HYDROCHEMICAL MONITORING AND PRELIMINARY RESULTSFROM THE MATSI SPRING FEN IN THE TRANSBOUNDARY

GAUJA-KOIVA RIVER BASIN, SE ESTONIAKarin Sisask, Pamela Abreldaal

Tallinn University, Institute of Ecology, Tallinn, Estonia

The study is carried out within the project “Joint management of groundwater dependent ecosystems in transboundaryGauja-Koiva river basin” (GroundEco, Est-Lat62) funded by ERDF Interreg Estonia-Latvia cooperation programme.

Introduction

Matsi spring fen

Methodology

Results

Analysis quality

Acknowledgements

Matsi spring fen is located in the Gauja-Koiva river basinin Võru County South-Estonia by the Mustjõgi river.The total area of the spring fen complex is 4.6 ha and itcomprises three nearby parts separated by ditches androads.

● Water samples were collected since April of 2019 withan average sampling interval of two months. Overallthere has been five sampling campaigns with 22monitoring points: borewells, dug wells, shallowpiezometers, springs and streams

● Sampling rig: a Solinst 410 Peristaltic Pump with anin-line 0,45 um RC filter assembly, Grundfos MP-1 fordeeper wells

● Samples were handled in 100 ml HDPE syringes● Bottling (HDPE) and preservation:

Cations (15 ml) – HNO3

Anions (15 ml)Trace elements (15 ml) – HNO3

TP (175 ml) – H2SO4

DOC/TN (60 ml) - HCl● Ionic analyses (Na+, NH4

+, K+, Mg2+, Ca2+, F-, Cl-, NO2-,

NO3-, Br-, PO4

3-, SO42-) were performed in Tallinn

University using Shimadzu Prominence HPLC● Macronutrients (C, N, P) were analysed using a

Shimadzu UV-1800 Spectrophotometer and AnalytikJena AG - multi N/C® 3100 carbon/nitrogen analyzer

● Trace elements were analysed in Latvian Universityusing "Thermo Scientific" Inc. ICP-OES spectrometer"iCAP7000"

● Carbonate hardness and HCO3- were determined in-

situ during sampling campaigns● The data is presented as of November 2019

Groundwater-dependent ecosystems influence manyprocesses in nature, such as the regulation of waterand nutrient cycles and binding carbon from theatmosphere. They are also characterized by their highbiodiversity. Their presence and quality are largelyaffected by different economic factors. Hence it isimportant to identify, evaluate, characterize andprotect groundwater-dependent ecosystems.

Water sample quantity (currently) n=75

Mean charge balance error (CBE) -0,46±4,68%

Na+ (mg/l) K+ (mg/l)

Ca2+ (mg/l) Mg2+ (mg/l)

Cl- (mg/l) SO42- (mg/l)

HCO3- (mg/l) Mn (mg/l)

Fe (mg/l) Carbon (mg C/l)

Phosphorus (mg P/l) Nitrogen (mg N/l)

CBE (%)