For decades, there have been stories of monsters living in freshwater: tales of beasts that can swallow men whole, leaving no trace of their existence. While there may have been some exaggeration, there is no doubt that some of these creatures did, and still do, exist, although not in the numbers they did before. The truth is that these animals are dying out, and they won’t be here for very long.

Here Are Some Stats:

  • Freshwater systems (rivers and lakes) only take up 1% of the Earth’s surface, but 33% of all vertebrates call them home.
  • Between 1970 and 2012, the large freshwater animal population declined by 88%, more than twice the amount of any land or marine-based ecosystem in the same amount of time.

The Most Threatened Ecosystem on the Planet

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Freshwater ecosystems are some of the most diverse on the planet, and despite the fact that they only make up a small percentage of the earth’s surface, conservation efforts remain minimal. A recent study by Fengzhi He from the Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Berlin, Germany highlighted the numerous problems these systems face, and almost all of them are at the hands of us humans.

Television shows like “River Monsters,” “Fish Warrior,” and “Man vs. Monster” have all shown us that there is freshwater megafauna, but it’s too bad that barely anyone wants to get a closer look at them. Despite the little attention gained from these shows, it pales in comparison to what sea turtles, tigers, and Sumatran elephants get.

The megafauna is already at a disadvantage as their large sizes, unique habitat requirements, and late age of maturity make them more prone to extinction. Of all different species of megafauna, the mega fish are the ones most at risk, as some of their numbers have gone down by 94%.

Overfishing Increased Their Value


In many places, mega fish are caught and killed for their meat, eggs, and in some instances, their skin. Sturgeon fish eggs, a type of caviar and a food synonymous with wealth and luxury, have been harvested for decades and now they are suffering because of it. To harvest these unfertilized eggs or roe, they must be cut open, thereby killing the animal. Beluga sturgeon fish are currently listed as critically endangered and are banned from being imported in several countries.

In some parts of the world, the rarity of the fish just adds to the desire. In many places, including Vietnam, there are restaurants that advertise critically endangered animals on their menus. Despite the ban placed on harvesting and selling these animals, some governments don’t enforce the laws.

River Damming is Damaging Freshwater Habitats

Dams are a necessary evil; they reduce flooding, produce power, and store water, but they also disrupt the surrounding ecosystems. Not only do they cut off the natural migration routes of many of the animals, but they also limit the animals’ feeding grounds and reproductive pool. Dams can also change the water temperature as well as its natural flow, increasing the chances of invasive species thriving in the environment. Approximately 3,700 are being built  or in the planning phase as you read, 800 of which will be constructed in “biodiversity hot spots.”

All Hope is Not Lost


We’ve already established that freshwater megafauna is down in numbers, but all hope is not lost; there have been a few success stories. The Irrawaddy dolphins are increasing in numbers, the American and Eurasian beavers are making a comeback, and the green sturgeon population is also increasing. With that being said, there is still a long way to go.