Recurrent jellyfish blooms are a consequence of global oscillations.

A perceived recent increase in global jellyfish abundance has been portrayed as a symptom of degraded oceans. This perception is based primarily on a few case studies and anecdotal evidence, but a formal analysis of global temporal trends in jellyfish populations has been missing. Here, we analyze all available long-term datasets on changes in jellyfish abundance across multiple coastal stations, using linear and logistic mixed models and effect-size analysis to show that there is no robust evidence for a global increase in jellyfish. Although there has been a small linear increase in jellyfish since the 1970s, this trend was unsubstantiated by effect-size analysis that showed no difference in the proportion of increasing vs. decreasing jellyfish populations over all time periods examined. Rather, the strongest nonrandom trend indicated jellyfish populations undergo larger, worldwide oscillations with an approximate 20-y periodicity, including a rising phase during the 1990s that contributed to the perception of a global increase in jellyfish abundance. Sustained monitoring is required over the next decade to elucidate with statistical confidence whether the weak increasing linear trend in jellyfish after 1970 is an actual shift in the baseline or part of an oscillation. Irrespective of the nature of increase, given the potential damage posed by jellyfish blooms to fisheries, tourism, and other human industries, our findings foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face.

Perspectives on managing fisheries for community wellbeing in the face of climate change.

Coastal communities are being impacted by climate change, affecting the livelihoods, food security, and wellbeing of residents. Human wellbeing is influenced by the heath of the environment through numerous pathways and is increasingly being included as a desired outcome in environmental management. However, the contributors to wellbeing can be subjective and the values and perspectives of decision-makers can affect the aspects of wellbeing that are included in planning. We used Q methodology to examine how a group of individuals in fisheries management prioritize components of wellbeing that may be important to coastal communities in the California Current social-ecological system (SES). The California Current SES is an integrated system of ecological and human communities with complex linkages and connections where commercial fishing is part of the culture and an important livelihood. We asked individuals that sit on advisory bodies to the Pacific Fisheries Management Council to rank 36 statements about coastal community wellbeing, ultimately revealing three discourses about how we can best support or improve wellbeing in those communities. We examine how the priorities differ between the discourses, identify areas of consensus, and discuss how these perspectives may influence decision-making when it comes to tradeoffs inherent in climate adaptation in fisheries. Lastly, we consider if and how thoughts about priorities have been affected by the COVID-19 pandemic.