There is a lack of understanding of the main drivers that form the picture of biological communities of transitional waters in deltaic ecosystems under the influence of terrestrial sources. Analysis of hydrochemical parameters in relation to phytoplankton communities in the Ukrainian part of the Danube coastal zone (in August 2018) is the focus of current work. The goal was to identify patterns in the distribution of environmental parameters (salinity and nutrients) in the area of the shipping channel through the Bystry arm, as well as to assess the state of water quality. The ecological bioindicators approach using modern statistical methods, and ecological mapping shows sufficient achievements in interpreting the results. The indicators of salinity (mesohalobes) had better describe the character of the transportation of fresh riverine waters than salinity gradient. The composition of 35 indicator phytoplankton species corresponds to 3 and 4 water quality classes in the coastal zone. High N:P ratios showed an imbalance in the ecosystem as an indicator of production and destruction processes. Statistical maps of the indicator species distribution revealed the river current’s influence on the nearshore water mass. Ecological maps of surface and bottom variables show various environmental impacts resulting from dredging in the shipping channel and excavated soil dumping. Canonical correspondence analysis (CCA) and statistical maps revealed two pools of factors with oppositely directed effects on phytoplankton: salinity, on one hand, and nutrients, on the other. Miozoa and Chlorophyta have an opposite interaction with salinity and oxygen and can be ecosystem change indicators in further analysis.
Bibliographical noteFunding Information:
The work was done in the framework of scientific work of the Institute of marine biology of the NAS of Ukraine No 0119U000625 ?Control monitoring observations during operation of the deep-water shipway the Danube?Black Sea (marine part)? and fundamental national scientific work ?Patterns of the functioning of contour assemblages of the Black Sea ecosystems in view of disbalance of natural processes?.
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Danube Delta
- Ecological mapping
- Nearshore area
- Transformation zones
ASJC Scopus subject areas
- Global and Planetary Change
- Nature and Landscape Conservation