Award: OCE-1736943

Intellectual Merit: This award re-evaluated the role of predation risk on prey populations in the wild, because an influential narrative among researchers is that predators control prey populations mainly by frightening prey, rather than by eating them. This project showed that although it is possible to statistically detect the effects of predation risk on populations of prey in natural settings, they are both inconsistent in time and washed out by environmental differences across space (Figure 1). In addition to using broad scale surveys and outdoor experiments, this project used quantitative modeling to further reveal that predation risk effects are only a minor contribution to explaining the abundance of important prey such as oysters (Figure 2). These findings from a Florida estuary were also supported by two reviews of over 4,000 studies in the published literature on predation risk effects, which is being increasingly studied by ecologists and their supporting funding agencies (Figure 3). The results of this project will lead to a shift in research effort, funding, and publication space away from simply detecting predation risk effects to more comprehensive evaluations of their costs, benefits, and long-term consequences, with an emphasis on how important they are for applied research and societal needs regarding agriculture, fisheries, and conservation. Overall, this will improve our ability to understand and manage natural resources. Broader Impacts: The project also had broader impacts specific to the study system, with results informing the restoration and management of oysters in the Guana Tolomato Matanzas National Estuarine Research Reserve (GTM NERR). Specifically, this research helped fulfill a priority research need of GTM NERR by evaluating which areas of the large estuary have sustainable oyster reefs versus unsustainable reefs. This research priority need was driven by The Oyster and Water Quality Task Force, which is a partnership between GTM NERR and local stakeholders, that has been tasked to make informed decisions on how the oyster resource should be managed. To promote additional Broader Impacts and Outreach, the project purchased a software license that supported touch screen content designed to engage elementary students with key ecological concepts via a virtual scavenger hunt. The GTM NERR recorded that the touchscreen content and scavenger hunt engaged 1,112 elementary students in 2019. This does not include Visitor Center guest numbers (6,737) outside of elementary school programs. Finally, this project resulted in the training of 2 undergraduate (one completing an honors thesis, graduating, and becoming manager of research lab at Louisina State University) and 3 graduate students. Interactions between the teams at Northeastern University and the Oregon State postdoc were crucial to broadening the post-doc?s expertise (applied mathematics) to include concepts in benthic marine ecology and population dynamics; she will carry that expertise with her as she begins a faculty job at Bates College in 2022. In addition, one technician gained sufficient research experience to become a manager of a research laboratory at Virginia Tech while the other technician moved forward to pursue a PhD in marine science. Finally, a high school intern who participated in some of the laboratory research moved on to attend Duke University and is majoring in Earth and Ocean Sciences. Award Outcomes: (1) Completed annual field survey of oyster individual traits, population size structure and abundance, reef substrate amount, and predator density in 2019 and 2020 (2) The award quantified environmental properties of water flow, pH, and phytoplankton (chl a concentration) at 9 locations throughout a Floridian estuary. (3) The award conducted a predator-exclosure experiment with juvenile oysters at 9 locations throughout a Floridian estuary to quantify difference in oyster growth and survival due to the environment as well as predation. (4) The award finished a previous experiment that manipulated predation risk signals at three sites spanning strong environmental gradients (5) The award developed a size-structured Integral projection model with experimental results to determine if long term population growth of prey is affected by empirically observed predation risk effects (6) At a site with high predation risk, the project conducted a 1.5 year long experiment that removed predation risk signals, and then evaluated response of the oyster population. (7) The project also conducted a reciprocal transplant experiment between two sites to evaluate the role of local adaptation for prey trait responses to predation risk effects. (8) The project used mathematical modeling to inform conservation and restoration practices of the Guana Tolomato Matanzas National Estuarine Research Reserve. (9) The project has already produced five publications (2 in Ecology, 1 in Ecology Letters, 1 in Journal of Experimental Marine Biology and Ecology, and 1 in Estuaries and Coasts), with 6 more in preparation for submission by end of 2022. Last Modified: 10/31/2022 Submitted by: David Kimbro