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Wyszukujesz frazę "benthic sediments" wg kryterium: Wszystkie pola


Wyświetlanie 1-3 z 3
Tytuł:
Seasonal variability of benthic ammonium release in the surface sediments of the Gulf of Gdańsk (Southern Baltic Sea)
Autorzy:
Maksymowska-Brossard, D.
Piekarek-Jankowska, H.
Powiązania:
https://bibliotekanauki.pl/articles/48426.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
ammonium
spatial variation
seasonal variation
Baltic Sea
sediment
Gdansk Gulf
benthic flux
benthic ammonium
Opis:
This paper describes the seasonal and spatial variations of diffusive sediment– water ammonium fluxes in the western part of the Gulf of Gdańsk (southern Baltic). It assesses the potential environmental controls of these fluxes, such as the inflow of organic matter to bottom sediments and its quality, temperature-induced degradation of organic matter, and the redox potential of sediments. Ammonium fluxes, calculated using Fick’s first law, were always in the direction from the sediment into the water column and differed significantly with respect to sediment type. Fluxes were most intensive in sediments with the highest silt-clay fraction located in the deepest parts of the study area. The mean annual diffusive fluxes of ammonium from sediments to near-bottom water were estimated at 5.24 tonnes km−2 year−1 for silty-clays, 1.85 tonnes km−2 year−1 for silty-sands and 1.03 tonnes km−2 year−1 for sandy sediments. There was a high seasonal variation, with the greatest ammonium release in summer and early autumn, when the temperature of near-bottom water was the highest. On the basis of the calculated diffusive ammonium fluxes, we estimated that approximately 2700 tonnes of N–NH+4 are released annually from the surface sediments of the western part of the Gulf of Gdańsk, providing a minimum of 10% of the mineral nitrogen essential for primary production in surface waters. Our results are undoubtedly underestimated, as we disregarded advective ammonium fluxes, which in some areas of the Gulf of Gdańsk could well be comparable to diffusive fluxes.
Źródło:
Oceanologia; 2001, 43, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Benthic diffusive fluxes of organic and inorganic carbon, ammonium and phosphates from deep water sediments of the Baltic Sea
Autorzy:
Lengier, M.
Szymczycha, B.
Brodecka-Goluch, A.
Klostowska, Z.
Kulinski, K.
Powiązania:
https://bibliotekanauki.pl/articles/2078878.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
biogeochemistry
benthic flux
organic carbon
organic matter
remineralization
dissolved organic carbon
dissolved inorganic carbon
ammonium
phosphate
oxygen availability
deep water sediment
Baltic Sea
Opis:
In this study, Baltic Sea sediments, as a source of dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), ammonium (NH4 +), and phosphates (PO4 3−), were investigated based on samples obtained in 2017 and 2018, shortly after a sequence of inflows from the North Sea that occurred between 2014 and 2017. Two different data sets (I and II) were used to assess benthic diffusive fluxes and thus elucidate both the temporal conditions at the time of sampling (data set I) and the diffusion potential of the sediments (data set II). The estimated fluxes were characterized by a high spatial variability within the whole Baltic Sea and ranged between −0.01 and 3.33 mmol m−2 d−1 for DIC, −0.02 and 0.44 mmol m−2 d−1 for DOC, −40.5 and 1370.1 μmol m−2 d−1 for NH4 +, and −5.9 and 60.9 μmol m−2 d−1 for PO4 3−. The estimated benthic diffusive fluxes indicated a high potential for DIC, DOC, NH4 +, and PO4 3− release from Baltic Sea sediments. The high O2 concentrations in the water column of the Gulf of Bothnia together with major Baltic inflows (MBIs) bringing oxygenated seawater to the Baltic Proper and to some extent the Eastern Gotland Basin regulate the amounts of chemicals released from the sediment. Our study showed that a sequence of inflows has greater impact on the diminution of diffusive fluxes than does a single MBI and that the sediments of the Baltic Proper, even under the influence of inflows, are an important source of C, N, and P (159 kt yr−1 for DIC+DOC, 6.3
Źródło:
Oceanologia; 2021, 63, 3; 370-384
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microphytobenthic primary production on exposed coastal sandy sediments of the Southern Baltic Sea using ex situ sediment cores and oxygen optodes
Autorzy:
Kuriyama, K.
Grundling-Pfaff, S.
Diehl, N.
Woelfel, J.
Karsten, U.
Powiązania:
https://bibliotekanauki.pl/articles/2078927.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
microphytobenthos
primary production
sandy sediment
coastal water
benthic diatom
oxygen consumption
oxygen production
respiration
hydrodynamics
Baltic Sea
Opis:
The shallow coastal water zone of the tide-less southern Baltic Sea is dominated by exposed sandy sediments which are typically inhabited by microphytobenthic communities, but their primary production is poorly studied, and hence four stations between 3.0 and 6.2 m depth were investigated. Sediment cores were carefully taken to keep the natural layering and exposed in a controlled self-constructed incubator. Respiratory oxygen consumption and photosynthetic oxygen production were recorded applying planar oxygen optode sensors. We hypothesized that with increasing water depths the effects of wind- and wave-induced erosion and mixing of the upper sediment layer are dampened and expected higher microphytobenthic biomass and primary production in the incubated cores. Our data partly confirm this hypothesis, as cores sampled at the most exposed stations contained only 50% chlorophyll a m−2 compared to the deeper stations. However, primary production was highly variable, probably due to fluctuating sediment-disturbing conditions before the cores were taken. Due to these physical forces sand grains were highly mobile and rounded, and small epipsamic benthic diatoms dominated, which preferentially occurred in some cracks and crevices as visualized by scanning electron microscopy. The data fill an important gap in reliable production data for sandy sediments of the southern Baltic Sea, and point to the ecological importance and relevant contribution of microphytobenthic communities to the total primary production of this marine ecosystem. Oxygen planar optode sensor spots proved to be a reliable, sensitive and fast detection system for ex situ oxygen exchange measurements in the overlying water of intact sediment cores.
Źródło:
Oceanologia; 2021, 63, 2; 247-260
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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