Fishing for Mosquitos

Fishing with beljal (Kishoreganj, Bangladesh)

A recent article in Ambio (Jones & Unsworth 2019; cf Note 1) addresses the increasing use of mosquito nets as fishing nets. Before continuing, it should be established that a "mosquito net" is not a fishing net per se (the word "net" referred originally to the material and not its use). Mosquito nets, originally referred to as "bed nets", are intended as protection against malaria, and are distributed mostly for free in huge quantities throughout the world. This article does not restate the arguments in the ScienceDaily article. Instead it, first, shares own experiences from anthropological fieldwork in Bangladesh (cf Note 2) and, second, presents some ideas on how this issue can be addressed.

Mosquito nets obviously catch more fish than regular nets, given their much smaller mesh size. And it is intuitively clear why poor fishermen opt to repurpose mosquito nets as fishing nets. In a situation of decreasing availability of fish as well as increasing number of people engaged in the sector, it is perfectly understandable why fishermen adapt and adopt new tools and technology, in order for purposes of both food security (consumption) and livelihood (marketing).

Case I: Bangladesh, Fisheries Sector Changing Technologies

I have experience with traditional small-scale fisheries in several countries in West-Africa, the Black Sea region, Middle East, and South Asia. Throughout I have found that fishermen began using nets with smaller mesh sizes well before mosquito nets became available.

During the 1980s I did anthropological fieldwork among a caste of Hindu fishermen in the haors (depressions with often no outlet that are replenished annually during the monsoon) area in Sunamgonj in north east Bangladesh. Traditional cotton fishing nets were still in use, and the laborious task of impregnating them was still done annually. Different species of fish required different methods and tools, where, importantly, the mesh size was a key variable. It was accordingly to a large extent possible to fish for particular species of fish. To take an example, the Boal, locally referred to as Goal or Mully (Wallago attu), is a fairly large species of catfish. A type of large dragnet with quite large mesh size, and which required operation by several men, was used to fish for Boal

At the same time nylon nets had been recently introduced. My stay in this fishing village accordingly coincided with the gradual introduction of new factory produced nylon nets that replaced the traditional nets. These nylon nets, which had small mesh sizes, were used specifically in the form of throw nets, while children and women would use them in the form of filter nets. They also began being used in bel jal (cf Notes 3 and 4). The result was that the traditional large variety of different types of nets gradually became replaced by a much smaller number of nylon-based nets. The new nets had in common that they had smaller mesh sizes, which still differed for the few new types of nets. The latter was, however, to change.

The reasons for this shift to using nylon nets with smaller mesh sizes is understandable. They are cheap. The onerous task of impregnating cotton nets (a fruit from a local tree is the key ingredient in the liquid that is prepared) is not necessary. And, perhaps most importantly, they fish better.

I went back to this fishing village in 2009, around 20-25 years later. By that time the shift to using only nylon nets was complete. There were no cotton-based nets in use any more. Also, the fishing nets used were smaller often much smaller  and seldom required the combined efforts of a team of fishermen. The traditional species-purpose type of fishing had all but disappeared. As a side issue, this change in net type, specifically from larger to smaller nets, likely has consequences for the types of boats used.

This last visit was prior to the free distribution of mosquito nets. I have no information about the use of mosquito nets in this village today, and in fact throughout Bangladesh. A recent internet search gave no results.

The Consequences

The availability of fresh water fish in Bangladesh, including in my study village, has decreased markedly since several years. There are a number of reasons for this, including agricultural run-off, building of roads that impede the annual flooding of the haors and beels, overfishing (including by Muslims who traditionally do not fish, but have no other option upon losing their land due to indebtedness), and for a more recent factor, the use of mosquito nets.

The effects of fishing with mosquito nets globally appears to be devastating. Whole year classes of many if not all available species of fish may be close to disappearing. There are, to my knowledge, no global statistics about the effects of mosquito fishing. The data reported in the article in ScienceDaily gives, however, a stark reminder about the situation in the study area in Mozambique. Two tell-tale figures: in the overall catch composition in the study area, 56 % of the species and 62 % of the total biomass were juveniles. This points to a type of overfishing which is anything but sustainable. Moreover, it means that the availability of fish as a food decrease dramatically.

