fracturing. As of 2014, measures were taken by the Australian government to mitigate water impacts from longwall mining. Legislative assemblies have called for action to improve mine infrastructure to minimize disturbances. As a result of bedrock cracking from mining beneath waters such as lakes or rivers, there have been groundwater losses of varying extents. Mines within a few hundred meters of the surface are susceptible to receiving great inputs of water from these bodies. Moreover, after mining interference disturbing the natural landscape near the mines, the natural water flow paths can be redirected which results in additional erosion across a stream or river bank. Additional mining in concentrated areas continuously move these water flow paths, which take years to return to their original states. Ecosystem impacts Many ecosystems rely on the annual consistency of water inputs and outputs, and disturbing these patterns can result in unsustainable conditions for species reliant on water for species reproduction. Longwall mining can also result in localized water temperature change, stimulating algal bloom which can use up available oxygen required for other species health. Longwall mining has limited available research on the impacts of nearby forests, however emerging satellite imagery studies have shown possible relations to drier surface soil near regions where longwall mining has recently occurred. In addition to drier soils, forest canopy moisture has been observed to be reduced. Gas emissions Longwall mines have been observed to release methane gas, a common greenhouse gas into the environment, however the increase of a typical longwall mine face from was not found to release significantly more methane. Methane emissions from closed longwall mines can continue for up to fifteen years, however it is possible to measure the volume of potential methane emissions based on water flow in the closed mines. In Canada Canada has some of the largest coal reserves in the world, and until 2013 there had been no longwall mines in Canada for over 25 years. A mine was opened by HD Mining in 2015 in British Columbia, causing disputes because of the hiring of foreign workers instead of Canadians and because of its potential impact on the environment. This mine expected to have carbon dioxide emissions of 17 megatons per year; however, a carbon cap was placed on it by the Canadian federal government to keep the emissions at 500,000 tonnes per year. See also Drift mining Shaft mining Slope mining Strip