Photo Shows What Happens to a Tank of Dirty Water When Freshwater Mussels Are Introduced for 90 Minutes

Freshwater mussels are natural vacuum cleaners and play a key role in the water ecosystem. Often called “the liver of the river,” the mollusks filter out water bodies from pollutants and harmful algae, reducing turbidity and maintaining the freshwater ecosystem, per the U.S. Fish & Wildlife Service (FWS). However, freshwater mussels are now facing a threat in the U.S. as their populations are decreasing in several regions. To offer a glimpse into the contributions of these tiny species, the FWS (@USFWS) posted an interesting picture on X (formerly Twitter) that proved the filtration power of these freshwater mussels. 

Power of freshwater mussels

On November 3, 2024, the U.S. Fish and Wildlife Service shared an image of two small tanks filled with muddy lake water, on X (formerly Twitter). It was originally taken by the Partnership for the Delaware Estuary, per the source. The muddy water in each tank contained sediment and algae but one of them was complemented with about 15 mussels. The experiment was done to showcase the filtration abilities of the mussels and rightfully so, the tank had crisp clear water within 90 minutes of the mussels' inclusion.

Whereas, the other tank had the same muddy dirty water as before. “Never underestimate the power of freshwater mussels,” the post’s caption stated, emphasizing the role these mollusks play in the environment. A single freshwater mussel can pump and filter around 8 to 15 gallons of water singlehandedly, per the report by FWS. Besides filtration, mussels also stabilize stream beds by embedding themselves in the river beds and balancing the sediments in rivers. But with industrialization, the populations of these integral creatures are threatened with more and more dead mussels washing up on shores.

Mussels facing threat due to human intrusion

Authorities have witnessed an increase in mass mortality rates of freshwater mussels over the years, particularly across Michigan, Minnesota, North Carolina, Ohio, Oregon, Virginia, Washington, and Wisconsin, the FWS reported. For those wondering about the lifespan of mussels, these creatures live up to a century. So, the increased deaths are not linked to their life cycle but due to habitat changes and degradation. 

However, a 2020 study discovered a new virus of the Densovirinae subfamily prevalent among the sick and dying mussels compared to the healthy ones. Experts deduced the virus could potentially pose a risk to the mussel population at large. Therefore, Tony Goldberg, author of the study and professor at the University of Wisconsin-Madison said in a press release, “If we lose mussels, the rivers, lakes, and things that depend on them will never be the same.” 

Additionally, their populations are said to be at an all-time low currently due to pollution, infrastructure development, and overharvesting done in the early 1900s, per the source. The Minnesota Department of Natural Resources revealed that 28 out of 51 native mussel species are either endangered, threatened, or of special concern in Minnesota. Mussel biologist, Nick Utrup said the massive sedimentation in the Minnesota River is one reason for the low populations of freshwater mussels. Zebra mussels, an invasive species, have also contributed to the endangering of freshwater mussel populations.