The decrease in fish production is especially dramatic in countries and cultures where other sources of animal protein are not available or too costly, or else carries a cultural or religious prohibition on consumption.

The use of mosquito nets can, over time, be understood to contrast two different points of view on poverty alleviation: on the short term there is increased opportunity and empowerment, while on the longer term there is reduced food security. 

Why Does this Happen?

The term "tragedy of the commons" comes to mind. Fish, as a common property good, are in many but not all cases owned by everyone. This means that property rights are not controlled by anyone in particular. While fishing and subsequent consumption by one fisherman imposes an opportunity cost on others, he cannot prevent another fisherman from fishing. Everyone owns the fish, and can receive the benefits of consumption. No one can be excluded. And the more who fish, the larger the outtake, and, as pointed out above, increasingly juveniles are taken out.

In some cases, fishing is not a case of open access, however. This was the situation in my fieldwork location in Bangladesh. The local rich family traditionally had acquired use rights to fisheries in some waterbodies through a lease from the government, and hired local fishermen to fish for him. From the point of view of fish production this may or may not increase the production, as this type of fishing traditionally took place using large nets and large teams. Today this type of fishing may be of less importance, certainly in terms of its degree of unsustainability, as leasing of fish grounds is now replaced by more controlled licensing. One can only hope this means that the fishermen gets more out of the time and resources invested.

In general, overfishing happens because there is, on the part of the public sector, no, or else very lax, control, coupled with no or a lacking legal system that controls access and outtake. As for the use of mosquito nets, this is such a recent phenomenon that the public sector has not yet understood the potential future implications, and accordingly not addressed it.

What Should Be Done, I?

Fresh water fish resources are being depleted around the world at an alarming rate. This occurs for a number of reasons, including: pesticides and insecticides from agricultural run-off, building of levees and roads (thus preventing flow of water and fingerlings from rivers into lakes and marshlands during rains and flooding), increase in number of fishermen (often occurring when for example farmers loose land due to indebtedness), and using illegal methods (for example, poison and dynamite). Mosquito net fishing is likely the most recent issue to be added to this list. These reasons are connected in various ways, and they are in turn all connected with poverty, which itself is the result of a whole set of different reasons. And, just to make things more complex, there are positive and negative feedbacks between all of these reasons or factors.

Case II: Bangladesh, Fisheries Sector Institutional Reform

Clearly, all concerned stakeholders need to be involved in addressing this. A key issue is the sharing of responsibility between public sector and civil society. To illustrate this I return to Bangladesh, and to some relevant data from the fisheries sector in that country, based on my work on the World Bank financed Third Fisheries Project (1990-97) and Fourth Fisheries Project (1999-2006). The former project, in particular, aimed partly at contributing to achieving institutional reform in the sector. First, the relevant stakeholders in the fisheries sector, prior to initiating this institutional reform (up to the 1970s), should be established (Soeftestad 1998)

  • Public Sector Min. of Fisheries and Livestock, Dept. of Fisheries (DOF), Bangladesh Fisheries Development Corporation, Fisheries Research Institute, Min. of Land, Upazilla Parishads, Min. of Irrigation, Flood Control and Water Development, Min. of Local Government, Rural Development and Cooperatives, Min. of Industry, Min. of Commerce, Min. of Shipping, Min. of Education, Min. of Finance, Forestry Dept., nationalized banks, Planning Commission,
  • Private Sector Fishermen, fish traders, hatchery and nursery operators, fish seed traders, operators of fish ponds, and
  • Civil Society NGOs.

The NGOs could be characterized as follows: a small number were active, there was collaboration between them, a variety of management approaches were tried out, there was little emphasis on learning, and there was no collaboration with DOF. As for DOF, it was characterized by lack of a clear mandate, it had structural weaknesses, there was managerial constraints, and insufficiently trained staff. The management approach was based in fisheries biology and gave emphasis to production, which, under the prevailing regulatory system, had two implications: (1) local elites made enormous profits from inland floodplain fisheries, and (2) local fishermen were impoverished due to overfishing and lack of access. This situation was not satisfactory because there was lack of equity, environmental sustainability, and accountability.

