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The effects of elevated CO 2 on the growth and toxicity of field populations and cultures of the saxitoxin‐producing dinoflagellate, A lexandrium fundyense
Author(s) -
HattenrathLehmann Theresa K.,
Smith Juliette L.,
Wallace Ryan B.,
Merlo Lucas R.,
Koch Florian,
Mittelsdorf Heidi,
Goleski Jennifer A.,
Anderson Donald M.,
Gobler Christopher J.
Publication year - 2015
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.1002/lno.10012
Subject(s) - saxitoxin , bay , dinoflagellate , eutrophication , bloom , algal bloom , alexandrium tamarense , paralytic shellfish poisoning , biology , toxicity , red tide , environmental chemistry , phytoplankton , ecology , oceanography , chemistry , fishery , shellfish , toxin , microbiology and biotechnology , aquatic animal , geology , nutrient , organic chemistry , fish <actinopterygii>
The effects of coastal acidification on the growth and toxicity of the saxitoxin‐producing dinoflagellate Alexandrium fundyense were examined in culture and ecosystem studies. In culture experiments, Alexandrium strains isolated from Northport Bay, New York, and the Bay of Fundy, Canada, grew significantly faster (16–190%; p < 0.05) when exposed to elevated levels ofP CO2(∼ 90–190 Pa = 900–1900 μatm) compared to lower levels (∼ 40 Pa = 400 μatm). Exposure to higher levels ofP CO2also resulted in significant increases (71–81%) in total cellular toxicity (fg saxitoxin equivalents cell −1 ) in the Northport Bay strain, while no changes in toxicity were detected in the Bay of Fundy strain. The positive relationship betweenP CO2enrichment and elevated growth was reproducible in natural populations from New York waters. Alexandrium densities were significantly and consistently enhanced when natural populations were incubated at 150 PaP CO2compared to ∼ 39 Pa. During natural Alexandrium blooms in Northport Bay,P CO2concentrations increased over the course of a bloom to more than 170 Pa and were highest in regions with the greatest Alexandrium abundances, suggesting Alexandrium may further exacerbate acidification and/or be especially adapted to these acidified conditions. The co‐occurrence of Alexandrium blooms and elevatedP CO2represents a previously unrecognized, compounding environmental threat to coastal ecosystems. The ability of elevatedP CO2to enhance the growth and toxicity of Alexandrium indicates that acidification promoted by eutrophication or climate change can intensify these, and perhaps other, harmful algal blooms.