- Date: February 23, 2021
Dazzlingly diverse, freshwater fishes are vital for communities, economies, and ecosystems but are routinely undervalued and overlooked. They’re also under ever-increasing threats. Before we can secure their future, we must better understand their importance and what their well-being means for all of us.
1. More fish are found in fresh water than the ocean
51% of all fish species are found in fresh water—that’s more than 18,000 different species. And they make up ¼ of all the world’s vertebrate species. Of course, those are just the ones we know of – More than 100 new species were discovered in South America alone every year during the last decade.
With such an awesome variety, there are some freshwater fish that really stand out:
- Archerfish spit water to knock unsuspecting prey into the water.
- Africa’s elephant fishes use weak electrical pulses to communicate with others about sex, size, predators, and prey.
- Siamese fighting fish build a nest of bubbles for their eggs.
- Leaf fishes mimic dead and decaying leaves to catch their prey unawares.
- The cuckoo catfish tricks thick-lipped cichlid into caring for the wrong eggs.
- Sturgeon lived alongside the dinosaurs and the jawless lamprey fish has been around for 530 million years.
2. Healthy freshwater fisheries = healthy rivers, lakes, and wetlands
Healthy freshwater ecosystems are critical for thriving populations of freshwater fish and for human well-being. Rivers provide at least 2 billion people directly with their drinking water and support ¼ of the world’s food production.
Protecting freshwater fisheries supports the greater ecosystem and benefits all who rely on it.
Alaska’s salmon river runs fatten up bears ahead of hibernation and transport essential nutrients from the sea to nourish riparian woodlands. In the Amazon, fish help disperse seeds of tropical floodplain trees. And migrating fishes of the Mekong provide an impetus for movements of the river’s top predator – the Irrawaddy river dolphin.
The decline in freshwater fish populations is the clearest indicator of the damage humans have done – and are still doing – to our rivers, lakes, and wetlands.
3. 60 million people rely on freshwater fish for their livelihoods
At least 200 million people rely on freshwater fish as their major source of protein, many in land-locked and low-income countries. Today, 60 million people—more than half of them women—depend on freshwater fish for their livelihoods.
In the US alone, freshwater fisheries generate $38 billion in revenue and recreational fishing brings in another $100 billion per year, pumping much-needed cash into local and national economies, and boosting employment.
4. Nearly one-third of all freshwater fish are threatened with extinction
Freshwater fish populations are collapsing. Nearly 1/3 of all freshwater fish are threatened with extinction. In 2020 alone, 16 freshwater fish species were declared extinct. Since 1970, mega-fish—those that weigh over 66lbs—have declined in number by 94% and migratory freshwater fish saw a 76 % decline.
Nowhere is the world’s biodiversity crisis more acute than in freshwater ecosystems. Around 35% of wetlands have been lost in the past 50 years and only 1/3 of the world’s large rivers are still free flowing.
Why are freshwater fish in such a crisis? Mostly due to human activities. Poorly planned dams fracture rivers across the world. Up to 400 million tons of pollution are dropped into freshwater ecosystems every year. Today, agriculture is the largest user of the world’s available fresh water and as human populations grow, the demand will only increase. Overfishing and invasive species are devastating freshwater fish populations and the climate crisis is especially difficult for fish that can’t tolerate changes in temperature.
5. A brighter future for freshwater fish is possible
Today, governments can reverse the loss of nature and put the world back onto a sustainable path. This includes measures that let rivers flow more naturally, protect, and restore critical habitats and species, and reduce pollution levels. We must stop the spread of invasive species and end overfishing.
While many of these solutions exist, real progress will only be achieved through collective action involving governments, businesses, investors, NGOs, and communities. And critically, we must better understand freshwater fish. They might be out-of-sight below the surface of our rivers, lakes, and wetlands, but their role couldn’t be clearer.
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