scholarly journals Evidence of eutrophication in Arctic lakes

2021 ◽  
Author(s):  
Paola Ayala-Borda ◽  
Connie Lovejoy ◽  
Michael Power ◽  
Milla Rautio
Keyword(s):  
Climate Change ◽  
Chemical Composition ◽  
Satellite Imagery ◽  
Trophic Status ◽  
Snow Accumulation ◽  
Arctic Lakes ◽  
Nutrient Concentrations ◽  
Human Influence ◽  
Phytoplankton Communities ◽  
Total Phytoplankton

Lakes and ponds are dominant components of Arctic landscapes and provide food and water for northern communities. In the Greiner Lake watershed, in Cambridge Bay (Nunavut, Canada), water bodies are small (84% < 5 ha) and shallow (99% <4 m). Such characteristics make them vulnerable to eutrophication as temperatures rise and nutrient concentrations from the greening landscape increase. Here, we investigated and compared 35 lakes and ponds in the Greiner watershed in August 2018 and 2019 to determine their current trophic states based on their chemical composition and phytoplankton communities. The ponds had higher trophic status than the lakes, but overall, most sites were oligotrophic. Lake ERA5, located upstream of any direct human influence was classified as eutrophic due to high total phosphorus (32.3 µg L<sup>-1</sup>) and a high proportion of Cyanobacteria (42.9% of total phytoplankton biovolume). Satellite imagery suggests the lake may have been eutrophic for the last 30 years. We hypothesize that the coupled effects of catchment characteristics and elevated local snow accumulation patterns promote higher nutrient leaching rates from the soils. We recommend further analysis and monitoring as eutrophication could become more widespread with ongoing climate change and the associated increases in temperature, precipitation, and catchment-lake coupling.

scholarly journals Phytoplankton Communities of Temporary Ponds Under Different Climate Scenarios: Experiments on Vernal Pool Microcosms

2021 ◽  
Author(s):  
Sofia Celewicz ◽  
Bartłomiej Gołdyn
Keyword(s):  
Climate Change ◽  
Species Abundance ◽  
Vernal Pool ◽  
Vernal Pools ◽  
Temporary Ponds ◽  
Climate Scenarios ◽  
As Species ◽  
Phytoplankton Communities ◽  
Total Phytoplankton ◽  
Cold Spring

Abstract Temporary water bodies, especially vernal pools, are the most sensitive to climate change, yet the least studied aquatic environments. Their functioning largely depends on the phytoplankton communities structure. This study aimed to determine how temperature and photoperiod length (simulating inundation in different parts of the year under six climate scenarios) affect the succession and the structure of phytoplankton communities soon after inundation. For longer photoperiods and at lower temperatures in vernal pool microcosms (simulating a cold spring after a warm snowless winter), the phytoplankton community evolved into chlorophytes and cryptophytes. At short photoperiod (inudation in winter, followed by freezing of the water surface) the communities evolved into the euglenoids. Medium temperatures and long photoperiods (late inundation during cool spring) promoted the development of chlorophytes, with high total phytoplankton abundance as well as species richness and diversity. The lack of cyanobacteria dominance, suggests that they will not be the leading group in vernal pools in the temperate zone with progressive global warming. Our study shows that climate change will result in the seasonal shifts of the species abundance or even in their disappearance, and finally in strong changes in the biodiversity and food web of aquatic ecosystems in the future.

Climate change: the potential for latitudinal effects on algal biomass in aquatic ecosystems

2003 ◽  
Vol 60 (6) ◽  
pp. 635-639 ◽  
Author(s):  
Kyla M Flanagan ◽  
Edward McCauley ◽  
Frederick Wrona ◽  
Terry Prowse
Keyword(s):  
Climate Change ◽  
Algal Biomass ◽  
Negative Impact ◽  
Abiotic Factors ◽  
Arctic Lakes ◽  
Nutrient Concentrations ◽  
Published Data ◽  
Change Models ◽  
Significant Negative Impact ◽  
Latitudinal Effect

