Biodiversity and Climate Changes in East Africa: Lake Victoria IDEAL Limnology

东非的生物多样性和气候变化：维多利亚湖 IDEAL Limnology

• 批准号: 9318035
• 负责人: John Lehman
• 金额: $ 29.3万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-03-15 至 1999-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9318035&HistoricalAwards=false
• 关键词: Biodiversity; Climate; Changes; East; Africa

9318035 Lehman Lake Victoria, the second largest lake on earth, has experienced striking changes during recent decades. Water transparency, oxygen concentrations, nutrients, algae, and fish communities have all changed markedly from historical conditions. The lake now supports an introduced fish fauna of reduced species diversity than in its indigenous state, and the future yield of the fishery is in doubt. Three hypotheses have been advanced to account for these changes: (1) nutrient inputs have accelerated from atmospheric sources and regional land use, (2) changes in regional climate have altered physical mixing of the lake, permitting prolonged periods of stratification and deoxigenation, and (3) the introduction of piscivorous fish has disrupted food webs reducing total fish biomass. This research will test hypothesis (1) critically, and provide a basis for subsequently testing the others if this hypothesis proves false. %%% This research is part of the goals of IDEAL, the International Decade for East African Lakes. Discrimination of these hypotheses could prompt remedial action, permit prediction of future states of the lake and its potential to produce harvestable protein, and provide the data to evaluate and interpret paleostratigraphic records. The results from this research will be instrumental in a reconstruction of the changes in Lake Victoria during the past century, and in calibrating the responses of continental regions to global and regional climate change over much longer time periods.

9318035雷曼湖维多利亚，地球上的第二大湖，在最近几十年里经历了惊人的变化。水的透明度、氧气浓度、营养物质、藻类和鱼类群落都与历史条件发生了显着变化。该湖现在支持引进的鱼类动物群，其物种多样性比其本土状态减少，渔业的未来产量值得怀疑。三个假设已经先进的解释这些变化：（1）营养输入加速从大气来源和区域土地利用，（2）区域气候的变化已经改变了湖泊的物理混合，允许长期的分层和脱氧，（3）引进食鱼鱼类破坏了食物网，减少鱼类总生物量。这项研究将严格检验假设（1），并为随后检验其他假设提供基础，如果这个假设被证明是错误的。 这项研究是东非湖泊国际十年（IDEAL）目标的一部分。这些假设的歧视，可以促使补救措施，允许预测未来的湖泊状态和其生产可收获的蛋白质的潜力，并提供数据，以评估和解释古地层记录。这项研究的结果将有助于重建维多利亚湖在过去世纪的变化，并校准大陆地区对全球和区域气候变化的反应在更长的时间段。