Environmental controls on Emiliania huxleyi morphotypes in the Benguela coastal upwelling system (SE Atlantic)

Henderiks, Jorijntje; Winter, Amos; Elbrächter, Malte; Feistel, Rainer; Plas, Anja van der; Nausch, Guenther; Barlow, Ray

doi:10.3354/meps09535

Cited by 60 publications

(69 citation statements)

References 56 publications

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“…4). This second hypothesis is also consistent with the following observations: (1) the presence of a subsurface chlorophyll a maximum in the study region during spring and summer (Parslow et al, 2001;Trull et al, 2001b); (2) reports of high E. huxleyi cell accumulations associated with the nutricline in other settings of the world oceans (Beaufort et al, 2008;Henderiks et al, 2012) and (3) peak annual sedimentation in late February of the diatom Thalassiothrix antarctica (Rigual- Hernández et al, 2015a), a typical component of the "shade flora" (Kemp et al, 2000;Quéguiner, 2013). Further sampling and taxonomic analysis of the vertical distributions of phytoplankton in the AZ-S south of Australia are required to assess these hypotheses.…”

Section: Seasonal Dynamics Of the Calcareous And Siliceous Phytoplanksupporting

confidence: 91%

Coccolithophore populations and their contribution to carbonate export during an annual cycle in the Australian sector of the Antarctic zone

et al. 2018

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Abstract. The Southern Ocean is experiencing rapid and relentless change in its physical and biogeochemical properties. The rate of warming of the Antarctic Circumpolar Current exceeds that of the global ocean, and the enhanced uptake of carbon dioxide is causing basin-wide ocean acidification. Observational data suggest that these changes are influencing the distribution and composition of pelagic plankton communities. Long-term and annual field observations on key environmental variables and organisms are a critical basis for predicting changes in Southern Ocean ecosystems. These observations are particularly needed, since highlatitude systems have been projected to experience the most severe impacts of ocean acidification and invasions of allochthonous species.

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Section: Seasonal Dynamics Of the Calcareous And Siliceous Phytoplanksupporting

confidence: 91%

Coccolithophore populations and their contribution to carbonate export during an annual cycle in the Australian sector of the Antarctic zone

et al. 2018

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“…However, at the lowest end of the E. huxleyi temperature range, populations are often found to be dominated by more lightly calcified morphotypes (Cubillos et al, 2007); thus a relationship to temperature would have to be very nonlinear. More importantly, while a "type A over-calcified" type was reported in winter waters of the Bay of Biscay (Smith et al, 2012) and a heavily calcified type "A * " was reported in the Benguela coastal upwelling (Henderiks et al, 2012) (both exhibiting only overgrowth of the central area by tube elements but not fusion of distal shield elements), the exceptionally robust R/overcalcified forms seen near Chile have not been reported from these other upwelling systems. Therefore, we set out here to test the simplest hypothesis -focusing on a single factorthat these forms may be adapted to resist high-CO 2 -low-pH conditions.…”

Section: P Von Dassow Et Al: Over-calcified Forms Of the Coccolithomentioning

confidence: 93%

“…Some other factor must select for the R/overcalcified morphotype in the coastal zone of Chile. An A morphotype (A * ) exhibiting partial and irregular extension of inner tube elements over the central area (but not closure of spaces between distal shield radial elements) was dominant in the Benguela upwelling zone (not the more extreme R/over-calcified types) (Henderiks et al, 2012), while the A_CC type, although rare off the coast of Chile, was dominant in the northeastern Atlantic (Bay of Biscay) in winter (Smith et al, 2012). It is interesting to speculate that highproductivity conditions in eastern boundary coastal waters promote persistently higher abundances of grazers or phytopathogenic bacteria, against which the over-calcified coccoliths might provide better defense.…”

Section: P Von Dassow Et Al: Over-calcified Forms Of the Coccolithomentioning

confidence: 99%

Over-calcified forms of the coccolithophore Emiliania huxleyi in high-CO2 waters are not preadapted to ocean acidification

et al. 2018

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Abstract. Marine multicellular organisms inhabiting waters with natural high fluctuations in pH appear more tolerant to acidification than conspecifics occurring in nearby stable waters, suggesting that environments of fluctuating pH hold genetic reservoirs for adaptation of key groups to ocean acidification (OA). The abundant and cosmopolitan calcifying phytoplankton Emiliania huxleyi exhibits a range of morphotypes with varying degrees of coccolith mineralization. We show that E. huxleyi populations in the naturally acidified upwelling waters of the eastern South Pacific, where pH drops below 7.8 as is predicted for the global surface ocean by the year 2100, are dominated by exceptionally over-calcified morphotypes whose distal coccolith shield can be almost solid calcite. Shifts in morphotype composition of E. huxleyi populations correlate with changes in carbonate system parameters. We tested if these correlations indicate that the hyper-calcified morphotype is adapted to OA. In experimental exposures to present-day vs. future pCO2 (400 vs. 1200 µatm), the over-calcified morphotypes showed the same growth inhibition (−29.1±6.3 %) as moderately calcified morphotypes isolated from non-acidified water (−30.7±8.8 %). Under the high-CO2–low-pH condition, production rates of particulate organic carbon (POC) increased, while production rates of particulate inorganic carbon (PIC) were maintained or decreased slightly (but not significantly), leading to lowered PIC ∕ POC ratios in all strains. There were no consistent correlations of response intensity with strain origin. The high-CO2–low-pH condition affected coccolith morphology equally or more strongly in over-calcified strains compared to moderately calcified strains. High-CO2–low-pH conditions appear not to directly select for exceptionally over-calcified morphotypes over other morphotypes, but perhaps indirectly by ecologically correlated factors. More generally, these results suggest that oceanic planktonic microorganisms, despite their rapid turnover and large population sizes, do not necessarily exhibit adaptations to naturally high-CO2 upwellings, and this ubiquitous coccolithophore may be near the limit of its capacity to adapt to ongoing ocean acidification.

