Environmental control on phytoplankton community structure in the NE Black Sea

Силкин, В. А.; Паутова, Л. А.; Pakhomova, Svetlana; Lifanchuk, Anna V.; Yakushev, E. V.; Часовников, В. К.

doi:10.1016/j.jembe.2014.08.009

Cited by 43 publications

(25 citation statements)

References 25 publications

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“…Today, coccolithophores are present in all oceans and most marginal seas, including the semi-enclosed Mediterranean, Black and Caspian Sea, as well as the western but not the eastern part of the Baltic Sea (Kideys et al, 2005;Moore et al, 2012;Silkin et al, 2014;Tyrrell et al, 2008). The Black Sea has considerably higher total alkalinities than the global ocean, leading to high availability of HCO 3 À substrate and comparatively lower [H + ] at atmosphere-equilibrated pCO 2 (Goyet et al, 1991).…”

Section: Implications: Past Present and Futurementioning

confidence: 99%

A unifying concept of coccolithophore sensitivity to changing carbonate chemistry embedded in an ecological framework

Bach

Riebesell

Gutowska

et al. 2015

Progress in Oceanography

122

133

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a b s t r a c tCoccolithophores are a group of unicellular phytoplankton species whose ability to calcify has a profound influence on biogeochemical element cycling. Calcification rates are controlled by a large variety of biotic and abiotic factors. Among these factors, carbonate chemistry has gained considerable attention during the last years as coccolithophores have been identified to be particularly sensitive to ocean acidification. Despite intense research in this area, a general concept harmonizing the numerous and sometimes (seemingly) contradictory responses of coccolithophores to changing carbonate chemistry is still lacking to date. Here, we present the ''substrate-inhibitor concept'' which describes the dependence of calcification rates on carbonate chemistry speciation. It is based on observations that calcification rate scales positively with bicarbonate (HCO 3 À ), the primary substrate for calcification, and carbon dioxide (CO 2 ), which can limit cell growth, whereas it is inhibited by protons (H + ). This concept was implemented in a model equation, tested against experimental data, and then applied to understand and reconcile the diverging responses of coccolithophorid calcification rates to ocean acidification obtained in culture experiments. Furthermore, we (i) discuss how other important calcification-influencing factors (e.g. temperature and light) could be implemented in our concept and (ii) embed it in Hutchinson's niche theory, thereby providing a framework for how carbonate chemistry-induced changes in calcification rates could be linked with changing coccolithophore abundance in the oceans. Our results suggest that the projected increase of H + in the near future (next couple of thousand years), paralleled by only a minor increase of inorganic carbon substrate, could impede calcification rates if coccolithophores are unable to fully adapt. However, if calcium carbonate (CaCO 3 ) sediment dissolution and terrestrial weathering begin to increase the oceans' HCO 3 À and decrease its H + concentrations in the far future (10-100 kyears), coccolithophores could find themselves in carbonate chemistry conditions which may be more favorable for calcification than they were before the Anthropocene.

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Section: Implications: Past Present and Futurementioning

confidence: 99%

A unifying concept of coccolithophore sensitivity to changing carbonate chemistry embedded in an ecological framework

Bach

Riebesell

Gutowska

et al. 2015

Progress in Oceanography

122

133

View full text Add to dashboard Cite

show abstract

“…P is a vital nutrient utilized by all marine organisms in essential biomolecules, including nucleic acids, phospholipids, ATP and other energyconserving compounds Diaz et al, 2012). While P is often thought to limit global primary production over geologic timescales, recent evidence suggests that P availability may also influence phytoplankton cellular composition, community structure, growth and production in the modern ocean (Benitez-Nelson, 2000;Paytan and McLaughlin, 2007;Karl, 2014;Silkin et al, 2014). This has led to more focused investigations regarding P speciation and cycling over short time scales (e.g., Diaz et al, 2012;Martin et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Cycling of suspended particulate phosphorus in the redoxcline of the Cariaco Basin

