High-resolution monitoring of Salish Sea estuarine communities through participatory science

Agents of global change, such as climate disruptions, habitat loss, and biological invasions, affect nearshore and intertidal ecological communities in acute and chronic ways. Biological monitoring aims to track the changes in ecological communities over time, yet temporal mismatches between sampling regimes, environmental stressors, and corresponding ecological responses of interest often limit the utility of monitoring data for testing hypotheses related to these changes. Participatory science, alternatively “citizen science”, can increase the geographic and temporal scale of monitoring and can be a tool to address this limitation. By improving statistical power through higher resolution and a larger scale of data, participatory science programs can detect how global change alters highly dynamic ecological communities. In this study, we evaluate insights from a participatory science dataset (Washington Sea Grant Crab Team) on nearshore mobile epifaunal communities in the Salish Sea, how they differ across habitat types and over time and how they responded to an atmospheric heatwave. Nearshore communities varied across channel, lagoon, and tideflat habitat types, with community metrics and species identities aligning with the environmental characteristics of each habitat type. Though these communities experience high seasonal variability, habitat type differences were consistent over the seven years of data collected. While some sites did experience extreme excursions of water temperature as a result of the 2021 atmospheric heatwave, neither short- nor long-term impacts were detected in the ecological communities monitored at the regional scale. Two factors are likely important in this conclusion: 1. We monitored mobile epifauna, which may be able to migrate to mitigate extreme events and 2. Water temperatures during the heatwave rarely exceeded those experienced at the sites during other times of year. The seasonal variability of the ecological communities observed in these dynamic environments suggests avoiding snapshot sampling in favor of an approach that offers high temporal resolution, as some participatory science programs can, to be able to accurately disentangle effects of acute stressors from the noise of natural variability.