Assessing the impacts of aquaculture and pesticide use in a protected tropical wetland(Loktak Lake, India)

洛克塔克湖位于曼尼普尔，是印度东北部最大的淡水湖，1990年被宣布为拉姆萨尔遗址。它被分成三个主要盆地，根据当地居民的不同土地利用方式，南部位于凯布尔·兰乔国家公园。这个国家公园也是曼尼普尔斑羚(Rucervus Eldii Eldii)最后的自然栖息地。近几十年来，由于水产养殖扩张、土地利用变化和森林砍伐、杀虫剂使用量迅速增加、城市上游污染和气候变化，这种原始环境面临着越来越大的压力。这导致水质急剧恶化和水位波动(由于1993年修建伊泰大坝，导致泥沙滞留增加，情况更加复杂)。通过对乐达湖三个不同土地利用区域的沉积物岩心(n=3)的~(210)Pb、~(137)Cs的采集和测年，该项目将量化人类对该湖的影响以来沉积有机质含量、水生态和农药积累率的变化。随着时间的推移，将确定杀虫剂的浓度和鉴定，以及藻类色素和稳定同位素(13C、15N、C/N比)的浓度，以确定水产养殖的影响。这个项目的目标是：1.重建(过去约300年)洛克塔克湖三个盆地的水产养殖实践，并确定这对水生生态的影响2.重建跨越Loktak湖三个盆地的农药使用开始，并确定和量化所使用的主要化学物质3.量化自伊泰河大坝形成以来湖泊沉积物滞留和有机碳埋藏的变化学生将在英国地质调查局的国家环境同位素设施和诺丁汉大学地理学院之间工作，由同位素地球科学家和古生物学家组成的团队。该项目正在接受BGS大学资金倡议提供的额外资金。

Loktak Lake, located in Manipur, is the largest freshwater lake in NE India, declared a Ramsar site in 1990. It is divided into three main basins which have different land use practices by local populations, with the southern being in the Keibul Lamjao National Park. This National Park is also the last natural habitat of the Manipur Brow deer (Rucervus eldii eldii). In recent decades this pristine environment has been placed under increasing pressures from aquaculture expansion, land use alteration and deforestation, rapidly increasing pesticide use, upstream pollution from conurbations, and climate change. This has resulted in drastic water quality deterioration and water level fluctuations (further complicated by the construction of the Ithai dam in 1993 which has prompted increased sediment retention). While toxic bioaccumulation due to pervasive pesticide use has impactedthe natural food web structure prompting serious concerns to human health.Via the collection and dating (210Pb, 137Cs) of lake sediment cores (n=3) from three different land use regions of Loktak Lake this project will quantify changes in sedimentary organic content, aquatic ecology and pesticide accumulation rates since the initiation of human impacts upon the lake. The concentration and identification of pesticides will be established over time, along with the concentrations of algal pigmentsand stable isotopes (13C, 15N, C/N ratios) to determine the impact of aquaculture, pesticide use and climate change upon the lake.The aims of this project are to:1.Reconstruct (the past c. 300 years) the initiation of aquacultural practices across the three basins of Loktak Lake and identify the impacts this has had on aquatic ecology 2.Reconstruct the initiation of pesticide use across the three basins of Loktak Lake across and identify and quantify the key chemicals used3.Quantify changes in lake sediment retention and organic carbon burial since the formation of the Ithai damThe student will work between the National Environmental Isotope Facility at the British Geological Survey and the School of Geography at the University of Nottingham, being embedded within a team of isotope geoscientists and palaeolimnologists. This project is in receipt of additional funding from the BGS University Funding Initiative.