Sandy shallow part at the junction of the Kalchik and Kalmius rivers, Mariupol, Ukraine

57th place in Biotope Aquarium Design Contest 2019

Ukraine. Artem Bereznev

Volume: 200 L
Dimensions: 100x50x50 cm
List of fishes: Pseudorasbora parva, Rutilus rutilus, Rhodeus sericeus, Gobio gobio, Gasterosteus aculeatus, Perca fluviatilis, Neogobius melanostomus, Babka gymnotrachelus, Anodonta, Dreissena, Theodoxus fluviatilis, Physa, Astacus astacus
List of plants: Stratiotes aloides, Phragmites australis, Ceratophyllum
Description of decorations: Soil AQUAXER sand granite, 0.5-2 mm, driftwood from KORAGI.NET
Description of equipment: external filter – Eheim Experience 350, 1050
water pump – Atman AT- 203, AT-2220, ViaAqua-470B, 1800
lamp – Ptero Ray 5950/90-100
lamp – Ptero Ray Mini 25
Water parameters: temperature – 24С
рН- 7,8
gH -34
Additional info: weekly water change 30%


Description of the area surrounding the biotope: The Kalchik River is a right tributary of the Kalmius River, which flows through the territory of the Donetsk region of Ukraine.
Kalchik flows into Kalmius 6km from its mouth. The length is 88 km, the catchment area is 1.263 km². Water consumption ranges from 3.0 to 30 m³ / s. Inflow – Small Kalchik.
Pool r. Kalchik in its geographical position belongs to the Central steppe. The climate is continental, formed under the influence of climate-forming factors: solar radiation, atmospheric circulation and the underlying surface.

Description of the underwater landscape of the biotope: The water has a high content of petroleum products and non-volatile phenols. Water salinity increases from source to mouth.
The composition of the water varies from bicarbonate to sulfate class of sodium group, has a brownish yellow color
Many deciduous forests grow along the river banks, therefore flooded driftwood is often found in the river. The bed of sand, consisting of granite chips and sand of yellow color

Description of the parameters of the habitat: The average annual temperature is + 7.8 ° C.
The average temperature of the warmest month (July) is + 22 ° С, the coldest (January) is 6.3 ° С.
The absolute maximum temperature in July is + 38 ° C, and the absolute minimum in January is 36 ° C. The distribution of precipitation is uneven. They decrease from north to south (Donetsk – 522 mm, Mariupol – 457 mm) with an increase on the Donetsk ridge and Azov elevation.
The total mineralization in the middle reaches varies within 1.60 – 2.28 g / l, and at the mouth (Mariupol) reaches 7.0 g / l.
The pH of the water decreases from the headwaters of the river to the mouth in the range of 8.6 – 7.6

List of fishes and invertebrates occurring in the nature biotope: Pseudorasbora parva
Rutilus rutilus
Rhodeus sericeus
Gobio gobio
Gasterosteus aculeatus
Perca fluviatilis
Neogobius melanostomus
Babka gymnotrachelus
Carassius carassius
Rutilus heckelii
Scardinius erythrophthalmus
Tinca tinca
Esox lucius

List of plants found in the nature biotope: Bútomus umbellátus
Stratiótes aloídes
Potamogéton críspus
Phragmítes austrális

Threats to the ecology: The aquarium was created to attract the public to the problem of river pollution by the metallurgical enterprises of the city. Analysis of the ecological state of the basin makes it possible to identify the main causes of the current situation and to determine the range of the most important problems that require a phased solution. The high level of pollution in the Kalchik river basin occurs due to the inefficient operation of most water treatment plants and water disposal systems of enterprises; high anthropogenic load on the river basin, as a consequence of the extensive mode of economic development;Imperfection and non-observance of the current economic mechanism for water use and the implementation of environmental protection measures, the allocation of insufficient funds for water protection purposes; poor management and non-compliance with environmental legislation.
Pollution of river waters in the territory of Mariupol
occurs by sewage and sewage
metallurgical enterprises.
Metallurgical wastewater
enterprises located in the city, is
about 800–900 million m3. It was determined that the content of such
heavy metals like iron, zinc, manganese, lead and even cadmium
significantly exceeds the MPC level.
In 2006, while trying to clear the river bed in it for 12 km, living organisms died. This happened after the sludge collected during the clearing process was dumped into the quarries of the Ilyich Iron and Steel Works with blast-furnace and open-hearth slags. As a result of a chemical reaction, liquid ammonia and hydrogen sulfide were released. The concentration of hydrogen sulfide reached 200 milligrams per liter, and ammonia – up to 150 milligrams per liter.
In the waters of the Kalchik and Kalmius rivers in the city
Pdc excess detected for iron and zinc, excess for chromium
4-5 times, and the highest for manganese – up to 10 times. It should be noted,
that 10 km upstream the river waters also contain
heavy metals in fairly noticeable concentrations. Content
heavy metals in river waters, as well as in bottom sediments for
the last three years has grown.
Based on the complexity of the chemical composition, treatment systems
suggest multi-stage processing of contaminated liquid
using various methods.
Source processing scheme
the material must include not only the purification of the liquid to
compliance with standards, but also the ability to extract from the sludge
valuable items for their reuse.
In recent years, the Kalmius River (in Donetsk) and the Kalchik River (in Mariupol) were cleared, but this did not affect the health of the Kalmius ecosystem as a whole.

Sources of information:

Comments of the members of the jury of Biotope Aquarium Design Contest 2019