Transparent exopolymer particles (TEP) are key components of the marine carbon cycle, coupling biological productivity with biogeochemical and operational processes in coastal environments. This study quantified ex-situ surface TEP concentrations during three harmful algal blooms (HABs) in Todos Santos Bay (Mexico) between 2022 and 2024, each representing a different bloom stage and dominated by a distinct species: Prorocentrum micans (2022), Pseudo-nitzschiacf.australis (2023), and Lingulaulax polyedra (2024). Surface TEP concentrations increased from 163 μg XG eq·L-1 in 2022 to 693 μg XG eq·L-1 in 2023 and 778 μg XG eq·L-1 in 2024. The highest TEP-to-biomass ratio occurred during the P. australis bloom, coinciding with low nutrients levels (PO₄3- = 0.4 μM; NN = 2.4 μM) and moderate upwelling conditions (BEUTI = 1.0 mmol m-3 s-1). The L. polyedra bloom developed under stratified, warm conditions (SST ≈ 18.5 °C), with high PO₄3- concentration (0.8 μM) and operational impacts including filter clogging at a desalination plant. In contrast, P. micans occurred under higher nutrient availability (PO₄3- = 2.46 μM; NN = 6.9 μM) and lower TEP levels. TEP-C contributed up to 87 % of the particulate carbon pool during the P. australis event, suggesting species-specific physiological control on exopolymer formation. Overall, each event represented a different bloom stage, underscoring how bloom progression, species dominance, and environmental forcing together shape TEP dynamics in coastal upwelling systems.
Zumaya-Basurto et al. (Sat,) studied this question.