et al. 2015

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The Cariaco Basin, located off the coast of Venezuela, is anoxic below~250 m and has a productive redoxcline where several chemical gradients support multiple biogeochemical reactions. Thus, the Cariaco Basin is an ideal study site for investigating how redox chemistry influences phosphorus (P) biogeochemistry across oxic/ anoxic boundaries. While sinking particles in the Cariaco Basin have been investigated previously for P composition and flux, this is the first study to describe P within suspended particulate particles, a key phase connecting particulate and dissolved P pools. Analysis of samples collected between April 2008 and April 2012, indicates that secondary peaks in total suspended particulate P (TSPP) concentrations (88 ± 60 nM) were present in the redoxcline and were similar in magnitude to those measured in the upper 100 m (84 ± 77 nM TSPP). However, the composition of TSPP was significantly different between the surface and the redoxcline. Suspended soluble reactive phosphorus (SSRP) was on average 3 ± 2 times greater in the redoxcline than observed in surface waters. Furthermore, composition of the TSPP pool significantly changed from less biologically available P forms (~45% organic P) above and below the redoxcline to more biologically available P forms (~80% loosely/oxidebound P) within the redoxcline. We argue that the abrupt increases and transformations in the TSPP pool within the redoxcline result from both abiotic reactions associated with a manganese and iron redox shuttle and biotic reactions associated with a large and diverse chemoautotrophic prokaryotic community. These results suggest that the biogeochemical cycling of P may be altered within oxygen depleted water columns in unexpected ways.

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“…In a number of works [3,4] it was shown that interannual variability of chlorophyll a concentration is closely related to the minimum winter temperature of the sea surface (SST) which is an indicator of winter severity and vertical mixing intensity. The bloom of phytoplankton, for example coccolithophores, in the warm period of the year significantly depends on winter cooling and on the amount of nutrients supplied during the winter, the phosphates in particular [9,10]. Among other important mechanisms of nutrient supply, horizontal cross-shelf transport can be noted.…”

mentioning

confidence: 99%

Impact of Winter Cooling on Water Vertical Entrainment and Intensity of Phytoplankton Bloom in the Black Sea

Kubryakova¹,

Kubryakov²,

Stanichny³

2018

PhO

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Vertical entrainment of nutrients and phytoplankton from the subsurface layers in autumn -winter is a cause of the surface phytoplankton bloom in the Black Sea in winter. Relationship of the winter heat flux and the sea surface temperature (SST) with the integral and surface phytoplankton biomass is assessed based on a series of simulations performed due to a 1D-biogeochemical model. The results show that during severe winters, intensity of phytoplankton bloom is 50% higher than that in warm winters. Winter entrainment of nutrients influences the phytoplankton biomass in the subsurface layer in summer, namely, after cold winters its maximum value exceeds the analogous one after warm winters by ≈30%. In-situ data is used to estimate the relation between the upper mixed layer depth and density, and the integral concentration of nitrates and phosphates in various regions of the basin. It is revealed that growth of the upper mixed layer density from 1014.0 to 1014.2 kg/m 3 results in increase of the integral concentration of nutrients in the upper layer by 2-2.5 times in the center and on the periphery of the basin; and when the density value achieves 1014.5 kg/m 3 the integral concentration becomes higher by 4-5 times. Thus the upper mixed layer density serves a good indicator of intensity of the nutrients inflow to the sea upper layers. Impact of winter cooling upon the upper mixed layer density is investigated using the model and in-situ data. It is shown that density equal to 1014.2 kg/m 3 is achieved in the basin center at SST 7.5-8° C, and on the sea periphery -at 6.5° C. The maximum density value 1014.8 kg/m 3 is recorded in the center of the sea (depth exceeds 2000 m) at SST < 5.5° C. During the same atmospheric conditions, the vertical nutrient transport is different in various regions of the Black Sea, which can affect the spatial features of bloom intensity in the basin. Acknowledgements:The data were obtained and processed within the framework of the State Order No. 0827-2014-0011 "The research of regularities of marine environment condition changes on the basis of operational observations and the data of marine area condition nowcast, forecast and reanalysis system" ("Operative oceanography" code); model calculations were carried out with the financial support of RFBR

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Environmental control on phytoplankton community structure in the NE Black Sea

Cited by 43 publications

References 25 publications

A unifying concept of coccolithophore sensitivity to changing carbonate chemistry embedded in an ecological framework

A unifying concept of coccolithophore sensitivity to changing carbonate chemistry embedded in an ecological framework

Cycling of suspended particulate phosphorus in the redoxcline of the Cariaco Basin

Impact of Winter Cooling on Water Vertical Entrainment and Intensity of Phytoplankton Bloom in the Black Sea

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