scholarly journals Phytoplankton Morpho-Functional Trait Variability along Coastal Environmental Gradients

2021 ◽  
Vol 9 (12) ◽  
pp. 2477
Author(s):  
Sirpa Lehtinen ◽  
Sanna Suikkanen ◽  
Heidi Hällfors ◽  
Jarno Tuimala ◽  
Harri Kuosa
Keyword(s):  
Baltic Sea ◽  
Nutrient Availability ◽  
Nutrient Loading ◽  
Environmental Gradients ◽  
Global Climate ◽  
Functional Trait ◽  
Total Biomass ◽  
Source Type ◽  
The Baltic ◽  
Physical Features

We utilized the trait-based approach in a novel way to examine how specific phytoplankton traits are related to physical features connected to global change, water quality features connected to catchment change, and nutrient availability connected to nutrient loading. For the analyses, we used summertime monitoring data originating from the coastal northern Baltic Sea and generalized additive mixed modeling (GAMM). Of the physical features connected to global climate change, temperature was the most important affecting several studied traits. Nitrogen-fixing, buoyant, non-motile, and autotrophic phytoplankton, as well as harmful cyanobacteria, benefited from a higher temperature. Salinity and stratification did not have clear effects on the traits. Water transparency, which in the Baltic Sea is connected to catchment change, had a mostly negative relation to the studied traits. Harmfulness was negatively correlated with transparency, while the share of non-harmful and large-sized phytoplankton was positively related to it. We used nutrient loading source type and total phosphorus (TP) as proxies for nutrient availability connected to anthropogenic eutrophication. The nutrient loading source type did not relate to any of the traits. Our result showing that N-fixing was not related to TP is discussed. The regionality analysis demonstrated that traits should be calculated in both absolute terms (biomass) and proportions (share of total biomass) to get a better view of community changes and to potentially supplement the environmental status assessments.

scholarly journals Nitrogen fixation estimates for the Baltic Sea indicate high rates for the previously overlooked Bothnian Sea

AMBIO ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 203-214 ◽  
Author(s):  
Malin Olofsson ◽  
Isabell Klawonn ◽  
Bengt Karlson
Keyword(s):  
Nitrogen Fixation ◽  
Baltic Sea ◽  
Nutrient Loading ◽  
External Input ◽  
Nitrogen Loading ◽  
External Loading ◽  
The Baltic Sea ◽  
Positive Effects ◽  
The Baltic ◽  
Bothnian Sea

AbstractDense blooms of diazotrophic filamentous cyanobacteria are formed every summer in the Baltic Sea. We estimated their contribution to nitrogen fixation by combining two decades of cyanobacterial biovolume monitoring data with recently measured genera-specific nitrogen fixation rates. In the Bothnian Sea, estimated nitrogen fixation rates were 80 kt N year−1, which has doubled during recent decades and now exceeds external loading from rivers and atmospheric deposition of 69 kt year−1. The estimated contribution to the Baltic Proper was 399 kt N year−1, which agrees well with previous estimates using other approaches and is greater than the external input of 374 kt N year−1. Our approach can potentially be applied to continuously estimate nitrogen loads via nitrogen fixation. Those estimates are crucial for ecosystem adaptive management since internal nitrogen loading may counteract the positive effects of decreased external nutrient loading.

Influence of environmental conditions, population density, and prey type on the lipid content in Baltic herring (Clupea harengus membras) from the northern Baltic Sea

2019 ◽  
Vol 76 (4) ◽  
pp. 576-585 ◽  
Author(s):  
Marjut Rajasilta ◽  
Jari Hänninen ◽  
Lea Laaksonen ◽  
Päivi Laine ◽  
Jukka-Pekka Suomela ◽  
...  
Keyword(s):  
Climate Change ◽  
Baltic Sea ◽  
Lipid Content ◽  
Sea Water ◽  
Energy Content ◽  
Global Climate ◽  
Clupea Harengus ◽  
Composition Analysis ◽  
Baltic Herring ◽  
The Baltic

Global climate change can affect the energy content of fish by altering their lipid physiology and consumption. We investigated the effects of different environmental stressors on the lipid content of the Baltic herring (Clupea harengus membras) from spawning ground samples that were collected annually in the northern Baltic Sea. During 1987–2014, the average lipid content of herring muscle decreased from 5%–6% (wet mass) to 1.5% (wet mass). Generalized linear mixed models indicated that sea water salinity and the size of the herring stock explained best the declining trend of lipid content. We estimated that the amount of the lipid storage incorporated in the spawning stock decreased by approximately 45% during the study, with respective energy content decreases. Fatty acid composition analysis revealed that herring lipids contained a high proportion of EPA (eicosapentaenoic acid; 20:5n-3) and DHA (docosahexaenoic acid; 22:6n-3), which likely originated from its main summertime prey, Limnocalanus macrurus. The results illustrate various climate change-induced processes leading to changes in the lipid content of the Baltic herring and, consequently, to changes in the energy flows of the northern Baltic ecosystem.

scholarly journals Evolution at two time-frames: ancient and common origin of two structural variants involved in local adaptation of the European plaice (Pleuronectes platessa)

2019 ◽  
Author(s):  
Alan Le Moan ◽  
Dorte Bekkevold ◽  
Jakob Hemmer-Hansen
Keyword(s):  
Population Structure ◽  
Baltic Sea ◽  
Allele Frequency ◽  
Environmental Gradients ◽  
Common Origin ◽  
The Baltic Sea ◽  
Pleuronectes Platessa ◽  
The North ◽  
The Baltic ◽  
Time Frames

