The direct physical, chemical and biotic impacts on Australian coastal waters due to recreational boating.

In economically developed countries it is projected that by around 2015 over 50% of a person’s lifetime will become available for leisure. Demand for leisure needs, already strong, will continue to increase. One segment of the market, outdoor nature-based recreation (including tourism), is growing strongly worldwide. A substantial proportion of these activities are water-based. The associated demand for recreational vessels has increased rapidly in recent years and is projected to continue to trend upwards. Australian trends mirror those internationally. Using Australia as a case study, we review the direct physical, chemical and biotic impacts associated with recreational boating in coastal water environments. Major physical impacts include disturbance due to movement of craft in shallow waters (e.g., turbulence) and the effects of anchoring/drag, noise/interference/collision that impacts on wildlife. The most critical chemical impacts result from pollution due to fuels and oils, defouling treatments (even those not legislated in-country), and human waste (e.g., sewage effluent). Important biotic impacts are the potential continued introduction and secondary spread of non-native species. We conclude that while greater research effort will provide more environmentally benign products, with the increasing popularity of recreation vessels, it will be beyond the resources of Australian governments to police legislation effectively. However, based on Australian’s demonstrated engagement with government in terrestrial environmental management, with their deliberate engagement with the boating fraternity, the impacts of recreational boating would be lessened.