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What Is Eutrophication | Agriculture | Biology | FuseSchool


Eutrophication is the process that can happen in a water body, like a river or a lake, when too many nutrients are added to the system. Eutrophication starts with fertilizers, which are rich in nutrients like nitrate and phosphate, are washed into the river or lake system. This leads to an increase in nutrient concentrations in the water. The nutrients are food for algae. The algae grow and reproduce quickly, forming a thick green bloom in the water. This algal bloom will absorb sunlight shining on the water so the sunlight can’t reach the bottom. Plants who need this light to photosynthesis will die. The algae will also start to die when they eat up all of the nutrients and run out of food. Next, bacteria start to breakdown the dead plants and algae. That releases more nutrients back into the water continuing the Algal Bloom Cycle. The bacteria, with a continuing supply of food, reproduce into much larger numbers consuming oxygen as they grow and respire. There is not much oxygen in the water to begin with so when the bacteria consume it quickly it might run out completely. Water without oxygen is called Anoxic. If the water turns anoxic all non-bacterial life in the water, including fish and other animals, will die. So, eutrophication happens when nutrients are added to water which causes an algal bloom, cutting off sunlight and feeding bacteria. The bacteria use up oxygen in the water which becomes an anoxic, causing everything living in the water to die. Eutrophication is one reason why we need to be carefull with fertilizers when we are growing crops.

100 Comments

  1. Kingmzu Zolani Author

    This question gives me problems in getting it correct out of 10 marks.

    Provide a brief discussion on the role of pH during canning of low acid food.

    Reply
  2. Prof Dr Ing Jürgen Michele Author

    Stop eutrophication!
    Reduce the “limiting” element phosphorus.
    Oxygen can solve cyanobacterial problems …

    In our five year project we removed 5.4ton of phosphorus from the water
    column of a fairly big lake:P. Lücking, J. Michele: "Lake Bant": A five
    year project to solve cyanobacterial problems           
     https://www.researchgate.net/publication/281714490_Lake_Bant_A_five_year_project_to_solve_cyanobacterial_problems https://www.researchgate.net/publication/281934265_Ubersetzung_Veroffentlichung_18_Sept_2015

    Theoretical basics were published in Limnologica 2002:
    http://www.sciencedirect.com/science/article/pii/S007595110280024X
        free access!

    In 2009 a poster presentation was given on „Limnologentagung in
    Oldenburg“ Where it was shown that vertical free jets have only a
    limited efficiency:
    https://www.researchgate.net/publication/281775597_Poster_presentation_2009_in_Oldenburg_Germany
    https://www.researchgate.net/publication/261364449_Destratification_Why_has_this_method_not_been_successful_in_many_cases_in_the_past  

    Free jet flow visualization:      
    https://www.youtube.com/watch?v=sPWzSuUdOMw   (German)
    https://www.youtube.com/watch?v=Bz2MFCbsjps   (English)

    Energy input was really only 3kW.

    Reply
  3. Kristin Crawford Author

    Nice, but I thought the phrase where it says the algae use up all the nutrients and "run out of food" was confusing. They're producers.

    Reply
  4. W.D. Gamer Author

    for everyone using this as an example for a project, or exam here is all the text.

    Eutrophication is the process that can happen in a water body, like a river or a lake, when too many nutrients are added to the system. Eutrophication starts with fertilizers, which are rich in nutrients like nitrate and phosphate, are washed into the river or lake system. This leads to an increase in nutrient concentrations in the water. The nutrients are food for algae. The algae grow and reproduce quickly, forming a thick green bloom in the water. This algal bloom will absorb sunlight shining on the water so the sunlight can't reach the bottom. Plants who need this light to photosynthesis will die. The algae will also start to die when they eat up all of the nutrients and run out of food. Next, bacteria start to breakdown the dead plants and algae. That releases more nutrients back into the water continuing the Algal Bloom Cycle. The bacteria, with a continuing supply of food, reproduce into much larger numbers consuming oxygen as they grow and respire. There is not much oxygen in the water to begin with so when the bacteria consume it quickly it might run out completely. All non-bacterial life in the water, including fish and other animals, will die. So, eutrophication happens when nutrients are added to water which causes an algal bloom, cutting off sunlight and feeding bacteria. The bacteria use up oxygen in the water which becomes anoxic, causing everything living in the water to die. Eutrophication is one reason why we need to be careful with fertilizers when we are growing crops.

    Ur welcome

    Reply
  5. anonymous Author

    Our teacher didnt get the time to explain it properly and I was still confused ….not anymore! you explain it so well! Thank you 🙂

    Reply

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