Nature reflects our nature
basic chemicals have been created which are used in killing pests and are sold in different brand names . The US alone uses 500 chemicals annually to which plants and animals are forced to adapt every year which is completely outside of its biological limit ( DDT and Related Compounds , 2011 ). DDT is used either in oil or diluted form as pesticides . Oil or diluted form of DDT is toxic which enters and gets accumulated in organs rich in fatty acid causing various short term and long-term effects , especially on birds . DDT thus used were washed into nearby waterways which were absorbed by plants , animals and other organisms present there which in turn were consumed by Bald Eagle .
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This invasion of DDT on the food chain was responsible for the fact that Bald Eagles were ceasing to breed on the East coast and their Eggshell was growing too thin and brittle to withstand the weight of brooding adult making it nearly impossible for eggs to hatch . DDT itself was not lethal to an
Bald Eagle adult bird but it interfered with birds ’ calcium metabolisms causing sterility and unable to lay healthy eggs . The reason for a thin Eggshell was that DDT inhibited
the Calcium aptase in the membrane of Shell which reduced the transport of Calcium carbonate from blood to eggshell . These abundant shells were supposed to have ten times the critical concentration of DDT of which a bald eagle can maintain . In addition to the softening of the shells , the embryonic and chick survival likeliness decreases .
In 1940 Bald Eagle Protection Act was passed noting that the species was threatened with extinction which prohibited killing , selling , and processing the species . After Richard Carson cataloged environmental impact coincide with the widespread use of DDT as a pesticide in agriculture in his book “ Silent Spring ” the environmental protection agency took a historic step of banning DDT in the US in 1972 and it was the first step to recover bald eagles . Back then in 1967 AD , the secretary of interior listed bald eagle under the Endangered Species Act of 1966 . Listing this species in the endangered list forced Service and its partner to accelerate the pace of its recovery . In July 1995 service announced Bald eagle had recovered in lower 48 states from the endangered list to threatened . Again in 1999 , the bald eagle was removed from the list of threatened too . Service estimated around 9,789 nesting pairs of bald eagle by 2006 . Thus , finally on 28th June 2007 , Service announced the complete recovery of America ’ s national bird Bald Eagle . Despite its new status , the bird will be still protected by state statutes and a federal law passed by Congress in 1940 which makes the killing of the Bald Eagle illegal .( Federal Laws that Protects Bald Eagle and Golden Eagle , 2020 ). While coming to 2020 Bald eagle is no more an endangered species however are still protected under multiple laws and regulation .
Sarana Tuladhar Environmental Science
Batch 2017
Nature and Social Concern Society 67