Coastal Aquaculture in Sri Lanka: Opportunities and Environmental Challenges

Abstract

In Sri Lanka, coastal aquaculture has been a recent development which was mainly concentrated in the north-western province (NWP), and was severely affected by the outbreak of White Spot Virus (WSV) during 1990s. In the proposed Aquaculture and Culture Based Fisheries Sector Development Plan (2021-2025) of National Aquaculture Development Authority of Sri Lanka (NAQDA), under the coastal aquaculture sub-sector, the objectives set out are to increase the coastal aquaculture production from 20,000 t in 2020 to 60,000 t in 2025. To achieve the envisaged targets in coastal aquaculture and mariculture, NAQDA has planned to launch several new development projects. Conventionally, the black tiger prawn, Penaeus monodon was cultured in Sri Lanka, but recently the Pacific white shrimp Penaeus (= Litopenaeus ) vannamei was introduced mainly to revive the shrimp farming sector, which has faced crop failures caused by the fatal white spot disease. Development of aquaculture of several other species such as sea bass, sea cucumber, milkfish and mud carb is also envisaged. In Sri Lanka, there is an urgent need to revise the effluent quality standards for coastal water bodies used for aquaculture. In addition to maintenance of water quality, appropriate technologies should be in place to mitigate the problems related to sediment loading. Aquaculture farmers should strive to adopt, maintain and improve better management practices (BMPs) in all aspects of farm operations. Adoption of BMPs during site selection, pond construction and preparation, selection of post larvae for stocking, bottom sediment management and disease management may also reduce the risk of the impacts due to climate change.