WWW.WAS.ORG • WORLD AQUACULTURE • DECEMBER 2014 19 (Boaventura et al. 1997). Fish on the downstream part of the river live in effluent from farms located upstream. Water quality is not the only factor affecting rainbow trout health. Crowding, improper handling, grading, pond cleaning and other routine activities are additional factors that stress fish and can lead to increased susceptibility to pathogens (Pickering 1992). In many countries, fish farmers are assisted in the management of water quality and environmental parameters by government and academic institutes and extension agents, but this is not the case for the trout farmers of Lebanon. Aquaculture has generated massive enthusiasm in the past two decades, with some viewing its development as a ‘blue revolution’ with tremendous potential for food security, economic growth in rural areas and poverty alleviation. However, growth in fish farming, as with all farming activities, has environmental impacts, which must be managed if production is to be sustainable. Other than the flow rate of the Assi River, very little is known about water quality and no studies of the impact of trout aquaculture on the Lebanon portion of the stream are available. Here we describe a study performed on the river to assess levels of pollution, effects of aquaculture on river water quality and local stakeholder perceptions of aquaculture and the environment. Study Survey A survey of trout farmers along the length of the Assi River in Lebanon was done in 2012. Farms were identified and a list of 49 farmers who fully or partially own ponds along the Assi River was established. Geographic coordinates of each farm were estimated using Google Earth imagery. Survey results cover 199 ponds from the source of the Assi River to the last accessible point before the Lebanon-Syria border. Every trout farm owner or manager along the river was interviewed and informal conversations with the mayor of Hermel, recreational activity (e.g. rafting and camping) organizers and restaurant owners bordering the river, were recorded. A detailed questionnaire was prepared in English and translated to Arabic. It included questions related to land and ponds, fish production, feeding and environmental practices and the farmers’ personal opinion about the state of aquaculture in the river valley. Questions were posed at random and in no specific order. The veracity of some answers was controlled by asking some farmers if the information given by other farmers was correct. Raceway Design and Construction The design and construction of ponds and raceways on fish farms of the Assi River valley is diverse. Only earthen raceways (Fig. 4) are used by 43 percent of farmers, both earthen and concrete raceways are used by 34 percent and only concrete raceways (Fig. 5) are used by 23 percent. In general, those with concrete raceways thought they were better and those with earthen raceways defended their use. There are two main reasons to explain the prevalence of earthen raceways along the Assi River. First, earthen raceways are less expensive to build than concrete raceways. Trout farmers who believe that concrete raceways are better often lack the funds to transform their earthen raceways to concrete. Some trout farmers who rent raceways perceive the expense of transforming earthen raceways to concrete raceways as unnecessary, inasmuch as they will not benefit from the investment over time because they do not own them. The other reason to explain the prevalence of earthen raceways is that many farmers assert that trout reared in earthen raceways are healthier, more colorful and a better-quality product. Thirty-eight percent of farmers believe that earthen raceways are better for trout health and welfare than concrete raceways. Some of the reasons given were that fish feed on small plants growing in the soil and hence obtain more nutrients and grow faster. Also, some believe the soil acts as a filter, cleaning the water in which trout are grown. A majority (53 percent) of trout farmers thought yields from earthen raceways were better than from concrete raceways. Another 13 percent believe that rearing rainbow trout in earthen or concrete raceways gives similar results and therefore deem the additional expense of building a concrete raceway unnecessary. Piper et al. (1982) also reported that some trout farmers stand by their opinion with respect to high yields from earthen raceways. Survival of rainbow trout does not seem to depend on the type of the raceway, earthen or concrete. Thirty four percent believed that concrete tanks were better because, in contrast to earthen tanks, they can be totally cleaned of waste. Furthermore, no aquatic animal can dig into them and allow fish to escape. They are difficult for pests or predators (e.g. snakes, rats or frogs) to enter and prey upon trout fingerlings. Eleven percent of farmers stated that they were certain that concrete raceways helped reduce fingerling mortality and offered better population control. Fish and water quality in concrete raceways are much easier to manage than in earthen raceways (Piper et al. 1982, Hinshaw 2000, Dunning and Sloan 2001). (CONTINUED ON PAGE 20) TOP, FIGURE 4. Earthen raceways along the Assi River, Lebanon. BOTTOM, FIGURE 5. Concrete raceways along the Assi River, Lebanon.
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