Potaro River shore shoal, Essequibo River tributary, Guyana

_ place in Biotope Aquarium Design Contest 2019

Volume: 288 L
Dimensions: 120×60×40 cm
List of fishes: Hemigrammus ocellifer/Hemigrammus erythrozonus/Hemigrammus armstrongi
List of plants: No water plants were found in the ecological environment I described, only some inundated terrestrial plants and some dead terrestrial plants that floated near the river bank.
Description of decorations: The materials I chose were collected in rivers, riverbanks and forest parks. Some of them were purchased in China. Here I add some driftwood simulations like trunks and many twigs to simulate the accumulation of trees in the beach and shoal.
Description of equipment: Filter equipment:
ATMAN-CF1200 External Filter ×2 / Pre-filter ×2
Degreasing Film Filter ×2
Lamps:
Netlea/Nitley LED 6500K 50W×3 / Spotlight 5W×4
Heating device:
EHEIM IHAN heating rod 200W ×2 (with one device, without heating device in summer)
Others: oxygen pumps
Water parameters: Temperature: 25 (±)
PH: 6.5
GH:6
TDS:9
Additional info: In my aquarium, I used a lot of drifting trees, branches and dead leaves to simulate the accumulation of trees and branches along the beach and river bank, and a lot of light background color to simulate the beach color of habitat. I used two larger external filters and two pre-filters for both physical filtration and nitrifying bacteria cultivation. I use pure water and a small amount of domestic water to mix to ensure the balance of GH/TDS values, because there are a lot of driftwood and dead leaves in the tank, they can control the fluctuation of PH values very well. It’s easy for me to control algae growth by changing water and controlling light time. In daily maintenance, only changing water and cleaning the glass of fish tank. In the photos and videos, you can see that the fish are in excellent condition. They like the ecological environment I simulate very much, and I am very happy about it.

INFORMATION ABOUT BIOTOPE

Description of the area surrounding the biotope: The Essequibo River is a river in central Guyana. Originating from the Akali Mountains in the southern part of the Guyana Plateau, it flows northward through the tropical grasslands and rainforests and into the Atlantic Ocean 20 kilometers west of Georgetown. It is about 1,010 kilometers long and is the largest river in Guyana. The main tributaries are the Mazaruni, Kuyuni and Rupununi rivers. The watershed covers more than half of Guyana’s total area. The estuary is 32 kilometers wide and has many islands and beaches. There are many rapids and waterfalls in the upper and middle reaches, which are not conducive to shipping. Ships can travel 81 kilometres from the estuary to Battica. The Escuibo River, which runs north-south in central Guyana, South America, is the largest river between the Amazon and Orinoco rivers. Originating on the northwest slope of the Akali Mountains at the junction of Guyana and Brazil, the river flows northward, through a series of waterfalls and dangerous beaches, across the savanna, and into the Atlantic Ocean 20 km west of Georgetown. The total length of the river is about 1014 km, the area of the river basin is 69,000 square kilometers, the average annual discharge is 2234 cubic meters per second, the average annual runoff is 70.5 billion cubic meters, the maximum measured flow is 8010 cubic meters per second, and the minimum measured flow is 145 cubic meters per second. The basin is situated at 58 10′- 62 40′, 1 23′- 6 58′. It flows northward through damp forests and grasslands. There are many waterfalls on the river, one of which is Kurupkari Falls. There are islands in the middle and lower reaches. When it flows into the Atlantic 21 kilometers north of Georgetown, it forms an estuary 20 kilometers wide, with many islands. The climate is hot and humid, and there are two rainy seasons from April to August and November to January. Guyana’s rainforests are rich in animals and plants, as are rivers, where many kinds of fish live.

Description of the underwater landscape of the biotope: It belongs to the tropical rainforest climate with rich and diverse species. The water is yellowish and somewhat turbid, but the fish like this environment. The bottom of the river is mostly composed of sand and drifting wood and deciduous leaves. It is very suitable for fish to inhabit and reproduce. When the rainy season comes, the river floods its banks. It is originally a habitat for birds, and in a twinkling it becomes a paradise for fish.
The simulated habitat is the beach (shoal) on both sides of the river. When the rainy season comes, the river rises, a large number of beaches are submerged, and the shore (shoal) accumulates a large number of driftwood, forming a unique underwater landscape. This is a perfect combination of sand and wood, showing the unique creativity of nature.

Description of the parameters of the habitat: The Potalo River is a large tributary of the middle reaches of the Escuibo River, with many sandy beaches. It originates from the eastern slope of the Karima River, which borders Guyana and Brazil. It flows from west to East through the famous Kaieteur Falls and Marina Falls, and flows into the Escuibo River 10 km east of Tumatu Mali. The average annual discharge of the river is 521 cubic meters per second, the maximum discharge is 2223 cubic meters per second and the minimum discharge is 44 cubic meters per second.The water of a river may be more turbid or transparent and brown depending on the season. Natural habitat water parameters: pH 5.0-6.5, hardness 0.5-1 dgh, KH 0.
The illumination time is about 5 hours in rainy season, less than 7 hours in dry season. The water quality in rainy season is about 6-6.5, the temperature is about 24 C. The water level in dry season decreases, the temperature is about 5, the temperature is about 28-32 C. The tannic acid content of deciduous trees accumulates in the river bottom increases, and the water is “tea-colored”. The bottom is covered with fine sand, sometimes silted. Because this part of the river is located in the forest zone, there are fragments of branches and leaves at the bottom. During the flood, the water level rose and some of the trees growing along the coast were flooded. Because of the rapid flow of water and the scarcity of aquatic vegetation, it can only be found in coastal areas, relatively shallow waters or backwater.

List of fishes and invertebrates occurring in the nature biotope: Arapaima gigas, Pygocentrus nattereri, Hemigrammus erythrozonus, Carnegiella strigata, Corydoras aeneus, Heros severus, Metynnis argenteus, Hoplosternum thoracatum, Guianacara geayi

List of plants found in the nature biotope: Echinodorus grisebachii, Echinodorus bolivianus, Cabomba furcata, Eleocharis acicularis.

Threats to the ecology: The main oil reserves along Guyana’s coast have been discovered. Both the local government and oil companies in Guyana denounce the country’s “unthinkable wealth”. However, the general concern of the public is that this is a disaster for Guyana and the whole planet. Nigeria, Angola, Chad and Guyana’s neighbours, Venezuela, for example, are all corrupt, environmentally disastrous and over-reliant on a single economy because of oil production. Oil companies and a few people have become extremely wealthy, while ordinary people have little to do with their livelihoods. There are already signs to follow in this regard. At the same time, it seems that the impact of oil production on global climate change, which is a very big threat to life on the planet, has not been noticed. Exxon Mobil Oil is valued at more than 3.2 billion barrels of oil in its franchise so far. Once used, more than one billion tons of carbon dioxide will be emitted into the atmosphere. Guyana will be transformed from a primitive tropical rainforest country into a carbon emitter.

Sources of information:

http://www.iqiyi.com/a_19rrhb9ot1.html?vfm=2008_aldbd
http://tv.cctv.com/2017/02/27/VIDEPfjngxoKREsX2ZCs25R2170227.shtml
http://m.zwbk.org/lemma/464892
https://baike.baidu.com/item/%E5%9F%83%E5%A1%9E%E5%A5%8E%E5%8D%9A%E6%B2%B3/9822573?fr=aladdin
http://tv.cntv.cn/video/C14099/44ea189caeaa4d82bf0084ef91fbd670

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