Fish of various species have, in recent years, also been subjected to such planned breeding. Genetically-engineered organisms for human consumption are not too far away in the future, if not already in the market. If we recall the Green Revolution, the creation and use of HYVs plants have created numerous serious problems. They may alter or impoverish the existing communities and populations of the receiving ecosystems through inter-breeding, predation and competition for food, space, habitats, etc. Genetic pollution of indigenous stocks is possible.
Some countries recognise the danger of genetic pollution and have taken preventive measures.
In Norway, the number of salmon escaping from fish farms exceeds the wild population, resulting in wild types diminished due to introgression of domestic stocks, loss of genetic adaptation to local conditions as well as potential susceptibility to diseases. It has prohibited siting of salmon farms within 30km of important salmon runs. Marine environment and preservation of the marine biodiversity does not only concern developing countries but more so than ever concerns the industrialised countries which have lost much of theirs. Spectrum of risks posed by GMOs include adverse effects on humans and animals as well as disruption of ecological processes. Currently, there are no effective regulations of control.