Global use of mosquito nets for fishing is potential threat to both humans and nature

First-ever global assessment reveals full scale of the practice and calls for collaborative solutions.

Mosquito nets distributed to combat malaria in developing tropical countries are being routinely used for fishing instead, according to the first-ever attempt to gauge the international scale of a practice that is of increasing concern to the global conservation and healthcare communities alike.

Published in the journal PLOS ONE, this collaborative study involving researchers from the Department of Zoology highlights the widespread nature of mosquito net fishing (MNF) – raising questions regarding the threats to biodiversity this practice poses, as well as its impact on both the fish populations that represent critical sources of food for many poor people, and human health. 

The researchers surveyed expert witnesses living and working in malarial zones around the world, in order to produce a rapid global assessment of the extent and characteristics of MNF. The study found evidence that this practice occurs to some extent across most of the world’s tropical latitudes, impacting a broad range of different marine and freshwater habitats and species.

Commenting on the study, lead author Rebecca Short of the Interdisciplinary Centre for Conservation Science (ICCS) said: “Recent decades have seen the broad distribution of free or subsidised mosquito nets, which has had a hugely important impact on reducing incidences of malaria in developing countries. While anecdotal evidence has long existed about these mosquito nets often being diverted into artisanal fishing, our study represents the first concerted attempt to gauge the scale and extent of this problem worldwide."

We are wholly supportive of the efforts of the healthcare community to tackle this disease, which is so damaging to many people’s lives, but there needs to be further research into the potential impacts of this unintended consequence.

Particularly prevalent in Sub-Saharan Africa, MNF is conducted at a range of scales, using a variety of different fishing methods that often result in the capture of juvenile fish. This may undermine fisheries’ management efforts, potentially threatening these fish stocks and the human populations that rely on them for their survival. However, the study also points to this activity often being conducted by vulnerable fishers, providing a valuable source of food for poor families and calling in to question whether simply criminalising MNF is an appropriate response.

As well as attempting to measure the true scale of the issue, the study makes a number of recommendations for policy priorities designed to mitigate against, and address the drivers of, MNF in the future. These include better planning for mosquito net distribution efforts and for their disposal after use, as part of efforts to protect marine and freshwater biodiversity whilst conserving vital fish stocks.

Co-author Professor EJ Milner-Gulland, the Department's Tasso Leventis Professor of Biodiversity, said: “We hope that this study will encourage closer cooperation between healthcare, international aid/development bodies and conservationists to develop collaborative solutions to a complex issue that is linked to wider issues of poverty and food shortages in these malaria-afflicted regions.”