Why Tanzania’s blue economy depends on what happens on land

Tanzania’s ambition to build a $1 trillion economy by 2050 could be undermined unless it addresses the impact of agricultural activities on coastal and marine ecosystems, the Tanzania Agricultural Research Institute (Tari) has warned. Tari Director General, Dr Thomas Bwana, said activities on land were directly linked to the health of the sea, making agricultural research and sustainable farming technologies critical to protecting the country’s blue economy. He said Tanzania could not achieve the goals of Vision 2050 without increasing agricultural productivity while ensuring farming practices do not further degrade the environment and coastal ecosystems. “Our landscape is dominated by agricultural activities, so what happens on land has a direct connection with what happens in the seascape,” he said. Dr Bwana was speaking during a discussion on the relationship between land-based activities, agricultural research and the blue economy. He said agriculture was expected to contribute significantly to Tanzania’s economic transformation through GDP, foreign exchange earnings, industrial raw materials and employment. However, he said higher productivity had to go hand in hand with technologies that addressed climate change, soil degradation, water scarcity, pests and diseases. “The growth we want cannot happen without agricultural growth, and agricultural growth cannot happen unless productivity increases. Productivity will increase when we use appropriate technologies, and those technologies come from research,” he said. Dr Bwana cited the decline in prawn catches as an example of why pressure on marine resources cannot be addressed by focusing only on activities at sea. The government stopped prawn fishing in 2007 to allow stocks to recover, but when the fishery reopened in 2015, there was no significant increase in catches. “This tells us that the idea we had at that time—that it was simply overfishing—may not have been the whole story,” he said. Researchers are now examining whether mangrove degradation, land clearance, soil erosion and sedimentation could also be contributing to the decline in marine resources. Agricultural activities in river catchments can cause soil, fertilisers, pesticides and other materials to be washed downstream and deposited in coastal and marine ecosystems. Dr Bwana said the problem was particularly concerning where mangroves were being cleared for rice farming and settlements, while activities further inland contributed to erosion and runoff. “We need to rethink our approach and put more effort into managing inland activities rather than concentrating only on the seascape,” he said. Tari is developing technologies aimed at increasing agricultural productivity while reducing its environmental footprint. These include climate-resilient and pest- and disease-resistant crop varieties, improved soil and nutrient management, efficient irrigation, conservation agriculture, biopesticides, and digital and precision farming. Dr Bwana said improved irrigation was particularly important in rice production, where farmers often use more water than necessary. Research has shown that rice can be grown with considerably less standing water, helping reduce water losses and the amount of sediment and other materials carried downstream. Tari is also exploring alternatives to practices that contribute to forest degradation, including the use of firewood to cure tobacco. Dr Bwana urged blue economy stakeholders to work more closely with agricultural researchers to identify land-based solutions to challenges affecting coastal and marine ecosystems. “We are not doing research simply for the sake of research. Research has to provide an input, a technology or evidence that creates an impact,” he said. Bagaye Mbwana of the Mwambao Coastal Community Network said the organisation was also examining how agricultural activities upstream affect marine ecosystems, noting that the consequences of activities on land eventually reach the sea. He said agricultural chemicals and destructive practices could damage important marine habitats, including mangroves, coral reefs and seagrass beds. Mr Mbwana called for stronger collaboration among institutions to ensure conservation and development efforts on land supported those being undertaken in coastal and marine areas. He also called for research-based livelihood solutions for coastal communities affected by climate change, including access to crops suited to coastal conditions that could provide alternative sources of food and income and reduce pressure on fisheries.