Freshwater Habitats Trust, Bury Knowle House, North Place, Headington, Oxford OX3 9HY, UK.
Freshwater Habitats Trust, Bury Knowle House, North Place, Headington, Oxford OX3 9HY, UK.
Sci Total Environ. 2017 Mar 1;581-582:105-116. doi: 10.1016/j.scitotenv.2016.11.215. Epub 2017 Jan 7.
This study investigated patterns of nutrient pollution in waterbody types across Greater London. Nitrate and phosphate data were collected by both citizen scientists and professional ecologists and their results were compared. The professional survey comprised 495 randomly selected pond, lake, river, stream and ditch sites. Citizen science survey sites were self-selected and comprised 76 ponds, lakes, rivers and streams. At each site, nutrient concentrations were assessed using field chemistry kits to measure nitrate-N and phosphate-P. The professional and the citizen science datasets both showed that standing waterbodies had significantly lower average nutrient concentrations than running waters. In the professional datasets 46% of ponds and lakes had nutrient levels below the threshold at which biological impairment is likely, whereas only 3% of running waters were unimpaired by nutrients. The citizen science dataset showed the same broad pattern, but there was a trend towards selection of higher quality waterbodies with 77% standing waters and 14% of rivers and streams unimpaired. Waterbody nutrient levels in the professional dataset were broadly correlated with landuse intensity. Rivers and streams had a significantly higher proportion of urban and suburban land cover than other waterbody types. Ponds had higher percentage of semi-natural vegetation within their much smaller catchments. Relationships with land cover and water quality were less apparent in the citizen-collected dataset probably because the areas visited by citizens were less representative of the landscape as whole. The results suggest that standing waterbodies, especially ponds, may represent an important clean water resource within urban areas. Small waterbodies, including ponds, small lakes<50ha and ditches, are rarely part of the statutory water quality monitoring programmes and are frequently overlooked. Citizen scientist data have the potential to partly fill this gap if they are co-ordinated to reduce bias in the type and location of the waterbodies selected.
本研究调查了大伦敦地区不同水体类型的营养污染模式。硝酸盐和磷酸盐数据由公民科学家和专业生态学家收集，并对其结果进行了比较。专业调查包括 495 个随机选择的池塘、湖泊、河流、溪流和沟渠地点。公民科学调查地点是自行选择的，包括 76 个池塘、湖泊、河流和溪流。在每个地点，使用现场化学试剂盒评估营养浓度，以测量硝酸盐-N 和磷酸盐-P。专业和公民科学数据集均表明，静水的平均营养浓度明显低于流水。在专业数据集中，46%的池塘和湖泊的营养水平低于可能导致生物受损的阈值，而只有 3%的流水不受营养物质的影响。公民科学数据集显示出相同的广泛模式，但存在选择高质量水体的趋势，77%的静水和 14%的河流和溪流不受营养物质的影响。专业数据集的水体营养水平与土地利用强度广泛相关。河流和溪流的城市和郊区土地覆盖比例明显高于其他水体类型。池塘在其小得多的集水区内有更高比例的半自然植被。在公民收集的数据集与土地覆盖和水质的关系不太明显，可能是因为公民访问的区域不能代表整个景观的代表性。结果表明，静水，特别是池塘，可能是城市地区重要的清洁水资源。小水体，包括池塘、面积小于 50 公顷的小湖泊和沟渠，很少作为法定水质监测计划的一部分，经常被忽视。如果公民科学家的数据能够协调起来，减少所选水体类型和位置的偏差，那么它们有可能部分填补这一空白。
