Freshwater biodiversity is highly threatened today - a fact that should
be on the mind of every serious aquariast. The natural habitats of
tropical freshwater fish are increasingly threatened by human
activities, and while at times the hobby has been been at odds with
conservation, the role of aquariasts in preserving species is growing in
As their natural habitats are lost, freshwater fish species are
disappearing. A Malaysian study found fewer than half of the 266
resident fish species, while more than 30% of Singapore's fish species
are thought to be extinct. Freshwater biodiversity is highly
vulnerable. Habitats tend to be largely discontinuous meaning species
cannot easily cross land barriers that separate lakes and watersheds.
Thus freshwater fauna is generally localized, static, and subject
changing conditions. Whereas terrestrial species simply migrate in
response to habitat changes, freshwater species must cope with
ecological and climatic changes in order to persist.
Freshwater habitats are facing an onslaught of threats from
deforestation, waterway modification and dam construction, the
introduction exotic species, pollution, and over exploitation.
Deforestation in particular has major consequences for species popular
in the hobby. Erosion and the loss of habitat can severely affect fish
populations. Similarly damaging, the introduction of non-native species
(exotics) can devastate the local fauna as in the case of the Nile Perch
in Lake Victoria which has caused the extinction of endemic
Collection for the hobby has had a direct impact on some species to the
extent that they have become locally extinct over parts of their
ranges. For example the Bala shark is highly threatened in its native
Sumatra and Borneo due to its popularity as an aquarium fish. In the
past the Bala Shark (Balantiocheilus melanopterus) was heavily collected
since it did not readily reproduce in captivity (this has changed as
Balas are now captivity bred in fish farms). To optimize exploitation,
collectors targeted breeding grounds where Balas congregate for mass
spawning. The removal of breeding adults coupled with loss of habitat
from deforestation significantly impacted local populations. Similar
over harvesting has been documented among characins and the Arowana.
Today the role of aquariasts in conservation is changing. As habitat
loss continues -- especially the destruction of tropical forests -- the
importance of aquariasts in conservation is expanding. Aquariasts are
helping to maintain species (such as Cherry barbs and certain Killifish)
that are essentially extinct in the wild. By keeping these species and
populations viable, the fish-keeping community is protecting against
extinction. When and if reintroduction to natural habitats becomes
possible, it will be in part thanks to aquariasts.
Time has effectively run out for many species. Aquariasts can do their
part in preventing the further extinction of some freshwater fish.