Biogeochemistry and community ecology in a spring-fed urban river following a major earthquake

In February 2011 a Mw 6.3 earthquake in Christchurch, New Zealand inundated urban waterways with sediment from liquefaction and triggered sewage spills. The impacts of, and recovery from, this natural disaster on the stream biogeochemistry and biology were assessed over six months along a longitudinal impact gradient in an urban river. The impact of liquefaction was masked by earthquake triggered sewage spills (∼20,000 m³ day⁻¹ entering the river for one month). Within 10 days of the earthquake dissolved oxygen in the lowest reaches was