Stoichiometry of mesozooplankton in N- and P-limited areas of the Baltic Sea

Pertola, Sari; Koski, Marja; Viitasalo, Markku

doi:10.1007/s00227-001-0723-3

Cited by 27 publications

(5 citation statements)

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“…To our knowledge, there are no measurements of phytoplankton stoichiometry in the Gulf of Bothnia that could be used to validate the model. Pertola et al (2002) reported an N:P ratio of 21 in the POM from three measurements around midsummer 1999 in the Gulf of Bothnia, which is much lower than the N:P ratios of our modeled phytoplankton. The N:P ratio in POM is, however, also influenced by other factors such as preferential remineralization, the stoichiometry of zooplankton, and aggregating allochthonous DOM.…”

Section: The Importance Of Phytoplankton Stoichiometric Plasticitycontrasting

confidence: 75%

“…In the variablestoichiometry approach, the internal C:N and C:P ratios of the phytoplankton reach values several times higher than the Redfield ratio; up to 22 and 550, respectively (Figure 8), contributing to the higher primary production and DIC assimilation than in the FIX experiment. Pertola et al (2002) measured C:N and C:P ratios in POM in the Gulf of Bothnia reaching up to 14 and 338, respectively, suggesting that the phytoplankton internal ratios could deviate far from the Redfield ratios. It is, however, not only the flexible internal ratio of carbon to nutrients that plays an important role for the pCO 2 drawdown in the REF simulation; a substantial part, 26, 37, and 52% of the fixed carbon, is released as extracellular carbohydrates (semilabile DOC) in the Bothnian Sea, the Northern Quark, and the Bothnian Bay, respectively.…”

Section: The Importance Of Phytoplankton Stoichiometric Plasticitymentioning

confidence: 95%

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Non‐Redfieldian Dynamics Explain Seasonal pCO₂Drawdown in the Gulf of Bothnia

Fransner

Gustafsson²,

Tedesco

et al. 2018

JGR Oceans

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High inputs of nutrients and organic matter make coastal seas places of intense air‐sea CO2 exchange. Due to their complexity, the role of coastal seas in the global air‐sea CO2 exchange is, however, still uncertain. Here, we investigate the role of phytoplankton stoichiometric flexibility and extracellular DOC production for the seasonal nutrient and CO2 partial pressure (pCO2) dynamics in the Gulf of Bothnia, Northern Baltic Sea. A 3‐D ocean biogeochemical‐physical model with variable phytoplankton stoichiometry is for the first time implemented in the area and validated against observations. By simulating non‐Redfieldian internal phytoplankton stoichiometry, and a relatively large production of extracellular dissolved organic carbon (DOC), the model adequately reproduces observed seasonal cycles in macronutrients and pCO2. The uptake of atmospheric CO2 is underestimated by 50% if instead using the Redfield ratio to determine the carbon assimilation, as in other Baltic Sea models currently in use. The model further suggests, based on the observed drawdown of pCO2, that observational estimates of organic carbon production in the Gulf of Bothnia, derived with the 14C method, may be heavily underestimated. We conclude that stoichiometric variability and uncoupling of carbon and nutrient assimilation have to be considered in order to better understand the carbon cycle in coastal seas.

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Section: The Importance Of Phytoplankton Stoichiometric Plasticitycontrasting

confidence: 75%

Section: The Importance Of Phytoplankton Stoichiometric Plasticitymentioning

confidence: 95%

Non‐Redfieldian Dynamics Explain Seasonal pCO₂Drawdown in the Gulf of Bothnia

Fransner

Gustafsson²,

Tedesco

et al. 2018

JGR Oceans

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“…Since copepods such as Acartia contain more N than P (Pertola et al 2002), the amount of the former in a given phytoplankton cell might be more important than P in determining food quality for these copepods. The exceptionally high mortality in HD-N def could have been caused by a combined and synergistic effect of crowding (160 Acartia L 21 in HD, compared to 16 Acartia L 21 in LD) and a low N content of food.…”

Section: Npmentioning

confidence: 99%

Grazer‐induced defence in Phaeocystis globosa (Prymnesiophyceae): Influence of different nutrient conditions

