Millions of dead fish have been washing up on Australia’s east coast in recent weeks, as the region experiences a severe heat wave. The mass fish deaths are primarily in New South Wales and have been attributed to high temperatures and low levels of oxygen in the water. The fish, which include carp, bony bream, catfish and mullet, are believed to have suffocated due to the lack of oxygen in the water. Water temperatures are believed to have reached up to 37 degrees Celsius in some areas, which is higher than the optimal temperature for most fish species. Local authorities are currently working to clear the fish from the shoreline, however, the sheer number of dead fish means that efforts to clean up the beaches may take some time.