Middle course of Tung Chung River, Lantau Island, Hong Kong
25th place in Biotope Aquarium Design Contest 2018
Belgium. Xavier Bourdet
Volume: 96 L
Dimensions: 120x40x20 cm
List of fishes: Rhinogobius duospilus
List of plants: N/A
Description of decorations: The substrate consists of large and small river pebbles, with large river rocks scattered along the bottom. Different types of algae flourish in this aquarium giving it a natural feel.
Description of equipment: Extern filter JBL Cristalprofi e1501 greenline 1400 lph (2x), Juwel Helialux 1200 54 W, 6750 Lumen.
Water parameters: Temperature ranges from 18°C to 24°C, pH is 7.5, gH is 10.
INFORMATION ABOUT BIOTOPE
Description of the area surrounding the biotope: Tung Chung River, originating at an altitude of 880 metres, between Fung Leng and Wong Leng of Lantau Peak, flows through northern Lantau Island, and reaches the sea southwest of Tung Chung new town. It ranks third in terms of the height of river origin in Hong Kong. The main stream flows north through Pak Tin Mun, Tei Tong Tsai, Chap Mun Tau and Mok Ka, and merges with a major tributary (East Stream) at midway between Ngau Au and Wong Ka Wai, before entering Tung Chung Bay.
Description of the underwater landscape of the biotope: The water at the middle course is very clear, large and small pebbles are seen at the bottom of the shallow water, large rocks protrude from the river bed. The water is well oxygenated in the fast-flowing stream due to the good mix of air and water. Organisms living there must have developed adaptive features to prevent them from being washed away.
Description of the parameters of the habitat: The temperature of river water is affected by the weather conditions and environmental variations, e.g. the shading of trees. The average temperature is around 18-24°C. The time of year with warmer water lasts for 4.5 months, from May 30 to October 14, with an average temperature above 26°C. The time of year with cooler water lasts for 3.5 months, from December 12 to March 27, with an average temperature below 20°C. Conductivity is also affected by temperature: the warmer the water, the higher the conductivity. For this reason, conductivity is reported as conductivity at 25°C and generally ranges from 50-1500 µs/cm. The pH of the natural waters hover between 6.5 and 8.5.
List of fishes and invertebrates occurring in the nature biotope: Anguilla marmorata, Anguilla japonica, Parazacco spilurus, Acrossocheilus beijiangensis, Liniparhomaloptera disparis, Pseudogastromyzon myersi, Pterocryptis cochinchinensis, Rhinogobius duospilus, Stiphodon atropurpureum.
List of plants found in the nature biotope: N/A
Threats to the ecology: In today’s Hong Kong, with a dense population and highrise buildings along the rivers, the usual practice is to straighten and broaden river channels and cover them with concrete to control flooding. The natural river landscapes have vanished, Tung Chung River is the only remaining large natural river in Hong Kong, with a rare estuary that is still free from serious damage by development projects. Tung Chung River originates from Lantau Peak and Sunset Peak and flows to Tung Chung Bay. The flow is abundant, with rich biodiversity. The river is home to quite a few rare and endangered species: Beijiang Thick-lipped Barb (Acrossocheilus beijiangensis), Romer’s Tree Frog (Philautusromeri), Hong Kong Newt (Paramesotriton hongkongensis), Tri-spine Horseshoe Crab (Tachypleus tridentatus) and Pipefish. It has the richest freshwater fish species among local rivers and is designated as an “Ecologically Important Stream”. Even after recovering to its natural state after the ‘Tung Chung River Incident’, the river faces the ever continuing threat of the urbanisation of Hong Kong.
Sources of information:
Dudgeon and Richard Corlett – Hills and Streams: An Ecology of Hong Kong (book)
Comments of the members of the jury of Biotope Aquarium Design Contest 2018
Good, different work. Nice algae, interesting fish and perfect size for this type of aquarium. It might not be as spectacular as other styles, but it is effective.