Human activities change marine ecosystems by altering predation risk

Area of Science:

• Marine Ecology
• Conservation Biology
• Ecosystem Dynamics

Background:

• Human activities are increasingly altering marine ecosystems globally.
• Indirect, risk-mediated effects of human actions are understudied in marine environments compared to terrestrial ones.
• Changes in predation risk, both increases and decreases, are significant drivers of ecosystem structure.

Purpose of the Study:

• To synthesize evidence on how human activities alter marine predation risk and its cascading effects.
• To highlight the underappreciated role of indirect, risk-based effects in marine ecosystem structuring.
• To explore the implications for marine conservation and management policies.

Main Methods:

• Literature synthesis and data analysis to explore multiple lines of evidence.
• Examination of human activities, including overfishing, and their impact on predation risk landscapes.
• Development of a predictive framework for human-induced risk alterations.

Main Results:

• Diverse human activities significantly alter marine ecosystems, including carbon storage, by modifying predation risk.
• Overfishing, a key human activity, causes cascading risk effects that can exceed direct lethal impacts.
• Previously unexplained ecological findings may be attributable to these indirect risk effects.

Conclusions:

• Human-induced changes in marine predation risk have profound, cascading effects on ecosystems.
• Conservation and management must account for these indirect effects to ensure success and avoid surprises.
• Future research should focus on understanding and predicting these risk-mediated ecosystem alterations.