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“…braarudii is common in coastal upwelling regions of the Northeast and Southeast Atlantic (e.g. Cachão and Moita, 2000;Henderiks et al, 2012).…”

Section: A C Gerecht Et Al: High Temperature Decreases the Pic / Pmentioning

confidence: 99%

High temperature decreases the PIC / POC ratio and increases phosphorus requirements in Coccolithus pelagicus (Haptophyta)

et al. 2014

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Abstract. Rising ocean temperatures will likely increase stratification of the water column and reduce nutrient input into the photic zone. This will increase the likelihood of nutrient limitation in marine microalgae, leading to changes in the abundance and composition of phytoplankton communities, which in turn will affect global biogeochemical cycles. Calcifying algae, such as coccolithophores, influence the carbon cycle by fixing CO 2 into particulate organic carbon through photosynthesis (POC production) and into particulate inorganic carbon through calcification (PIC production). As calcification produces a net release of CO 2 , the ratio of PIC to POC production determines whether coccolithophores act as a source (high PIC / POC) or a sink (low PIC / POC) of atmospheric CO 2 . We studied the effect of phosphorus (P-) limitation and high temperature on the physiology and the PIC / POC ratio of two subspecies of Coccolithus pelagicus. This large and heavily calcified species is a major contributor to calcite export from the photic zone into deep-sea reservoirs. Phosphorus limitation did not influence exponential growth rates in either subspecies, but P-limited cells had significantly lower cellular P-content. One of the subspecies was subjected to a 5 • C temperature increase from 10 • C to 15 • C, which did not affect exponential growth rates either, but nearly doubled cellular P-content under both high and low phosphate availability. This temperature increase reduced the PIC / POC ratio by 40-60 %, whereas the PIC / POC ratio did not differ between P-limited and nutrientreplete cultures when the subspecies were grown near their respective isolation temperature. Both P-limitation and elevated temperature significantly increased coccolith malformations. Our results suggest that a temperature increase may intensify P-limitation due to a higher P-requirement to maintain growth and POC production rates, possibly reducing abundances in a warmer ocean. Under such a scenario C. pelagicus may decrease its calcification rate relative to photosynthesis, thus favouring CO 2 sequestration over release. It seems unlikely that P-limitation by itself causes changes in the PIC / POC ratio in this species.

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Environmental controls on Emiliania huxleyi morphotypes in the Benguela coastal upwelling system (SE Atlantic)

Cited by 60 publications

References 56 publications

Coccolithophore populations and their contribution to carbonate export during an annual cycle in the Australian sector of the Antarctic zone

Coccolithophore populations and their contribution to carbonate export during an annual cycle in the Australian sector of the Antarctic zone

Over-calcified forms of the coccolithophore <i>Emiliania huxleyi</i> in high-CO<sub>2</sub> waters are not preadapted to ocean acidification

High temperature decreases the PIC / POC ratio and increases phosphorus requirements in <i>Coccolithus pelagicus</i> (Haptophyta)

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Environmental controls on Emiliania huxleyi morphotypes in the Benguela coastal upwelling system (SE Atlantic)

Cited by 60 publications

References 56 publications

Coccolithophore populations and their contribution to carbonate export during an annual cycle in the Australian sector of the Antarctic zone

Coccolithophore populations and their contribution to carbonate export during an annual cycle in the Australian sector of the Antarctic zone

Over-calcified forms of the coccolithophore &lt;i&gt;Emiliania huxleyi&lt;/i&gt; in high-CO&lt;sub&gt;2&lt;/sub&gt; waters are not preadapted to ocean acidification

High temperature decreases the PIC / POC ratio and increases phosphorus requirements in &lt;i&gt;Coccolithus pelagicus&lt;/i&gt; (Haptophyta)

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Over-calcified forms of the coccolithophore <i>Emiliania huxleyi</i> in high-CO<sub>2</sub> waters are not preadapted to ocean acidification

High temperature decreases the PIC / POC ratio and increases phosphorus requirements in <i>Coccolithus pelagicus</i> (Haptophyta)