CO2 effects on diatoms: a synthesis of more than a decade of ocean acidification experiments with natural communities

Diatoms account for 40 % of marine primary production and are considered to be key players in the biological carbon pump. Ocean acidification (OA) is expected to affect diatoms primarily by changing the availability of CO2 as a substrate for photosynthesis or through altered ecological interactions within the marine food web. Yet, there is little consensus how entire diatom communities will respond to increasing CO2. To address this question, we synthesized the literature from over a decade of OA-experiments with natural diatom communities to uncover: 1) if and how bulk diatom communities respond to elevated CO2; 2) if shifts within the diatom communities could be expected and how they are expressed with respect to taxonomic affiliation and size structure. We found that diatom communities responded to high CO2 in ~60 % of the experiments and in this case more often positively (56 %) than negatively (32 %; 12 % did not report the direction of change). Shifts among different diatom species were observed in 65 % of the experiments. Our synthesis supports the hypothesis that high CO2 particularly favors larger species as 12 out of 13 experiments which investigated cell size found a shift towards larger species. Unraveling winners and losers with respect to taxonomic affiliation was difficult due to a limited database, but there is evidence that the genus Pseudo-nitzschia could be among the losers. We conclude that OA-induced changes in diatom competitiveness and assemblage structure must be classified as a “risk for ecosystem services” due to the pivotal role diatoms play in trophic transfer and biogeochemical cycles.

Bach L. & Taucher J., 2019. CO2 effects on diatoms: a Synthesis of more than a decade of ocean acidification experiments with natural communities. Ocean Science Discussions. Article.

0 Responses to “CO2 effects on diatoms: a synthesis of more than a decade of ocean acidification experiments with natural communities”



  1. Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.




Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 1,244,087 hits

OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book