| |
Records |
Links |
|
Author |
Raike, A.; Kortelainen, P.; Mattsson, T.; Thomas, D.N. |
|
| |
Title |
36 year trends in dissolved organic carbon export from Finnish rivers to the Baltic Sea |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
The Science of the Total Environment |
Abbreviated Journal |
Sci Total Environ |
|
| |
Volume |
435-436 |
Issue |
|
Pages |
188-201 |
|
| |
Keywords |
Baltic States; Carbon/*chemistry; Finland; Hydrology; Oceans and Seas; Rivers/*chemistry; Seasons; Soil/chemistry |
|
| |
Abstract |
Increasing dissolved organic carbon (DOC) concentrations in lakes, rivers and streams in northern mid latitudes have been widely reported during the last two decades, but relatively few studies have dealt with trends in DOC export. We studied the export of DOC from Finnish rivers to the Baltic Sea between 1975 and 2010, and estimated trends in DOC fluxes (both flow normalised and non-normalised). The study encompassed the whole Finnish Baltic Sea catchment area (301,000 km(2)) covering major land use patterns in the boreal zone. Finnish rivers exported annually over 900,000 t DOC to the Baltic Sea, and the mean area specific export was 3.5 t km(-2). The highest export (7.3t km(-2)) was measured in peat dominated catchments, whereas catchments rich in lakes had the lowest export (2.2 t km(-2)). Inter-annual variation in DOC export was high and controlled mainly by hydrology. There was no overall trend in the annual water flow, although winter flow increased in northern Finland over 36 years. Despite the numerous studies showing increases in DOC concentrations in streams and rivers in the northern hemisphere, we could not find any evidence of increases in DOC export to the northern Baltic Sea from Finnish catchments since 1975. |
|
| |
Address |
Finnish Environment Institute (SYKE), P.O. Box 140, FI-00251, Helsinki, Finland. antti.raike@ymparisto.fi |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language  |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0048-9697 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:22854090 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
12986 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Lakaniemi, A.-M.; Hulatt, C.J.; Wakeman, K.D.; Thomas, D.N.; Puhakka, J.A. |
|
| |
Title |
Eukaryotic and prokaryotic microbial communities during microalgal biomass production |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
Bioresource Technology |
Abbreviated Journal |
Bioresour Technol |
|
| |
Volume |
124 |
Issue |
|
Pages |
387-393 |
|
| |
Keywords |
Bacteria/classification/genetics/metabolism; *Biomass; Electrophoresis, Polyacrylamide Gel; Eukaryotic Cells; Microalgae/*metabolism; Phylogeny; Polymerase Chain Reaction; Prokaryotic Cells |
|
| |
Abstract |
Eukaryotic and bacterial communities were characterized and quantified in microalgal photobioreactor cultures of freshwater Chlorella vulgaris and marine Dunaliella tertiolecta. The microalgae exhibited good growth, whilst both cultures contained diverse bacterial communities. Both cultures included Proteobacteria and Bacteroidetes, while C. vulgaris cultures also contained Actinobacteria. The bacterial genera present in the cultures were different due to different growth medium salinities and possibly different extracellular products. Bacterial community profiles were relatively stable in D. tertiolecta cultures but not in C. vulgaris cultures likely due to presence of ciliates (Colpoda sp.) in the latter. The presence of ciliates did not, however, cause decrease in total number of C. vulgaris or bacteria during 14 days of cultivation. Quantitative PCR (qPCR) reliably showed relative microalgal and bacterial cell numbers in the batch cultures with stable microbial communities, but was not effective when bacterial communities varied. Raw culture samples were successfully used as qPCR templates. |
|
| |
Address |
Department of Chemistry and Bioengineering, Tampere University of Technology, Tampere, Finland. aino-maija.lakaniemi@tut.fi |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0960-8524 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:22995170 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
12987 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Granskog, M.A.; Kaartokallio, H.; Kuosa, H.; Thomas, D.N.; Ehn, J.; Sonninen, E. |
|
| |
Title |
Scales of horizontal patchiness in chlorophyll a, chemical and physical properties of landfast sea ice in the Gulf of Finland (Baltic Sea) |
Type |
Journal Article |
| |
Year |
2005 |
Publication |
Polar Biology |
Abbreviated Journal |
Polar Biol |
|
| |
Volume |
28 |
Issue |
4 |
Pages |
276-283 |
|
| |
Keywords |
|
|
| |
Abstract |
Horizontal variation of first-year landfast sea ice properties was studied in the Gulf of Finland, the Baltic Sea. Several scales of variation were considered; a number of arrays with core spacings of 0.2, 2 and 20 m were sampled at different stages of the ice season for small-scale patchiness. Spacing between these arrays was from hundreds of meters to kilometers to study mesoscale variability, and once an onshore–offshore 40-km transect was sampled to study regional scale variability. Measured variables included salinity, stable oxygen isotopes (δ18O), chlorophyll a (chl-a), nutrients and dissolved organic carbon. On a large scale, a combination of variations in the under-ice water salinity (ice porosity), nutrient supply and the stage of ice development control the build-up of ice algal biomass. At scales of hundreds of meters to kilometers, there was significant variability in several parameters (salinity, chl-a, snow depth and ice thickness). Analyses of the data from the arrays did not show evidence of significant patchiness at scales <20 m for algal biomass. The results imply that the sampling effort in Baltic Sea ice studies should be concentrated on scales of hundreds of meters to kilometers. Using the variations observed in the study area, the estimate for depth-integrated algal biomass in landfast sea ice in the Gulf of Finland (March 2003) is 5.5±4.4 mg chl-a m-2. |
