Abstract
The sinking properties of three strains of Emiliania huxleyi in response to temperature changes were examined. We used a recently proposed approach to calculate sinking velocities from coccosphere architecture, which has the advantage to be applicable not only to culture samples, but also to field samples including fossil material. Our data show that temperature in the sub-optimal range impacts sinking velocity of E. huxleyi. This response is widespread among strains isolated in different locations and moreover comparatively predictable, as indicated by the similar slopes of the linear regressions. Sinking velocity was positively correlated to temperature as well as individual cell PIC/POC over the sub-optimum to optimum temperature range in all strains. In the context of climate change our data point to an important influence of global warming on sinking velocities. It has recently been shown that seawater acidification has no effect on sinking velocity of a Mediterranean E. huxleyi strain, while nutrient limitation seems to have a small negative effect on sinking velocity. Given that warming, acidification, and lowered nutrient availability will occur simultaneously under climate change scenarios, the question is what the net effect of different influential factors will be. For example, will the effects of warming and nutrient limitation cancel? This question cannot be answered conclusively but analyses of field samples in addition to laboratory culture studies will improve predictions because in field samples multi-factor influences and even evolutionary changes are not excluded. As mentioned above, the approach of determining sinking rate followed here is applicable to field samples. Future studies could use it to analyse not only seasonal and geographic patterns but also changes in sinking velocity over geological time scales.
Highlights
It is generally acknowledged that global climate change will impact marine phytoplankton in terms of physiology
There were no significant differences in the interaction between treatment and strain of the three strains (F4 = 0.37, p = 0.824), so there were no significant differences between their slopes, even though the number of attached coccoliths of the strain IAN01 was lower than that of the other two strains
We demonstrate that the particulate inorganic carbon (PIC): particulate organic carbon (POC) vs sinking velocity relationship can be determined based on geometrically derived PIC and POC quotas using raw data other than the FIB-SEMapproach [26]
Summary
It is generally acknowledged that global climate change will impact marine phytoplankton in terms of physiology. These physiological changes are usually considered in isolation. Uk/ (GL); the “MECD/SGU/DGPU, Programa Estatal de Promocion del Talento y su Empleabilidad” (Becas FPU) of the MINECO, Spain, http://www. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have