Ocean acidification increases domoic acid contents during a spring to summer succession of coastal phytoplankton

Enrichment of the oceans with CO2 may be beneficial for some marine phytoplankton, including harmful algae. Numerous laboratory experiments provided valuable insights into the effects of elevated pCO(2) on the growth and physiology of harmful algal species, including the production of phycotoxins. E...

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Bibliographic Details
Published in:Harmful Algae
Main Authors: Wohlrab, Sylke, John, Uwe, Klemm, Kerstin, Eberlein, Tim, Forsberg Grivogiannis, Anna Maria, Krock, Bernd, Frickenhaus, Stephan, Bach, Lennart T., Rost, Björn, Riebesell, Ulf, Van de Waal, Dedmer B.
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier 2020
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Online Access:https://oceanrep.geomar.de/id/eprint/49468/
https://oceanrep.geomar.de/id/eprint/49468/1/Wohlrab%20et%20al.%202019%20Harmful%20Algae.pdf
https://doi.org/10.1016/j.hal.2019.101697
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Summary:Enrichment of the oceans with CO2 may be beneficial for some marine phytoplankton, including harmful algae. Numerous laboratory experiments provided valuable insights into the effects of elevated pCO(2) on the growth and physiology of harmful algal species, including the production of phycotoxins. Experiments close to natural conditions are the next step to improve predictions, as they consider the complex interplay between biotic and abiotic factors that can confound the direct effects of ocean acidification. We therefore investigated the effect of ocean acidification on the occurrence and abundance of phycotoxins in bulk plankton samples during a long-term mesocosm experiment in the Gullmar Fjord, Sweden, an area frequently experiencing harmful algal blooms. During the experimental period, a total of seven phycotoxin-producing harmful algal genera were identified in the fjord, and in accordance, six toxin classes were detected. However, within the mesocosms, only domoic acid and the corresponding producer Pseudo-nitzschia spp. was observed. Despite high variation within treatments, significantly higher particulate domoic acid contents were measured in the mesocosms with elevated pCO(2). Higher particulate domoic acid contents were additionally associated with macronutrient limitation. The risks associated with potentially higher phycotoxin levels in the future ocean warrants attention and should be considered in prospective monitoring strategies for coastal marine waters.