Long-term changes in oxygen depletion in a small temperate lake: effects of climate change and eutrophication

摘要: 1. We analysed 41 years of data (1968–2008) from Blelham Tarn, U.K., to determine the consequences eutrophication and climate warming on hypolimnetic dissolved oxygen (DO). 2. The establishment thermal stratification was strongly related onset DO depletion in lower hypolimnion. As a result progressively earlier later overturn, duration increased by 38 ± 8 days over years. 3. The observed rate volumetric (VHODobs) ranged 0.131 0.252 g O2 m−3 per day decreased significantly study period, despite increase mean chlorophyll (Chl a) concentration growing season. The vertical transport represented 0 30% VHODobs, while adjustments for interannual differences temperature were less important, ranging −11 9% VHODobs. 4. The wind speed during May made strongest significant contribution variation VHODobs. VHODobs adjusted differences, VHODadj, upper mixed layer Chl spring. 5. Hypolimnetic anoxia (HA) 27 168 year time, which undoubtedly had negative ecological lake. 6. In similar small temperate lakes, effects are likely be exacerbated changes lake structure brought about climate, may undermine management efforts alleviate anthropogenic eutrophication.