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Fisheries in mountains
Mountain lakes, streams, rivers and reservoirs are home to a rich reserve of fish and fisheries that can provide a key source of food and income to mountain communities. Protein is often in short supply in mountain regions. Freshwater fish therefore offers a much-needed source of animal protein, micronutrients and essential fatty acids. And local freshwater fisheries are particularly important in mountainous land-locked countries or remote mountain areas with little or no access to marine fishery resources.
Until now, the importance of building and protecting fisheries and aquaculture in mountain regions, particularly in developing countries, has received little attention. However fishing and fish farming could be a vital component of overall development plans, and a significant means of supplementing incomes and improving impoverished diets.
A hard life for freshwater fish
Environment is key to the health of fish stock, and the deterioration of the aquatic habitat can have a detrimental effect on fish populations. So when mountain watersheds become degraded or depleted as a result of abuse and over-use of natural resources, the fish population is necessarily negatively affected too. Deforestation and soil erosion, leading to an increased silt load in streams and rivers, can harm precious aquatic systems, and the fish species that depend on them.
Equally industry and agriculture frequently interfere with the health of aquatic environments. Water pollution in the form of industrial pollutants and agrochemicals – herbicides, fertilizers and pesticides – can cause considerable damage to fish populations.
Mountain fisheries are also under pressure in food-insecure areas where fish stocks are limited and easily over-exploited. Fish are under threat at every stage of their life cycle. They have a hard job making their way upstream to spawn, a struggle aggravated by the existence of dams and other obstacles that they might encounter along the way. Fish need to be protected in the places where they spawn or when eggs are developing. Humans find it all too easy to pick off the gravid (egg-laden) fish with spears and sticks en route. Other unsustainable fishing techniques such as the use of dynamite and electro-fishing are still practised. Poaching is also a serious problem, and one that threatens the viability of many privatized fisheries.
All of these factors mean that many indigenous fish species, such as the mahseer, a native to the Himalayan regions, are threatened with extinction. And restocking these endangered species can be a costly process.
Introducing fish-friendly dams
In mountain regions dams are important as sources of energy and for irrigation but they upset ecosystems and have a devastating affect on fish stocks: they obstruct the migratory path of fish and modify the habitat by changing or halting the riverine flow. As a result, the fish population is prevented from reaching its traditional areas of spawning and feeding. In Europe and North America legislation exists to ensure that dams are equipped with usable fish passes, but this is not the case in many developing countries. These passes – or “ladders” can help fish to swim upriver to spawn by providing a series of stepped pools that can easily be negotiated. The main challenge lies in the appropriate design of these fish ladders: they have to be well-adapted to the biology and behaviour of the species concerned. In other words, they have to be built in such a way that all fish can swim upstream and do not have to leap to negotiate the obstacle.
Fisheries and the law
Regulating fisheries activities is essential, but restrictions need to be realistically applied. Licences could be imposed in some areas, and privatized fisheries protected. Equally the needs of other water users need to be reconciled with fisheries management. When it comes to the observance of regulations, education is all important; mountain people need to be made aware of the importance of encouraging sustainable fisheries management and protecting species and stock.
Where neighbouring countries share water resources, and thus migratory fish stocks, cooperation on a regional basis should also be made a priority. This may become the most cost-effective way to address common problems in fisheries’ initiatives, and share experiences.
Making mountain fisheries sustainable
In many mountain areas of the developing world, the breeding and culture of cold water fish species has yet to be introduced. However rehabilitating rivers and lakes can help conserve threatened fish species and improve privatized fisheries on inland waters. In order to maintain the sustainability of native fish and increase fish production, many mountain countries now practice aquaculture and stock enhancement.
Selected fish species can be stocked in order to increase the fish resources in large inland water bodies, such as lakes and reservoirs, and as a means of introducing species that are more productive. In order to integrate fisheries into rural development and water resource development initiatives, more information is needed on the biology and behaviour of existing fish stocks, migration patterns and rates of depletion of stock. Above all, it is important to assess how heavily waters are fished in specific regions. This data is not easy to determine because freshwater fishing in these areas is generally a part-time occupation, practiced by many but only on an intermittent basis.
Setting up aquaculture programmes – however viable they may eventually become – can prove a costly business initially. A recent aquaculture project in the mountainous provinces of northern Viet Nam, has been very successful in alleviating poverty and enhancing livelihoods among poor ethnic minorities. In this case a microfinance programme gave the initial impetus to the project. Many mountain communities could certainly benefit from this example.
When existing fish stocks become depleted, restocking is the only viable alternative. But restocking can be a delicate operation, especially when non-indigenous species are introduced that could compete with indigenous fish or spread new diseases. Restocking can also be expensive, and costs can be prohibitive for poor communities, or else need to be weighed carefully against the eventual income generated from fisheries.
Developing fisheries within irrigation canals
There is a huge potential for the development of fisheries in irrigation canals. Aspects of fish production have rarely been given high consideration in irrigation engineering. But recently expert consultations have taken place between fisheries and irrigation specialists in order to tap into this huge potential. In addition to providing a valuable food source, the presence of some species is beneficial in reducing waterborne diseases, given that they prey on disease carriers such as snails and insect larvae.
If fisheries in irrigation canals are to be exploited, the design of irrigation structures needs to be adapted – to prevent fish from swimming unobstructed into the canals or being sucked out of rivers by the pumping stations. It is also important to ensure that non-indigenous fish species, which might successfully compete with local species and eventually threaten their existence, are kept out of these canals.
Raising fish in paddy fields
Fish are one of many aquatic species that can make their habitats in rice fields, along with reptiles, molluscs and crustaceans. The presence of these species ensures biodiversity health; that is the control of pests and disease that could harm crops and livestock, while also providing an important food source for poor rural populations alongside the staple rice. But population pressure and intensified farming methods are seriously threatening this aquatic biodiversity. Pollutants and destructive fishing methods are combining to kill off these ecosystems. There is growing evidence that natural aquatic resources are on the decline. The International Year of Rice in 2004 has provided an opportunity to draw attention to the importance of these aquatic resources and the risks to which they are exposed.
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