Adsorption capacity of phosphorus in Baltic Sea sediments

Carman, Rolf; Wulff, Fredrik

doi:10.1016/0272-7714(89)90079-6

Cited by 41 publications

(21 citation statements)

References 24 publications

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“…These very low ratios resulted from extremely high P-PO4 fluxes observed under anoxic conditions which exhibited a relatively larger increase than fluxes of N-NH, under similar conditions. Since the organic source for these sediments is mainly phytoplankton detritus with a n initial N:P composition ratio of about 12:l (Leppanen 1988) it is probable that the extreme departures from stoichiometric ratios that we observed at Stns 1 and 2 were of a transient nature resulting from the rapid release of recently deposited P as well as P sequestered in oxidised surficial sediments via mechanisms such as those suggested by Klump &Martens (1981) andCarman &. Interestingly, sediments at the deepest station had N : P flux ratios closer to those expected based on the composition of the source material.…”

Section: Nutrient Flux Ratiosmentioning

confidence: 84%

Sediment-water oxygen and nutrient exchanges along a depth gradient in the Baltic Sea

Koop¹,

Boynton²,

Wulff³

et al. 1990

Mar. Ecol. Prog. Ser.

117

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Bottom water and sediment characteristics and net sediment-water fluxes of oxygen, nitrogen, phosphorus and hydrogen sulphide were measured under oxic a n d experimentally induced anoxic conditions along a depth gradient (47 to 130 m) during summer in the Baltic proper. Temperature, salinity and dissolved nutrient concentrations (particularly phosphorus and nitrate) in bottom waters increased with depth while oxygen concentrations decreased sharply. Sediment organic content was much higher in sediments located beneath the permanent pycnocline (ca 65 m). Sediments at all stations were somewhat depleted in total N relative to total C (C.N -10). Sediments at the shallow station (47 m ) were highly enriched with total P relative to C or N (C:N P = 18:2:1) but were somewhat depleted in P at the deeper stations (C:N:P = 120:12:1). Under oxic conditions oxygen fluxes ranged from 214 to 777 pm01 0 m Q-' and decreased with depth. Phosphorus and nitrite fluxes were always very small and were directed either into or out of the sediments. Ammonium fluxes were small (1 to 30 pm01 N m-' h-') at all stations and did not exhibit a clear pattern with depth; 0 : N -N H , flux ratios were close to expected 'Redfield ratios' at the deep station (16:l) but were much higher (>55:1) at the shallower sites indicating that processes other than only an~monificatlon were taking place in sediments. Nitrate was always consumed by sediments (ca 1 to 16 ktn~ol N m-' h-') and fluxes were proportional to nitrate concentrations in the overlying water. Under anomc conditions there was a dramatic increase in P-PO4 fluxes (2 to 40 pm01 P m-' h-') and a smaller lncrease In N-NH, fluxes (14 to 35 pm01 N m-2 h ' ) . Large hydrogen sulphide fluxes (>40 pm01 S m-' h-') were observed in sediments from the deepest station only. Under oxic conditions sediment recycling of N and particularly of P were small compared to estimated rates of burial of P and burial plus denitrification of N However, under anoxic conditions, sediment recycling of both N and P were similar to or much greater than sedlment loss terms of burial and denitrification. Sediment regeneration under oxic conditions could supply 1 to 8 % and 0 to 2 % of estimated phytoplankton demand of N and P, respectively; under anoxic conditions 12 % of N and u p to 200 O/o of P demand could be met via sediment recycling.

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Section: Nutrient Flux Ratiosmentioning

confidence: 84%

Sediment-water oxygen and nutrient exchanges along a depth gradient in the Baltic Sea

Koop¹,

Boynton²,

Wulff³

et al. 1990

Mar. Ecol. Prog. Ser.