|
| |
Address |
Granskog: Arctic Centre, University of Lapland, P.O. Box 122, 96101 Rovaniemi, Finland |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Springer-Verlag |
Place of Publication |
Heidelberg |
Editor |
|
|
| |
Language |
English |
Summary Language |
English |
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0722-4060 |
ISBN |
|
Medium |
|
|
| |
Area |
Baltic Sea; Gulf of Finland |
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
refbase @ admin @ Granskog++2005 |
Serial |
739 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Steffens, M.; Granskog, M.A.; Kaartokallio, H.; Kuosa, H.; Luodekari, K.; Papadimitriou, S.; Thomas, D.N. |
|
| |
Title |
Spatial variation of biogeochemical properties of landfast sea ice in the Gulf of Bothnia, Baltic Sea |
Type |
Conference Article |
| |
Year |
2006 |
Publication |
Annals of Glaciology |
Abbreviated Journal |
Ann Glaciol |
|
| |
Volume |
44 |
Issue |
1 |
Pages |
80-87 |
|
| |
Keywords |
Sea ice; Fast ice; Sea ice properties; Ice algae; Chlorophyll; Biogeochemistry; Nutrients (mineral); Particulate organic matter; Dissolved organic matter; Salinity; Spatial scale; Spatial variability; Horizontal patchiness; Sampling design; Brackish water; Ane; Baltic Sea; Gulf of Bothnia |
|
| |
Abstract |
Horizontal variation of landfast sea-ice properties was studied in the Gulf of Bothnia, Baltic Sea, during March 2004. In order to estimate their variability among and within different spatial levels, 72 ice cores were sampled on five spatial scales (with spacings of 10 cm, 2.5 m, 25 m, 250 m and 2.5 km) using a hierarchical sampling design. Entire cores were melted, and bulk-ice salinity, concentrations of chlorophyll a (Chl a), phaeophytin (Phaeo), dissolved nitrate plus nitrite (DIN) as well as dissolved organic carbon (DOC) and nitrogen (DON) were determined. All sampling sites were covered by a 5.5-23 cm thick layer of snow. Ice thicknesses of cores varied from 26 to 58 cm, with bulk-ice salinities ranging between 0.2 and 0.7 as is typical for Baltic Sea ice. Observed values for Chl a (range: 0.8-6.0 μg Chl a l-1; median: 2.9 μg Chl a l -1) and DOC (range: 37-397 μM; median: 95 μM) were comparable to values reported by previous sea-ice studies from the Baltic Sea. Analysis of variance among different spatial levels revealed significant differences on the 2.5 km scale for ice thickness, DOC and Phaeo (with the latter two being positively correlated with ice thickness). For salinity and Chl a, the 250 m scale was found to be the largest scale where significant differences could be detected, while snow depth only varied significantly on the 25 m scale. Variability on the 2.5 m scale contributed significantly to the total variation for ice thickness, salinity, Chl a and DIN. In the case of DON, none of the investigated levels exhibited variation that was significantly different from the considerable amount of variation found between replicate cores. Results from a principal component analysis suggest that ice thickness is one of the main elements structuring the investigated ice habitat on a large scale, while snow depth, nutrients and salinity seem to be of secondary importance. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
International Glaciological Society |
Place of Publication |
Cambridge |
Editor |
|
|
| |
Language |
English |
Summary Language |
English |
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0260-3055 |
ISBN |
|
Medium |
|
|
| |
Area |
Baltic Sea; Gulf of Bothnia |
Expedition |
|
Conference |
International Symposium on Sea Ice, Dunedin (New Zealand), 5-9 Dec 2005 |
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
refbase @ admin @ Steffens++2006 |
Serial |
754 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Thomas, D.N. |
|
| |
Title |
Photosynthetic microbes in freezing deserts |
Type |
Journal Article |
| |
Year |
2005 |
Publication |
Trends in Microbiology |
Abbreviated Journal |
Trends Microbiol |
|
| |
Volume |
13 |
Issue |
3 |
Pages |
87-88 |
|
| |
Keywords |
|
|
| |
Abstract |
Polar deserts are not devoid of life despite the extreme low temperature and scarcity of water. Recently, patterned stone fields – caused by periglacial activity – have been surveyed in the Arctic and Antarctic. It was found that the productivity of the cyanobacteria and algae (hypoliths) that colonise the underside of the stones is strongly related to the pattern of the stones. The hypolith assemblages were in some cases as productive as lichens, bryophytes and plants that resided nearby. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Elsevier Science B.V. |
Place of Publication |
Amsterdam |
Editor |
|
|
| |
Language |
English |
Summary Language |
English |
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0966-842X |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
refbase @ admin @ Thomas2005 |
Serial |
755 |
|
| Permanent link to this record |
