Oreochromis / Sarotherodon / Tilapia spp.
Good management of farm siting can help to mitigate possible negative impacts on resources and the environment including: the impingement on natural ecosystems such as mangrove and wetlands and the species that live within them; the discharge of sediment into natural waters; and over-abstraction of freshwater supplies1, 2. Because inappropriate siting, design and construction of tilapia ponds can have negative impacts on resources and the environment, buyers should seek assurances from their suppliers that all national and local laws are adhered to, and that all farms have the required licences, permits and registrations in regards to their site and its operations, and that documentation is kept as evidence of compliance.
New farms should be located within appropriately identified aquaculture zones3 and ideally in areas where aquaculture development plans exist. Farm and pond developments should take place on land that has previously been used for agriculture or aquaculture (for at least 10 years). Existing and new farmers should consider carrying out assessments such as Biodiversity Environmental Impact Assessments (B-EIA) which are participatory and open in terms of results and outcomes. Where B-EIAs require rehabilitation of affected ecosystems then procedures should follow approved restoration guidelines.
A large proportion of tilapia farms in China have been converted from former agricultural land or shrimp ponds2. New farms should not be situated in mangrove ecosystems or other natural wetlands of ecological importance, although allowance can be made for pumping stations and inlet / outlet canals providing they are permitted.
As tilapia farms are often located in areas with relatively rich wildlife, species that prey on fish can be attracted to them. This can potentially cause problems due to direct losses as a result of predation, as well as having wider impacts on the stock due to stress and injuries. Tilapia farmers should ensure all possible management measures are taken to protect stocks from predators. This might be via netting of smaller ponds or fencing site perimeters. Deterrents, scarers and increased on-site activity may be effective and are preferable to lethal methods of predator control, which should only be resorted to when other methods have failed, and then only when appropriate licences are in place. Care should be taken to ensure that predator prevention does not potentially damage threatened, endangered or protected species.
Tilapia farms can apply for third-party certification which ensures they address issues such as conservation of natural habitats and endangered species, location that allows connectivity of wildlife and human traffic, compliance with water abstraction limits and so forth4.