A Few Case Studies of Biodiversity Degradation

Transcription

1 Chapter V A Few Case Studies of Biodiversity Degradation How the situation has dramatically shifted from only isolated events to a global biodiversity loss A living fossil: Gymnocrinus richeri

2 Introduction Chapter V: A Few Case Studies of Biodiversity Degradation This chapter presents a few case studies of biodiversity degradation. While it is often said that humans learn from past mistakes, this statement does not seem to apply to the conservation of biodiversity. There are multitude of specific examples of anthropic activities which have resulted in severe impacts on wildlife and biodiversity, yet we have still not understood the lessons especially when it comes to the extinction of species. Despite that a few adjustments and precautions have been taken following punctual events, still major and much more spread devastation is occurring today on a global scale as a result of overexploitation of resources and pollution. Climate change being on the top of the agenda when it comes to massive extinction of species. Despite high level negotiations which have been adopted for more than 3 decades now (e.g. Agenda 21). Biodiversity conservation policies remain global failures. Deforestation is still going on at alarming rates and the rate has actually worsen. Global warming negotiations are struggling to even tackle basic requirements, overexploitation of natural resources is at its worse and the list goes on. Often the concept of sustainable development first introduced during the Brundtland Commission and suggesting that developments must take equally into consideration environmental, social and economical issues is misused and environmental irreversible degradations still result as a consequence of current development models. If we are to preserve biodiversity, such perception and the way we deal with our environment must change All rights reserved. 122

3 V.1 (a) Case Study 1: Oil Spill, Exxon Valdez & Deepwater Horizon The Exxon Valdez oil spill occurred in the Prince William Sound, Alaska, on March 23, It is considered one of the most devastating human-caused environmental disasters ever to occur at sea. The region was a habitat for salmon, sea otters, seals and seabirds. The vessel spilled about 40 million litres of crude oil into the sea, and the oil eventually covered 3,400 km 2 of ocean. Thousands of animals died immediately; the best estimates include 250,000 to as many as 500,000 seabirds, at least 1,000 sea otters, approximately 12 river otters, 300 harbor seals, 250 bald eagles, and 22 orcas, as well as the destruction of billions of salmon and herring eggs. The effects of the spill continue to be felt today. Deepwater horizon: On April 20, 2010, the pressure in a well in the Gulf of Mexico blew its top. The result was an explosion and the collapse of the oil rig into the bottom of the ocean. At least 84,000 barrels equivalent of oil were spewing into the water daily. Despite the previous oil spill of the Exxon Valdez, this event which has been described as one of the worse environmental disasters in US history is a reminder of the threat of the oil industry on biodiversity All rights reserved. 123

4 V.1 (b) With the constantly growing number of large ships and the aging of the worlds shipping fleets, the threat of oil spills is rapidly growing. Despite the strengthening of international shipping regulations requiring oil tankers to have a double layer for their oil containers, many aging ships still to date do not meet this preventive requirement All rights reserved. 124

5 V.1 (c) Oil spills have long term devastating effects on marine life, seabirds and coastal species. Oil drilling in the sea beds is becoming a major threat to sea life. As oil reserves are depleting, oil companies need to search for oil in areas that are difficult to access: the deep sea beds. However, the current technology to do such drilling remains inappropriate and very risky for the surrounding environment. As recent events demonstrate when a problem arises at these depths, there is little control we can have on the proliferation of the oil in the oceans. Even in the 21 st century, our knowledge of life in the deep oceans remains virtually unknown. If we destroy this life through such contaminations, we will never know what was lost All rights reserved. 125

6 V.1 (d) Coastal ecosystems are very vulnerable to oil spills and other contaminants All rights reserved. 126

7 V.2 Case Study: Mining in New Caledonia New Caledonia, a French island located in the Southern Pacific, is classified as one of the worlds 18 biodiversity hotspots. Due to its isolation and uniqueness of its lateritic soil, New Caledonia has developed over millions of years of a very unique fauna and flora which is more than 80% endemic to the island (i.e. these species are found no where else in the world). The destruction: Since the past few decades, large mining companies are exploiting the island for its rich soils in Nickel and other minerals. In addition to the mining process itself that literally clears all the top part of the soil (over hundreds of km 2 ), numerous fires are set on regular basis to prospect for new mining sites. The impacts: The direct impact is the total destruction of habitats and the likely disappearance of thousands of unknown species which have very restricted repartition areas coinciding with the mining sites (these include plants, reptiles and insects, only found in these specific sites). In addition to the terrestrial destruction, tremendous quantities of contaminants and soil are dumped into the world s largest lagoon impacting coral reef ecosystems over unprecedented surfaces. => Mining in New Caledonia is a good example of un-sustainable development on a large scale All rights reserved. 127

