Ocean fronts are meeting places of life in the oceans. Marine organisms from plankton to blue whales congregate at the interface of cooler and warmer waters, due to the prevalence of enhanced productivity at fronts. The technology for identifying ocean fronts is well-established, including mapping from remotely sensed SST and altimetry. However, the management of fronts is in its infancy, as is understanding how fronts will vary with climate change. This means that much of the information available about ocean fronts and their response to climate change is not available to managers making decisions about how to achieve local, regional, and national conservation and Sustainable Development Goals (SDG). The goal of this proposal is to provide marine planners and managers with physical and biological information critical to meeting these planning needs in marine conservation and sustainable fisheries. This project works with conservation and fishing stakeholders in the Mozambique Channel to design research about ocean fronts, their use by marine species and fisheries and how front variability will change in the future. We work with stakeholder communities to create conservation and sustainable fishing solutions for fronts. We use global remote sensing analysis to find other areas in which the conditions that make these solutions relevant apply. The outcomes of this project fill critical gaps in information identified by stakeholders and planners, helping them to meet individual and collective responsibilities relating to the nature of the ocean and its sustainable use as climate changes. We will provide this information globally for the tropics and in more detail for our focal region in the Mozambique Channel. This contribution comes at a critical time, as governments commit to Sustainable Development Goals, communities are struggling to understand how to adapt resource management to climate change and conservation groups look for ways to protect marine life at fronts that are moving in response to climate change.

Tropical freshwater systems support fisheries that provide food security and incomes for hundreds of millions of people worldwide. These fisheries are more likely to be heavily exploited across all species, size classes and trophic levels, in contrast to temperate target fisheries where capital cost, barriers to entry, and travel distance focus exploitation on high value species. Almost nothing is known about how tropical indiscriminate fisheries respond to change. They may be fragile due to chaotic interactions between complex biology and complex human use, or their foodwebs may be simplified by heavy exploitation in ways that make them robust and resilient in the face of change. Climate change therefore puts these systems at risk in ways that have huge repercussions for poverty alleviation but are very poorly understood. Here, we propose to (i) construct a general theory for understanding the social and ecological implications of truly indiscriminate fisheries under climate change, and; (ii) develop and test a specific application of this theory for the important case of the Tonle Sap fishery, Cambodia. Our focus on the Tonle Sap—perhaps the largest indiscriminate tropical freshwater fishery—allows us to inform responses to climate change in a fishery of major importance and one in which climate change interacts with other flow modifications (such as upstream development). We bring social science, fisheries, economics and management expertise to bear on this problem from research labs in eight universities and NGOs across three continents. The results of the research will be integrated into management through partners in three ministries, multiple communities and NGOs. Social impact in Cambodia will result by informing implementation of recent major management changes that have converted privately held fishing lots into community fisheries. Our team includes NGOs, local universities and early-career researchers to help effect this change. Internationally, our results will inform similar systems that feed and provide income for millions of people by revealing management tools effective in heavily exploited, dynamic freshwater fisheries as climate changes.