117

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“…Re-suspended particles can in fact release, absorb or have no effect on soluble reactive phosphorus depending on water and particle phosphate concentrations (Søndergaard et al, 1992) and water pH, with release driven by high pH values (Koski-Vähälä and Hartikainen, 2001). In oxic conditions, the sediment is generally a sink of phosphate which co-precipitates with iron and manganese oxides; the occurrence of anoxic conditions, often present in semi-enclosed stratified waters in late summer and in deep sediment horizons, can determine sediment phosphate release (Carman and Wulff, 1989;Sundby et al, 1992). The regression model explained a low percentage of the deviance because it described only the winter release of phosphate, however, once again we could be underestimating the phosphate flux due to the lack of a stirring system that simulates the effect of resuspension in incubation chambers (Almroth et al, 2009).…”

Section: Phosphate Sediment-water Fluxesmentioning

confidence: 99%

Statistical Modeling of Variability in Sediment-Water Nutrient and Oxygen Fluxes

2016

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Mineralisation of organic detritus in the marine surficial sediments generates a flux of dissolved inorganic nutrient between the sediment and overlying water column. This is a key process in the marine ecosystem, which links the food webs of the sea-floor and the overlying water-column, and is potentially affected by a range of interacting environmental and sedimentary factors. Here, we use General Additive Models (GAM) to statistically disentangle some of the factors controlling the seasonal and spatial variability in nutrients and oxygen fluxes in a field dataset collected in the North Sea off the northeast coast of Scotland. We show that sediment grain size, turbidity due to sediment re-suspension, temperature, and sediment chlorophyll content were the key factors affecting oxygen, ammonia, and silicate fluxes. However, phosphate fluxes were only related to suspended sediment concentrations, whilst nitrate fluxes showed no clear relationship to any of the expected drivers of change, probably due to the effects of denitrification. Our analyses show that the stoichiometry of nutrient regeneration in the ecosystem is not necessarily constant and may be affected by combinations of processes.

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“…These isotherms are linear for low to moderate equilibrium PO 4 -P (e.g., Krom and Berner 1980;Carman and Wulff 1989) and can be expressed as (Froelich 1988) …”

Section: Methodsmentioning

confidence: 99%

Phosphorus availability in the Paraná floodplain lakes (Argentina): Influence of pH andphosphate buffering by fluvial sediments

Carignan

Vaithiyanathan

1999

Limnology & Oceanography

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The phosphate-buffering properties and P chemistry of suspended particulate matter (SPM) collected in three geologically contrasting rivers (Bermejo, Paraguay, and Upper Paraná) are compared in order to explain the abundance of dissolved PO 4 -P in the Paraná floodplain lakes. The rivers show distinctive P-buffering capacities related to the chemical composition of their SPM. At natural pH, the linear adsorption coefficient of PO 4 -P (K d ) ranges from 0.25 liter g Ϫ1 for the Paraguay River to 1.38 liter g Ϫ1 for the Upper Paraná River. Equilibrium PO 4 -P ranges from 0.17 mol liter Ϫ1 for the Upper Paraná River to 2.92 mol liter Ϫ1 for the Bermejo River. Short-term (60 h) desorbable PO 4 -P ranges from 0.23 mol g Ϫ1 for the Paraguay to 0.77 mol g Ϫ1 for the Upper Paraná. These values increase substantially with a small decrease in pH representative of conditions experienced by riverine SPM when it enters the floodplain environment. For the carbonate-bearing SPM of the Bermejo and Paraguay Rivers, a pH decrease of 1-1.5 units causes a 10-fold increase in equilibrium PO 4 -P and a 5-to 10-fold increase in desorbable PO 4 -P, and it is associated with the release of Ca. In the Upper Paraná, a similar decrease in pH has opposite effects that are consistent with a stronger complexation of PO 4 -P by hydrous iron oxides at low pH. Compared to the parent riverine SPM, floodplain lake sediments are depleted in Ca-bound P and enriched in Fe-bound P. Although Ca-bound P is often considered biologically unavailable, our observations suggest that in the Paraná floodplain lakes, most of the available P originates from the acid dissolution of Ca-bound P. Loading of fluvial sediments to the lakes and the acidic dissolution of Ca-bound P appear sufficient to explain the permanent excess of dissolved PO 4 -P in these waters.

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Adsorption capacity of phosphorus in Baltic Sea sediments

Cited by 41 publications

References 24 publications

Sediment-water oxygen and nutrient exchanges along a depth gradient in the Baltic Sea

Sediment-water oxygen and nutrient exchanges along a depth gradient in the Baltic Sea

Statistical Modeling of Variability in Sediment-Water Nutrient and Oxygen Fluxes

Phosphorus availability in the Paraná floodplain lakes (Argentina): Influence of pH andphosphate buffering by fluvial sediments

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