New invasive fish species – Sri Lanka food source
Sri Lanka has a large number of inland water resources such as rivers, natural lakes as well as man-made lakes, tanks, and various other water resources. These water resources collect millions of cubic feet of freshwater every year. This water is used in many ways on the island. Primarily it is a source of water for cultivations and fish breeding.
The inland water resources are also used in the tourism industry. Some of the water resources such as the Bentota river, and Madu river are very popular places for boat tours in Sri Lanka and they attract a large number of travellers every year. These water resources are particularly popular among travellers as they are located near the west coast beach resorts of Sri Lanka. Bentota River is also very popular among foreign travellers due to the water sports centres, these water sports centres enable the travellers to engage in many interesting water sports such as boating, surfing, banana boating, water scooter riding etc.
Some of the island water resorces in Sri Lanka provide a platform for travellers to engage in adventure activities. Kitulgala, which is popular as the adventure playground of Sri Lanka enables travellers to engage in many adrenaline-pumping activities such as whitewater rafting, waterfall abseiling, canoeing, trekking, hiking, and mountain climbing.
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 for using those freshwater resources such as rivers, canals, and 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 Parakrama Samudra, Minneriya tank, Karapara villlu.
Inland fishing provides jobs for a large number of people on the island and at 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 are 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 are 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, where most fish species lay their eggs. According to the fisher in the region, the introduction of 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 inland fishing is contributing immensely to the growing fish demand in the country 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.