Marine geology of the Gulf of Trieste (northern Adriatic): Geochemical aspects

Faganeli, Jadran; Planinc, R; Pezdič,; Smodiš, Borut; Stegnar, P.; Ogorelec, Bojan

doi:10.1016/0025-3227(91)90085-i

Cited by 77 publications

(24 citation statements)

References 26 publications

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“…In coastal sediments, this pool comprises a wide spectrum of inorganic and organic compounds, with the former fraction mainly represented by fixed ammonium ions entrapped in illite crystal structure (Schubert and Calvert 2001). At St. C1, this inorganic fraction cannot be excluded since its amount was reported to not exceed ~20% of the whole pool (Faganeli et al 1991). Nevertheless, TOC (wt %) and TN (wt %) resulted tightly correlated (n=28, r=0.67; p<1×10 -5 ) as reported also by Rumolo et al (2011) in the harbour of Naples (Southern Tyrrhenian Sea).…”

Section: Discussionmentioning

confidence: 99%

Microbial processing of sedimentary organic matter at a shallow LTER site in the northern Adriatic Sea: an 8-year case study

Franzo¹,

Celussi²,

Bazzaro³

et al. 2019

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Benthic prokaryotes are the key-players in C-cycling at the sediment-seawater interface, one of the largest biologically active interfaces on Earth. Here, microbial-mediated processes, such as the degradation of organic matter and the incorporation of mobilized C into microbial biomass, depend on several factors such as environmental temperature and substrate availability, especially in shallow sediments at mid-high latitudes where seasonal fluctuations of these variables occur. In the present study, four degradative activities (β-glucosidase, lipase, chitinase and aminopeptidase), Heterotrophic C Production (HCP), Total Organic C (TOC), Total Nitrogen (TN) and Biopolymeric C (BPC) were investigated seasonally from April 2010 to April 2018 in the surface sediments of a shallow Long-Term Ecological Research (LTER) station of the northern Adriatic Sea. Significant temperature-dependences were described by Arrhenius-type equations for HCP and each of the degradative activities tested with the exception of aminopeptidase. The relatively low apparent Activation Energies suggested that these microbial-mediated processes were enhanced by the availability of palatable substrates over the study period. Nevertheless, a clear and tight dependence from such substrates was detected only for aminopeptidase, the most pronounced degradative activity observed. TN was identified by the stepwise multiple regression analysis as the environmental variable that mainly drove this exoenzymatic activity. Enhanced aminopeptidase rates mirrored peaks of TN that seemed, in turn, linked to the seasonal proliferation of benthic microalgae. By supplying prokaryotes with promptly available substrates, these autotrophs, represented mainly by diatoms, seemed to play an important role in the C-cycling regulation at the studied LTER station.

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Section: Discussionmentioning

confidence: 99%

Microbial processing of sedimentary organic matter at a shallow LTER site in the northern Adriatic Sea: an 8-year case study

Franzo¹,

Celussi²,

Bazzaro³

et al. 2019

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“…This can best be done in cores by comparing the pollutant concentrations in the upper sediments layers with their preindustrial concentration in the deeper layers of the same core (Siegel et al 1994;Faganeli et al 1991). Using this approach for a practical assessment of contamination, it is possible to establish a local "baseline" concentration for each core by taking the mean of several low concentration samples selected from the deep, least impacted levels of sediment cores.…”

Section: Background Values From Average Crustal Concentrationsmentioning

confidence: 99%

Assessment of heavy metal enrichment factors and the degree of contamination in marine sediments from Tamaki Estuary, Auckland, New Zealand

Abrahim¹,

Parker²

2007

Environ Monit Assess

1,007

493

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Eight sediment cores recovered from Tamaki Estuary were analysed for Cu, Pb, Zn, and Cd using downward cored sub-samples. The results indicate a significant upward enrichment in heavy metals with the highest concentrations found in the uppermost 0-10 cm layer. Assessment of heavy metal pollution in marine sediments requires knowledge of pre-anthropogenic metal concentrations to act as a reference against which measured values can be compared. Pristine values for the cored sediments were determined from flat "base-line" metal trends evident in lower core samples. Various methods for calculating metal enrichment and contamination factors are reviewed in detail and a modified and more robust version of the procedure for calculating the degree of contamination is proposed. The revised procedure allows the incorporation of a flexible range of pollutants, including various organic species, and the degree of contamination is expressed as an average ratio rather than an absolute summation number. Comparative data for normalized enrichment factors and the modified degree of contamination show that Tamaki Estuary sediments have suffered significant systematic heavy metal contamination following catchment urbanization. Compared to baseline values the uppermost sediment layers show four-fold enrichment averaged across eight cores and four analysed metals.

