RIASSUNTO
Summary
A regulatory authority may adopt different schemes for the assessment, management and mitigation of environmental risk from a given human activity. We review two basic types of current or contemplated risk management schemes for underwater noise, species-based and place-based, and the respective implications of these different risk management strategies. Management of species risks may produce adverse consequences for other species or the overall functioning of the ecosystem. Management of ecosystem risk may result in increased risk to some species at the expense of overall biodiversity, ecosystem resilience, or productivity goals. And, finally, monitoring and mitigation actions to assess the status and trends of a species, stock or population will differ from monitoring and mitigation actions to assess overall biodiversity, ecosystem health metrics like productivity, energy flow across functional trophic levels, and resilience to perturbations.
Introduction
The earliest and perhaps most familiar management scheme is species-based management as expressed by the US Endangered Species Act and Marine Mammal Protection Act. Another increasingly common scheme is Spatial or Ecosystem Based Management. Examples include the US Marine Sanctuaries Act, EU Marine Strategy Framework Directive (MSFD), and the Australian Environmental Protection and Biodiversity Conservation Act of 1999 (EPBC Act) under which management is typically defined for a specified area, but with metrics of success based on biodiversity or abundance of key indicator species.
Recently, and of greatest interest to this community, there has been discussion of Soundscape Management for marine environments, a variant on Spatial Management. This theme has seen its greatest development in planning of urban areas and parks, with the goals of reducing the effects of anthropogenic noise on human well-being and/or wildlife. The EU Marine Strategy Framework Directive Descriptor 11 addresses "Energy Including Underwater Noise". The assumption is that meeting benchmarks for all eleven descriptors (contaminants, commercial fishing, eutrophication, etc.) will enable the marine environment to achieve stated ecosystem health goals such as biodiversity and productivity. While there is no basis in law for such management schemes in the US at this time, NOAA and other agencies have begun to discuss soundscape management and have begun to explore spatial mapping of sound through websites like the NOAA CetSound website.