Wednesday November 19, 2025, 4 pm CET

Aubrey Trapp

Novel Applications of Solid-phase Adsorption Toxin Tracking for Monitoring Harmful Algal Blooms

Solid-phase adsorption toxin tracking (SPATT) is a passive sampling method for monitoring dissolved toxins and other compounds. It has gained global popularity due to its high sensitivity, low-cost, and ease of use. This talk will overview traditional and novel applications of SPATT from a HAB monitoring perspective. On the California coast, SPATT is routinely deployed to monitor domoic acid, which causes Amnesiac Shellfish Poisoning (ASP). We developed new methodology in line with the existing protocols to measure a group of copepod exudates called copepodamides. Copepodamides are known to induce domoic acid production in Pseudo-nitzschia diatoms, but grazer effects are rarely considered in monitoring efforts. The inclusion of copepodamides measured over 28 weeks improved HAB predictions in empirical models, suggesting utility for including top-down information in HAB monitoring. We also used archived SPATT extracts to explore environmental metabolomics during recent toxin events in Monterey Bay using untargeted mass spectrometry. Results emphasized the interdisciplinary complexity of HAB drivers and encourage ongoing efforts to elucidate microbial interactions related to toxin production. Collectively, these projects expand the breadth of information that can be included in future HAB monitoring programs using passive chemical sampling.