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Mosquito Nets – good or bad for our environment?

Tomorrow, 20th August, is World Mosquito Day. The day which raises awareness on the importance of mosquito control and the prevention of malaria. On their website, WHO records that there were an estimated 228 million cases of malaria worldwide in 2018, with Africa having a disproportionately high share of global malaria cases at 93%. Their recommendation for prevention is to use insecticide-treated mosquito nets and indoor residual spraying which “are effective in a wide range of circumstances”.

Every year thousands of insecticide-treated mosquito nets are donated to African countries by international charities, foundations and NGOs which have been used to prevent countless cases of malaria, saving lives. However, there is a downside to these donated nets, as not all of them are used to sleep, under but are stitched together and used as fishing nets.

Checking the size of fish trapped in illegal nets

The legal size of fishing nets are between 3.5 and 4 inches. Illegal nets can be smaller than an inch, with mosquito netting being tiny. These homemade fishing nets sweep up all the tiny fish, removing them before they can grow to replenish the fish population in the lakes and rivers, rapidly depleting fish stocks.

A further problem is that donated nets are treated with insecticides which are safe for humans, but harmful to mosquitoes. These insecticides are also extremely toxic to fish and our aquatic environments, as the insecticides leach into the water.

Illegal Nets found on Lake Itezi-Tezi

Illegal nets taken out of Lake Itezi-Tezi

One Hon. Wildlife Police Officer (HWPO) operation at Lake Itezi-Tezi found fishermen crammed onto the islands on the lake. Many were using the wrong sized fishing nets. One of these illegal nets was 100m long – being hand stitched together from shade cloth and mosquito netting. Because the water level in the lake had gone down, nets were also found tangled up in the trees and a dead crocodile was discovered having become tangled up and unable to escape. These abandoned nets pose a huge threat to small animals and roosting birds who become entrapped, then die of starvation. In this two day operation on the lake, 28 illegal nets and 1 tonne of illegal dried tiny fish were confiscated.

Nets tangled up in trees ensnare small birds, reptiles and animals

Illegal Nets found in the Kafue River

Over 2 kilometres of illegal fishing nets found in one river

Another HWPO patrol, this time on the Kafue River, found over 2 km of illegal fishing nets being used. Again these were handmade nets made from mosquito nets. These small meshed nets are often called ‘video’ nets, taking out all the fish from the river. These are not isolated cases, with HWPO patrols finding illegal nets being used every year all over the country.

Give Ethically

Unfortunately fishing using mosquito nets appears to be widely practised. Sadly the donors that hand out these nets, which do save millions of lives across Africa, do not take the misuse of their nets seriously. By ignoring this misuse it could lead to irreversible ecological damage to the delicate biodiversity of our rivers and lakes – smaller birds and animals suffer needless deaths and reduced fish stocks threaten our food security.

So this World Mosquito Day, if you are thinking about making a donation to your preferred medical charity, do check what methods they are using to fight malaria. Otherwise you might find you are unwittingly adding to the long term ecological damage of the countries that you are actually trying to help.

Thank you to the HWPO Unit for their operational information and use of their photographs. For more information on the volunteer work that the HWPO Unit undertakes with the Department of National Parks and Wildlife, then check out their Facebook Page.