UC San Diego
Ecosystem-based management for the oceanic commons : Applying the concepts of ecosystem services, indicators, and trade-offs to make informed decisions
- Author(s): Martin, Summer Lynn
- et al.
The ocean provides numerous ecosystem services, or natural benefits, which are critical to the well-being of humanity. Over the last century, however, humans have had tremendous impacts on the ocean. Overexploitation of resources, habitat destruction, pollution and anthropogenic climate change jeopardize the ocean's ability to support a growing population. The ocean will provide essential ecosystem services if human activities are managed sustainably. Traditional management, with its focus on single sectors or species, has often failed to conserve natural resources. Ecosystem-based management (EBM) has been proposed as an alternative, holistic approach which considers the entire social-ecological system, including humans. It calls for maintaining healthy, productive and resilient ecosystems. Implementation of marine EBM has largely focused on coastal areas. There has been much less emphasis on oceanic ecosystems. These systems represent a large proportion of the earth's surface and face complex challenges - they include oceanic commons, multiple jurisdictions, trans-boundary resources, and global services. For these reasons, a more holistic approach is needed. This dissertation applies theoretical concepts of EBM to oceanic ecosystems in the eastern Pacific Ocean. Through analysis of long-term datasets containing biological, fisheries, oceanographic, and economic information, this research offers new perspectives to support oceanic EBM. The first two chapters focus on the eastern tropical Pacific (ETP), and the last chapter on the California Current Ecosystem. The chapters follow a progression from broad-scale, big- picture challenges to fine-scale, specific problems. The first chapter provides an ecosystem-level perspective, focusing on broad-scale benefits provided by oceanic systems. It highlights and quantifies the variety of services in the ETP and sets the stage for further analysis of trade-offs. The second chapter focuses on the use of indicators to predict ecosystem characteristics that are associated with desired services. It demonstrates that tuna fishery metrics can be used as biological indicators for cetacean densities in the ETP. The third chapter focuses on fine-scale problems that arise when EBM goals conflict and decisions must be made. It provides a quantitative tool for assessing bycatch of protected species in fisheries. Together, the results from the three chapters show promise for the implementation of EBM in oceanic ecosystems