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Saxitoxin and tetrodotoxin bioavailability increases in future oceans

Roggatz, C. C.; Fletcher, N.; Benoit, D. M.; Algar, A. C.; Doroff, A.; Wright, B.; Wollenberg Valero, K. C.; Hardege, J. D.


C. C. Roggatz

N. Fletcher

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Dr David Benoit
Senior Lecturer in Molecular Physics and Astrochemistry

A. C. Algar

A. Doroff

B. Wright

K. C. Wollenberg Valero

J. D. Hardege


© 2019, The Author(s), under exclusive licence to Springer Nature Limited. Increasing atmospheric CO2 levels are largely absorbed by the ocean, decreasing surface water pH1. In combination with increasing ocean temperatures, these changes have been identified as a major sustainability threat to future marine life2. Interactions between marine organisms are known to depend on biomolecules, although the influence of oceanic pH on their bioavailability and functionality remains unexplored. Here we show that global change substantially impacts two ecological keystone molecules3 in the ocean, the paralytic neurotoxins saxitoxin and tetrodotoxin. Increasing temperatures and declining pH increase the abundance of their toxic forms in the water. Our geospatial global model predicts where this increased toxicity could intensify the devastating impact of harmful algal blooms, for example through an increased incidence of paralytic shellfish poisoning. Calculations of future saxitoxin toxicity levels in Alaskan clams, Saxidomus gigantea, show critical exceedance of limits safe for consumption. Our findings for saxitoxin and tetrodotoxin exemplify potential consequences of changing pH and temperature on chemicals dissolved in the sea. This reveals major implications not only for ecotoxicology, but also for chemical signals that mediate species interactions such as foraging, reproduction or predation in the ocean, with unexplored consequences for ecosystem stability and ecosystem services.


Roggatz, C. C., Fletcher, N., Benoit, D. M., Algar, A. C., Doroff, A., Wright, B., …Hardege, J. D. (2019). Saxitoxin and tetrodotoxin bioavailability increases in future oceans. Nature Climate Change, 9(11), 840-844.

Journal Article Type Article
Acceptance Date Aug 30, 2019
Online Publication Date Oct 7, 2019
Publication Date Nov 1, 2019
Deposit Date Oct 11, 2019
Publicly Available Date Apr 8, 2020
Journal Nature Climate Change
Print ISSN 1758-678X
Electronic ISSN 1758-6798
Peer Reviewed Peer Reviewed
Volume 9
Issue 11
Pages 840-844
Keywords Climate-change ecology; Ecological modelling; Environmental chemistry
Public URL
Publisher URL
Additional Information Received: 21 February 2019; Accepted: 30 August 2019; First Online: 7 October 2019; : The authors declare no competing interests.


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