Introduction

Increasing impact on the world's oceans from development, pollution, overharvesting of resources and other human-related causes stems from our failure to recognize that our oceans are not an indestructible and infinite resource. Today, signs of stress and the diminishing health of our oceans are commonplace and globally we have begun to acknowledge that our oceans are in crisis (Pauly et al., 1998; Mora et al., 2009). Marine life and vital coastal habitats are under increasing pressure from overuse, and the cumulative effects of human activities in the ocean reduces its ability to function as a healthy ecosystem (Halpern et al., 2008). The costs of pollution, overfishing, and destruction of habitats threaten local food security, livelihoods, and the health and welfare of human communities reliant on the ocean (Kent, 1997; Bell et al., 2009; Halpern et al., 2012). Current approaches to management, planning and policy have thus far relied too heavily on fragmented and piecemeal governance, rather than systematic, ecosystem-based approaches that are needed to preserve ocean ecosystem health and the resilience of human communities (Crowder et al., 2006; Spalding et al., 2008; Pressey & Bottrill, 2009).

Impacts and depletion of marine mammals is a subset of the global crisis facing our ocean. Persistent and major threats to marine mammals include historical exploitation, habitat loss and by-catch, pollution, ocean noise, and overharvesting (Erbe, 2002; Schipper et al., 2008; Simmonds & Isaac, 2007; McClenachan & Cooper, 2008). Reducing these threats requires a systematic approach to management of marine mammals, with multi-dimensional responses that are both species- and location-specific (Taylor et al., 2000; Marsh et al., 2003).