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“…The intercept value indicates that some inorganic N may be present in these sediments. Previous estimates of exchangeable ammonium, nitrite and nitrate comprised up to 15 % of TN, while fixed ammonium comprised up to 56 % of TN in the sediments (Faganeli et al, 1987(Faganeli et al, , 1991. The δ 13 C org values ranged from − 21.5 to − 26.2 ‰, and from 1.7 to 7.8 ‰ for δ 15 N values.…”

Section: Resultsmentioning

confidence: 89%

The origin of organic matter in Holocene sediments in the Bay of Koper (Gulf of Trieste, northern Adriatic Sea)

Ogrinc¹,

Faganeli²,

Ogorelec³

et al. 2007

Geologija

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Three cores, V-3, V-5 and MK-6, drilled in the inner part of the Bay of Koper were used to reconstruct the paleoenvironmental conditions occurring during the Holocene. Based on stable isotope results two depositing environments can be distinguished in the cores: the upper, marine and lower, brackish sedimentation. Marine sedimentation prevailed over fluvial sedimentation at depths of 15 m, 19 m and 10 m in the V-3, MK-6 and V-5 cores respectively. The marine part of the core V-3 was influenced by varying amounts of land-derived organic carbon transported by the River Ri`ana, while in MK-6 and V-5 cores the marine algae and/or microphytes constituted the main source of sedimentary organic carbon. The fluvial sedimentation has typically lower δ 13 C org and higher C/N ratios, ∼ -26 ‰ and > 12 respectively and based on stable carbon isotope mass balance the terrestrial organic carbon present up to 70 to 100 % of the sedimentary organic carbon. On the other hand, the higher δ 15 N values observed at some depths in the fluvial sedimentation indicated that nitrogen could be of marine origin. The observed data in parallel with previous studies are in good agreement with the simultaneous rise of the sea level in the Northern Adriatic. Izvle~ekJedra vrtin V-3, V-5 in MK-6, izvrtanih v notranjem delu Koprskega zaliva smo uporabili za rekonstrukcijo paleookoljskih razmer v ~asu holocena. Na osnovi rezultatov izotopskih meritev 13 C in 15 N v organski snovi lahko v njih dolo~imo dve sedimenatcijski okolji -zgornje morsko in spodnje braki~no. Morsko sedimentacijsko okolje prevladuje do globine 15 m v vrtini V-3, 19 m v MK-6 in 10 m v vrtini V-5. Morska sedimentacija v vrtini V-3 je bila pod variabilnim vplivom vnosa kopenske organske snovi z reko Rižano, medtem ko opažamo, da izvira organska snov v vrtinah MK-6 in V-5 pretežno iz morskih mikroalg in makrofitov. Okolje re~ne sedimentacije karakterizirata nižja vrednost δ 13 C org ∼ -26 ‰ in vi{je razmerje C/N > 12. Delež kopenskega organskega ogljika v teh delih sedimenta, dolo~en na osnovi masne bilance, zna{a 70-100 %. Povi{ane vrednosti δ 15 N ugotovljene v nekaterih globinah re~ne sedimenatcijske sekvence kažejo, da je N tudi morskega izvora. Na{e ugotovitve, vzporedno s predhodnimi raziskavami, so ujemajo z dvigovanjem morja v severnem Jadranu v holocenu.

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Marine geology of the Gulf of Trieste (northern Adriatic): Geochemical aspects

Cited by 77 publications

References 26 publications

Microbial processing of sedimentary organic matter at a shallow LTER site in the northern Adriatic Sea: an 8-year case study

Microbial processing of sedimentary organic matter at a shallow LTER site in the northern Adriatic Sea: an 8-year case study

Assessment of heavy metal enrichment factors and the degree of contamination in marine sediments from Tamaki Estuary, Auckland, New Zealand

The origin of organic matter in Holocene sediments in the Bay of Koper (Gulf of Trieste, northern Adriatic Sea)

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