Service Pilot 3: Aquaculture in Tanzania

Aquaculture now accounts for nearly 50% of the world's food fish consumption. In Europe aquaculture provides 1.25million tons of seafood annually, valued at over 4 billion euro. Diminishing supply of wild captured fish and fish products and global increase in demand for fish and fish products provides an incentive to increase the supply through development and promotion of sustainable aquaculture in Africa. Throughout the world, aquaculture has proven to be a success, evidenced by the global increase in the contribution of shellfish, fish and fish products from aquaculture in recent years. However, some of the major fishing countries in Africa (the United Republic of Tanzania, Egypt and the Democratic Republic of the Congo) have reported reduced catches in inland waters. Such decreases are directly attributed to pollution, environmental degradation and, limited habitat leading to overfishing.

The aquaculture service pilot will be undertaken with the FAO Fisheries and Aquaculture Resources Use and Conservation Division and FAO’s partner in Tanzania – the Institute of Marine Sciences at the University of Dar es Salaam. The trial in Tanzania is designed to extend existing FAO activities in Tanzania thereby creating synergies between the FS-TEP project and FAO’s activities.

Trial Service: EO-Mangrove

The clearing of mangroves for aquaculture use is not recommended as intact mangroves provide essential habitat for fisheries and other vital ecosystem services. As such, mangrove classification maps will be created for all coastal areas in Tanzania on an annual basis (2017 and 2018), with change detection done to observe where mangrove habitat may have been lost due to aquaculture developments.  

In this trial service, remote sensing techniques were used to map mangrove habitat (change/clearance) as indicator of aquaculture development. In Tanzania, mangroves may be cleared to increase production of fish, prawn and crab aquaculture. EO-Mangrove is an automated algorithm to create binary mangrove maps across large areas using a Random Forest machine learning algorithm and Sentinel-2 data. The code runs inside a docker container that is deployed in the FS-TEP. The services are already publicly available on the platform (EO Composites and EO Mangrove) and the associated documentation for public release can be reached via this link.


Trial Service: EO-Seaweed

On the islands of Zanzibar in Tanzania, the livelihoods of thousands of women and their families depend on farming seaweed. According to the government, the sector used to employ 23,000 people, 90% of whom were women (BBC, 2014). Recent changes in the world market and the farming environment are threatening this industry. In particular, Eucheuma cottonii – the most profitable seaweed species – is now failing to grow in areas where it used to, due to changes in environmental conditions (Figure 9). These changes include the rise in seawater temperatures, epiphytism, and fouling. To increase production, moving seaweed farms to cooler water further from shore is being considered.

In this trial service, geospatial zonation techniques will be used to model suitability of Zanzibar seaweed production offshore. The geospatial model considers a variety of constrains, including:

  • Gender constraints, including that women are rarely taught how to swim in the communities currently involved in seaweed farming adding access and safety constraints;
  • Ocean currents and water quality considerations (such as sea-surface temperature, turbidity and salinity) play a role in seaweed growth;
  • the islands of Unguja and Pemba have different geographical features so may experience climate change at different rates; 
  • conflicts with hotels, dive sites and historic sites should be minimised; and
  • shipping channels and other common marine traffic routes should be avoided.