Arctic aquatic systems are considered to be highly susceptible to climate change. Both increases in temperature and nutrient input would be anticipated to alter primary production within these lakes. Consequently, understanding the current relationship between nutrients and productivity is crucial for predicting the effects of climate change. In this paper, we synthesize published data on algal biomass, total phosphorus, total nitrogen, maximum depth, altitude, longitude, and latitude to determine whether average algal biomass differs for temperate and arctic lakes. A total of 57 sources were used, resulting in data for 433 lake-years, ranging in latitudes from 41 to 79°N. Average algal biomass observed during the ice-free season increased significantly with phosphorous levels, but the latitude of the system had a significant negative impact on algal biomass. We briefly outline two major hypotheses, based on existing empirical evidence, for the lower algal yield found in higher latitude systems. The first hypothesis discusses bottom-up control and the influence of abiotic factors on algal biomass. The second hypothesis relates to food chain composition and top-down influences. The latitudinal effect on algal yield suggests that arctic lakes could dramatically increase in productivity if these systems experience increases in temperature and nutrient concentrations as predicted by climate change models.

Nutrient Input and Trophic Status of the “Neue Donau”, a High-Water Control System along the River Danube in Vienna, Austria

1990 ◽  
Vol 22 (5) ◽  
pp. 137-144 ◽  
Author(s):  
M. T. Dokulil ◽  
G. A. Janauer
Keyword(s):  
Water Quality ◽  
Control System ◽  
Trophic Status ◽  
High Water ◽  
Nutrient Concentrations ◽  
Nutrient Input ◽  
Water Control ◽  
Trophic Conditions ◽  
River Danube ◽  
High Nutrient

The system “Neue Donau” functions as a control system for high waters of the river Danube and is an important recreational area for many people. Water quality and trophic status of the water body is thereforeof prime importance. The high nutrient concentrations of the river Danube (P-tot 238±41µg/l, N-tot 2.53±0.78 mg/l) reach the system via groundwater seepage. Present conditions in the basin of Neue Donau are,as a result of this nutrient in-flux,eutrophic to hypertrophic. Average values during the summer period have declined from 366 µg/l total phosphorus to 78 µg/l, and from 86 µg/l chlorophyll-a tol7µg/l between the years 1985 and 1988. However, a dam which is planned in the river at Vienna will permanently raise the water level of the river thus increasing the the groundwater flow in the direction to the Neue Donau and therefore the nutrient input which will enhance trophic conditions in the impoundment. Since macrophytes play an important role in one part of the system macrophyte management together with measures along the river are some of the suggested strategies to keep the system Neue Donau at acceptable trophic conditions and good water quality.

scholarly journals The Effect of Elicitors and Canopy Management in the Chemical Composition of Vitis vinifera Red Varieties in Warm and Hot Areas in Spain

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1192
Author(s):  
Natalia Gutiérrez ◽  
Leyre López-de-Silanes ◽  
Carlos Escott ◽  
Iris Loira ◽  
Juan Manuel del Fresno ◽  
...  
Keyword(s):  
Climate Change ◽  
Chemical Composition ◽  
Vitis Vinifera ◽  
Climate Changes ◽  
Management Practices ◽  
Total Phenolic ◽  
Phenolic Fraction ◽  
Biological Origin ◽  
Phenolic Index ◽  
Canopy Management

Canopy management practices in vineyards, such as sprawling systems and shoot trimming, can change the accumulation of metabolites in grapes. The use of elicitors of biological origin on grapevines of Vitis vinifera red grape varieties may also modulate the chemical composition of the berries. These modifications are often observed in the accumulation of phenolic compounds, including pigments. Both technical approaches are alternatives involved in minimizing the effects of global climate change in warm areas. The increase of temperature related to climate change accelerates the accumulation of sugars, but produces unbalanced grapes. This work establishes the use of button sensors to monitor the climate changes occurring at grape cluster level. Together with climate monitoring, conventional instrumental analytical techniques are used to follow up the chemical composition and the phenolic fraction of grapes in four different production areas in Spain. The effect of either treatment seems variable and to be affected by external factors besides the treatment itself and the climate conditions. While there is a fine effect that correlates with the use of elicitors in varieties like Merlot and Tempranillo, there is minimal improvement observed in Tintilla de Rota. The total phenolic index increases were between 2.3% and 11.8% in the first two parcels. The same happened with the vineyard’s canopy management systems, with increased pigment accumulation and the total phenolic index rising (37.7% to 68.7%) after applying intense shoot trimming, or a variation in sugar concentrations when using sprawl conduction. This study aims to provide viticulturists and oenologists in particular, and farmers in general, with data on the field regarding the use of alternative sustainable practices in the cultivation of grapes. The techniques used involved 100% natural products without adjuvants. The benefits obtained from applying some of these practices would be to produce technically mature grapes despite climate changes, and the elaboration of more balanced wines.

