(7/7) ESS SL IA: dissolved oxygen level and growth of duckweed (식물 키우는 실험, eutrophication 관련)

본 문서는 2021년 May session 최종 제출한 ESS IA로 파이널 점수 7점을 받았습니다.
Research Quesion은 “What is the impact on the dissolved oxygen level and growth of duckweed (Lemna Perpusilla Torr.) with the addition of different concentrations of sodium nitrates (NaNO3 (aq)) in an aquatic environment mesocosm?”입니다.
식물을 키우는 실험을 진행하고 싶으신 분이나 eutrophication 관련 주제로 IA를 쓰고 싶으신 분들에게 도움이 될 것 같습니다.

[본문내용]

Research Question
What is the impact on the dissolved oxygen level and growth of duckweed (Lemna Perpusilla Torr.) with the addition of different concentrations of sodium nitrates (NaNO3 (aq)) in an aquatic environment mesocosm?

Background Information
Eutrophication is an excessive plant and algal bloom due to increased limiting growth factors such as sunlight, carbon dioxide, and nutrient fertilizers (Chislock F, 2013). Eutrophication has become a serious environmental problem since algal blooms can contaminate drinking water, and produce extremely dangerous toxins that can damage people and animals. Additionally, algal blooms can create dead zones, which are anoxic areas in aquatic environments caused by excessive nutrient pollution from human activities (NOAA, 2012). For harmful algal blooms to occur, sunlight, slow-moving water, and nutrients such as nitrogen and phosphorus are required (EPA, 2017). Nowadays, nutrient pollution from human activities makes the problem worse, leading to more often and more severe blooms (EPA, 2017).

An increase in nutrients such as nitrates and phosphates that are mostly derived from human activities are a primary cause of eutrophication. Drainage water from agricultural land contains phosphorus and nitrogen (UNEP, n. d.). Overuse of fertilizers results in significant concentrations of nutrients in agricultural runoff. Rainwater also contains phosphorus and nitrogen from air pollution, and the main sources of pollution in the atmosphere are from industries and automobile exhaust without proper filtering systems (UNEP, n. d.). Moreover, in many lakes and reservoirs wastewater is the main source of eutrophication since untreated or mistreated wastewater still contains nitrogen and phosphate.

There are several consequences of eutrophication. Firstly, penetration of light into the water is diminished because the algae forms mats, and diminished light penetration also decreases the productivity of plants living in the deeper waters (Patricia M, 2012). As excess algae die and decompose, oxygen is consumed by decomposers, and lowered oxygen results in the death of fish that need high levels of dissolved oxygen, such as trout and salmon (Patricia M, 2012). As the composition of community changes due to algal bloom, biodiversity decreases, causing food web to be affected as well…

• 총 페이지수: 13 pages
• 과목명: Environmental Systems and Societies
• 주제: What is the impact on the dissolved oxygen level and growth of duckweed (Lemna Perpusilla Torr.) with the addition of different concentrations of sodium nitrates (NaNO3 (aq)) in an aquatic environment mesocosm?
• The file is in PDF format.