Ethics deals with moral behavior in a professional context; ideally, it leads to a set of governing principles through which the appropriateness of any activity may be determined or assessed. Environmental ethics specifically deals with how humans interact with the biosphere. It is clear, however, that, as a species, we are failing in our duty of environmental stewardship. The encroachment of human activity into the natural environment is inexorable, and almost always deleterious. Any response to mitigate loss of taxa or ecosystems will have economic implications, and these are often considerable. In finding effective solutions, a process soon becomes political. In light of this we must reflect upon the leadership role that biologists have, especially our impact on policy development that pertains to natural resource management. Although our track record is no worse than any other professional group, biologists by way of training usually have a greater understanding of natural processes and must be prepared to articulate these publically. We have an ethical mandate to question decisions, policies and legislation that impact negatively upon biological systems: a mandate guided through logic, grounded in empirical science, and hopefully coupled with a deep understanding of the true value of both the living world and the physical world which sustains it. This paper uses Australian examples to demonstrate the frequent clashes between economics and biology, in anticipation that we should strive to achieve the underlying principles of sustainability, environmental stewardship and resource management in both daily decision-making and in long-term planning.