THE GEO. In The Arctic Region

Transcription

1 THE GEO In The Arctic Region

2 BIOMAGNIFICATION OF TOXINS Biomagnification is concentration of a substance that is toxic in the tissues of an organism at successfully high levels in the food chain Did you know: the dose of these toxin gets greater with every arrow in the food chain even if one is affected!!! WHAT IS BIOMAGNIFICATION OF TOXINS?? HOW ARE THESE ORGANISMS TOXINATED?? These toxins are found in polluted or contaminated environments where the organisms absorb them through their environment or food consumption Did you know: The toxins are stored in the fatty tissues of the organisms THE AMOUNT OF PESTICIDE TAKEN BY OF FISH IS 50 FOR EG: SO IF A BIGGER FISH EATS 50 OF SUCH TOXINATED FISH THE DOSE=50 TIMES THUS THE BIG FISH WILL DIE!!

3 The arctic regions are being largely impacted by biomagnification,but first lets see how the pollutants and toxins reach the arctic. C.Biomagnification and current situation in the arctic: The arctic regions are being largely impacted by biomagnification,but first lets see how the pollutants and toxins reach the arctic. Toxins reach the arctic through a process called the grasshopper effect. or global distillation. This is when the toxins that are used or released in other parts of the world accumulate in the atmosphere and are released through precipitation.however,wind and ocean currents carry these substances from warmer to cooler regions - therefore they land up in the arctic. Also, nearby,leakage from ships and oil spills may contaminate the water heavily,while oil and gas drilling and mining will contaminate the land. Pollutants can also be released due to global warming.when ice melts due to global warming,the pollutants that were frozen and locked inside it are then freed and can affect the surrounding environment. Unfortunately,due to factors like reduced sunlight,extensive ice cover and cold temperatures,the contaminants will break down much more slowly,therefore increasing the risk and rate of biomagnification. This is worsened due to the fact that many arctic animals have a large amount of fat or blubber to keep warm.this allows for more storage of toxins. An example of a food chain in the arctic that could be be affected is : Phytoplankton > Zooplankton > Arctic cod > Ringed seal > Polar bear

4 D.Case study: Methyl mercury is a potent and toxic chemical formed when microorganisms eat or absorb mercury and convert it into a compound.it is considered a persistent bioaccumulative toxin because it remains in the environment without breaking down Methyl mercury can accumulate and biomagnify in organisms in concentrations upto a million times more than naturally found in the environment. Scientists and environmentalists are concerned that mercury levels are increasing in some arctic species although nearby regions like europe,north america and russia have seen mercury emission reductions. This is because emissions in other parts of the world such as china have increased.china is now the number 1 mercury polluter and accounts for nearly half of the global emissions. Infact,more than 2000 tonnes of mercury is emitted into the atmosphere each year and large parts of that is transported to the arctic region due to the grasshopper effect. It turns out that twice as much as mercury in the arctic ocean comes from rivers as from the atmosphere. The lena,ob and yenisei rivers flow into the arctic ocean from siberia.these 3 rivers together account for 10% of the world s freshwater discharge into the oceans.however,the arctic ocean is shallow and therefore is more sensitive to polluted inputs from these rivers. These rivers may be getting polluted because of runoff fro gold,silver and mercury mines in siberia. However,climate change and global warming may also be another factor for the increase in amount of mercury in the arctic region as explained above. Studies have shown that there has been a ten fold increase in mercury levels in top predators over the past 150 years.over 80% of this mercury comes from human sources. The diet of the arctic locals,or Inuits mainly consists of fish and marine mammals like seals,polar bears and whales.all of these are apex predators with high concentrations of mercury.this makes the inuits susceptible to the effects of methylmercury exposure. Animals and humans can both suffer from neurological damage when exposed to high levels of methylmercury. In humans,it can cause long-term developmental delays in children and impair cardiovascular health in adults. Cause for concern is that at this rate, global mercury emissions could grow by 25% by 2020.

5 biomagnification will eventually affect us top consumers The toxins accumulated in these organisms like a fish for EG: reaches us and we consume those toxins this can be fatal!! This can cause different failures and cancer most probably it may also cause food poisoning!!! some examples of toxins are DDT and mercury impact on the animals and Toxins can also affect reproductive systems in animals causing this to pass generation by generation and also cause animals to form differently than their species leading to extinction!!!!! This will affect the whole food chain destroying a eco system which eventually will affect humans!!! what are humans doing and what they be doing to reduce biomagnifications of toxins in the arctic region?? Several organisations are are about these situations and have taken action by sending their teams to such places.these people educate the farmers and local about the topic and the consequences of these actions and how fatal it can be to stop toxins being produced into a food chain.governments are supporting these organisations and also put a ban on harmful toxins used such as mercury. They should do checks of all kinds of food consumed by humans and animal and do research on the chemicals so there can be less amount of toxication they should educate civilians and farmers and about the consequences of these actions