The reform process in the fisheries sector involved some partly new stakeholders: a political party, local and international scientific / research communities, NGOs, and the international donor community. As for the World Bank, in the Third Fisheries Project, at mid-term is was agreed to give major emphasis to local-level management by NGOs. Key lessons learned and achievements from this project (Soeftestad 1998):

  • All stakeholders to be involved from the identification stage,
  • Mechanisms for cost recovery and/or sharing to be agreed with all concerned parties during preparation,
  • NGOs more effective than public sector agencies in motivation and formation of beneficiary groups,
  • Proactive supervision, leading to adjustments in design during implementation, can play an important role in achieving a successful outcome, including: (1) reduction in project design, (2) increased role of NGOs, (3) changes in stocking regimes, (4) development of a community-based management program,
  • Policy that mandates licensing instead of leasing,
  • New revenue collection system,
  • Production of fingerlings transferred to private sector,
  • NGOs have an informal yet legitimate responsibility for local-level organizing,
  • Organization of fishermen in occupationally based groups,
  • Institutional reform is achieved in an informal, incremental and evolutionary way,
  • The institutional reform emphasized increased interaction between public sector, private sector and civil society, and was premised upon a very strong NGO sector, and
  • The institutional reform process to some extent bypassed DOF in creating alternative management and service delivery structures.

This series of actions, lessons learned, and achievements were aimed at improving the overall project and its impact on the ground. Although the implications of fishing with mosquito nets were not an issue at the time, these lessons and achievements are nonetheless relevant for how to address and tackle also this issue. 

What Should Be Done, II? (cont'd)

It would be crucial to address and correct this misuse of mosquito nets, and the sooner it is done the better. This is by no means an easy task. It would have to be addressed in several different arenas, involving different stakeholders and experts, and it would take time before any effects are noticeable.

As the ScienceDaily article points out: (1) it would be necessary to work directly with fishermen, and (2) an interdisciplinary effort would be needed. These are two important suggestions. Following the experience from Bangladesh presented above, however, the primary emphasis should be on civil society. But also, the public sector needs to be involved, albeit in a more limited role, seeing to it that necessary legal and institutional reforms are addressed, as well as in financing any activities that are implemented, including those by civil society. A not exhaustive list of activities to be undertaken would include the following:

  • Discuss with the organizations that distribute bed nets the unintended effects, and any alternatives to it,
  • Stop giving bed nets away for free,
  • Charge local people for the bed nets,
  • Make it illegal to use bed nets for fishing, and fine those that violate the rule,
  • Set up a monitoring system,
  • Develop extensive information and education material, to be delivered via targeted training, and
  • Training to be made different for the various stakeholder groups in public sector, private sector and civil society.

As a social scientist (social anthropologist to be specific), one tool or approach I would recommend would certainly be social media marketing. Here is one effort at delineating what social marketing is (California PTC n.d.):

Social marketing is the use of commercial marketing principles and techniques to improve the welfare of people and the physical, social and economic environment in which they live. It is a carefully planned, long-term approach to changing human behavior. Social marketing is the use of commercial marketing principles and techniques to improve the welfare of people and the physical, social and economic environment in which they live. It is a carefully planned, long-term approach to changing human behavior.

A key term in the above quote is "behaviour". The goal of social marketing is always to change as well as to maintain how people behave. The focus is not on what they think or their degree of awareness about an issue. Social marketing does not aim to only increase awareness or knowledge, or change attitudes. Furthermore, the goal with social marketing is defined by the people who are targeted by the intervention (note that the people who are targeted are also involved in defining what it is that will benefit them).

There are similarities between social marketing and traditional commercial marketing, namely the so-called "4Ps".

