Scientists Offer Blueprint for Managing Ocean Ecosystems on the Brink of Collapse

We have long observed that marine ecosystems can undergo sudden, dramatic shifts - coral-dominated reefs transitioning to macroalgal-dominated systems, the rapid loss of kelp cover after urchin population explosions, or the sudden development of anoxic conditions in estuaries. These rapid ecological shifts may surprise managers, particularly when linear, gradual responses to human impacts are assumed. Such unanticipated changes can be socially, culturally, and economically costly.

To address this challenge, we conducted five workshops in 2013 and 2014 with subsets of coauthors and a dozen other scientists, marine managers, stewards, and policymakers. The goal was to generate and prioritize principles for managing marine ecosystems prone to tipping points, translating broad scientific insights into specific planning guidelines.

The research revealed seven core principles for managing ecosystem tipping points. Most significantly, analysis of 736 stressor-response relationships in marine systems showed that over half were nonlinear, indicating widespread potential for threshold effects. We found that tipping points are possible everywhere, especially where human impacts are intense or multifaceted.

A key finding was that management strategies that explicitly monitor ecosystem state and identify measurable tipping points tend to be more effective in achieving conservation goals than strategies that do not consider possible tipping points. The research suggests that early action to preserve system resilience is likely more practical, affordable, and effective than late action to halt or reverse a tipping point.

The study provides a framework for managers to work with uncertainty while acknowledging nonlinear relationships in marine systems. The seven principles offer practical guidance for ecosystem-based management, environmental restoration, and comprehensive spatial planning in marine environments prone to dramatic ecological changes.

Citation

Selkoe, Kimberly A.; Blenckner, Thorsten; Caldwell, Margaret R.; Crowder, Larry B.; Erickson, Ashley L.; Essington, Timothy E.; Estes, James A.; Fujita, Rod M.; Halpern, Benjamin S.; Hunsicker, Mary E.; Kappel, Carrie V.; Kelly, Ryan P.; Kittinger, John N.; Levin, Phillip S.; Lynham, John M.; Mach, Megan E.; Martone, Rebecca G.; Mease, Lindley A.; Salomon, Anne K.; Samhouri, Jameal F.; Scarborough, Courtney; Stier, Adrian C.; White, Crow; Zedler, Joy (2015). Principles for managing marine ecosystems prone to tipping points. Ecosystem Health and Sustainability.

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