Anthropogenic pressures seem to have been low at that time (An and Wang, 2008). Information on the pristine state of the lake is sparse, however a Chinese song “Beautiful Taihu” (太湖美, Long-Fei) written in 1978 tells that the water was beautiful with flourishing fish swirling in the lake, with a mysterious water and green reeds along the shore.

According to macrophyte records check details taken in the 1960s (Fig. 5), macrophytes were indeed present at the shores and bays with the east of the lake being most vegetated (Qin et al., 2007). However, it is likely that the lake has never been totally vegetated as a result of strong winds that act as a destructive force on the lake’s centre. Remnants of long-term wind forcing can also be seen in the absence of fine sediments in the lake (Shen et al., 2011). Therefore it is arguable that the lake centre has always Selleckchem Roxadustat lacked macrophytes and appeared turbid on days of strong wind. Phytoplankton concentrations were thought to be low during this time (Zheng et al., 2009). Increasing anthropogenic pressure caused a change to this pristine situation. After the end of the Taiping rebellion (1850–1864) population grew exponentially, demanding a higher food production (Ellis and Wang, 1997). However, agricultural

land in the Taihu Basin became limited, requiring a means to increase productivity (e.g. fertilisers, pesticides and higher irrigation efficiency) to meet the food demand (Ellis and Wang, 1997). In the end, agricultural innovation allowed for more than a tripling of population in 150 years to more than 40 million people at the start of the 21st century (An et al., 1996, Ellis and Wang, 1997, Tian et al., 2011 and Zhang et al., 2008). Small villages and cities in the Taihu basin grew rapidly and merged into one of the world’s largest “megalopolitan regions” (based on population) (Tian et al., 2011).

Due to this urbanisation, waste water production has locally intensified and exceeded the increment in wastewater treatment capacity (Gao and Zhang, 2010). Cesspits that used to be emptied on the fields for fertilisation were replaced by flush toilets, resulting in better hygiene, but negatively impacting the nutrient cycle (Ellis and Wang, 1997 and Gao and Zhang, 2010). not In 2009, domestic wastes contributed more than 40% of the total waste input (Liu et al., 2013). Eutrophication has been further amplified by industries and the world’s largest aquacultural fish production (Guo, 2007, Liu and Diamond, 2005 and Qin et al., 2007). The construction of concrete embankment around most of the lake in 1991 as a response to flood events, destroyed the connection between the lake and its surrounding wetlands (Yang and Liu, 2010). Sluices are now regulating water levels within the lake which means a loss of the natural water level fluctuations (Yang and Liu, 2010).