A River's Ecosystem

As a majority of you may know already, it’s Friendly River Week here at the center and we couldn’t be more thankful for how excited and supportive the whole community has been in celebrating this special week with us. And we are so ecstatic for this weekend’s Crow River clean up event.

Before we ask the community to volunteer their time with us, however, we figured it would be good to start a conversation about the different aspects of a river’s ecosystem. We believe this is important because having a better idea about the ins and outs of a river will help develop a stronger understanding of the relationship between a river’s natural environment and the human-shaped world.

An ecosystem, as defined in CREEC’s educational materials, is a community of plants, animals, bacteria, etc. that is formed by the all of these organisms’ interaction with the physical environment.

What’s important to note about a river ecosystem is that they are quite different than other bodies of water and their ecosystems; mainly because of a few unique aspects. First and foremost, river ecosystems differ than other water ecosystems in that they are lotic. In other terms, rivers are constantly flowing, which means they are in a state of continuous physical change. Additionally, they have variability in water flow due to rain, melting snow, and groundwater. Yes, other bodies of water experience changes in water levels, but since rivers cover such long ranges, they are more directly impacted by these types of factors.

Diving down underneath the river’s water (we couldn’t resist the pun), one of the more unnoticeable parts of a river’s ecosystem is the bacteria that can be found in it. Rivers have a relatively large number of bacteria that live within their waters. As bad as that may sound, bacteria are actually very beneficial to river ecosystems because they play a significant role in recycling energy by decomposing organic material.

Thinking a little bigger, plants also play a crucial role in a river’s ecosystem due to the fact that they are responsible for taking in sunlight and converting it into energy for the river’s organisms through the process of photosynthesis. Furthermore, plants provide protection against the current and predators for numerous species.

Then there are the invertebrates. Although these are the creatures that we often think of as the squirmy, and maybe even “gross” creepy crawlies, they too are necessary to the health of a river’s ecosystem. Most river invertebrates are insects, and they act as both consumers of the river’s plant species, as well as prey for the other animals that live both in and on the river.

Last, but not least, are the vertebrates. The most common that can be found actively interacting with the other parts of a river’s ecosystem are birds and fish. Fish are food sources for one another, as well as help regulate certain plant populations. Without them, rivers could quickly become dirty and sickly, as sometimes too much of one plant can actually be detrimental to the health of a river. Even though birds are not solely tied to the river, they also help with population regulation, especially with the different fish species.

It is also important to note that humans, too, are a part of a river’s ecosystem. River pollution caused by human activity has continuously been getting worse, causing toxic waters and the depletion of certain plant and animal species. Overfishing is another activity that can lead to dramatic changes within a river, often resulting in negative consequences. It is vital to also recognize that the health of a river impacts humanity, as river water is often a source of freshwater for several communities.

In the end, all of these interdependent parts come together to develop one ecosystem. Although they are all a part of smaller, individual habitats, they would not be able to thrive, let alone survive, without the other parts. It is only through a symbiotic relationship that all plants, vertebrates, bacteria, and invertebrates can live in the ever changing world.