Eco-Assessment of Streams of Konya Closed River Basin (Turkey) Using Various Ecoregional Diatom Indices

Ecological assessments of freshwater ecosystems based on diatom metrics are an important issue to attain environmental sustainability. The present study aimed to evaluate differences in the diatom-stressors relationship in relatively least disturbed streams in the Konya closed river basin using multivariate analyses and to bio-assess streams by application of different ecoregional diatom indices. Cocconeis euglypta, Cymbella excisa, Cocconeis placentula, and Achnanthidium minutissimum are the most contributing species to the dissimilarity of sampling stations between rainy and dry seasons and also between altitude (A2 800-<1600 m and A3 ≥1600 m) groups. A strong (82.8%) correlation between diatom species and stressors was expressed by the first two axes of canonical correspondence analysis. Diatom species displayed distinct responses to environmental variables (electrical conductivity, Ni, Cu, B, and altitude) playing important roles on the distribution of diatom species. Diatom indices indicated different ecological statuses of stations from a bad to a high. European diatom indices except Duero Diatom Index-DDI and Trophic Diatom Index-TDI showed well responses to the eco-assessment of streams and indicated high ecological status for the least disturbed sampling stations symbolized as S16, S20, S24, S25, S27-29, S37, and 39. These results were also supported by abiotic evaluation. Among diatom indices, although TIT was more competitive in the bio-assessment of streams, it is necessary to increase its species list by determining their trophic weights in future studies. This indicates that the revision of ecoregional specific diatom metrics with the enhancement of diatom species numbers according to their ecological preferences is needed to correctly interpret the water quality.

USING DIATOMS IN BIOLOGICAL ASSESSMENT OF THE WATER QUALITY ON THE EXAMPLE OF SMALL KARSTIC RIVER IN BOSNIA AND HERZEGOVINA

UDK: 574.5(282.249 Bunica) Research into the benthic diatoms in the Bunica River was performed during the period from 5th May 2013 to 9th January 2014 on three different sites, from the headwaters to the mouth. The Bunica River is located in the south-eastern part of the Mostar valley, in the south of Bosnia and Herzegovina. The aim of this research was to test the use of benthic diatoms as indicators and the use of diatom indices as a tool for estimating water quality in an example of a small karstic river. For that purpose, diatom indices were calculated using OMNIDIA GB 5.3 software. This was the first testing of diatom indices for a small karstic river. Diatom indices showed different results and huge variations between sites on the Bunica River. According to the results, the indices in the OMNIDIA software are not applicable for karstic rivers in Bosnia and Herzegovina and they must be modified for this purpose. This paper can be the first step towards calibration indices for karstic region. Also, it can be useful for the development of biomonitoring tool for karstic rivers in Bosnia and Herzegovina.

Biodiversity and seasonal distribution of benthic diatom assemblages as an indicator of water quality of small karstic river in Bosnia and Herzegovina

The aims of this paper were to describe seasonal changes in the qualitative and quantitative composition of diatom taxa and the potential application of benthic diatoms for ecological status evaluation. Diatom indices (IPS and TI) were calculated from data from three different locations along a longitudinal profile of the Bunica, a small karstic river in Bosnia and Herzegovina. A total of 147 taxa were recorded in 12 samples. The most common taxa were Meridion circulare (Greville) C.Agardh and Ulnaria ulna (Nitzsch) Compère. Physical and chemical analyses showed low concentrations of nutrients, good oxygenation, typical pH for carbonate bed/origin and generally oligotrophic conditions and high ecological status. All sites had similar physico-chemical conditions and there were only few seasonal differences. Ordination of the diatom data showed that samples showed neither longitudinal nor seasonal patterns. Median value for IPS (16.8) and for TI (7.3) can be possible ‘‘expected’’ values for ecological status assessment for small karstic rivers in the Mediterranean region. We propose the use of the phytobenthos Intercalibration Common Metric (pICM - an index that combines the IPS and TI) as a national metric for countries developing WFD diatom methods at a late stage. One situation is described, and a solution, which is potentially transferable to other locations in Bosnia and Herzegovina and also to other countries facing similar challenges.

Ecological status assessment of the Samokovska river: 2018 case study

The Samokovska River, as the most important watercourse of the Kopaonik National Park, has been poorly investigated from algological and water quality aspects. This river is not covered by the monitoring program of the Serbian Environmental Protection Agency routine. Our research performed in October 2018 aimed to present an algal diversity, ecological status assessment, and negative anthropogenic impacts threatening this river. For ecological status assessment purposes, the diatom indices phytobenthos and physico-chemical parameters of water were used. The typology and the problem of reliable assessing of the ecological status were also discussed on the example of the Samokovska River.

Substrate type selection in diatom based lake water quality assessment

Various studies report contrasting results on the substrate-type effect on diatom community composition, but the particularly important question is whether or not it affects diatom-based assessments of water quality. We investigated whether the substrate type is a significant predictor of the diatom community composition and if it affects lake water quality assessment based on diatom indices. This study took place in Sava Lake (Serbia). We used glass, ceramic, willow and yew tree tiles as artificial substrates for periphyton development, and pebbles from the lake littoral as natural substrate. Results revealed differences in both the diatom community composition and diatom indices values related to the substrates. A distinction was recognized between natural, artificial wooden, and artificial inert substrates. However, the final lake quality assessment based on diatom indices was more or less similar in all substrate types in our study, and depended on value ranges associated with water quality classification and on diatom index choices. Artificial substrates in our study did show potential as an alternative for natural substrate, but further studies are required, particularly in various types of lentic ecosystems to confirm our findings and support artificial substrate employment in lake water quality assessment.

Ecological status estimation of eight creeks in the Lake Sapanca Basin (Sakarya, Turkey) using diatom indices

It is important to determine the water quality of the creeks in the Lake Sapanca basin since it is used for drinking water supply. For this purpose, environmental parameters and diatom assemblages as biological quality components were investigated to determine the ecological status of eight creeks with monthly intervals between March 2015 and February 2016. During the studied period, 19 taxa increased their relative abundance higher than 30% in at least one sample and showed a different seasonal pattern. Main nutrients [(nitrate-nitrogen, orthophosphate, total phosphorus (TP)] and some other parameters (specific conductance, temperature, pH, and dissolved oxygen) had strong impacts on the distribution of diatom assemblages. The ecological status of the creeks was characterized by using four different diatom indices, however, only Trophic Index Turkey (TIT) represented significant positive correlations with log (TP) gradient and separated the creeks as good and moderate ecological status. According to TIT, the 4th and 6th stations had a good ecological condition and were characterized by pollution-sensitive species such as Cymbella affinis, Reimeria sinuata, and Nitzschia dissipata. On the other hand, TIT resulted in the other stations having moderate ecological conditions, which had high nutrient levels and EC. Moreover, the occurrence of pollution-tolerant taxa such as Gomphonema angustatum, Ulnaria ulna, and Achnanthidium affine endorsed the moderate ecological conditions in these creeks. Based on the results, the TIT as a biological metric could be a useful tool for the assessment of running waters in the Sakarya river basin.