METHODS OF CAPTURE
Although capture with poison has been banned for a long time, the use of cyanide or quinaldine is still practiced, especially in Southeast Asia (Indonesia and the Philippines) where most of the coral fishes are exported from. [1] In addition to corals and invertebrates, many unwanted fishes die even the fishermen suffer health problems from the poison.
Studies have shown that up to 80 percent of the target fishes can die – on site, during transport or in the aquarium – before reaching an aquarium. [2][3][4]
More targeted (‘non-destructive’) fishing methods, such as hand nets, can also be harmful to the reefs, depending on the size of a population and the distribution of a species.
Fishes living in greater depths should be placed in a cage and brought up slowly (3 metres every 30 minutes) not to burst their swim bladder. However, to be more efficient, the catchers often bring their prey immediately to the water surface. The swollen swim bladder is deflated with a pinprick through the abdominal cavity, which causes a lot of suffering and can often lead to death of the animals. This can have welfare implications. [5]
TRANSPORT
In the countries of origin, the fishes are usually quarantined or await export, which could take for a few hours or a few weeks. [6] Before transport, they are starved for another 48 hours in plastic bags filled with water. This is so they do not contaminate the water with their faeces during transport. This seemingly calms certain fish species and reduces growth of harmful bacteria, which in turn minimises algae. [7]
Depending on the species, the fishes are packed individually or in smaller groups in plastic bags and sometimes covered with cardboard or newspaper. Fishes with spikes are usually packed in two plastic bags. Sedatives are sometimes added to the water, including antibiotics and water stabilisers. This also helps to reduce the aggressive tendency of fishes that are packed closely together. As marine ornamental fishes are quite expensive, they are often individually packaged to reduce mortality, unlike freshwater fishes. The air in the plastic bag is saturated with oxygen and the bags are packed in a Styrofoam box. These have a certain thickness depending on the temperature and season of the recipient country and contain cooling or heating elements as appropriate. [6]
