260 - The runnel concept, from past practice to expansion and recent application for marsh restoration, wildlife conservation and perhaps to mitigate climate change.

Abstract: Runnels, shallow spoon shaped channels, were first developed in SE Australia (Queensland and NSW) in the mid 1980s for the primary purpose of controlling salt marsh mosquitoes, thereby reducing reliance on larvicides, but also minimising impacts on the saltmarsh. The method was designed to follow the local topography and increase tidal flushing but not to drain saltmarshes. Runnels are a minimal form of Open Water Marsh Management source reduction, as it was implemented in the 1960s in eastern USA. At first there was curiosity about the method in the USA and then interest was shown in the early 1990s, with runnelling included in a range of source reduction methods. Subsequently, the runnel concept has evolved and its objectives have expanded to embrace salt marsh restoration and to protect endangered species habitats. More recently, faced with increasing sea level rise in NE USA, the method has been adapted aiming to assist in marsh restoration, while also controlling mosquito larval populations. There is currently also interest in Europe in runnelling to reduce the mosquito control related disturbance to wildlife, both on the ground and from the air.