Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Maria Laamanen is active.

Publication


Featured researches published by Maria Laamanen.


Marine Pollution Bulletin | 2010

HELCOM Baltic Sea Action Plan--a regional programme of measures for the marine environment based on the Ecosystem Approach.

Hermanni Backer; Juha-Markku Leppänen; Anne Christine Brusendorff; Kaj Forsius; Monika Stankiewicz; Jukka Mehtonen; Minna Pyhälä; Maria Laamanen; Hanna Paulomäki; Nikolay Vlasov; Tarja Haaranen

The Helsinki Commission (HELCOM) Baltic Sea Action Plan, adopted by the coastal countries of the Baltic Sea and the European Community in November 2007, is a regional intergovernmental programme of measures for the protection and management of the marine environment explicitly based on the Ecosystem Approach. The Action Plan is structured around a set of Ecological Objectives used to define indicators and targets, including effect-based nutrient input ceilings, and to monitor implementation. The Action Plan strongly links Baltic marine environmental concerns to important socio-economic fields such as agriculture and fisheries and promotes cross-sectoral tools including marine spatial planning. Due to complementarities with the European Union (EU) Marine Strategy Framework Directive, the Action Plan is in essence a pilot for this process without neglecting the important role of the Russian Federation - the only Baltic coastal country not a member of the EU.


Applied and Environmental Microbiology | 2001

Diversity of toxic and nontoxic nodularia isolates (cyanobacteria) and filaments from the Baltic Sea.

Maria Laamanen; Muriel Gugger; Jaana M. Lehtimäki; Kaisa Haukka; Kaarina Sivonen

ABSTRACT Cyanobacteria of the genus Nodularia form toxic blooms in brackish waters worldwide. In addition,Nodularia spp. are found in benthic, periphytic, and soil habitats. The majority of the planktic isolates produce a pentapeptide hepatotoxin nodularin. We examined the morphologic, toxicologic, and molecular characters of 18 nodularin-producing and nontoxic Nodularia strains to find appropriate markers for distinguishing the toxic strains from the nontoxic ones in field samples. After classical taxonomy, the examined strains were identified as Nodularia sp., Nodularia spumigena,N. baltica, N. harveyana, and N. sphaerocarpa. Morphologic characters were ambiguous in terms of distinguishing between the toxic and the nontoxic strains. DNA sequences from the short 16S-23S rRNA internally transcribed spacer (ITS1-S) and from the phycocyanin operon intergenic spacer and its flanking regions (PC-IGS) were different for the toxic and the nontoxic strains. Phylogenetic analysis of the ITS1-S and PC-IGS sequences from strains identified as N. spumigena, and N. baltica, and N. litorea indicated that the division of the planktic Nodularia into the three species is not supported by the ITS1-S and PC-IGS sequences. However, the ITS1-S and PC-IGS sequences supported the separation of strains designated N. harveyana and N. sphaerocarpa from one another and the planktic strains.HaeIII digestion of PCR amplified PC-IGS regions of all examined 186 Nodularia filaments collected from the Baltic Sea produced a digestion pattern similar to that found in toxic isolates. Our results suggest that only one plankticNodularia species is present in the Baltic Sea plankton and that it is nodularin producing.


Applied and Environmental Microbiology | 2002

Diversity of Aphanizomenon flos-aquae (cyanobacterium) populations along a Baltic Sea salinity gradient.

Maria Laamanen; Laura Forsström; Kaarina Sivonen

ABSTRACT Colony-forming cyanobacteria of the genus Aphanizomenon form massive blooms in the brackish water of the Baltic Sea during the warmest summer months. There have been recent suggestions claiming that the Baltic Sea Aphanizomenon species may be different from Aphanizomenonflos-aquae found in lakes. In this study, we examined variability in the morphology and 16S-23S rRNA internal transcribed spacer (ITS) sequences of A. flos-aquae populations along a salinity gradient from a string of lakes to a fjord-like extension of the Baltic Sea to the open Baltic Sea. Morphological differences among the populations were negligible. We found that the Baltic Sea was dominated (25 out of 27 sequences) by one ITS1-S (shorter band of ITS 1 [ITS1]) genotype, which also was found in the lakes. The lake populations of A. flos-aquae tended to be genetically more diverse than the Baltic Sea populations. Since the lake ITS1-S genotypes of A. flos-aquae are continuously introduced to the Baltic Sea via inflowing waters, it seems that only one ITS1 genotype is able to persist in the Baltic Sea populations. The results suggest that one of the ITS1-S genotypes found in the lakes is better adapted to the conditions of the Baltic Sea and that natural selection removes most of the lake genotypes from the Baltic Sea A. flos-aquae populations.


AMBIO: A Journal of the Human Environment | 2008

Long-term Development of Inorganic Nutrients and Chlorophyll α in the Open Northern Baltic Sea

