Towards Better Trout Farming

Towards Better Trout Farming

12 December 2013
Greater Kashmir
Malik Zahid

Srinagar: Fish have great significance in the life of mankind. Not only is it a natural source of protein, it also provides many useful byproducts and thereby has become an indispensable source of economic sustenance of many nations. But the gradual erosion of commercial fish stocks, primarily because of over exploitation, alteration in habitat and pollution remains a concern. It is well established that fisheries and aquaculture is an important sector of food production in India as well. Thus it provides nutritional security to the food basket, contributes to the agricultural exports and engages about fourteen million people in different day to day activities. India constitutes nearly 4.4% of the global fish production. This sector contributes to 1.1% of the GDP and 4.7% of the agricultural GDP. The total fish production of 6.57 million metric tonnes presently has nearly 55% contribution from the inland sector and almost the same percentage from culture fisheries. Among the plethora of fish farming practices, trout farming undisputedly remains one of the oldest forms of commercial fish production. It dates back to 400 years ago in Europe, 150 years in the United States of America and about 100 years in South Africa. In Jammu and Kashmir, the trout culture started about 113 years ago, according to the state fisheries department website. As things stand today, the state has a long way to go in terms of per capita production, use of advanced technology and export despite over a century long experience. An analysis of the state of affairs clearly reveals that we stand nowhere when compared to other countries where trout fish farming is practiced. Trout belongs to the group of fishes known as Salmonids which are cold water fishes. Due to their popularity as a sport fish and as a food fish, trout have been widely distributed and are now cultured in waters around the world. Jammu and Kashmir is no exception. Here trout culture is being carried out at Kokernag and many other places. If the department’s information is anything to go by, the fish farm in Kokernag in South Kashmir is Asia’s largest trout culture facility. In natural water bodies trout spawns in cold and well oxygenated streams, rivers and brooks bearing gravel bedding and in wild trout matures at the age of three. It requires a temperature between 4 to 26°C for optimum growth and 12 to 16°C for spawning. In wild trout spawning varies from place to place as photoperiod and temperature play a deciding role on the onset of fish spawning and its regression. So, for the fish culture in general and trout culture in particular, we need to take care of the stress which fish undergo during the culture practices. While in culture trout overloading can result in decreased dissolved oxygen and increased ammonia levels. These conditions reduce growth rates and increase fish stress. A recent study in Integrative Fish Biology group at University of Liverpool, England concluded that like in human beings, the stress can affect the Salmons (trout) as well. But the traditional means in place in Kashmir would not help in detecting the problem. So it is high time that the authorities wake up and set up well equipped research facilities to study the cause and effect of the stress and thus save the treasure trove from nearing extinction. When salmon are transferred from rearing tanks to other water bodies for aquaculture purposes, or if they are migrating from freshwater to the sea, their ability to learn and adapt rapidly to the new environments will dictate their future success. Moreover researchers have also showed that salmon exposed to poor water quality were poorer learners and that markers in the brain can show the fish have experienced chronic mild stress (Grassie et al 2013). Another research has proved that after identifying the environmental situations that cause chronic or mild stress to salmon population will surely improve fish welfare and reduce losses in fish aquaculture. Good animal welfare is characterized by a broad predictive physiological, cognitive, and behavioural capacity to anticipate and respond to environmental challenges in a way that matches the environmental demands. The above findings demonstrate that alternative rearing strategies for restoration fish need to be found. The physiological and mental robustness indicators will provide important information in the evaluation of the fishes’ robustness towards future challenges. So while the trout farming needs a fresh lease of life for improved results, the need of the hour is also to focus on how to ensure the welfare of the fish. This will, on a larger scale, increase the production of the fish and thus bridge the demand supply gap. To sum it up the concerned authorities need to prioritize welfare and wellbeing of the trout fish to enhance the per capita population of the species. (Malik Zahid is a Senior Research Fellow at DST-IRHPA Centre For Excellence in Biological Rhythm Research, Department of Zoology, University of Lucknow, Lucknow.