Northern California Current Ecosystem Modeling
Project Lead: Dylan Gomes (Postdoctoral Scholar)
Collaborators: Lisa Crozier (NOAA NWFSC); James Ruzicka (NOAA PIFSC); David Huff (NOAA NWFSC)
We are using end-to-end ecosystem models to explore the role that marine heatwaves play on marine ecosystems, the effects of predators, competitors, and prey on endangered populations of salmon, and how changing climate and fishery practices can exacerbate or mitigate declining salmon populations.
Marine heatwaves are increasing in intensity and prevalence due to human-induced climate change, yet little is known about the ecosystem-level consequences of such disturbances. While the effects of marine heatwaves have been documented for individual taxa or groups of species, a more holistic understanding of the impact of heatwaves on entire systems is needed. This knowledge gap is understandable, as ecosystem models are data-hungry and require information on every trophic level across sufficient time-spans to parameterize both pre- and post- heatwave conditions. We have leveraged a new diet database and six long-term monitoring efforts of 361 taxa, grouped into 86 functional groups, to build comparable pre- and post-heatwave ecosystem models of an ecologically and economically important marine system (the Northeast Pacific Ocean) that recently experienced one of the most intense marine heatwaves in recorded history.
Endangered Pacific salmon
Salmon are an iconic species of great ecological, cultural, and economical importance. Multiple species of salmon, globally, are imperiled, and many populations of pacific salmon, specifically, are threatened or endangered. The reasons for these declines are thought to be many (i.e., death by a thousand cuts), yet many modern assessments de-emphasize the role that humans may play in the status of salmon populations (either through direct impacts such as fishing and habitat degradation, or indirect effects such as climate change) and instead focus on other predators, such as marine mammals and seabirds. We use end-to-end ecosystem modeling approaches to explore the influence that prey, competitors, and predators have on juvenile and adult salmonids in the ocean. We are also able to use this flexible simulation-based framework to explore the role of fishery fleets (via changes to competitors and predators) and a warming ocean (via changes to prey) play on salmonids in the food web.