2018 journal article
Interactive effects of temperature, CO2 and nitrogen source on a coastal California diatom assemblage
JOURNAL OF PLANKTON RESEARCH, 40(2), 151–164.
We investigated the response of a natural diatom-dominated assemblage in coastal California to interactions between the variables nitrogen (nitrate and (19 and 23 and CO 2 (380 and 800 ppm) in a factorial experimental matrix using continuous culture (ecostat) methods. The community included diatoms of the cosmopolitan genera Pseudo-nitzschia and Chaetoceros as well as Leptocylindrus and Cylindrotheca . Our results demonstrate strong interactive effects of these variables on community composition; notably, nitrogen source alone and nitrogen and CO 2 together had a much greater in fl uence on diatom community structure at 23 ° C compared with 19 ° C. In addition, warming and acidi fi cation interactions signi fi cantly increased cellular quotas of the neurotoxin domoic acid produced by Pseudo-nitzschia multiseries . In general, the effects observed for the factors tested dif-fered signi fi cantly between the various diatom genera in this assemblage, suggesting potentially divergent responses of some of these ecologically and biogeochemically important phytoplankton taxa to interactions between global-scale and local-scale anthropogenic stressors in a changing ocean.