Marine heatwaves are increasingly affecting marine ecosystems, with cascading impacts on coastal economies, communities, and food systems. Studies of heatwaves provide crucial insights into potential ecosystem shifts under future climate change and put fisheries social-ecological systems through "stress tests" that expose both vulnerabilities and resilience. The 2014-16 Northeast Pacific heatwave was the strongest and longest marine heatwave on record and resulted in profound ecological changes that impacted fisheries, fisheries management, and human livelihoods. Here, we synthesize the impacts of the 2014-2016 marine heatwave on US and Canada West Coast fisheries and extract key lessons for preparing global fisheries science, management, and industries for the future. We set the stage with a brief review of the impacts of the heatwave on marine ecosystems and the first systematic analysis of the economic | 653 FREE et al. 1. INTRODUCTION 2. THE 2014-2016 MARINE HEATWAVE 3. SOCIOECONOMIC IMPACTS OF THE HEATWAVE ON FISHERIES 4. CASE STUDIES 4.1. Pacific cod 4.2. Kelp, urchin, abalone 4.3. Chinook salmon 4.4. Dungeness crab 4.5. Pacific sardine and northern anchovy 4.6. Pacific bluefin tuna 4.7. California market squid 4.8. Shrimp species 4.9. Bocaccio rockfish 4.10. Shortbelly rockfish 5. LESSONS LEARNED 5.1. Lessons for improving monitoring 5.2. Lessons for improving management 5.3. Lessons for improving adaptive capacity of fishing communities 5.4. Lessons for and from other regions 6. CONCLUSIONS

Many reports have categorized the frequency, circumstances, and causes for interactions between sharks and humans, often using the behaviorally inaccurate term “attack.” The California Department of Fish and Wildlife (Department) instead uses the term “incident,” defined as interactions where a shark touches a person, their board, or kayak, without provocation and with or without causing injury. We created a comprehensive database of California shark incidents by reviewing, verifying, and updating past records, and examined the frequency of confirmed incidents, updated reports with new information, and examined similarities and differences in incident circumstances. Two hundred and one incidents were verified in California waters between 1950 and 2021, with 107 causing injury and 15 resulting in fatalities. The vast majority (178) involved White Sharks (Carcharodon carcharias). Contrary to past reports of White Shark incidents being concentrated in a portion of northern California, incidents have occurred statewide, with some of the highest numbers in Southern California. While total reported incidents are increasing, the annual number of incidents resulting in injuries or fatalities remains low. Frequency of incidents was not found to be greater around the full moon, dawn, or dusk but was greater during summer and fall months, as expected.