In Zanzibar fishers and ZMT scientists work together to find solutions for the sustainable use of marine ressources

2.09.17 | As a member of  the SUTAS - Leibniz Graduate School, fsheries ecologist Jennifer Rehren’s doctoral thesis was supervised in Bremen and Zanzibar. Social scientist Prof. Dr. Achim Schlüter heads the research group on “Institutional and Behavioural Economics”. Here, they talk about interdisciplinary science, one of the dsitinctive characteristics of the Leibniz Centre for Tropical Marine Research (ZMT).

What problems do fishermen face in Zanzibar?

Jennifer Rehren: In the fishing villages, many of the fisher-men are convinced that the resources in Chwaka Bay are being overfished.

Achim Schlüter: Also, there is a quarrel between two neighbouring villages which each use different fishing methods: dragnet and trap-fishery. In the past, the trawlers were constantly being accused of using environmentally harmful fishing methods and not being prepared to cooperate.

Are there any solutions to the issues?

Achim Schlüter: All the fishermen realise that they have to pull together if they want to establish sustainable fisheries management in the region.

Jennifer Rehren: There have been attempts to prohibit trawling in the bay and to exchange illegal fishing gear. But this did not help the situation.

Achim Schlüter: It is because of the fishermen’s eco-nomic dependence. A boat with trawls feeds about ten fishermen. If they were made redundant they would have to invest in their own fish traps and boats. And this is out of the question.

How can ZMT’s interdisciplinary research help?

Achim Schlüter: Research on the socio-economic background is very useful when it comes to finding options for action. We have also studied collaborative behaviour in the case of two villages and discovered that the use of sustainable fishing methods does not necessarily go hand in hand with a willingness to cooperate for more sustainable fishing.

Rather, it depends on how experienced the fishermen are at working together. Local trawling requires more individual cooperation than trap-fishery which is carried out autonomously. Insights of this kind help everyone involved in their dealings with one another.

Jennifer Rehren: I also spent a year working together very closely with the fishermen on fisheries assessment of target resources in Chwaka Bay. We now know that in the case of three local fish species that are important in the region, there really are signs of overfishing, and we also know which fishing methods put them under the most pressure.

Surprisingly, it is effective trap-fishery that is responsible for the most pressure. During a workshop with fishermen from three villages, I passed on these findings and discussed them with them. They accepted them and were quite willing to cooperate.

The result was that the fishermen came out with very concrete suggestions as to how they should respond: one idea was a marine sanctuary where fishing would be prohibited; another was to create an artificial reef to increase the biomass. The fishermen’s suggestions are now

*ZMT’s policy briefs seek to highlight the practical use of the institute’s research and formulate concrete environmental policy recommendations for political decision-makers.

Author: Bettina Mittelstrass