The world’s first public aquarium specialising in clownfish has now opened its door for visitors. The aquarium, which is located in Taitung County in Taiwan, will eventually house 1500 clown fish from 18 different species.

The aim of the clownfish aquarium is to educate the public about clownfish life-cycles and captive breeding techniques, and specimens will be sent to the aquarium by breeders such as the Eastern Marine Biology Research Center in Taitung.

“By meeting market needs we are helping to ease the crisis of clownfish species being endangered”, says researcher and museum planner Ho Yuan-hsing. “Due to the increasing number of artificially-bred clown fish, the fishing of clownfish is no longer seen in Taiwan’s coastal areas because it is unnecessary.”

AC comment:

The movie “Finding Nemo” made a lot of people interested in getting their own “Nemo”, but few were willing to learn how to properly maintain a saltwater aquarium. Before you decide to get a clownfish, please keep in mind that these are marine fishes. Simply adding some salt to your freshwater aquarium will not make is a suitable home for marine fish; not even for the sturdy clownfish. Even though the worst Nemo-craze seems to have cooled off now, a lot of “Nemos” still face an early death in the hands of uninformed fish keepers; deaths that could have been easily prevented.

The oceans of the world absorb a large part of the carbon dioxide released into the atmosphere by us burning fossil fuels, burning forests to make room for fields, etc. This have helped slow down global warming, but new studies shows that it might have a devastating effects on certain fish species such as clown fish. Tests performed on clown fish larvae have shown that increased levels of carbon dioxide can make them disoriented an unable to find a suitable home and avoid predators. The pH level in the ocean has dropped 0.1 since pre-industrial times due to the absorption of carbon dioxide and researchers believe that it will fall another 0.3-0.4 before the end of this century.

This increased acidicy of the water can cause serious problems for clown fish larvae, since clownfish larvae lose the ability to sense vital odours in more acidic waters – probably owing to the damage caused to their olfactory systems. Kjell Døving (Oslo University), co-author of the rapport that was published in US journal Proceedings of the National Academy of Sciences, says “They can’t distinguish between their own parents and other fish, and they become attracted to substances they previously avoided. It means the larvae will have less opportunity to find the right habitat, which could be devastating for their populations.“

The research indicates that other species might be affected in a similar way and might have a hard time finding their way to suitable habitats if carbon dioxide levels raises in the oceans.

About the study

The study was executed in such a way that the researchers checked how well clownfish larvae could detect smells in normal sea water (pH 8.15) and how well they could detect odours in more acidic water (at levels predicted to be a reality around the year 2100 and later). The test showed that at pH 7.8 the larvae stopped following scent trails released by reefs and anemones and started following sent trails they would normally avoid; scents that are associated with environments not suitable for clown fish. The larvae also lost the ability to use smell to distinguish between their parents and other fish. At pH 7.6 the larvae were unable to follow any kind of odour in the water, and instead swam in random directions.

Many of us may think about clown fish as commonly found reef fish but the fact is that many clownfish species might becoming endangered in some areas such as of the coast of Australia at least if we should believe Dr Billy Sinclair, University of Cumbria.. A big culprit is the aquarium trade. Just five years ago there were still plenty of clownfish out there but than come the very popular movie finding Nemo from pixar. The movie which was a success in theatres and have sold over 40 million DVDs created an instant demand for clown fish species looking like Nemo. (like the Percula clownfish) Even though a lot of clownfish is being bred in captivity each year the captive bred stock couldn’t satisfy the demand and therefore over-harvesting of wild specimens became a reality. Many (most) marine biologists agree with the effect the movie has created.

A problem is that people who buy them don’t know how to manage a marine aquarium and just set one up like they would a goldfish bowl. This often leads to death of the fish as the owners don’t know how to care for them or a saltwater tank.

Clownfish sales have gone up eight-fold since the movie was released and not only biologist like Dr Billy Sinclair see a decline in the wild populations. Divers also reports how much rarer it has become to see clownfish. It has also become much rarer for clownfish to be caught accidentally by commercial fishermen

The study done by Dr Billy Sinclair shows that shoals that used to number dozens of clownfish now only contain a few specimens. This makes it harder for the species to breed. In some area they are more or less gone completely. Hopefully however populations can recover quickly if the pressure from the collection of clownfish from the pet trade can be reduced. The pet trade is however not the only culprit in the population declines. Coral bleaching and die off (caused by rising temperatures) is also believed to play a role.