Sources of the Krężniczanka river near Bełżyce, Poland

_st place in Biotope Aquarium Design Contest 2022

Volume of aquarium: 135

Dimensions of aquarium: 90x50x30

List of fishes: Gasterosteus aculeatus, Pseudorasbora parva

List of plants: N/A

Description of Decorations and Substrate: Elements of decoration came from the river. Sand, mud, deadwood, roots and reeds

Description of Equipment: Aquael Ultramax 1500, LED lighting 6500K 200w, DIY water cooler.

Water Parameters: Water temperature ranges from 10(January) to 21°C, hardness is 20dH and the pH is 7.5

Additional Info: Water change ones a week 20%, Reeds are changed every 6-8 months. In January, the water temperature drops to 10°C.

Aquarium video:

Description of the Area Surrounding the Biotope: A river in the Lubelskie Voivodeship, a left tributary of the Bystrzyca River. The river is over 20 km long and ends its course near Lublin, affecting the marshy area to the Bystrzyca river. The described biotope is located on the outskirts of the city of Belżyce. It is a small source that supplies the river. The area around the biotope is covered with huge Populus, Alnus and Sambucus nigra. The shores are overgrown with reeds. The area is specific because it is located in a city, despite it is wild. They visit rare species of birds (Ardea alba, Ciconia ciconia, Alcedo atthis). The biotope is intensively shaped by beavers, we can find many fallen trees and branches there.

Description of the Underwater Landscape of the Biotope: The source forms a small pond, its diameter is about 3 meters and the average depth is about 30 cm. The bottom is covered with silt, lots of branches, leaves, plant debris. Only in the place where the water comes out from under the ground do we see fine quartz sand, small limestone pebbles and pieces of shells. There are also plants, but the place is very shaded and they do not grow abundantly there.

Description of the Habitat Parameters: Crystal water with low and constant temperature flows from the ground. pH 7,8, ppm 321, temp. in winter is 9-10° C, uS – 656.

List of Fishes and Invertebrates Occurring in the Nature Biotope: Gasterosteus aculeatus, Pseudorasbora parva, Gobio gobio, Perca fluviatilis, Salmo trutta, Thymallus thymallus, Rutilus rutilus.

List of Plants Found in the Nature Biotope: Callitriche palustris, veronica sp.

Threats to the Ecology of the Biotope: The river was severely polluted in the 1980s and 1990s, leading to the complete extinction of Astacus astacus and Pseudanodonta complanata. Unfortunately, all the time Krezniczanka is exposed to the negative impact caused by humans, littering or flushed fertilizers from nearby fields negatively affect this small ecosystem.

Sources of Information:
I personally study biotopes my local river for several years, I have been observing changes every year and I am getting to know it again.