New invasive fish species – Sri Lanka food source
There are around 200,000 acres of freshwater resources in Sri Lanka, out of which around 150,000 acres have been identified as potential for the fisheries industry. But there is no proper system of using those freshwater resources such as rivers, canals, tanks.
In 1956 fish breeding centre was started in Polonnaruwa and species such as Gurami, Tilapia and carp were populated from the breeding centre. A large number of fish was introduced to other regions from the breeding centre and there had been sharp development in the inland fishing afterwards. Some of the noteworthy places for inland fishing are Parkrama samudar, Minneriya tank, Karapara villlu.
Inland fishing provides the jobs for a large number of people in the island and the same time it helps to meet the fish demand, in the area away from the sea, where the sea fish is scared.
Hurulu wewa (Reservoir) in Anuradhapura north-central Sri Lanka is affected by new unknown species of invasive fish. The fishing community in the area is complaining about the destructive living pattern of the fish. The new species id multiplying very fast ultimately makes a threat to the existence of many local fish species as well as endemic fish species.
The new fish species has a very fast breeding pattern and it looks similar to the “Tank cleaner”, which is used as a cleaner in the ornamental fish tanks.
According to the members of the Fisheries Cooperative Society of Huruluwewa, new fish species is spreading very quickly and it needs only about three to four months for breeding. The tank was inhabited by a number of local fish species such as Snakehead Murrel (Ophiocephalus striatus), Tilapia (Oreochromis), and Cat Fish (Siluriformes). But with the invasion of new fish species, local fish varieties are reducing in great numbers and seen rarely today.
The feeding habit of the new fish species has been identified as a threat to the local fish species, while invasive species feed on the eggs of other fish species as well as smaller fish.
The new species were mostly seen in the places where there are rocks, logs, aquatic plants etc. these are the places, that most fish species lay their eggs. According to the fisher in the region, the introduction of the invasive fish is not known. It is believed that the freshwater fish propagators have introduced it into the reservoir.
Inland fishing is a very popular livelihood of the people around the Huruluwewa reservoir and the inland fishing is contributing immensely for the growing fish demand in the country and it is a popular Sri Lanka food source especially among the people away from the sea. According to the fishers in the area, the fish harvest has been reduced to 2 to 3 kg of fish from 10 to 20 kg of fish after the invasion of new fish species.