Vivi Fleming-Lehtinen; Maria Laamanen; Harri Kuosa; Hannu Haahti; Riitta Olsonen

Abstract Eutrophication is an ongoing process in most parts of the Baltic Sea. This article reports on the changes during recent decades of several eutrophication-related variables in the open sea areas surrounding Finland (wintertime nutrient concentrations, wintertime nutrient ratios, and summer time chlorophyll α concentrations at the surface). The sum of nitrate- and nitrite-nitrogen ([NO3+NO2]-N) was observed to increase nearly fourfold in the Northern Baltic Proper and the Gulf of Finland and almost double in the Bothnian Sea from the 1960s until the 1980s or 1990s. The increase was followed by a decrease, which was modest in the two former subregions. Phosphate-phosphorus (PO4-P) concentrations followed a similar pattern in the Northern Baltic Proper (threefold increase and subsequent slight decrease) and Bothnian Sea (30% increase and subsequent decrease), but increased throughout the study in the Gulf of Finland, with the present concentration being threefold to the measurements made in the early 1970s. The PO4-P concentration decreased throughout the study in the Bothnian Bay. Silicate-silicon (SiO4-Si) concentrations decreased 30–50% from the early 1970s to the late 1990s and increased 20–40% thereafter in the Northern Baltic Proper, the Gulf of Finland, and the Bothnian Sea. Chlorophyll α showed an increase of over 150% in the Northern Baltic Proper and the Gulf of Finland from the 1970s until the early 2000s. In the Bothnian Sea the chlorophyll α concentration increased more than 180% from the late 1970s until the late 1990s, and decreased thereafter. According to these long-term observations, the Gulf of Finland and Northern Baltic Proper show clear signs of eutrophication, which may be emphasized by hydrographical changes affecting the phytoplankton communities and thus the algal biomass.


Applied and Environmental Microbiology | 2005

Responses of Baltic Sea Ice and Open-Water Natural Bacterial Communities to Salinity Change

Hermanni Kaartokallio; Maria Laamanen; Kaarina Sivonen

ABSTRACT To investigate the responses of Baltic Sea wintertime bacterial communities to changing salinity (5 to 26 practical salinity units), an experimental study was conducted. Bacterial communities of Baltic seawater and sea ice from a coastal site in southwest Finland were used in two batch culture experiments run for 17 or 18 days at 0°C. Bacterial abundance, cell volume, and leucine and thymidine incorporation were measured during the experiments. The bacterial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified partial 16S rRNA genes with sequencing of DGGE bands from initial communities and communities of day 10 or 13 of the experiment. The sea ice-derived bacterial community was metabolically more active than the open-water community at the start of the experiment. Ice-derived bacterial communities were able to adapt to salinity change with smaller effects on physiology and community structure, whereas in the open-water bacterial communities, the bacterial cell volume evolution, bacterial abundance, and community structure responses indicated the presence of salinity stress. The closest relatives for all eight partial 16S rRNA gene sequences obtained were either organisms found in polar sea ice and other cold habitats or those found in summertime Baltic seawater. All sequences except one were associated with the α- and γ-proteobacteria or the Cytophaga-Flavobacterium-Bacteroides group. The overall physiological and community structure responses were parallel in ice-derived and open-water bacterial assemblages, which points to a linkage between community structure and physiology. These results support previous assumptions of the role of salinity fluctuation as a major selective factor shaping the sea ice bacterial community structure.


PLOS ONE | 2016

Cost-Effective Marine Protection - A Pragmatic Approach

Soile Oinonen; Kari Hyytiäinen; Lassi Ahlvik; Maria Laamanen; Virpi Lehtoranta; Joona Salojärvi; Jarno Virtanen

This paper puts forward a framework for probabilistic and holistic cost-effectiveness analysis to provide support in selecting the least-cost set of measures to reach a multidimensional environmental objective. Following the principles of ecosystem-based management, the framework includes a flexible methodology for deriving and populating criteria for effectiveness and costs and analyzing complex ecological-economic trade-offs under uncertainty. The framework is applied in the development of the Finnish Programme of Measures (PoM) for reaching the targets of the EU Marine Strategy Framework Directive (MSFD). The numerical results demonstrate that substantial cost savings can be realized from careful consideration of the costs and multiple effects of management measures. If adopted, the proposed PoM would yield improvements in the state of the Baltic Sea, but the overall objective of the MSFD would not be reached by the target year of 2020; for various environmental and administrative reasons, it would take longer for most measures to take full effect.


Estuarine Coastal and Shelf Science | 2007

Long-term changes in summer phytoplankton communities of the open northern Baltic Sea

Sanna Suikkanen; Maria Laamanen; Maija Huttunen


Ecology Letters | 2007

Colourful coexistence of red and green picocyanobacteria in lakes and seas.

Maayke Stomp; Jef Huisman; Lajos Vörös; Frances R. Pick; Maria Laamanen; Thomas Hendricus Augustus Haverkamp; Lucas J. Stal


International Journal of Systematic and Evolutionary Microbiology | 2005

Benthic cyanobacteria of the genus Nodularia are non-toxic, without gas vacuoles, able to glide and genetically more diverse than planktonic Nodularia

Christina Lyra; Maria Laamanen; Jaana M. Lehtimäki; Anu Surakka; Kaarina Sivonen


Biogeochemistry | 2011

Getting the measure of eutrophication in the Baltic Sea: towards improved assessment principles and methods

Jesper H. Andersen; Philip Axe; Hermanni Backer; Jacob Carstensen; Ulrich Claussen; Vivi Fleming-Lehtinen; Marko Järvinen; Hermanni Kaartokallio; Seppo Knuuttila; Samuli Korpinen; Aiste Kubiliute; Maria Laamanen; Elzbieta Lysiak-Pastuszak; Georg Martin; Ciarán Murray; Flemming Møhlenberg; Guenther Nausch; Alf Norkko; Anna Villnäs

Collaboration


Dive into the Maria Laamanen's collaboration.

Top Co-Authors

Avatar

Hermanni Kaartokallio

Finnish Environment Institute

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Vivi Fleming-Lehtinen

Finnish Environment Institute

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Maija Huttunen

Finnish Institute of Marine Research

View shared research outputs
Top Co-Authors

Avatar

Minna Pyhälä

Baltic Marine Environment Protection Commission

View shared research outputs
Top Co-Authors

Avatar

Sanna Suikkanen

Finnish Institute of Marine Research

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge