scholarly journals Effects of settling organic matter on the bioaccumulation of cadmium and BDE-99 by Baltic Sea benthic invertebrates

2008 ◽  
Vol 65 (3) ◽  
pp. 264-281 ◽  
Author(s):  
Maria H. Thorsson ◽  
Jenny E. Hedman ◽  
Clare Bradshaw ◽  
Jonas S. Gunnarsson ◽  
Michael Gilek
Keyword(s):  
Organic Matter ◽  
Baltic Sea ◽  
Benthic Invertebrates

scholarly journals Cell-free extracellular enzymatic activity is linked to seasonal temperature changes: a case study in the Baltic Sea

2016 ◽  
Vol 13 (9) ◽  
pp. 2815-2821 ◽  
Author(s):  
Federico Baltar ◽  
Catherine Legrand ◽  
Jarone Pinhassi
Keyword(s):  
Organic Matter ◽  
Baltic Sea ◽  
Extracellular Enzymes ◽  
Seasonal Pattern ◽  
Critical Factor ◽  
Hydrolytic Activity ◽  
Seasonal Temperature ◽  
The Baltic Sea ◽  
The Baltic ◽  
Hydrolysis Of

Abstract. Extracellular enzymatic activities (EEAs) are a crucial step in the degradation of organic matter. Dissolved (cell-free) extracellular enzymes in seawater can make up a significant contribution of the bulk EEA. However, the factors controlling the proportion of dissolved EEA in the marine environment remain unknown. Here we studied the seasonal changes in the proportion of dissolved relative to total EEA (of alkaline phosphatase (APase), β-glucosidase (BGase), and leucine aminopeptidase (LAPase)), in the Baltic Sea for 18 months. The proportion of dissolved EEA ranged between 37 and 100, 0 and 100, and 34 and 100 % for APase, BGase, and LAPase, respectively. A consistent seasonal pattern in the proportion of dissolved EEA was found among all the studied enzymes, with values up to 100 % during winter and  <  40 % during summer. A significant negative relation was found between the proportion of dissolved EEA and temperature, indicating that temperature might be a critical factor controlling the proportion of dissolved relative to total EEA in marine environments. Our results suggest a strong decoupling of hydrolysis rates from microbial dynamics in cold waters. This implies that under cold conditions, cell-free enzymes can contribute to substrate availability at large distances from the producing cell, increasing the dissociation between the hydrolysis of organic compounds and the actual microbes producing the enzymes. This might also suggest a potential effect of global warming on the hydrolysis of organic matter via a reduction of the contribution of cell-free enzymes to the bulk hydrolytic activity.

scholarly journals Pectenotoxin-2 and dinophysistoxin-1 in suspended and sedimenting organic matter in the Baltic Sea

2006 ◽  
Vol 51 (5) ◽  
pp. 2300-2307 ◽  
Author(s):  
Pirjo Kuuppo ◽  
Pauliina Uronen ◽  
Anika Petermann ◽  
Timo Tamminen ◽  
Edna Granéli
Keyword(s):  
Organic Matter ◽  
Baltic Sea ◽  
The Baltic Sea ◽  
The Baltic ◽  
Pectenotoxin 2

The influence of dissolved organic matter on the acid–base system of the Baltic Sea

2014 ◽  
Vol 132 ◽  
pp. 106-115 ◽  
Author(s):  
Karol Kuliński ◽  
Bernd Schneider ◽  
Karoline Hammer ◽  
Ulrike Machulik ◽  
Detlef Schulz-Bull
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Baltic Sea ◽  
Base System ◽  
The Baltic Sea ◽  
Acid Base ◽  
The Baltic

scholarly journals Timescales for the development of methanogenesis and free gas layers in recently-deposited sediments of Arkona Basin (Baltic Sea)

2012 ◽  
Vol 9 (5) ◽  
pp. 1915-1933 ◽  
Author(s):  
J. M. Mogollón ◽  
A. W. Dale ◽  
H. Fossing ◽  
P. Regnier
Keyword(s):  
Organic Matter ◽  
Baltic Sea ◽  
Reactive Transport ◽  
Reaction Pathway ◽  
Organic Matter Degradation ◽  
Muddy Sediment ◽  
Transport Models ◽  
Methane Gas ◽  
Geochemical Profiles ◽  
Arkona Basin

Abstract. Arkona Basin (southwestern Baltic Sea) is a seasonally-hypoxic basin characterized by the presence of free methane gas in its youngest organic-rich muddy stratum. Through the use of reactive transport models, this study tracks the development of the methane geochemistry in Arkona Basin as this muddy sediment became deposited during the last 8 kyr. Four cores are modeled each pertaining to a unique geochemical scenario according to their respective contemporary geochemical profiles. Ultimately the thickness of the muddy sediment and the flux of particulate organic carbon are crucial in determining the advent of both methanogenesis and free methane gas, the timescales over which methanogenesis takes over as a dominant reaction pathway for organic matter degradation, and the timescales required for free methane gas to form.

scholarly journals Study on organic matter fractions in the surface micro layer in the Baltic Sea by spectrophotometric and spectrofluorometric methods

2017 ◽  
Author(s):  
Violetta Drozdowska ◽  
Iwona Wróbel ◽  
Piotr Markuszewski ◽  
Przemyslaw Makuch ◽  
Anna Raczkowska ◽  
...  
Keyword(s):  
Organic Matter ◽  
Baltic Sea ◽  
Subsurface Layer ◽  
Molecular Size ◽  
Surface Microlayer ◽  
The Baltic Sea ◽  
Vistula River ◽  
Meteorological Observations ◽  
Organic Matter Fractions ◽  
The Baltic

Abstract. The fluorescence and absorption measurements of the samples collected from a surface microlayer (SML) and a subsurface layer (SS), a depth of 1 m were studied during three research cruises in the Baltic Sea along with hydrophysical studies and meteorological observations. Several absorption (E2 : E3, S, SR) and fluorescence (fluorescence intensities at peaks: A, C, M, T, the ratio (M + T) / (A + C), HIX) indices of colored and fluorescent organic matter (CDOM and FDOM) helped to describe the changes in molecular size and weight as well as in composition of organic matter. The investigation allow to assess a decrease in the contribution of two terrestrial components (A and C) with increasing salinity (~ 1.64 % and ~ 1.89 % in SML and ~ 0.78 % and ~ 0.71 % in SS, respectively) and an increase of in-situ produced components (M and T) with salinity (~ 0.52 % and ~ 2.83 % in SML and ~ 0.98 % and ~ 1.87 % in SS, respectively). Hence, a component T reveals the biggest relative changes along the transect from the Vistula River outlet to Gdansk Deep, both in SML and SS, however an increase was higher in SML than in SS (~ 18.5 % and ~ 12.3 %, respectively). The ratio E2 : E3

Accumulation of Mercury by Plankton and Benthic Invertebrates in Riverine Lakes of Northern Manitoba (Canada): Importance of Regionally and Seasonally Varying Environmental Factors

1988 ◽  
Vol 45 (10) ◽  
pp. 1744-1757 ◽  
Author(s):  
Togwell A. Jackson
Keyword(s):  
Organic Matter ◽  
Environmental Factors ◽  
Benthic Invertebrates ◽  
Spring Flood ◽  
Chironomid Larvae ◽  
Decomposition Of Organic Matter ◽  
Preferential Uptake ◽  
Predominant Effect ◽  
Benthic Animals ◽  
Hg Accumulation

Mercury (Hg) concentrations in plankton and benthic invertebrates from riverine lakes of northern Manitoba were generally found to be unrelated, or inversely related, to inorganic and methyl mercury levels and Hg methylation rates in their habitats but were strongly dependent on environmental factors. The relationships suggest that the uptake of Hg by these organisms was controlled largely by suspended and sedimentary Hg-binding substances such as FeOOH, MnOOH, organic matter, sulfides, and clay. The sole exception was midsummer phytoplankton, whose Hg content was a function of Hg levels in local sediments, probably because interference by suspended detritus was minimal; during the spring flood, such interference had a predominant effect. Aeration of lake water by fluvial currents probably enhances the availability of Hg to plankton by promoting decomposition of organic matter and sulfides but decreases the availability of Hg to some benthic animals by causing MnOOH precipitation. FeOOH apparently limits Hg uptake by chironomid larvae but MnOOH limits Hg uptake by oligochaetes, nematodes, and pelecypods, suggesting preferential uptake of certain forms of Hg by particular biological and mineral species. Decreases in temperature may also retard Hg uptake by benthos. Biodilution has no significant effect on Hg accumulation by benthos or plankton.

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