Lake Michigan fish populations threatened by decline of tiny creature

February 19, 2009

The quick decline of a tiny shrimp-like species, known scientifically as Diporeia, is
related to the aggressive population growth of non-native quagga mussels in the Great Lakes, say NOAA scientists. As invasive mussel numbers increase, food sources for Diporeia and many aquatic species have steadily and unilaterally declined.

A recent research study from NOAA's Great Lakes Environmental Laboratory published
this week in Freshwater Biology documents the recent decline of Diporeia and the explosive growth of quagga mussels in Lake Michigan. Over the past five years quagga mussels have displaced native Diporeia as the dominant bottom dwelling organism, leading to a major disruption in the lake's food web.

"Quagga mussels have displaced other more energy-rich food sources and leave fish
and other aquatic species with fewer food options," said Tom Nalepa, NOAA research biologist. "The invasive mussels are low in calories and their shell has no nutritional value. Fish feeding on quagga mussels expend considerable energy crushing and passing the indigestible shell."

Scientists at the NOAA Great Lakes lab project that impacts on fish populations will
continue and become more pronounced as quagga mussels further spread to all depths
occupied by the dwindling Diporeia. It is estimated that the mass of quagga mussels in the lake is now about four times the mass of all prey fish.

In Lake Michigan, declines in Diporeia masses were first observed in the early 1990s
soon after the discovery of invasive mussels in the Great Lakes. By 2005, lake populations of the tiny shrimp decreased 96 percent in the 10-year period of the study, with further observations indicating recovery of Diporeia improbable once it has disappeared.

Source: Wiley

Explore further: Chemical-munching mussels contaminating Great Lakes

Related Stories

Fighting invasive species in Michigan's lakes

February 25, 2015

Everyone knows that clean water is important. But for the state of Michigan, surrounded on three sides by the Great Lakes, it is absolutely essential—to the economy and the environment. That's why the research being done ...

Recommended for you

How bees naturally vaccinate their babies

July 31, 2015

When it comes to vaccinating their babies, bees don't have a choice—they naturally immunize their offspring against specific diseases found in their environments. And now for the first time, scientists have discovered how ...

Binary star system precisely timed with pulsar's gamma-rays

July 31, 2015

Pulsars are rapidly rotating compact remnants born in the explosions of massive stars. They can be observed through their lighthouse-like beams of radio waves and gamma-rays. Scientists at the Max Planck Institute for Gravitational ...

Image: Hubble sees a dying star's final moments

July 31, 2015

A dying star's final moments are captured in this image from the NASA/ESA Hubble Space Telescope. The death throes of this star may only last mere moments on a cosmological timescale, but this star's demise is still quite ...

Exoplanets 20/20: Looking back to the future

July 31, 2015

Geoff Marcy remembers the hair standing up on the back of his neck. Paul Butler remembers being dead tired. The two men had just made history: the first confirmation of a planet orbiting another star.

Earth flyby of 'space peanut' captured in new video

July 31, 2015

NASA scientists have used two giant, Earth-based radio telescopes to bounce radar signals off a passing asteroid and produce images of the peanut-shaped body as it approached close to Earth this past weekend.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.