Tanzania's Blue Economy Starts on Land, Scientists Warn at COP12

When governments talk about the ocean economy, they usually look at ports, fisheries and tourism. At the 12th Conference of the Parties to the Nairobi Convention, held in Dar es Salaam from 6 to 9 October, a scientist from the farming side of government made a different case: the health of Tanzania's seas is decided largely on dry land.

Dr Thomas Bwana, Director General of the Tanzania Agricultural Research Institute (TARI), spoke at a side event on the margins of the meeting, which this year marks four decades of regional cooperation to protect the Western Indian Ocean. His core message, as reported by The Citizen and Daily News, was that marine conservation cannot succeed if what happens inland is ignored. In his framing, the seascape depends on the landscape.

He pointed to a concrete symptom. Prawn catches along the Tanzanian coast have been falling, and while overfishing is the usual suspect, Bwana suggested land-based causes may be just as important. Mangrove clearance, soil erosion and agricultural runoff all damage the coastal nurseries where fish and crustaceans grow up. Disturb the mangroves, he explained, and the biomass, density and diversity of marine life follow them down.

The farming practices behind that pressure are often well-meant. Many rice farmers, Bwana noted, over-irrigate, believing the crop needs up to twenty centimetres of water when it needs closer to two. The excess carries soil, fertiliser and pesticide residues downstream and eventually to the coast. Cutting water and chemical use would therefore help both the farmer's costs and the ocean.

The stakes are national as well as ecological. Bwana said agriculture is expected to contribute 30 to 40 per cent of Tanzania's GDP and to supply 80 to 90 per cent of the raw materials for local industry, besides employing a large share of the population. A sector that central cannot simply be asked to shrink its footprint; it has to change how it works.

TARI says it is already doing that. Its researchers are developing climate-resilient and pest-resistant crop varieties, biopesticides to replace harsher chemicals, better soil and nutrient management, efficient irrigation, and digital and precision-farming tools. The institute is also exploring alternative livelihoods for communities that depend on stressed coastal resources.

Bwana's wider appeal was institutional. He urged agricultural researchers and blue economy stakeholders to collaborate more closely and asked that land-based activities receive more attention in future blue economy discussions, tying the request to Tanzania's Vision 2050 goals.

The setting gives the message weight. The Nairobi Convention brings together ten Western Indian Ocean countries, including Kenya, Mozambique, Madagascar, Mauritius, Seychelles, South Africa and Tanzania, and this year's agenda includes source-to-sea pollution, mangrove and seagrass restoration, marine spatial planning and financing for a sustainable blue economy. Bwana's intervention is a reminder that the largest lever for cleaner seas may sit in a rice paddy rather than a harbour.

Why it matters

Ocean policy is usually written by people who never visit a farm, yet this story shows the sea is downstream of every field. If Tanzania can align agriculture and marine planning, it protects fisheries, food supply and coastal jobs with the same set of measures.