2026/01/02 by Linda Medlin, Francisco Rodríguez, Gerardo Mengs +1 · 1 voice
Environmental Science · Earth and Planetary Sciences · Engineering · #Marine Toxins and Detection Methods #Marine Invertebrate Physiology and Ecology #Marine Biology and Environmental Chemistry
paper · pdf · doi:10.1080/00318884.2026.2616747
openalex publication_date 2026/01/02 · openalex created_date 2026/02/13 · openalex updated_date 2026/06/15
Increases in Harmful Algal Blooms (HABs) of toxic microalgae represent a growing concern worldwide. Poleward spread of HAB distribution is linked to climate change. Molecular tools permit more rapid and accurate responses, which complement traditional tools, for HAB species identification. Our electrochemical detection method, with a single unlabelled capture probe, represents a vast improvement over earlier methods using a sandwich hybridization method with two probes in that it is 10 times more sensitive. We analysed samples taken twice weekly in July 2022, from two locations in the northwestern Iberian Peninsula within the INTECMAR monitoring system in Galicia (Spain), and single samples from IPMA monitoring points in Porto and Aveiro (Portugal). Gambierdiscus spp. earlier reported offshore, were documented molecularly in coastal waters for the first time. Ostreopsis spp. earlier detected with microscopical and molecular methods, was also documented molecularly. This genus displayed an apparent range expansion in the southwestern Portuguese coasts, and along the northern (Bay of Biscay) and Mediterranean coasts of Spain. To increase species detection levels, 10 L samples were filtered, which is likely the reason why we found molecular signals where none of these cells were detected in the 50 mL settled volumes taken by the monitoring agencies and IEO. Improved calibration curves may revise lower inferred cell numbers because signals were normalized against a no DNA control, which was often high. The present study provides new information on emergent toxin-producing taxa of interest for regional monitoring programmes and their potential expansion in the area.