Enclosure culture as climate-resilient aquaculture systems

Abstract

India has vast and varied inland openwaters (viz., rivers, estuaries, reservoirs, wetlands, lakes etc.), which are important capture fishery resources of the country contributing significantly to the national economy while providing livelihood to millions of countrymen. Water area under reservoirs (approx. 29 lakh ha) and floodplain lakes & derelict waterbodies (approx. 7.98 lakh ha) are amenable for capture-based culture fisheries having huge potential in enhancing inland fish production. Enclosures (i.e., cages and pens) installed in such openwaters are useful for rearing fingerlings for in-situ enhancement programmes as well as for producing table fish having immense socio-economic implications for poor inland fishers. For installation of such enclosures, certain area of the waterbody, even if it is choked with aquatic macrophytes/ algal bloom and unproductive can be cleared off. This means that un-utilizable water areas are reclaimed for productive purposes. Floating nature of cage enclosures makes them most suitable for waterbodies which are affected by occasional flood and drought-like situations. Pen enclosures mostly installed in marginal areas of floodplain wetlands can be protected from high flood by increasing height of the net fencing on-demand. Economically important small indigenous fishes can be stocked in pens, which would reproduce in them and become a self-recruiting population providing nutritional securities to the fishers. Climate-resilience of these technologies is already evident from large volume of work done on the subject, which will lead to higher adoption and consequent increase in fish production from inland openwaters.