Particulate matter in the southern Adriatic and Ionian Sea: characterisation and downward fluxes

Boldrin, A.; Miserocchi, Stefano; Rabitti, Sandro; Turchetto, M.; Balboni, V.; Socal, Giorgio

doi:10.1016/s0924-7963(02)00068-4

Cited by 102 publications

(110 citation statements)

References 43 publications

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“…The efficiency of POC export to depth calculated for the SOFi site is consistent with values found in the literature for other oceanic systems (5 to 10%) (Buesseler, 1998). In the Eastern Mediterranean, similar values were found, with an export efficiency of 2 to 3% of the primary production in the Cretan Sea (Stavrakakis et al, 2000) and less than 4% in the Adriatic (Boldrin et al, 2002). Another study conducted in different parts of the Mediterranean evidenced an increase in the C export efficiency from the Eastern (3%) to the Western part (10%) of the Mediterranean (Danovaro et al, 1999), but our results are more consistent with values found for the Eastern basin.…”

Section: Si and C Budgets Efficiency Of The Silicate Pumpsupporting

confidence: 88%

Efficiency of the silicate pump at a coastal oligotrophic site in the Mediterranean Sea

et al. 2005

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Abstract.A one-year survey of the sedimenting particulate material was conducted at the SOFi site located on the edge of the continental slope in the Gulf of Lions (Northwestern Mediterranean) between September 1999 and December 2000. The main focus of this paper was to establish an annual budget of biogenic silica export, to describe the seasonnal pattern of Si fluxes in relation to the organic and mineral C fluxes and to quantify the Si/C decoupling processes during sedimentation. The pattern of the downward flux of BSi was partly typical with increased daily sedimentation rates during spring followed by smaller peaks during summer. However, an unusual sedimentation event was recorded in the bottom trap in February before the spring thermal stratification occurred, and represented 37% of the annual BSi mass flux. The total annual BSi flux at the SOFi site was estimated from the bottom trap and amounted to 86.8 mmol Si m −2 y −1 , while the organic carbon flux amounted to 154.9 mmol C m −2 y −1 . The overall efficiency of C export to depth compared to surface primary production budgets was low (3%) and similar to values found for oligotrophic regions of the Eastern Mediterranean. On the other hand, we documented a very high efficiency of the Si export at the SOFi site, with 62% of the Si produced in the surface layer exported to the bottom trap. The excellent correlation between BSi and particulate organic C (POC) in the bottom trap further indicates that the bulk of the organic matter is transferred to depth in association with diatoms. However, the main fraction of the C produced by phytoplankton is lost in the water column through oxidation or metabolisation, while biogenic silica is more efficiently transferred to depth. This strong Si/C decoupling with depth is likely to be the cause of the spring Correspondence to: K. Leblanc (leblanc@com.univ-mrs.fr) depletion of silicic acid over the entire water column which was observed by mid-April in a companion study (Leblanc et al., 2003) and may cause a severe Si limitation of the diatom spring bloom in this oligotrophic region of the Gulf of Lions.

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Section: Si and C Budgets Efficiency Of The Silicate Pumpsupporting

confidence: 88%

Efficiency of the silicate pump at a coastal oligotrophic site in the Mediterranean Sea

et al. 2005

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“…In the Mediterranean Sea, seasonal hydrological regime varies from winter mixing (January-February) to thermal stratification in summer and fall, causing nutrient depletion in the surface layer during summer, and reinjection to the surface layer during winter mixing (Marty et al, 2002). The same process was observed in the southern Adriatic Sea, where the supply of inorganic nutrients to the upper layer is followed by increased primary production and downward fluxes of particulate matter in early spring (Boldrin et al, 2002). The abundance of food may affect feeding rates and rates of water transport across the gills of filter-feeding organisms, thereby affecting the uptake of metals from both solution and food (Janssen and Scholz, 1979).…”

Section: Temporal Variations Of Digestive Gland Mass Cytosolic Mt Anmentioning

confidence: 79%

Is the digestive gland of Mytilus galloprovincialis a tissue of choice for estimating cadmium exposure by means of metallothioneins?

Raspor

Dragun

Erk

et al. 2004

Science of The Total Environment

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A study performed over 12 months with caged mussels M. galloprovincialis in the coastal marine zone which is under the urban pressure, reveales a temporal variation of digestive gland mass which causes "biological dilution" of cytosolic metallothionein (MT) and trace metal (Cd, Cu, Zn, Fe, Mn) concentrations. The dilution effect was corrected by expressing the cytosolic MT and metal concentrations as the tissue content.

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“…In addition there is biogenic particulate silica (BSi) derived from diatoms growing during the phytoplankton bloom in the S Adriatic in winter. Boldrin et al (2002) Thus the initial silicic acid value of 6.3 µmol Si kg −1 in the western Ionian deep water is preformed silicic acid plus BSi present in the downwelled ADW, which dissolved rapidly. This is considered reasonable since the deep water in the EMS is not only low in silicic acid concentration compared to other deep water locations in the ocean but is also relatively warm (∼ 13 • C) (Roether et al, 2007).…”

Section: Silicic Acid In Porewatersmentioning

confidence: 98%

Silica cycling in the ultra-oligotrophic eastern Mediterranean Sea

2014

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Abstract. Although silica is a key plant nutrient, there have been few studies aimed at understanding the Si cycle in the eastern Mediterranean Sea (EMS). Here we use a combination of new measurements and literature values to explain the silicic acid distribution across the basin and to calculate a silica budget to identify the key controlling processes. The surface water concentration of ∼ 1 µM, which is unchanging seasonally across the basin, was due to the inflow of western Mediterranean Sea (WMS) water at the Straits of Sicily. It does not change seasonally because there is only a sparse population of diatoms due to the low nutrient (N and P) supply to the photic zone in the EMS. The concentration of silicic acid in the deep water of the western Ionian Sea (6.3 µM) close to the S Adriatic are an of formation was due to the preformed silicic acid (3 µM) plus biogenic silica (BSi) from the dissolution of diatoms from the winter phytoplankton bloom (3.2 µM). The increase of 4.4 µM across the deep water of the EMS was due to silicic acid formed from in situ diagenetic weathering of aluminosilicate minerals fluxing out of the sediment. The major inputs to the EMS are silicic acid and BSi inflowing from the western Mediterranean (121 × 10 9 mol Si yr −1 silicic acid and 16 × 10 9 mol Si yr −1 BSi), silicic acid fluxing from the sediment (54 × 10 9 mol Si yr −1 ) and riverine (27 × 10 9 mol Si yr −1 ) and subterranean groundwater (9.7 × 10 9 mol Si yr −1 ) inputs, with only a minor direct input from dissolution of dust in the water column (1 × 10 9 mol Si yr −1 ). This budget shows the importance of rapidly dissolving BSi and in situ weathering of aluminosilicate minerals as sources of silica to balance the net export of silicic acid at the Straits of Sicily. Future measurements to improve the accuracy of this preliminary budget have been identified.

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Particulate matter in the southern Adriatic and Ionian Sea: characterisation and downward fluxes

Cited by 102 publications

References 43 publications

Efficiency of the silicate pump at a coastal oligotrophic site in the Mediterranean Sea

Efficiency of the silicate pump at a coastal oligotrophic site in the Mediterranean Sea

Is the digestive gland of Mytilus galloprovincialis a tissue of choice for estimating cadmium exposure by means of metallothioneins?

Silica cycling in the ultra-oligotrophic eastern Mediterranean Sea

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