scholarly journals Assessing Phytoplankton Bloom Phenology in Upwelling-Influenced Regions Using Ocean Color Remote Sensing

2021 ◽  
Vol 13 (4) ◽  
pp. 675
Author(s):  
Afonso Ferreira ◽  
Vanda Brotas ◽  
Carla Palma ◽  
Carlos Borges ◽  
Ana C. Brito
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
Phytoplankton Bloom ◽  
Ocean Color ◽  
Coastal Region ◽  
Coastal Areas ◽  
Ocean Color Remote Sensing ◽  
Chl A ◽  
Peak Biomass ◽  
Phytoplankton Communities

Phytoplankton bloom phenology studies are fundamental for the understanding of marine ecosystems. Mismatches between fish spawning and plankton peak biomass will become more frequent with climate change, highlighting the need for thorough phenology studies in coastal areas. This study was the first to assess phytoplankton bloom phenology in the Western Iberian Coast (WIC), a complex coastal region in SW Europe, using a multisensor long-term ocean color remote sensing dataset with daily resolution. Using surface chlorophyll a (chl-a) and biogeophysical datasets, five phenoregions (i.e., areas with coherent phenology patterns) were defined. Oceanic phytoplankton communities were seen to form long, low-biomass spring blooms, mainly influenced by atmospheric phenomena and water column conditions. Blooms in northern waters are more akin to the classical spring bloom, while blooms in southern waters typically initiate in late autumn and terminate in late spring. Coastal phytoplankton are characterized by short, high-biomass, highly heterogeneous blooms, as nutrients, sea surface height, and horizontal water transport are essential in shaping phenology. Wind-driven upwelling and riverine input were major factors influencing bloom phenology in the coastal areas. This work is expected to contribute to the management of the WIC and other upwelling systems, particularly under the threat of climate change.

scholarly journals Temporal and Spatial Variations of the Biochemical Composition of Phytoplankton and Potential Food Material (FM) in Jaran Bay, South Korea

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3093
Author(s):  
Jae Hyung Lee ◽  
Won-Chan Lee ◽  
Hyung Chul Kim ◽  
Naeun Jo ◽  
Kwanwoo Kim ◽  
...  
Keyword(s):  
South Korea ◽  
Food Source ◽  
Coastal Region ◽  
Controlling Factors ◽  
Spatial Variations ◽  
Nutrient Concentrations ◽  
Food Material ◽  
Biochemical Component ◽  
Phytoplankton Communities ◽  
Biochemical Compositions

Food material (FM) derived from biochemical components (e.g., proteins, lipids, and carbohydrates) of phytoplankton can provide important quantitative and qualitative information of the food available to filter-feeding animals. The main objective of this study was to observe the seasonal and spatial variations of the biochemical compositions of phytoplankton and to identify the major controlling factors of FM as a primary food source in Jaran Bay, a large shellfish aquaculture site in South Korea. Based on monthly sampling conducted during 2016, significant monthly variations in the depth-integrated concentrations of major inorganic nutrients and chlorophyll a within the euphotic water column and a predominance (49.9 ± 18.7%) of micro-sized phytoplankton (>20 μm) were observed in Jaran Bay. Carbohydrates were the dominant biochemical component (51.8 ± 8.7%), followed by lipids (27.3 ± 3.8%) and proteins (20.9 ± 7.4%), during the study period. The biochemical compositions and average monthly FM levels (411.7 ± 93.0 mg m−3) in Jaran Bay were not consistent among different bays in the southern coastal region of South Korea, possibly due to differences in controlling factors, such as environmental and biological factors. According to the results from multiple linear regression, the variations in FM could be explained by the relatively large phytoplankton and the P* (PO43− − 1/16 × NO3−) and NH4+ concentrations in Jaran Bay. The macromolecular compositions and FM, as alternatives food source materials, should be monitored in Jaran Bay due to recent changes in nutrient concentrations and phytoplankton communities.

