Seawater carbonate chemistry and toxicity of Pseudo-nitzschia fraudulenta in a laboratory experiment

• Main Authors: Tatters, Avery O, Fu, Feixue, Hutchins, David A
• Format: Dataset
• Language: English
• Published: PANGAEA 2012
• Subjects: Alkalinity; total; Aragonite saturation state; Bicarbonate ion; Biogenic silica; Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria (<20 L); Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; organic; particulate; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Cell density; Chromista; Coast and continental shelf; Coulometric titration; Domoic acid per cell; Domoic acid production per cell; EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Growth rate; High Performance Liquid Chromatography (HPLC); Immunology/Self-protection; Laboratory experiment; Macro-nutrients; Nitrogen; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Ochrophyta; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; pH; Phosphorus; Phytoplankton; Potentiometric; Pseudo-nitzschia fraudulenta; Replicate; Pacific; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.823383; https://doi.org/10.1594/PANGAEA.823383

Anthropogenic CO2 is progressively acidifying the ocean, but the responses of harmful algal bloom species that produce toxins that can bioaccumulate remain virtually unknown. The neurotoxin domoic acid is produced by the globally-distributed diatom genus Pseudo-nitzschia. This toxin is responsible for amnesic shellfish poisoning, which can result in illness or death in humans and regularly causes mass mortalities of marine mammals and birds. Domoic acid production by Pseudo-nitzschia cells is known to be regulated by nutrient availability, but potential interactions with increasing seawater CO2 concentrations are poorly understood. Here we present experiments measuring domoic acid production by acclimatized cultures of Pseudo-nitzschia fraudulenta that demonstrate a strong synergism between projected future CO2 levels (765 ppm) and silicate-limited growth, which greatly increases cellular toxicity relative to growth under modern atmospheric (360 ppm) or pre-industrial (200 ppm) CO2 conditions. Cellular Si:C ratios decrease with increasing CO2, in a trend opposite to that seen for domoic acid production. The coastal California upwelling system where this species was isolated currently exhibits rapidly increasing levels of anthropogenic acidification, as well as widespread episodic silicate limitation of diatom growth. Our results suggest that the current ecosystem and human health impacts of toxic Pseudo-nitzschia blooms could be greatly exacerbated by future ocean acidification and 'carbon fertilization' of the coastal ocean.