It's an Alien World in Every River
Rivers have always held a deep fascination for humans. They have been revered in ancient cultures as the provider of life, respite, and trade. Their sustained flow is crucial for agricultural societies and floodplains are teeming with life. However, what if I told you that there’s more to rivers than just water and fish? That there’s an alien world tucked away in every river?
It all starts with the riverbeds. Most of us visualize riverbeds as slippery, slimy, and mud-covered. But, the truth is they are diverse ecosystems with a plethora of living beings waiting to be discovered. If you take off your shoes and walk around the riverbed, you’ll likely encounter hundreds of tiny creatures crawling between your toes. These could be anything from insects to larvae, freshwater crustaceans, or snails. As you go deeper, you’re likely to come across larger creatures like fish, turtles, eels, and even snakes.
Thanks to the research done by Dr. Adam Kessler, a microbiologist from Montana State University, we now know that riverbeds also harbor microbes that are unique to each river. The microbes, called periphyton, attach themselves to surfaces in the riverbed, including rocks, leaves, and even the sand. Periphyton is not visible to the naked eye, but it plays a significant role in maintaining the river ecosystem, performing functions such as filtering pollutants and providing food for the higher creatures in the ecosystem.
Apart from those living in the riverbeds, a river's waters also play host to an astonishing array of living creatures. Fish are the most well-known among them, but they’re only a small part of the story. Rivers support a wide range of aquatic insects, reptiles, and mammals, with each having adapted to the unique conditions of their river.
Some animals are highly adapted to living in rivers, like the freshwater otter, which can hold its breath for up to eight minutes and feeds on fish and invertebrates that dwell in the river’s waters. Similarly, the giant river turtle has a hard shell that protects it from predators and strong hind legs that help it swim through the currents. Riverine insects, like the mayfly, have unique adaptations that allow them to navigate the rapids, find prey, and lay eggs underwater.
Some rivers have even evolved their unique creatures that are indigenous to their waters. For instance, the Amazon River is home to the pink river dolphin, which is native to the Amazon and Orinoco river systems. These dolphins are among the few freshwater dolphins in the world, and they’re considered a keystone species in the ecosystem.
Moreover, rivers are also a breeding ground for migratory fish, which travel long distances from the ocean to freshwater rivers to spawn. During their journey, these fish face numerous challenges, like overcoming obstacles like dams and waterfalls. However, despite these challenges, fish like salmon, which can travel thousands of miles to spawn, never cease to amaze us with their migrations.
Apart from the diverse living beings present in rivers, it’s also important to note that rivers are shaped by human actions. Dams disrupt natural river flows, and climate change is altering river flows and temperatures, which ultimately affect the creatures that live there. Chemical pollution, runoffs, and improper disposal of waste have harmful effects on aquatic creatures, affecting their reproductive rates and altering the balance of the broader ecosystem.
In summary, rivers are so much more than meets the eye. They’re teeming with life, and each river is home to a unique ecosystem of animals and plants. Even tiny creek and rivulets are home to crucially important living things. As humans, it’s essential to understand and appreciate the diverse wealth of life that exists within our river systems. Protecting and preserving these ecosystems is necessary not just for our survival, but also the survival of the beautiful creatures that call them home.