Rivers and lakes are the source of 13 million metric tonnes of fish annually, which in turn provide employment to 60 million people, the study by the United Nations Environment Program (UNEP) and the World Fish Center showed.
Fish from inland waters is also important for nutrition, especially in Africa and parts of Asia, by supplying micronutrients such as vitamin A, calcium, iron and zinc, the report added.
It said such factors highlighted the risks to humans from the destruction of freshwater ecosystems and the urgency to protect them from pollution, climate change, overfishing and construction of dams.
The report was released on the sidelines of an Oct 18-29 UN meeting in Nagoya, Japan, aimed at pushing governments and businesses to do more to fight accelerating losses in animal and plant species.
While fish production had grown in Asia and Africa over the past 40 years, catch in other regions had leveled off and in some cases, fallen, with environmental damage cited as a factor, the report said.
Fisheries in the Volga River in Europe have declined because of dams, while fisheries in Lake Malawi and Lake Malombe in Africa have fallen from overfishing and environmental degradation.
“It takes a concerted effort to protect and maintain these so-to-speak ‘free’ ecosystem services around the world,” Yumiko Kura of the World Fish Center told a news conference on the sidelines of the Nagoya meeting.
“It is important to maintain these natural ecosystem services from human destruction because it is very costly to replace these ecosystem services once they are lost.”