Despite being a mere dot on the map, Hong Kong harbours over 214 species of freshwater-dwelling fish, that's 20% of China's entire fish species! We owe this to our diverse topography, giving rise to a variety of aquatic habitats such as: lowland streams, hillstreams, rivers, estuaries, marshes, meanders, ponds and reservoirs.
Due to Hong Kong’s small size and mountainous terrain, there are no natural lakes in Hong Kong, with native freshwater fauna relying mainly on running-waters to survive (Chan, 2001). There are over 2500km of natural streams and rivers in Hong Kong and 33 of which are classified by the Agriculture, Fisheries and Conservation department as ‘Ecologically Important Streams/Rivers’ (ETWB, 2005). These watercourses provide habitat for 184 freshwater fish species, 123 dragonfly species and many other water-dependent taxa such as amphibians and reptiles (AFCD, 2019).
It has also been identified by the Freshwater Fishes Sub-group for HKBSAP (Hong Kong Biodiversity Strategy and Action Plan ) that lowland fish species currently face the greatest risk. Moreover, historically common lowland species like the Garnet Minnow (Aphyocypris lini) and White Cloud Mountain Minnow (Tanichthys albonubes) are now locally extinct. Meanwhile, species such as the White-spotted Walking Catfish (Clarias fuscus) and Hong Kong Paradise Fish (Macropodus hongkongensis) have become near threatened locally (Freshwater Fishes Sub-group, 2014).
Lowland habitats generally exist out of Country Park systems (Chu, 1998), making them vulnerable towards development pressure. In fact, development coupled with Hong Kong’s territory-wide flood control plan (Hong Kong Drainage Services Department, 2000) has caused stream and river habitats to face large-scale channelization and ecosystem-altering from both private and government sectors in the past two decades. However, instead of devising sustainable solutions e.g. catchment reforestation, preventing soil erosion, preventing illegal dumping in channels, etc. Government engineers have opted to transform and spread concrete channels through ‘channel improvement’ (Chan, 2001). The aim of ‘channel improvement’ is to increase the channel capacity and flow, which is done widening, deepening and smoothening existing watercourses. This often results in stretching the banks and the removal of natural substrate and rocks for deepening and smoothening to increase the flow, which may alter the hydrology (King, 2009) and cause negative impacts to native biodiversity.
Thus, as an ecologist, it is my duty to educate and raise awareness on these issues and conserve our existing habitats! I hope this database can encourage more people to go outdoors and explore. Below are some photos I have taken of my favourite aquatic animals that can still be found in Hong kong!