The combined impact of land use change and aquaculture on sediment and water quality in oligotrophic Lake Rupanco (North Patagonia, Chile, 40.8°S).
The combined impact of land use change and aquaculture on sediment and water quality in oligotrophic Lake Rupanco (North Patagonia, Chile, 40.8°S).
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DOI：
10.1016/j.jenvman.2013.05.008
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发表时间：
2013-10
影响因子：
8.7
通讯作者：
J. León-Muñoz;C. Echeverría;R. Marcé;Wolfgang Riss;B. Sherman;J. Iriarte
中科院分区：
文献类型：
--
作者：
J. León-Muñoz;C. Echeverría;R. Marcé;Wolfgang Riss;B. Sherman;J. Iriarte
北巴塔哥尼亚大型贫营养湖泊的水质和沉积物质量预计将受到影响，因为原生森林继续被分割和退化，其转换为作物和牧场的使用。土地使用的这些变化预计将增加该区域湖泊的营养负荷。此外，这些湖泊是世界第二大鲑鱼养殖业的所在地，为湖泊内提供了额外的点营养源。我们研究了土地利用变化和鲑鱼养殖对北巴塔哥尼亚湖（Rupanco湖，233 km 2水面，163米平均深度）的营养物质浓度的综合影响，在四个子流域范围从近原始森林的干扰53%转换为作物和牧场。随着农作物和牧场比例的增加，支流子流域的氮输出量从33 kg TN/km 2/y增加到621 kg TN/km 2/y。土地利用变化和鲑鱼养殖的综合营养负荷导致了湖泊水柱和湖泊近岸区域沉积物中氮浓度的显著差异。沉积物中的总氮浓度从37 ± 18 mg/kg（在没有鲑鱼养殖的接近原始的子流域）到6400 ± 698 mg/kg（在该子流域以作物和牧场为主，并有鲑鱼养殖）不等。这些结果表明，考虑鲑鱼养殖和土地利用对水和沉积物质量的影响，为未来的环境规划，管理和决策的重要性。
Water and sediment quality in North Patagonia's large, oligotrophic lakes are expected to suffer as native forest continues to be fragmented and degraded by its conversion to cropping and pasture land uses. These changes in land use are expected to increase diffuse nutrient loads to the region's lakes. In addition, these lakes are home to the world's second largest salmon aquaculture industry which provides additional point sources of nutrients within the lakes. We studied the combined influences of land use change and salmon farming on the nutrient concentrations in a North Patagonian lake (Lake Rupanco, 233 km2water surface, 163 m average depth) in four sub-watersheds ranging in disturbance from near-pristine forest to 53% converted to cropping and pasture. Nitrogen exports from the tributary sub-watersheds increased from 33 kg TN/km2/y to 621 kg TN/km2/y as the proportion of crop and pasture land increased. The combined nutrient load from land use change and salmon farming has led to significant differences in the nitrogen concentrations of the lake's water column and sediments in the near-shore zones across the lake. Total nitrogen concentrations in the sediments varied from 37 ± 18 mg/kg in near-pristine sub-watersheds without salmon farming to 6400 ± 698 mg/kg where the sub-watershed was dominated by crop and pasture lands combined with the presence of salmon farming. These results demonstrate the importance of considering the impacts of both salmon farming and land use on water and sediment quality for future environmental planning, management and decision making.