What Are Macroinvertebrates?

Macroinvertebrates serve as the ecological cleaning services in aquatic ecosystems. While the name may sound unfamiliar at first glance, Northwest Georgia is home to many macroinvertebrates you likely know, such as Crayfish, Mayflies, Dragonflies, Clams, Mussels, and more! While here these small and sometimes bothersome creatures may seem like little more than pests, they’re actually crucial to our rivers’ ecosystems. These organisms affect even our local water sources such as the Coosa River Basin and serve an equally important role.

Why Are They Important?

Macroinvertebrates are actually detritivores which means they consume dead and decaying organic matter, keeping our waterways clean and safe. Despite their size, macroinvertebrates are situated on the sixth trophic level putting them above even some apex predators in what they’re able to consume. This means they’re able to eat almost anything, typically after it’s already dead, but an impressive feat nonetheless. By eating matter that would otherwise be wasted, these animals sit at the very core of the ecosystems they’re a part of. They consume the decaying matter of plants and animals both and collect the nutrients that were previously going unused. These peculiar eating habits are how energy is recycled back into their habitat, with the decomposers taking energy from the very top of the trophic pyramid and bringing it right back down to the soil for the producers to use. Without macroinvertebrates energy becomes a much more limited resource, as it would no longer be recycled at the most efficient rate. This can lead to changes in migratory patterns to population imbalances, causing our waterways to no longer function as they should.

What’s The Big Deal?

The Coosa River itself is considered to be the 5th most polluted river in the United states, with the River Basin being where all of that water meets. Due to pollutants present from chemical dumping, sedimentary disturbances, and large scale air and water pollution, Macroinvertebrates are at risk. This puts the entire ecosystem of the Coosa River Basin and many other waterways like it in danger too. 

Sedimentary pollutants such as fertilizers and agricultural runoff cause an imbalance in the pH level of the stream, often making it too acidic or too basic to be livable for many of the creatures mentioned. This is due to the fact that many pesticides and fertilizers can cause a number of environmental extremes like lower oxygen levels, chlorine, elevated temperature, ammonia, and more. 

Chemical dumping is also actively affecting the Coosa River with an excess of nitrogen and carcinogenic chemicals found to have been dumped in recent years. This disturbs aquatic life and affects our drinking water as well. 

Coal Ash has also managed to find its way into the Coosa River systems affecting the water in many of the same ways as sedimentary disturbances do, adding high concentrations of Chromium, Radium, Lead, Arsenic, Selenium, and several other chemicals into the water. 

These conditions, being unlivable for most macroinvertebrates, drive their populations down drastically. 


Without these animals many of your day to day activities could be disrupted, By means of the decline of fish and bird populations. This alters the access you have to fishing and hunting and the water could potentially become unsafe. This is because when local populations of any particular species dwindle too low, this upsets the natural balance in place. When that balance is thrown off certain species become protected in or to revive the populations affected back to their normal state which can lead to some major disruption in many individuals day to day game habits.

The water being too toxic or too dangerous for these critters directly affects us as well, as much of our drinking water and groundwater is affected by these pollutants not dissimilarly to how it affects the macroinvertebrates. Without macroinvertebrates around to keep our rivers’ bioload at an acceptable level, the ecosystem around them quickly falls apart, damaging the natural equilibrium and creating problems for every living thing benefitting from our waterways.

What Can You Do About This?

Here at Coosa River Basin Initiative, our mission is to protect, preserve, and restore the river system. This includes bank stabilization to prevent sediment runoff, chemical monitoring, and advocating at the Georgia capital for better adherence to EPD standards. If you would like to join us in our mission go to https://coosa.org/join/

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