Oxbow Lake The Odra River. Brodno. Poland

_st place in Biotope Aquarium Design Contest 2022

Volume of aquarium: 288 L

Dimensions of aquarium: 120x60x40 cm

List of fishes:Gobio gobio, Gasterosteus aculeatus, Alburnus alburnus, Leucaspius delineatus, Unio tumidus, Aplaxa hypnorum

List of plants:Pharagmites australis, Cerex comans, Myriophyllum spicatum, Fontinalis antipyretica

Description of Decorations and Substrate:
For decoration, I used materials from the natural environment that I present. The natural substrate of the coastal zone. Live shoots of reed that now grow in the aquarium. Water plants, pieces of wood, small branches and roots of tree species growing on the banks of the reservoir. Sand, dry leaves of trees and reeds. Dead reed stalks to supplement live shoots. I collected all the material in the areas not covered by protection

Description of Equipment: Filtration – Aquael Fan2 – 450 l/h set to minimum flow. Strong aeration. Lighting 3x Halogen LED 50W 3500 lum. 4000K.

Water Parameters: Tem. 17-20 st.C ph-8 GH-23 KH-15 TDS- 450ppm

Additional Info: Water change twice a week 30%. Water for replacement filtered through a carbon filter. Frequent replacement and good oxygenation. Provide good water quality for residents Phragmites australis absorbs nitrogen and phosphorus compounds. The plant is used in ecological sewage treatment plants. Balanced diet. Frozen insects and spirulina. 3-4 times a day in small portions Lighting 10h / day.

Aquarium video:

Description of the Area Surrounding the Biotope: River reservoir “Starorzecze Brno”is located in Dolny Slask,on the western part of the valley Wroclaw,about 1km from Odra riverbed.This terytory is locatedaroundnatura 2000 Land of LEGI ODRZANSKIE.The enormouswealth of species of protected plantsand animals occures here.Numerous types of habitat like forests,alder trees,peat bogs,oxbow lakes and floodplain meadows,makes the territory very important for ecosystem.Haevily developed agriculture in this region shapes the landscape.Farmlands separate smaller and bigger forested terrytory with numerous water canals.Reservoir BRODNO is small 1.1km long 50-80m wide and around 6m deep.Varied coastline.North part of steep shoresis overgrown with slim belt of deciduous trees,they are making a boarder of farmland.On the south part,gentle desceants and shallows overgrowth with swamp vegetation,typical for this kind of enviroment.There is also small sand beach without any vegetation.Spring and summer time floating plants cover the water table.From east and west side reservoir is conected through canals with small river and lake.

Description of the Underwater Landscape of the Biotope:
Despite its small size, the reservoir is diversified in terms of habitats. Medium clear water with a slight yellow tint. Visibility about 1m. What we see underwater depends on the season. From spring to autumn, the shallows are filled with a dense forest of green reeds, sedges, mosses and lichens … This place becomes a home for young fish of many species, which spend most of their time here protecting themselves from predators. They find peace and nourishment here.
It was this coastal zone that became the inspiration and theme of My Aquarium.
There are few plants in the shade of trees growing at steep banks. The bottom is river mud made of light, medium and heavy loams. Sands in some places. Lots of pieces of wood that fell into the water and protruding roots. In the deep part, water lilies grow from the bottom covered with a layer of silt and organic debris, forming a forest of stems under the water, and a carpet of leaves and flowers on the surface. In addition to lilies, we can also meet many other species of aquatic plants … Unfortunately, winter causes the reservoir with all the richness of plants to die . The shallows become a gray forest of dead leaves and reeds … The deeper places are just a brown desert covered with sediment. On frosty days, everything is covered with a layer of ice. The reservoir is hibernating. He is resting before the spring bloom …..

