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Helsinki, Finland

The Finnish Institute of Marine Research was a research institute founded in 1918 that was subordinate to the Ministry of Transport and Communications. The institute's main objective was to produce marine-science information to facilitate decision-making, for Finns, and for use in seafaring.Since September 2005, the Finnish Institute of Marine Research had its headquarters in Dynamicum, a building it shares with the Finnish Meteorological Institute in Kumpula, Helsinki. The institute was closed in the beginning of 2009, and its functions were divided between the Finnish Environment Institute and the Finnish Meteorological Institute . Wikipedia.

Tammert H.,University of Tartu | Lignell R.,Finnish Institute of Marine Research | Kisand V.,University of Tartu | Olli K.,University of Tartu
Aquatic Biology

A 3 wk experiment with 9 mesocosms (51 m3) was carried out at a coastal site of the brackish northwest Gulf of Finland (Baltic Sea) to study the effects of nutrient limitation and labile carbon (C) amendment on the plankton community. A 5 d period with daily inorganic nitrogen (N) and phosphorus (P) additions boosted algal biomass increase and the demand for mineral nutrients. In the following 2 wk, the supply of 1 nutrient was cut, while keeping or increasing the other, thus inducing a gradient of nutrient-limitation regimes. Labile organic C (glucose) was added to increase bacterial growth and induce mineral nutrient competition between bacteria and algae. Here we report the effects of the treatments on bacterial abundance, production, and community composition. Addition of labile organic C led to a significant increase (p < 0.001) in the biomass of large filamentous bacteria and in bacterial productivity but not in the biomass of small coccoid bacteria. Addition of inorganic N and P did not have any clear-cut effect on bacterioplankton. Our results suggest that bacterial assemblages have the capacity to respond to enhanced substrate availability, and that glucose strongly enhances the development of filamentous bacteria, with implications for food-web structure, biodiversity, and biogeochemistry. © Inter-Research 2012. Source

Lehmann A.,Leibniz Institute of Marine Science | Hinrichsen H.-H.,Leibniz Institute of Marine Science | Getzlaff K.,Leibniz Institute of Marine Science | Myrberg K.,Finnish Institute of Marine Research | Myrberg K.,Klaipeda University
Journal of Marine Systems

The Baltic Sea deep waters suffer from extended areas of hypoxia and anoxia. Their intra- and inter-annual variability is mainly determined by saline inflows which transport oxygenated water to deeper layers. During the last decades, oxygen conditions in the Baltic Sea have generally worsened and thus, the extent of hypoxic as well as anoxic bottom water has increased considerably. Climate change may further increase hypoxia due to changes in the atmospheric forcing conditions resulting in less deep water renewal Baltic inflows, decreased oxygen solubility and increased respiration rates. Feedback from climate change can amplify effects from eutrophication. A decline in oxygen conditions has generally a negative impact on marine life in the Baltic Sea. Thus, a detailed description of the evolution of oxygenated, hypoxic and anoxic areas is particularly required when studying oxygen-related processes such as habitat utilization of spawning fish, survival rates of their eggs as well as settlement probability of juveniles. One of today's major challenges is still the modeling of deep water dissolved oxygen, especially for the Baltic Sea with its seasonal and quasi-permanent extended areas of oxygen deficiency. The detailed spatial and temporal evolution of the oxygen concentrations in the entire Baltic Sea have been simulated for the period 1970-2010 by utilizing a hydrodynamic Baltic Sea model coupled to a simple pelagic and benthic oxygen consumption model. Model results are in very good agreement with CTD/O2-profiles taken in different areas of the Baltic Sea. The model proved to be a useful tool to describe the detailed evolution of oxygenated, hypoxic and anoxic areas in the entire Baltic Sea. Model results are further applied to determine frequencies of the occurrence of areas of oxygen deficiency and cod reproduction volumes. © 2014 Elsevier B.V. Source

Marsan D.,University of Savoy | J'er Ome W.,CNRS Laboratory for Glaciology and Environmental Geophysics | M'etaxian J.-P.,University of Savoy | M'etaxian J.-P.,Paris West University Nanterre La Defense | And 3 more authors.
Journal of Glaciology

We report the detection of bursts of low-frequency waves, typically f=0.025Hz, on horizontal channels of broadband seismometers deployed on the Arctic sea-ice cover during the DAMOCLES (Developing Arctic Modeling and Observing Capabilities for Long-term Environmental Studies) experiment in spring 2007. These bursts have amplitudes well above the ambient ice swell and a lower frequency content. Their typical duration is of the order of minutes. They occur at irregular times, with periods of relative quietness alternating with periods of strong activity. A significant correlation between the rate of burst occurrences and the ice-cover deformation at the ?400 km scale centered on the seismic network suggests that these bursts are caused by remote, episodic deformation involving shearing across regional-scale leads. This observation opens the possibility of complementing satellite measurements of ice-cover deformation, by providing a much more precise temporal sampling, hence a better characterization of the processes involved during these deformation events. Source

