How will the key marine calcifier <i>Emiliania huxleyi</i> respond to a warmer and more thermally variable ocean?
<p>Global warming will be combined with predicted increases in thermal variability in the future surface ocean, but how temperature dynamics will affect phytoplankton biology and biogeochemistry is largely unknown. Here, we examine the responses of the globally important marine coccolithophore...
Main Authors: | , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2019-11-01
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Series: | Biogeosciences |
Online Access: | https://www.biogeosciences.net/16/4393/2019/bg-16-4393-2019.pdf |
Summary: | <p>Global warming will be combined with predicted increases in thermal
variability in the future surface ocean, but how temperature dynamics will
affect phytoplankton biology and biogeochemistry is largely unknown. Here,
we examine the responses of the globally important marine coccolithophore <i>Emiliania huxleyi</i> to thermal
variations at two frequencies (1 d and 2 d) at low (18.5 <span class="inline-formula"><sup>∘</sup></span>C)
and high (25.5 <span class="inline-formula"><sup>∘</sup></span>C) mean temperatures. Elevated temperature and thermal
variation decreased growth, calcification and physiological rates, both
individually and interactively. The 1 d thermal variation frequencies were
less inhibitory than 2 d variations under high temperatures, indicating
that high-frequency thermal fluctuations may reduce heat-induced mortality
and mitigate some impacts of extreme high-temperature events. Cellular
elemental composition and calcification was significantly affected by both
thermal variation treatments relative to each other and to the constant
temperature controls. The negative effects of thermal variation on <i>E. huxleyi</i> growth
rate and physiology are especially pronounced at high temperatures. These
responses of the key marine calcifier <i>E. huxleyi</i> to warmer, more variable temperature
regimes have potentially large implications for ocean productivity and
marine biogeochemical cycles under a future changing climate.</p> |
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ISSN: | 1726-4170 1726-4189 |