Lundgren

2010

Limnology & Oceanography

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We examined the combined effects of grazer infochemicals and nutrient status on colony development of Phaeocystis globosa cultures grown under nitrogen and phosphorus (NP)-sufficient, P-deficient, and N-deficient conditions exposed to high and low Acartia spp. density filtrates. Changes in colony development relative to controls receiving no grazer signals were estimated. P. globosa colony development responded to grazer infochemicals regardless of nutrient status, although the expression of the response varied between nutrients. Significant colony suppression (in terms of percent of cells allocated to colonies) occurred in both NP-sufficient and P-deficient experiments, with the response being dependent on the density of grazers for NP-sufficient cells. The percent of cells in colonial form in N-deficient P. globosa decreased in response to low grazer density filtrates but increased in response to high grazer density filtrates. These opposite results for the N-deficient experiment are related to a high mortality of Acartia in the high grazer density filtrate treatment, which may affect the infochemicals released from such grazers.

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“…However, the nutritional quality of prey has been increasingly regarded a major factor in prey selection of protists (Verity, 1991;John and Davidson, 2001;Shannon et al, 2007;Siuda and Dam, 2010;Ng et al, 2017). Generally, herbivores have a lower C:N ratio (with a C:N ratio ranging 4-6.3; Koski, 1999;Pertola et al, 2002;Ng et al, 2017) compared to phytoplankton (with a C:N ratio ranging 6-10; Quigg et al, 2003). According to Liebig's law of the minimum, phytoplankton N contents may determine the growth efficiency of the herbivores in terms of C (i.e., the efficiency of herbivores consuming carbon and converting it into biomass; Hessen et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Protistal Grazers Increase Grazing on Unicellular Cyanobacteria Diazotroph at Night

2020

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In this study, we have for the first time analyzed diel microzooplankton grazing selectivity on unicellular cyanobacterial diazotroph (i.e., Crocosphaera watsonii WH8501) and nondiazotrophic unicellular microalga (i.e., Chlorella autotrophica). A mixed diet consisting of these two phytoplankton was supplied to four species of protistal grazers during daytime and nighttime, respectively. C. watsonii fixes nitrogen during nighttime and showed a stronger diel pattern of cellular C:N ratio than C. autotrophica. All four grazers ingested more nighttime C. watsonii than daytime C. watsonii, suggesting the diazotroph became more nutritious (inferred by C:N ratio) and thus a preferred prey for grazers when it fixes nitrogen. In particular, Oxyrrhis marina changed from preferring C. autotrophica during daytime to preferring C. watsonii during nighttime. The rest grazers showed speciesspecific grazing preferences, which could be explained by extracellular polysaccharide production of C. watsonii, feeding mode, cingulum size and cell size of grazers.

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Stoichiometry of mesozooplankton in N- and P-limited areas of the Baltic Sea

Cited by 27 publications

References 0 publications

Non‐Redfieldian Dynamics Explain Seasonal pCO₂Drawdown in the Gulf of Bothnia

Non‐Redfieldian Dynamics Explain Seasonal pCO₂Drawdown in the Gulf of Bothnia

Grazer‐induced defence in Phaeocystis globosa (Prymnesiophyceae): Influence of different nutrient conditions

Protistal Grazers Increase Grazing on Unicellular Cyanobacteria Diazotroph at Night

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Stoichiometry of mesozooplankton in N- and P-limited areas of the Baltic Sea

Cited by 27 publications

References 0 publications

Non‐Redfieldian Dynamics Explain Seasonal pCO2Drawdown in the Gulf of Bothnia

Non‐Redfieldian Dynamics Explain Seasonal pCO2Drawdown in the Gulf of Bothnia

Grazer‐induced defence in Phaeocystis globosa (Prymnesiophyceae): Influence of different nutrient conditions

Protistal Grazers Increase Grazing on Unicellular Cyanobacteria Diazotroph at Night

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Non‐Redfieldian Dynamics Explain Seasonal pCO₂Drawdown in the Gulf of Bothnia

Non‐Redfieldian Dynamics Explain Seasonal pCO₂Drawdown in the Gulf of Bothnia