speculation during the river drought of 2005 was that over-extraction for bottling, by Nestlé's Powwow Water was a significant contributing factor. Indeed after extraction had stopped, and the river recovered somewhat, the bed was now so overgrown it was a struggle for the river to fully recover until much of the growth was removed by volunteers in 2012. In 2005 Councillor Justine Fulford campaigned to prevent the extension of the licence on the grounds that it was damaging to the local environment. Wildlife The Chess Valley is partly within the Chiltern Hills Area of Outstanding Natural Beauty (AONB), with wildlife characteristic of chalk streams and chiltern hills. It supports several key species listed in the Government's UK Biodiversity Action Plan. Mammals such as the water vole, birds including the green sandpiper, grey heron, grey wagtail, little egret, osprey, mute swan, European stonechat, water rail and kingfisher, flora such as water crowfoot, purple loosestrife, hemp agrimony, water forget-me not and branched bur-reed. Freshwater fish, found include specifically the brown trout, grayling and bullhead. To support the fish population there is a rich diversity of both invertebrates and of insects, including the mayfly. Human influences The valley has a long history of human habitation. There are a number of Roman villa sites along the valley, including Latimer Park. At Sarratt strip lynchets can be seen in terraces along the hillside made by the action of ploughing along the slope and thought to have been the site of medieval vineyards. Human habitation has altered the valley and the river in many ways, not all of them beneficial for wildlife. River modifications such as dredging and widening slow the current, allow silt to accumulate and smother the gravel riverbed. Changes in the land use adjacent to the river can also have impact. Water meadows have been replaced by arable fields and building developments, altering drainage patterns and causing pollution. Abstraction of water from the underlying chalk aquifer reduces river flows and lowers the river's ability to tolerate drought. The introduction of alien species to the catchment has had a major effect on the wildlife of the river. Water vole populations declined catastrophically along the Chess between 2001 & 2003 with a 97% population decrease being observed. This population crash was caused mainly by the North American mink, a species introduced to the British Isles originally for the fur trade. In 2004 a water vole