Experts agree that climate change is having an impact on fishing, but Zimbabwe has yet to study precisely how it is affecting supplies that for years have supported thousands of families across the country.
For Thandi Ncube, however, who sells fish around the densely populated townships of Bulawayo, business clearly is no longer what it used to be.
“The fishermen say their catch is getting low,” Ncube said.
Normally she buys in bulk, mostly kapenta and bream, from fishermen just outside Bulawayo, a city where consumers have for years turned to fish as a cheaper alternative to beef and chicken.
Ncube used to sell a kilogram of bream for around $3, while the same amount of beef costs up to $5. But fish is no longer available in the quantities that Ncube and her customers want.
“It is all kinds of fish that we do not get anymore. I have to sell other items such as tomatoes to survive,” she said.
In a country where the United Nations says millions survive on less than $1 a day, the usual laws of supply and demand do not always apply: raising the price of fish risks leaving vendors with unsold perishable stock if customers cannot afford the higher prices.
Rudo Sanyanga, the Africa programme director for International Rivers, a non-governmental organisation, said fish stocks normally surge in periods of high rainfall and fall when the water goes down.
But downpours that pounded Bulawayo in the first half of March weren’t enough to significantly replenish water levels in severely depleted reservoirs and ponds, Bulawayo municipality officials said.
The heavy rains were the first since last September, and the previous year’s rainy season was equally poor, officials say.
In an update issued at the end of February, the Zimbabwe National Water Authority said reservoir levels stood at 51 percent countrywide, with Upper Ncema dam, previously a site of thriving fisheries in Matebeleland South province, almost empty at just 1.8 percent of capacity.
“Ponds that used to provide us with fish have dried up,” said Thamsanqa Mloyi, a farmer in Filabusi, about 150km (90 miles) south of Bulawayo.
Sanyanga believes that climatic change, as well as regular variations in the weather, are contributing to changes in fish populations. That echoes concerns voiced by the U.N. Food and Agriculture Organization (FAO).
The agency said people dependent on fish as a major source of food are bearing the brunt of climate change impacts, and are seeing their incomes affected. Changes in the availability and quality of fish are also raising health risks, the FAO said.
Wilson Mhlanga, a researcher at the University of Zimbabwe’s Lake Kariba Fisheries Research Institute, said the country needs to do more to protect its fisheries.
Although Zimbabwe has laws aimed at protecting fish stocks – including a $3 per kilo fine for poaching – Mhlanga said they are not effective.
“The challenge is the effective enforcement of this legislation,” he said.
More research is also needed, bringing in both the government and fishermen, to understand clearly what is happening, he said.
“There is need for long-term stock assessments in rivers to base our conclusions not on anecdotal evidence but scientific research,” Mhlanga said.
“Another solution would be to raise awareness among populations who subsist on fisheries on the need to protect fish resources,” he said. Funding for all the initiatives, however, is in short supply, he said.
Sanyanga, of International Rivers, called for catchment restoration programmes to help stabilise fish stocks, but warned that the threat to fish in Zimbabwe extends beyond climate change and dwindling reservoir levels to human activity.
“Over-fishing is a symptom of poverty and, at times, greed. As long as fisheries resources are common, it will be difficult to eliminate overfishing practices,” she said.
But without action, she said, “it is probably too late to protect some of our fish populations.”