A GlowTracka was used to record daily patterns of stimulated bioluminescence at a remote shallow site in the Finnish Archipelago Sea during an Alexandrium ostenfeldii bloom. Transect measurements showed bioluminescence was highly localized prior to the peak of the bloom, which spanned 15 days in mid–August. Nightly intensities varied greatly throughout the duration of the event.

Bioluminescence emitted from A. ostenfeldii cells intensified after sundown, reaching a peak around midnight and continuing into the wee hours. Chlorophyll–a fluorescence was found to be strongly correlated with bioluminescence intensity during the bloom, and infrequent cell counts confirmed the presence of the dinoflagellate species.

Low concentrations of paralytic shellfish poisoning toxins were detected throughout the sampling period, while higher concentrations were limited to the period where bioluminescence was most intense, and could be visibly observed. This suggests that, under certain circumstances, autonomous optical measurements may be an effective tool for predicting the onset of toxic dinoflagellate blooms, though the localized nature of these events may require prior knowledge of potential bloom locations.

Link to full study: Stimulated bioluminescence as an early indicator of bloom development of the toxic dinoflagellate Alexandrium ostenfeldii

Detect Alexandrium ostenfeldii with Glowtracka

Chelsea Technologies’ GlowTracka detects bioluminescence from dinoflagellates and similar organisms. Originally developed by Plymouth Marine Laboratory in the UK, GlowTracka’s precision flow meter stimulates bioluminescent organisms and measures the light flashes as the organisms pass the detector, giving photon level sensitivity.

GlowTracka is highly flexible in its deployment options, including moorings, profiling (with pumped system) or deployment in towed vehicles.