Fish disease puts millions of livelihoods at risk

Millions of families’ livelihoods and food supplies are at threat from a killer fish disease. The disease, Epizootic Ulcerative Syndrome, or EUS, is caused by fungus, which isn’t harmful to people, but kills vast numbers of fish and makes them unfit to sell. It could seriously hit the food security and livelihoods of people in seven African countries the Zambezi River Valley, the United Nations Food and Agriculture Organisation (FAO) says.

So far, EUS has been confirmed in three African countries, Zambia, Namibia and Botswana. If not properly contained, there is the risk of the disease spreading to other countries surrounding the Zambezi River as well as other river systems in the region. “Indications are that EUS, which was first confirmed in Africa in 2007, is spreading both upstream and downstream of the Zambezi and risks taking hold in other parts of Africa,” the FAO said in a statement. It said although fish infected with EUS do not normally pose a threat to humans, the marks on their skin, caused by the fungus makes them unmarketable. Not being able to sell the fish threatens the 25 million people dependent on agriculture or fishing and fish farming in the Zambezi River basin with serious economic loss.

The disease is fairly new to Africa and was first seen there in 2007, but other regions of the world have felt its effects for a long time, says the UN’s senior fishery officer Rohana Subasinghe. In the early 1970s, it swept across many countries of Asia, Australia and the US, causing significant loss of income to fishers and fish farmers and also harming biodiversity. FAO officials think the disease may be triggered by environmental factors - things like water temperature or the rainy season. "In Africa, the rainy season begins around October, November. So we suspect to see another round of disease outbreak around October, November this year," says Subasinghe. As fish die off, the catch in later years will be smaller. That increases food insecurity and is likely to mean more food aid will be needed. "This has managed to almost completely eradicate certain species in the systems. I am a Sri Lankan. I have seen [it] in Sri Lanka. But it took four or five years to see these fish coming back in the rivers," he said.

EUS is very difficult to control in the wild, but it can be controlled in fish farms with simple precautions such as preventing possible carriers getting into the water or fish ponds, removing dead fish and improving water quality. Many fishers in the Zambezi River Valley may now need to diversify into fish farming to keep their livelihoods going.

By Hayley Jarvis for SOS Children