Description of the Habitat Parameters: The Brodno reservoir lies in the temperate climate zone. Annual rainfall approx. 540 mm / m2; temperature 9.7 ° C (from -30 ° C to + 38 ° C). In summer, 19-22 degrees Celsius. The average insolation is 1556 hours a year. Ph- 7.94-8.06 Gh-25 kH-15 TDS- 520ppm. The inflow of fresh water mainly from rain and snowfall.

List of Fishes and Invertebrates Occurring in the Nature Biotope: The list goes on and on. List the most important.
Gasterosteus aculeatus. Gobio gobio. Romanogobio albipinnatus. Alburnus alburnus. Leucaspius delineatus. Rhodeus sericeus. Cobitis taenia. Misgurnus fossilis. Aplexa hypnorum. Unio tumidus

List of Plants Found in the Nature Biotope: The list goes on and on. List the most important.
Trapa natans Nymphaea alba, Nymphaea candida. Salvinia natans. Nupher lutea. Utricularia vulgaris. Hydrocharis morsus-ranae. Myriophyllum spicatum. Fontinalis antipyretica..

Wetland plants:
Pharagmites australis. Glycerietum maximae. Sparganietum erecti. Carex acuta. Carex acutiformis. Iridetum pseudacori.
Quercus robur. Carpinus betulus. Tilia cordata Mill.

Threats to the Ecology of the Biotope: Oxbow lake Brodno.
When I first saw this reservoir in summer, its surface was covered with a carpet of leaves and flowers (Nopharo-Nymphaeetum albae). Such a sight does not leave anyone indifferent. This place is so beautiful and so little known. Thats why I decided to show this environment in my Biotope Aquarium.
The Maky water reservoir with such a wealth of flora and fauna is unique on a European scale. There are numerous species of fish and plants that are under protection due to the threat of extinction.On the southern shores there are Salvinia natans, which is under strict protection. Utricularia vulgaris also protected. In the northern part, in the deepest places, we can see floating vegetation. The main species for which the site is postulated for protection by naturalists is Nymphaea candida. Together with Nupher lutea it forms a assemblage of water lilies. They are accompanied by more common species. Some sources also mention a small population of Trapa natams. The plant is under strict legal protection. Rarely found in Poland and Europe.
The coastline is also very rich in marsh vegetation. Especially shallows where water heats up quickly. I will only mention a few here. Glycerietum maximae, Sparganietum erecti, Iridetum pseudacori, Caricetum acutiformis.
The reservoir is inhabited by endangered and protected species of fish: Rhodeus sericeus, Cobitis taenia, and Misgurnus fossilis. Gobio gobio.
Several species of amphibians Lissotriton vulgaris, Pelophylax ridibundus ..
The surrounding trees are a nesting place for several species of birds. Here they find peace and quiet to bring out the nests,and lay eggs.
In such a short study it is impossible to list all the richness of wildelife.
In terms of tourism, the area has been developed. A mole bridge was led through the shallows overgrown with marsh vegetation. The path is 250 m long. There is a large carport in the middle of the way. On the route we will meet information boards about the nature of the Oxbow lake and the entire Natura 2000 area of ​​Łęgi Odrzańskie.
Despite the lack of protection, it is a place with a high level of naturalness.
Unfortunately, fishing has a negative effect on native fish populations.
The fields adjacent to the reservoir are among the greatest threats. Fertilizers with rainwater go to the oxbow lake, changing the water parameters. This has a negative effect on wildlife.
Water in the reservoir is rarely replaced. After the flood in 1997, the flood protection infrastructure was developed, which completely isolated the Oxbow lake from the Odra river. Now the only source of fresh water is rainfall and snowfall, and a small channel connecting the reservoir with the river
I think that my project Biotope Aquarium “Oxbow lake Brodno” will make it possible to get to know this Treasure of Nature from a different perspective. For most people visiting this place, the view of the underwater landscape and life is unattainable … Such places should be protected. There is not many of them. And this place is Unique in every way. It’s good because it’s Polish.

Sources of Information:
Gps 51°13’47.3″N 16°34’59.9″E

Starorzecze Brodno