  • P1, Product In social marketing this is a behaviour change,
  • P2, Price In social marketing this is the cost of changing behaviours. The goal of social marketing is to reframe the recommended behaviour change in order that it becomes clear that the benefits or change outweigh the cost,
  • P3, Place In social marketing this represents the efforts to make the behaviour change as easy as possible,
  • P4, Promotion In social marketing this refers to the ways used to notify the public about the change messages, and advertising is just one method to achieve this, and
  • P5, Policy This component is not part of commercial campaigns. It is the intent to influence policy that will not be punitive, but will promote positive behaviour change.

To be more concrete, a number of steps can be identified in a social marketing intervention (adapted from McKenzie-Mohr 2019):

  1. Select behaviour,
  2. Scoping, Identify barriers and benefits,
  3. Develop strategies,
  4. Pilot,
  5. Implement,
  6. Evaluate, and
  7. Follow-up and broad-scale implementation.

How to Do it, and How to Proceed?

A number of things need to be addressed and done, some of them serially, and some of them in parallel. Here is a not-exclusive list of things that need to done, organized in a more or less logical order:

  1. Data Collection – More data on the situation on the ground, across regions and countries, in needed. That is, how use of mosquito nets impact aquatic ecosystems, and especially fish species,
  2. Data Analysis – The data need to be analysed. Comparisons across countries need to be established. Also, time series data on fish production at large, that is, at national levels, need to be analysed to search for trends in production,
  3. Stakeholders – Concerned stakeholders, in public sector, private sector and civil society, to be contacted. This includes, in particular, the international organizations that distribute bed nets around the world, mostly for free,
  4. Networking – An informal and virtual network of concerned activists, politicians, researchers, and scholars established,
  5. Tasks and Activities – The network take necessary action as regards, inter alia, funding, research, dissemination, and education, at national and regional workshops,
  6. Funding – Invite network members to contribute funding towards the network's activities. This concerns especially the organizations that distribute bed nets internationally,
  7. Research – locate lacunae in the available data on use and effect of mosquito net fishing, and organize necessary basic research. In terms of applied research, as suggestions for how to address the issue, organize necessary trials,
  8. Dissemination – Share research data and activities via social media platforms, and
  9. Education – Prepare training material, using the principles of social marketing, that are targeted at each stakeholder category.

(1) The articleIt is reviewed in ScienceDaily (ScienceDaily 2019).  (accessed 18 November 2019.)
(2) Apart from Bangladesh, I have worked on small-scale coastal and inland fisheries (partly under the larger heading of integrated coastal zone management, or ICZM), in the Black Sea region, Middle East, and West Africa.
(3) Bel jal ('jal' means '(fishing)net' in Bengali) is a type of stationary or passive fishing gear. It is operated via a simple lever mechanism, whereby the submerged net is lifted up in order that any fish on it can be removed. Further images showing bel-jal, from the haors area in northeast Bangladesh in November 2009, are available (credit: Supras Ltd.) - URL:
(4) Image credit: Supras Ltd. A bel-jal fishing net. The small mesh size is evident (Kishoreganj, Bangladesh, 14 Sep 2009).
(5) Permalink - URL:
(6) This article was published 18 Nov 2019. It was revised 10 Dec 2019.

California PTC. n.d. What is social marketing? URL:  (accessed 9 Decemberr 2019.)
Community-Based Social Marketing. URL:  (accessed 9 December 2019.)
Encyclonomic WEBopedia. n.d. "Common-property goods". URL:  (accessed 6 December 2019.)
Jones, B. L. & Unsworth, R. K. F. 2019. The perverse fisheries consequences of mosquito net malaria prophylaxis in East Africa. Ambio.  (accessed 18 November 2019.)
McKenzie-Mohr, D. 2019. Fostering sustainable behavior: An introduction to community-based social marketing. 3rd ed. Gabriola Island, B.C.: New Society. 
ScienceDaily. 2019. "Mosquito nets: are they catching more fishes than insects?" URL:  (accessed 18 November 2019.)
Soeftestad, L. 1998. "On institutional reform in the fisheries sector in Bangladesh". Presentation for the World Bank Fisheries and Aquaculture Thematic Team, World Bank Rural Week, 25-27 March 1998. URL:  (accessed 7 December 2019.)
Wikipedia. n.d. "Social marketing". URL:  (accessed 20 November 2019.)

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