Interactive Threats: Multi-stress Systems in Aquatic Environments

2].These stressors can be either biotic (e.g., predation [3], competition [4]) or abiotic (e.g., temperature, pH, salinity [1, 2]).Many of these stressors are worsening due to changes at global scales such as climate change [5], plastic pollution [6], and habitat modification [7, 8].Additionally, multi-stress systems are present in marine and freshwater environments [1, 2, 9] and impact a wide range of resident species.Despite growing recognition of multi stress systems, however, many outstanding questions remain regarding the interactive effects of simultaneous sources of stress on the physiology, behavior, ecology, and population status of aquatic organisms.This understanding is crucial to creating effective management strategies and quantifying the full impact human activities have on aquatic environments.We sought to address some of these questions regarding multi-stress systems in two California study systems.In the first, we investigated how microplastic ingestion impacted responses to thermal stress and parasites in the pacific mole crab, Emerita analoga from Fort Funston in San Francisco, CA.In the second, we looked at how abiotic (temperature and sedimentation) and biotic (chemical and visual predator cues) stressors impacted the escape behavior and movement speed of pacific giant salamander larvae, Dicamptodon tenebrous, from the Angelo Coast Range Reserve in Mendocino, CA, and how simulated summer conditions impact the larvae's heat shock protein expression levels.