World Aquaculture March 2019

24 MARCH 2019 • WORLD AQUACULTURE • WWW.WA S.ORG Nursery rearing of whiteleg shrimp at a commercial farm (Photo: TNJFU). is responsible for the bulk of shrimp production, followed by the recently introduced whiteleg shrimp, Litopenaeus vannamei , which is produced inland and is mainly destined for export. This species has rapidly replaced the black tiger shrimp. In fact, the culture of this shrimp picked up on par with tiger shrimp in very short span of time. The farming of shrimp is largely dependent on small holdings of less than 2 ha and these farms account for over 90 percent of the total area used for shrimp culture. Traditional systems of shrimp farming are applied to many of the farm holdings in Kerala and West Bengal. The majority of production takes place in ponds throughout the year. This is done in a traditional extensive way, with ponds of 1.5 ha and bigger, such as in Kerala and West Bengal, or a semi- intensive way, with ponds below 0.5 ha, as in Andhra Pradesh, West Bengal and Odisha. The latter production technique entails technical modifications and investment in fertilizers, pumps and construction. In traditional ponds, different species (fresh and brackishwater) are produced simultaneously and their growth rate is higher than in semi-intensive ponds. Often, farmers produce other products as well. Shrimp production takes place in different ways: 1) after the harvest of rice (polyculture), such as in central Kerala, Odisha, Karnataka, Goa and parts of West Bengal, 2) combined with the growing of rice, which is mainly practiced in Goa and West Bengal, or 3) in dedicated ponds using scientific methods, such as in Andhra Pradesh and parts of West-Bengal. The main regions for shrimp production in Andhra Pradesh are Bhimavaram and Visakhapatnam. It is expected that in Odisha, West Bengal and Gujarat, the production will increase and land conversion for the production of shrimps is currently underway. New development opportunities for shrimp production exist in West Bengal, Odisha and Gujarat. In Gujarat, shrimp farming is a fast-growing activity. Currently approximately 15,000 ha are used for brackishwater shrimp production and the land available for this industry could be up to 376,000 ha. The main districts are Valsad, Navsari, Surat and Bharuch, of which Surat is the foremost brackish aquaculture district. Further opportunities exist in Bhavnagar and Jamnagar region. In Kerala and Tamil Nadu, the aquaculture sector is smaller, but economically more important. The states heavily support the sector, which makes it interesting for investors to look for foreign expertise and technology. They also aim to make the process inclusive and the products exportable. Initiatives of the Indian government, demonstration projects of the Marine Products Export Development Authority (MPEDA), in combination with credit facilities provided by commercial banks, enabled the establishment of several shrimp hatcheries. Marine Aquaculture Marine aquaculture emphasizes the production of extractive species. In seawater, the major farmed species are the green mussel Perna viridis , Indian brown mussel Perna indica , Indian Deployment of long-arm paddlewheel aerators on a commercial shrimp farm (Photo: TNJFU). Crab cage culture (Photo: TNJFU). Shrimp harvest from inland shrimp farms, Tamil Nadu (Photo: TNJFU).