Climate change and agricultural pollution effects on the trophic status of a Mediterranean lake

2006 ◽  
Vol 34 (4) ◽  
pp. 349-359 ◽  
Author(s):  
Ilias Bertahas ◽  
Elias Dimitriou ◽  
Ioannis Karaouzas ◽  
Sofia Laschou ◽  
Ierotheos Zacharias
Keyword(s):  
Climate Change ◽  
Trophic Status ◽  
Agricultural Pollution ◽  
Pollution Effects ◽  
Mediterranean Lake

Effects of climate change on soil organic matter chemical composition and carbon content in different physical fractions

2021 ◽  
Author(s):  
Moritz Mohrlok ◽  
Victoria Martin ◽  
Alberto Canarini ◽  
Wolfgang Wanek ◽  
Michael Bahn ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Matter ◽  
Chemical Composition ◽  
Soil Organic Matter ◽  
Soil C ◽  
Size Classes ◽  
Soil Fractions ◽  
Total Soil ◽  
C And N ◽  
Amp Clay

&lt;p&gt;Soil organic matter (SOM) is composed of many pools with different properties (e.g. turnover times) which are generally used in biogeochemical models to predict carbon (C) dynamics. Physical fractionation methods are applied to isolate soil fractions that correspond to these pools. This allows the characterisation of chemical composition and C content of these fractions. There is still a lack of knowledge on how these individual fractions are affected by different climate change drivers, and therefore the fate of SOM remains elusive. We sampled soils from a multifactorial climate change experiment in a managed grassland in Austria four years after starting the experiment to investigate the response of SOM in physical soil fractions to temperature (eT: ambient and elevated by +3&amp;#176;C), atmospheric CO&lt;sub&gt;2&lt;/sub&gt;-concentration (eCO&lt;sub&gt;2&lt;/sub&gt;: ambient and elevated by +300 ppm) and to a future climate treatment (eT x eCO&lt;sub&gt;2&lt;/sub&gt;: +3&amp;#176;C and + 300 ppm). A combination of slaking and wet sieving was used to obtain three size classes: macro-aggregates (maA, &gt; 250 &amp;#181;m), micro-aggregates (miA, 63 &amp;#181;m &amp;#8211; 250 &amp;#181;m) and free silt &amp; clay (sc, &lt; 63 &amp;#181;m). In both maA and miA, four different physical OM fractions were then isolated by density fractionation (using sodium polytungstate of &amp;#961; = 1.6 g*cm&lt;sup&gt;-3&lt;/sup&gt;, ultrasonication and sieving): Free POM (fPOM), intra-aggregate POM (iPOM), silt &amp; clay associated OM (SCaOM) and sand-associated OM (SaOM). We measured C and N contents and isotopic composition by EA-IRMS in all fractions and size classes and used a Pyrolysis-GC/MS approach to assess their chemical composition. For eCO&lt;sub&gt;2&lt;/sub&gt; and eT x eCO&lt;sub&gt;2 &lt;/sub&gt;plots, an isotope mixing-model was used to calculate the proportion of recent C derived from the elevated CO&lt;sub&gt;2 &lt;/sub&gt;treatment. Total soil C and N did not significantly change with treatments.&amp;#160; eCO&lt;sub&gt;2&lt;/sub&gt; decreased the relative proportion of maA-mineral-associated C and increased C in fPOM and iPOM. About 20% of bulk soil C was represented by the recent C derived from the CO&lt;sub&gt;2&lt;/sub&gt; fumigation treatment. This significantly differed between size classes and density fractions (p &lt; 0.001), which indicates inherent differences in OM age and turnover. Warming reduced the amount of new C incorporated into size classes. We found that each size class and fraction possessed a unique chemical fingerprint, but this was not significantly changed by the treatments. Overall, our results show that while climate change effects on total soil C were not significant after 4 years, soil fractions showed specific effects. Chemical composition differed significantly between size classes and fractions but was unaffected by simulated climate change. This highlights the importance to separate SOM into differing pools, while including changes to the molecular composition might not be necessary for improving model predictions.&amp;#160;&amp;#160;&amp;#160;&amp;#160;&lt;/p&gt;

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