998) defined vulnerable species as a species listed as endangered or threatened (Wilcove, particularly at risk because of low or declining 1998). Tangley (1999), estimated that there are more than 1,000 animal species endangered worldwide, with more than 3,500 protected areas in existence. These areas include parks, wildlife responding to these genetic instructions refuges and other reserves. They cover a total of (Primack, 1998). For example, in the valleys of nearly 2 million square miles (5 million square central China, a fernlike weed called sweet Km), or 30% of our total land area. wormwood grows. This plant is the source of The greatest factor of concern is the rate artemisinin, a drug that is nearly 100% effective at which species are becoming extinct within the against malaria (Rice, 1997). If this plant were last 150 years. While species have evolved and lost to extinction, then the ability to control become extinct on a regular basis for the last malaria, even today a potent killer, would several hundred million years, the number of diminish. There are countless other examples of species becoming extinct since the Industrial chemicals unique to a certain species, whose Revolution has no precedent in biological only source is the species whose genetic factory history. If this rate of extinction continues, or makes that given substance. The number of more accelerates as now seems to be the case, the chemicals that have not yet been discovered and number of species becoming extinct in the next could vanish from the planet when further decade could number in the million (Flather, species become extinct cannot be determined, but 1998). While most people readily relate to it is a highly debated and influential point. endangerment of large mammals or birdlife, Though extinction can be a natural effect some of the greatest ecological issues are the of the process of natural selection, the current threats to stability of whole ecosystems if key extinction crisis is not related to that process species vanish at any level of the food chain. (Cox, 1997). At the present, the Earth has fallen According to Alper (1998), species from a peak of biodiversity, and is undergoing extinction in the ultimate concern, but there are the Holocene mass extinction period (Mader, four direct consequences of species extinction to 2001). Molles (1999), stated that, though these be considered: loss of species as a biological periods have occurred before without human entity, destabilization of an ecosystem, intervention, the current extinction period is endangerment of other species, and loss of unique. Previous periods were triggered by irreplaceable genetic material and associated physical causes, such as meteorite collision and biochemicals. volcanic eruption, all leading to climate change Chapin (1998), identified the loss of a (Cunningham and Saigo, 1997). The current species in and of itself as an important factor, extinction period is being caused by humans and both as diminution of the enjoyment of nature, began appropriately 100,000 years ago with the and as a moral issue for those who believe diaspora of humans to different parts of the humans are stewards of the natural environment. world. By entering new ecosystems which had Destabilization is a well understood outcome, never experienced the human presence, humans when an element of food or predation is removed disrupted the ecological balance by hunting and from an ecosystem (Harwell, 1997). Examples also possibly bringing disease. From this time up abound that other species are in turn affected, to approximately 10,000 years ago is known as such that populations increases or declines are 'phase one' of the sixth extinction period forthcoming in these secondary species. Drastic (Wilson, 1992). change or an unstable spiral can ensure, until Phase two of the period began other species are lost and the ecosystem structure approximately 10,000 years ago with the birth of is changed markedly and irreversibly. agriculture (Rice, 1997). With the birth of The fourth outcome is more subtle, but agriculture, humans did not have to rely on perhaps the most important point for mankind to interaction with other species for survival and so grasp. Each species carries unique genetic could begin to domesticate them; and they also material in its DNA, and in its chemical factory did not have to adhere to the limitations of the ecosystem's carrying capacity. Thus, humans Endangered Mammals became the first species lo be able to live outside Table 1 A: list of a very small local ecosystem (Alper, 1998). With the ability to Fraction of live outside of a local ecosystem, humans have known Endangered Mammals been free to breach the carrying capacity of areas Asian elephant (Elephax Banteng (Bos javanicus and overpopulate, putting ever more stress on the maxinnis) environment with destructive activities necessary Aye-aye (daubentonia Bonobo (Pan Paniscus) madagascariensis^ ) for more population growth. Today, those Bighorn sheep (o vi s Red wolf fOaHi.? ntftix) activities include tropical deforestation, coral Canadensis) loss, other habitat destruction, overexploitation Eastern gorilla (gorilla Gray bat of species, introduction of alien species into beringei) (Myoti.s ghsescens ecosystems and pollution (such as soil Blue whale (Balaenoptera Island fox contamination and greenhouse gases) (Flather, musculus) (Urocynn littoralis) Black rhinoceros (Diceros Leopard 1998). Among the various causes of pollution bicornis) (Panthera pardtts) (acid rain, eutrophication, ozone depletion), Ba lack- footed ferret (Mustela ni Kouprey (Bos sauveli) global warming is expected cause the most gripes instances of extinction Sei Whale (Balaenoptera Red panda boreal is) (A'durus fulgens) Bornean orangutan (Pongo Sea otter Conservation Status (pvgmaetts) (Enhydra htttris) The conservation status is an indicator of Common chimpanzee (Pan Indri (Indri indri) the likelihood of thai endangered species troglodytes) continuing to survive. Many factors are taken Tin whale (Bolaenoptera Iberian (lynx pardinus) into account when assessing the conservation physahis) Forest elephant (loxodonta Bonobo (Pan paniscm) status of a species; not simply the number cyclotis) remaining, but the overall increase or decrease in Javan rhinoceros (Rhinoceros Fossa (Cryptoprocta the population over time, breeding success rates, sandaicus} ferox)