Spatial and temporal distribution of coloured dissolved organic matter in a hypertrophic freshwater lagoon

Abstract

A dataset of 224 Medium Resolution Imaging Spectrometer (MERIS) full resolution satellite images were processed to retrieve the concentration of coloured dissolved organic matter (CDOM) in a hypertrophic estuary (Curonian Lagoon, Lithuania and Russia

Drivers of Cyanobacterial Blooms in a Hypertrophic Lagoon

“…Results based on a large number of images from 2004 to 2016 revealed temporal variability and small-scale spatial patchiness of chl-a Vaičiutė et al, 2015). The southern part of the lagoon exhibited high chl-a (up to 500 mg m −3 ) while the northern areas were characterized by lower values (∼50 mg m −3 ) Figure 2).…”

“…The lagoon has a relatively small hydrologic loading factor (ratio of watershed area to surface area), which makes this system similar to a flowthrough reactor, and provides an opportunity for mass balance studies Zilius et al, 2014;Vybernaite-Lubiene et al, 2017). Prior work by our multidisciplinary and multinational team has included assessment of nutrient loads from the Nemunas watershed, application of hydraulic models to simulate water circulation in response to changing discharge and wind conditions, investigation of seasonal dynamics of biogeochemical cycles, and use of satellite remote sensing to monitor phytoplankton blooms (Vaičiutė et al, 2015;Petkuviene et al, 2016;Umgiesser et al, 2016;Vybernaite-Lubiene et al, 2017. Our work at this site has also benefitted from longterm monitoring carried out by the Marine Research Department of the Lithuanian Ministry of Environment.…”

“…More recently, satellite remote sensing has substantially improved our ability to track the spatial and temporal dynamics of bloom events and draw links to local weather conditions. The first attempt to map algal blooms in the Curonian Lagoon utilized the MEdium Resolution Imaging Spectrometer (MERIS) on board the Envisat-1 satellite (Giardino et al, 2010;Bresciani et al, 2012;Vaičiutė et al, 2015). The combination of high spatial resolution (300 m) and short revisit time (2-3 days) greatly enhanced our ability to map chl-a.…”

Detecting Climate Driven Changes in Chlorophyll-a Using High Frequency Monitoring: The Impact of the 2019 European Heatwave in Three Contrasting Aquatic Systems

“…and Planktothrix agardhii . The concentration of Chl-a ranges from 4 to more than 400 mg m –3 [ 54 , 55 , 56 ] and total phosphorus ranges from around 34 µg L −1 in spring to around 211 µg L −1 in summer [ 57 ].…”

Synergistic Use of Synthetic Aperture Radar and Optical Imagery to Monitor Surface Accumulation of Cyanobacteria in the Curonian Lagoon

“…The 60 optical images are analyzed to map chlorophyll a (Chl-a) concentrations using two different band ratio algorithms applied to atmospherically-corrected data. Given the very low transparency typical of the waters of the Curonian Lagoon [32] and the tendency of algae dispersed in the water column to accumulate near the surface, satellite-based estimates of Chl-a concentrations are presumably relevant only for the upper layer of water and thus can be considered as a proxy of the scum presence. Indeed the shallow, weakly stratified lagoon remains very turbid due to solids (mainly sand and silt) being resuspended as a result of water mixing caused by local winds and intensive primary production [33,34].…”