AbstractChanging environmental conditions can lead to population diversification through differential selection on standing genetic variation. Structural variant (SV) polymorphisms provide examples of ancient alleles that in time become associated with novel environmental gradients. The European plaice (Pleuronectes platessa) is a marine flatfish showing large allele frequency differences at two putative SVs associated with environmental variation. In this study, we explored the contribution of these SVs to population structure across the North East Atlantic. We compared genome wide population structure using sets of RAD sequencing SNPs with the spatial structure of the SVs. We found that in contrast to the rest of the genome, the SVs were only weakly associated with an isolation-by-distance pattern. Indeed, both SVs showed important allele frequency differences associated with two different environmental gradients, with the same allele increasing both along the salinity gradient of the Baltic Sea, and the latitudinal gradient along the Norwegian coast. Nevertheless, both SVs were found to be polymorphic across most sampling sites, even in the Icelandic population inferred to originate from a different glacial refuge than the remaining populations from the European continental shelf. Phylogenetic analyses suggested that the SV alleles are much older than the age of the Baltic Sea itself. These results suggest that the SVs are older than the age of the environmental gradients with which they currently co-vary. Interestingly, both SVs shared similar phylogenetic and genetic diversity, suggesting that they have a common origin. Altogether, our results suggest that the plaice SVs were shaped by evolutionary processes occurring at two time-frames, firstly following their common origin and secondly related to their current association with more recent environmental gradients such as those found in the North Sea − Baltic Sea transition zone.

scholarly journals Uncertainties in Projections of the Baltic Sea Ecosystem Driven by an Ensemble of Global Climate Models

2019 ◽  
Vol 6 ◽  
Author(s):  
Sofia Saraiva ◽  
H. E. Markus Meier ◽  
Helén Andersson ◽  
Anders Höglund ◽  
Christian Dieterich ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Climate Models ◽  
Global Climate ◽  
Global Climate Models ◽  
The Baltic Sea ◽  
The Baltic

scholarly journals Impacts of changing society and climate on nutrient loading to the Baltic Sea

2020 ◽  
Vol 731 ◽  
pp. 138935 ◽  
Author(s):  
Sampo Pihlainen ◽  
Marianne Zandersen ◽  
Kari Hyytiäinen ◽  
Hans Estrup Andersen ◽  
Alena Bartosova ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Nutrient Loading ◽  
The Baltic Sea ◽  
The Baltic ◽  
Changing Society

scholarly journals Impact of change in climate and policy from 1988 to 2007 on environmental and microbial variables at the time series station Boknis Eck, Baltic Sea

2013 ◽  
Vol 10 (7) ◽  
pp. 4529-4546 ◽  
Author(s):  
H.-G. Hoppe ◽  
H. C. Giesenhagen ◽  
R. Koppe ◽  
H.-P. Hansen ◽  
K. Gocke
Keyword(s):  
Time Series ◽  
Baltic Sea ◽  
Global Climate ◽  
Time Lag ◽  
Vertical Mixing ◽  
Bacterial Biomass ◽  
Glucose Turnover ◽  
Positive Trend ◽  
The Baltic Sea ◽  
The Baltic

Abstract. Phytoplankton and bacteria are sensitive indicators of environmental change. The temporal development of these key organisms was monitored from 1988 to the end of 2007 at the time series station Boknis Eck in the western Baltic Sea. This period was characterized by the adaption of the Baltic Sea ecosystem to changes in the environmental conditions caused by the conversion of the political system in the southern and eastern border states, accompanied by the general effects of global climate change. Measured variables were chlorophyll, primary production, bacteria number, -biomass and -production, glucose turnover rate, macro-nutrients, pH, temperature and salinity. Negative trends with time were recorded for chlorophyll, bacteria number, bacterial biomass and bacterial production, nitrate, ammonia, phosphate, silicate, oxygen and salinity while temperature, pH, and the ratio between bacteria numbers and chlorophyll increased. Strongest reductions with time occurred for the annual maximum values, e.g. for chlorophyll during the spring bloom or for nitrate during winter, while the annual minimum values remained more stable. In deep water above sediment the negative trends of oxygen, nitrate, phosphate and bacterial variables as well as the positive trend of temperature were similar to those in the surface while the trends of salinity, ammonia and silicate were opposite to those in the surface. Decreasing oxygen, even in the surface layer, was of particular interest because it suggested enhanced recycling of nutrients from the deep hypoxic zones to the surface by vertical mixing. The long-term seasonal patterns of all variables correlated positively with temperature, except chlorophyll and salinity. Salinity correlated negatively with all bacterial variables (as well as precipitation) and positively with chlorophyll. Surprisingly, bacterial variables did not correlate with chlorophyll, which may be inherent with the time lag between the peaks of phytoplankton and bacteria during spring. Compared to the 20-yr averages of the environmental and microbial variables, the strongest negative deviations of corresponding annual averages were measured about ten years after political change for nitrate and bacterial secondary production (~ −60%), followed by chlorophyll (−50%) and bacterial biomass (−40%). Considering the circulation of surface currents in the Baltic Sea we interpret the observed patterns of the microbial variables at the Boknis Eck time series station as a consequence of the improved management of water resources after 1989 and – to a minor extent – the trends of the climate variables salinity and temperature.

Effects of climate change and agricultural adaptation on nutrient loading from Finnish catchments to the Baltic Sea

2015 ◽  
Vol 529 ◽  
pp. 168-181 ◽  
Author(s):  
Inese Huttunen ◽  
Heikki Lehtonen ◽  
Markus Huttunen ◽  
Vanamo Piirainen ◽  
Marie Korppoo ◽  
...  
Keyword(s):  
Climate Change ◽  
Baltic Sea ◽  
Nutrient Loading ◽  
The Baltic Sea ◽  
Agricultural Adaptation ◽  
The Baltic
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