Small Mussels with Big Effects: Invasive Quagga Mussels Eat Away at Great Lakes Food Web

by Kathe Glassner-Shwayder, NOAA Great Lakes Environmental Research Laboratory, and Bonnie Myers, NOAA Research Office of Communications

Since hitching unsolicited rides in boat ballast water in the late 1980s, invasive quagga mussels (Dreissena rostriformis bugensis), which are native to Ukraine, have caused massive changes to the ecology of the Great Lakes.  These invasive mussels have also taken a toll on the Great Lakes recreational and commercial fisheries, which are valued at $4-7 billion annually according to Michigan Sea Grant.

The quagga mussel had a sluggish start in its early expansion but is now present in large numbers far exceeding those of another invasive mussel in the Great Lakes, the zebra mussel, according to a publication by NOAA’s Great Lakes Environmental Research Laboratory (GLERL).

The filter-feeding quagga mussel has a high filtering rate for its size, and coupled with its high abundance, has a significant impact in invaded ecosystems, like the Great Lakes.  The mussel uses hair-like cilia on its gills to pull water into its shell through a siphon-like structure.  Materials collected are then sorted for ingestion inside the shell or for rejection through the siphon.

Student Amanda Netburn recovers an Oozeki midwater trawl net used to collect juvenile fishes from surface waters. Comparing trawl catch to acoustic data is a way to verify surveys of marine life populations on board R/V New Horizon. Credit: UC San Diego

Scientists have a limited understanding of the quagga mussel’s feeding habits, like the type and size of phytoplankton consumed in the quagga’s natural environment.  Thus, scientists from NOAA’s GLERL, the University of Michigan's Cooperative Institute for Limnology and Ecosystem Research, and South China Agricultural University recently conducted the first study of quagga mussel natural feeding habits in the Great Lakes to better understand the mussel’s effects on the food web.

Clouds capture morning light soon after the NASA DC-8 left the Azores en route to Bangor, Maine on Oct. 23, 2017 on the third leg of the Atmospheric Tomography Mission. Analyses of these first measurements of old smoke over the remote oceans captured during the mission revealed its important role in climate regulation. Credit: Sam Hall, NCAR

Surprisingly, the study found quagga mussels preferred to feed on specific phytoplankton species, rather than a particular size of phytoplankton, like how one might choose a banana over an apple.  This unanticipated finding of quagga mussel’s preference to certain phytoplankton species, like flagellates or diatoms, over phytoplankton size could have important implications on the food web. 

“This study is extremely significant given the unexpected results that showed quagga mussels are highly selective filter feeders and that the changes we have been seeing in the Great Lakes food web are likely driven by selective feeding of dreissenid [quagga and zebra] mussels,” said GLERL lead scientist, Dr. Henry Vanderploeg.

Researchers recover a BONGO net used to collect samples of larvae and small marine organisms off the California coast. Credit: UC San Diego

Karl Froyd, Principal Investigator of the NOAA Particle Analysis by Laser Mass Spectrometry instrument, is strapped in his workstation aboard the NASA DC-8 during the Atomic Tomography Mission. Measurements made by the PALMS instrument allowed the research team to document that dilute smoke was ubiquitous throughout the global atmosphere. Credit: Dan Murphy, NOAA

“The importance of quagga mussels in driving change in phytoplankton communities [was] an important lesson learned from this research,” noted Huijuan Tang, the lead author, from the College of Animal Science in the South China Agricultural University, on the paper, “Quagga mussel selective feeding of phytoplankton in Saginaw Bay,” which was published in the Journal of Great Lakes Research.

 “Since quagga mussels have many similarities with zebra mussels and marine mussels, [these] results may help anticipate changes caused by mussels in other invaded aquatic systems and in North America [e.g., Lake Granby and Lake Mead in Colorado],” said Tang.