Harrison P.J.,University of British Columbia | Lehtinen S.,Finnish Institute of Marine Research | Ramaiah N.,National Institute of Oceanography of India | Kraberg A.C.,Alfred Wegener Institute for Polar and Marine Research | And 3 more authors.
Estuarine, Coastal and Shelf Science

Globally there are numerous long-term time series measuring phytoplanton abundance. With appropriate conversion factors, numerical species abundance can be expressed as biovolume and then converted to phytoplankton carbon. To-date there has been no attempt to analyze globally distributed phytoplankton data sets to determine the most appropriate species-specific mean cell volume. We have determined phytoplankton cell volumes for 214 of the most common species found in globally distributed coastal time series. The cell volume, carbon/cell and cell density of large diatoms is 200,000, 20,000 and 0.1 times respectively, compared to small diatoms. The cell volume, carbon/cell and cell density of large dinoflagellates is 1500, 1000 and 0.7 times respectively, compared to small dinoflagellates. The range in diatom biovolumes is 100 times greater than across dinoflagellates (i.e. >200,000 vs. 1500 times) and within any diatom species, the range in biovolume is up to 10-fold. Variation in diatom cell volumes are the single largest source of uncertainty in community phytoplankton carbon estimates and greatly exceeds the uncertainty associated with the different volume to carbon estimates. Small diatoms have 10 times more carbon density than large diatoms and small dinoflagellates have 1.5 times more carbon density than large cells. However, carbon density varies relatively little compared to biovolume. We recommend that monthly biovolumes should be determined on field samples, at least for the most important species in each study area, since these measurements will incorporate the effects of variations in light, temperature, nutrients and life cycles. Since biovolumes of diatoms are particularly variable, the use of size classes will help to capture the percentage of large and small cells for each species at certain times of the year. This summary of global datasets of phytoplankton biovolumes is useful in order to evaluate where locally determined biovolumes lie within the global spectrum of spatial and temporal variations and may be used as a species cell volume reference where no locally determined volume estimates are available. There is a need to adopt standard protocols for measuring biovolumes and documenting the accompanying metadata which would improve inter-comparability among time series data sets. © 2015 Elsevier Ltd. Source

Riisgard H.U.,University of Southern Denmark | Larsen P.S.,Technical University of Denmark | Turja R.,Finnish Institute of Marine Research | Lundgreen K.,University of Southern Denmark
Marine Ecology Progress Series

Mussels within the Baltic Mytilus edulis × M. trossulus hybrid zone have adapted to the low salinities in the Baltic Sea which, however, results in slow-growing dwarfed mussels. To get a better understanding of the nature of dwarfism, we studied the ability of M. trossulus to feed and grow at low salinity (7 psu) compared with its performance at relatively high-salinity (20 psu) in controlled laboratory experiments, supplemented with field (Great Belt) growth experiments with M. trossulus and M. edulis in net-bags. Subsequently, the growth of M. trossulus transplanted in cages to various localities in the northern Baltic Sea was used to evaluate the effect of very low salinities, down to 3.4 psu. The laboratory feeding experiments with M. trossulus at 7 psu showed that the growth in shell length was negligible, whereas the body dry weight nearly doubled during the 15 d experiment, with a weight-specific growth rate of 3.7% d-1. The same parameters measured at 20 psu showed a pronounced growth in both shell length and body dry weight, with a weight-specific growth rate of 2.2% d-1. The growth rates of M. trossulus and M. edulis in suspended net-bags in the Great Belt (22 psu) were similar: 5.6 and 6.8% d-1, respectively. M. trossulus in cage experiments had positive growth rates at locations with salinities above 4.5 psu, up to 2.60% d-1, but negligible increase in the shell length, and at sites with salinities below about 4.5 psu, the somatic growth was negative, around -0.3% d-1, which indicates valve closure and respiratory weight loss. A trend line in a plot of all available growth data for both mussel species as a function of salinity indicates that the growth of mussels is steadily hampered by reduced salinities from 30 psu down to about 10 psu, below which the growth is rapidly reduced to become negative below 4.5 psu. We suggest that reduced ability to produce shell material at extremely low salinity may explain dwarfism of mussels in the Baltic Sea. Reduced bio-calcification at low salinity, however, may impede shell growth, but not somatic growth, and this may at first result in an increased condition index, as seen in the benthic Baltic Sea mussels transferred to cages suspended in the water column. © Inter-Research 2014. Source

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