Sponge aquaculture as an alternative means of income

Published: 26 April 2016
Last edited: 01 April 2019

The cultivation of seaweed for the production of carrageenan, a thickener widely used in foods, has been a major source of income for Zanzibari women for more than 20 years. An analysis of the local conditions revealed that the cultivation of seaweed is subject to a sharp decline in production due to increasing occurrences of diseases and pests, and a low world-market price. Consequently, unmarried women with kids are no longer able to make a living from seaweed farming.

When searching for alternative means of income many aspects such as the know-how of the parties involved, eco friendliness, market-opportunities, investment requirements, general acceptance of the method, scalability, and availability of resources need to be considered. Aquaculture of sponges was identified to be a suitable alternative to seaweed farming promising substantially higher incomes.


Education, training and other capacity development activities
Evaluation, effectiveness measures and learning
Sustainable financing
Sustainable livelihoods
Scale of implementation
Phase of solution
Planning phase

Enabling factors

  • The methods for cultivating sponges and seaweed share many aspects which made it easier to set-up sponge farms and train the women.
  • The shallow coastal waters are organised as common property and dedicated sites for sponge farms could be negotiated with the local fishers and communities.

Lessons learned

It was difficult to find women pioneering as sponge farmers willing to learn how to swim and to try something completely novel – a challenging task in Zanzibar’s traditional society.