8 V.3 Case Study: Acid Rains Acid rain is rain or any other form of precipitation that is unusually acidic, i.e. elevated levels of hydrogen ions (low ph) It can have harmful effects on plants, aquatic animals, and infrastructure through the process of wet deposition. Acid rain is caused by emissions of compounds of ammonium, carbon, nitrogen, and sulfur which react with the water molecules in the atmosphere to produce acids Governments have made efforts since the 1970s to reduce the production of sulfuric oxides into the Earth's atmosphere with positive results. However, it can also be caused naturally by the splitting of nitrogen compounds by the energy produced by lightning strikes, or the release of sulfur dioxide into the atmosphere by volcano eruptions. Acid rains have a negative impact on biodiversity over large surface areas by disturbing the ph of sensitive environments such as forest soil All rights reserved. 128

9 V.4 Case Study: Chernobyl The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in the Ukrainian Soviet Socialist Republic. It is considered to be the worst nuclear power plant disaster in history. After the disaster, four square kilometers of pine forest in the immediate vicinity of the reactor turned brown and died, earning the name of the "Red Forest". Some animals in the worst-hit areas also died or stopped reproducing. Most domestic animals were evacuated from the exclusion zone, but horses left on an island in the Pripyat River 6 km from the power plant died when their thyroid glands were destroyed by high radiation doses. Some cattle on the same island died and those that survived were stunted because of thyroid damage All rights reserved. 129

10 V.5 (a) Case Study: Introduction of Rabbits in Australia Rabbits were first introduced in Australia in Their effect on Australian ecology has since been devastating. Rabbits are one of the most significant factors in species loss in this country. Rabbit population spread at alarming rates after their introduction and became a serious disturbance to the natural ecology. Rabbits often kill young trees in the wild by eating the roots. As such, they are responsible for the loss of numerous plant species. Rabbits around a water hole at Wardang Island Australia in 1938 They are also responsible for serious erosion problems as they eat native plants leaving the soil exposed. Even to date 100 of millions of dollars are spent each year to deal with the rabbit problem All rights reserved. 130

11 V.5 (b) Introduction of Invasive Species. Case Study: the Red Fire Ant The red fire ant (Solenopsis Invicta) originates from South America. It can however now be commonly found in places such as the United States, Australia, Taiwan and south of China. These ants were accidentally introduced in these countries by plane or shipping. Red fire ants are excellent natural predators and responsible for serious damage to cultures such as sugar canes, various fruits. They feed on small insects and small mammals, reptiles and birds. They are known to be highly aggressive and competitive with other species. These ants cause million of dollars of damage and are driving many native species to extinction All rights reserved. 131

12 V.6 Biodiversity and Climate Change There is a close relationship between climate change and biodiversity. Case study: due to the rising temperatures and the prolongation of warmer periods, North American forests are increasingly affected by a species of Beatle that destroys the wood and kills the trees. As the temperatures no longer get cold long enough to kill the Beatles, these have proliferated in recent years resulting in very large amounts of trees to be left to rot. Such losses also directly translate to significant economical loss in several regions such as British Columbia in Canada where the timber industry had been a major source of revenues for decades All rights reserved. 132

13 V.7 (a) Global Biodiversity Loss We are no longer faced with individual or isolated cases of species extinction. What we are facing today is a global biodiversity loss which is occurring at increasing rate. The living environment is now reacting not to one threat but to an accumulation of pressures from anthropic activities. These pressures are driving species extinction many thousand of times the natural rate of extinction. Species are disappearing every day. Most people just do not know about it. The worst part is that we do not even know how many species are disappearing as we still to date only know a small portion of all the species on Earth. Most species have never been studied, described and for this matter given a name or an identity All rights reserved. 133

14 V.7 (b) Despite punctual degradation of the living environment, we must remember that the main threat to biodiversity is resulting globally as a combination of all anthropic pressures that we human beings have been and are continuing to put (at increasing rates) on the world ecosystems. Biodiversity loss has become critical and the situation has shifted form isolated and accidental impacts to a global crisis. Throughout the 21 st century every ecosystem in any location on the planet will be impacted by human induced environmental pressures which will inevitably lead to species extinctions. At the top of the list are climate change. global diluted pollution and rainforests deforestation All rights reserved. 134

15 V.7 (c) Today we are no longer faced with isolated extinction events but with a global loss of species on Earth as a result of a combine effect of anthropic pressures All rights reserved. 135

16 Conclusion Chapter V As highlighted in this chapter, punctual degradations of our environment are taking place around the world at increasing rates and have significant impacts on biodiversity. However, the real concern is that we have now clearly shifted from isolated extinction events to a global loss of species on Earth as a combine effect of all human related influences. The most concerning threats to global diversity are climate change, pollution and deforestation. At the current rate of warming of the climate system and deforestation, we will face very significant species loss throughout the century. By 2100 half of all the species present on Earth today could have become extinct All rights reserved. 136