The science of restoration ecology has advanced steadily since the 1970’s, as concern about losses of biological diversity in terrestrial and freshwater habitats has grown. This has led to measures that offset the degradation or destruction of habitat by creating, enhancing, restoring or protecting compensatory areas. A second related conservation measure involves mitigating damage caused by one activity to compensate for damage caused by another. Carbon-trading operates on this transference principle. All are intended to ensure ‘no net loss’ of ecosystem services.
Similar precautionary measures could be used to manage anthropogenic underwater noise impacts on vulnerable marine mammals, fishes and invertebrates. These could be an alternative to, or in addition to, population consequences of disturbance models (PCOD), which are parameterized using expert-judgement. A compensatory approach would be most applicable to areas with substantial pre-existing anthropogenic noise, and would lead to decisions that ensure there is ‘no net increase’ in noise levels in the underwater soundscape in an ecological area of interest, rather than a species-specific focus on concerns regarding the impacts of noise. A heuristic model of how this could be applied to Canada’s endangered population of southern resident killer whales is presented.
