Threats to biodiversity

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  • Threats to biodiversity
    • Habitat change
      • The Yannal Penninsula , Russia, has the largest natural gas reserves in the world. In the 198's, th Bovanenkova field was discovered. Roads, railways and housing were built and workers came in from outside the area.
        • Destruction of large areas of pasture with little/no consultation with reindeer herders (pop. 200,000)
          • Russia is becoming more market-oriented.
            • Habitat change
              • The Yannal Penninsula , Russia, has the largest natural gas reserves in the world. In the 198's, th Bovanenkova field was discovered. Roads, railways and housing were built and workers came in from outside the area.
                • Destruction of large areas of pasture with little/no consultation with reindeer herders (pop. 200,000)
                  • Russia is becoming more market-oriented.
                • Mineral and energy development
                • Military installations
                  • DEW (Distant Early Warning) system in NA to warn of a Soviet attack. Abandoned at the end of the Cold War and now contaminated with PCB's.
                • Agricultural use- main cause of habitat change
                  • Cultivation now covers 25% of Earth's surface.
                  • 10-20% of grassland and rainforest are projected to be converted for agricultural use by 2050.
                  • Every minute approx. 100 acres of rainforest is destroyed.
                • Recreational use- careless beating, diving, dropping anchor on corals, over-fishing.
        • Mineral and energy development
        • Military installations
          • DEW (Distant Early Warning) system in NA to warn of a Soviet attack. Abandoned at the end of the Cold War and now contaminated with PCB's.
        • Agricultural use- main cause of habitat change
          • Cultivation now covers 25% of Earth's surface.
          • 10-20% of grassland and rainforest are projected to be converted for agricultural use by 2050.
          • Every minute approx. 100 acres of rainforest is destroyed.
        • Recreational use- careless beating, diving, dropping anchor on corals, over-fishing.
      • Over-exploitation
        • Agricultural over-exploitation leads to desertification.
          • 10-20% of dryland ecosystems are already degraded; grasslands are vulnerable.
            • Once soil is eroded, ecosystem recovery is very difficult.
              • Over-grazing, climate change, poor farming practice and population pressure all contribute.
          • Over-grazing, climate change, poor farming practice and population pressure all contribute.
        • In terms of marine biodiversity, over-fishing twinned with more-efficient fishing technology (such as drag nests) is the main threat.
          • Demands of fish as food for people and as a feed for aquaculture is increasing resulting in an increased risk of major collapses of fish stocks.
        • Over-hunting of animals has been a significant cause of the extinction of hundreds of species and their endangerment (e.g. tigers)
        • Tourism for periphery pleasure in the Galapagos Islands went from 1,000 in 1960's to 70,000+ in 1990's.
          • Tourism acted as a magnet for migrants from the mainland as they moved to the Islands for work.
            • Overcrowding- detrimental effects to sea lions; affecting their breeding patterns.
      • Invasive, alien species
        • Species that are not native to an area but have been introduced, almost always by human activity.
          • Since Indo-Pacific live rock is exported widely, the risk of introducing Pacific organisms to the tropical Atlantic is high.
          • Along with the arrival of humans to the Galapagos Islands came introduced species of plants and animals.
            • Many having no natural predators or controls, exhibit rapid growth in numbers; threatening to dominate local ecosystems
              • Wild dogs found on several of the Islands- wiped out a colony of 500 land iguanas in Santa Cruz.
      • Pollution
        • Galapagos Islands- In january 2001, the cargo ship "Jessica" ran aground off the island of San Cristobal whilst carrying 240,000 gallons of oil.
          • In 2002, there was evidence of widespread contamination (affected 79 sea lions). The spill highlighted the modern pressures of these Islands.
        • Eutrophication- use of fertilisers causes rapid algal growth (algal bloom). Depletion of o2 available for fish and other aquatic species.
        • Pollution from industrial and urban waste and agrochemicals from farming that poison reefs.
          • The lichens in northern Scandanavia are still affected by the fallout of Chernobyl, 1986. Many lakes have been acidified as a result of acid rain.
      • Anthropogenic climate change
        • Changes in the frequency and severity of hydro-meteorological disasters.
          • In Australia, research suggests tropical cyclones will become less frequent but the severity will increase.
            • The Great Barrier Reef is greater in size than the UK, Holland and Switzerland combined.
              • 10% of the World's total fish species can be found just within the Great Barrier Reef.
              • Experienced a major coral bleaching event in 2002 where over 50% of the corals experienced some bleaching.
                • Coral reefs cover less than 1% of the ocean floor but support 25% of all marine creatures.
                • Scientists estimate that human factors- pollution, global warming and sedimentation- could kill 30% of the existing reefs in the next 30 years.
          • Tropical cyclones destroy coral reefs and mangroves.
        • Significant impacts on biodiversity and ecosystems. Including: changes to species distributions, population sizes, the timing of reproduction/migration and frequency of disease outbreaks.
          • Coral bleaching can be caused by a 1-2oc increase in average annual temperature.
            • In 1998, several reef localities ranged from 30.15oc to 31.78oc.
              • Largest bleaching and morality event on corals- 16% of the World's coral reef was damaged.
            • The greatest temperature changes are being experienced at high latiudes. In tundra ecosystems, the permafrost is melting causing desertification/ vegetation to die/insects to multiply.

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