In the United Nations biodiversity agreement, freshwater ecosystems were finally included as ‘inland waters’ in the commitment to safeguard and restore at least 30 per cent of the world’s lands, inland waters, coastal areas and oceans by 2030.
So, what is the freshwater biodiversity crisis, and why should we be concerned for people and wildlife?
Salmon leaping up waterfalls, dragonflies hovering over ponds, hobbies swooping down after them while herons stand like statues at the water’s edge, tadpoles dropping into rivers from spawn laid on overhanging leaves, shrimp buckets being hauled into boats and otter cubs making mischief underneath a bridge… the potential for thriving wildlife in our inland waters is endless.
And yet, despite most towns and cities being built on rivers, and the importance of clean freshwater in our lives, the importance of inland waters is constantly overlooked, and the natural world has been frequently labelled ‘land or sea’.
But ‘inland waters’ includes freshwater springs, streams, rivers, lakes, ponds, wetlands, and swamps; working together to protect them is of urgent importance.
According to the Living Planet Index, freshwater wildlife has been hit the hardest by the biodiversity crisis, with species of freshwater mammals, birds, amphibians, reptiles, and fish declining by an average of 83 per cent between 1970 and 2018.
In addition to the inherent value of life and our responsibility to curb the impact our activities are having on the natural world, there are many ways in which freshwater biodiversity supports us and enriches our lives, from food and climate to recreation and culture.
Most amphibians have at least one life stage which is dependent on a healthy freshwater habitat. © iStock
One of the world’s most important rivers: the Mekong
90 per cent of people live within 10km of a freshwater ecosystem and 90 per cent of fisheries in inland waters supply food for human consumption, a yield of over 10 million tonnes of fish and crustaceans.
Focusing in on what this means on the ground, let’s look at the Mekong River in Southeast Asia, the largest fishery of inland waters in the world. The Mekong River trickles down from the Himalayan Plateau in China, and flows through Myanmar, Lao PDR, Thailand, Cambodia, and Vietnam before it reaches its mouth in the Mekong Delta, releasing into the South China Sea.
This transboundary river supports 60-65 million people and provides around 25 per cent of the global freshwater fish catch and is second only to the Amazon for diversity of freshwater species.
However, most of the species that are important for this fishery are migratory, and consequently the construction of large hydropower dams present a colossal threat to biodiversity and food security.
The Don Sahong Dam is one of the hydroelectric dams on the Mekong River. It is a run-of-the-river dam (no reservoir) in the Siphandone area of Champasak Province, Lao PDR. © iStock
China has already constructed 11 hydropower dams along the mainstream in the Upper Me