New U center fighting water invaders with science
Pioneer Press, 12/18/2012
It's a fish tank.
Simple enough at first glance, the glass tank is probably unlike any you've seen.
The calmly sculling fish are silver carp, the leaping menace swimming their way up the Mississippi and Missouri rivers toward Minnesota and Wisconsin, where they threaten to upend the entire food chain that begins with minute plankton and ends, at least underwater, with our prized walleye, pike and bass.
With an injection of a chemical into the tank, these carp can be induced into a feeding frenzy.
In another tank, common carp -- a non-native fish that already has infested one-third of Minnesota's shallow lakes -- are fooled into breeding with the injection of a pheromone into the water.
In a nearby tank in this cavernous building, fish are restricted in their movement by a stream of bubbles that, apparently, produces an underwater sound certain fish are averse to.
If you're a non-native life form hoping to wreak havoc on Minnesota's waters, the University of Minnesota's Aquatic Invasive Species Research Center is a shop of horrors, place where scientists poke, prod and study you, revealing your vulnerabilities in hopes of someday eradicating your kind.
On Tuesday, Dec. 18, the center gave scientists, political leaders and the media a chance to see what is being done -- and what more can be done -- in the struggle to protect the Upper Midwest's waters from non-native species whose impact on native plants and animals are either bad or not fully understood.
"These are things that are coming into the state of Minnesota from elsewhere that are causing great harm," said Peter Sorensen, a U professor of fisheries, wildlife and conservation biology and the center's leader.
The center spans several university facilities. At its hub is the laboratory, the cavernous building holding the fish tanks and looking more like an aging waterworks than a scientific research institution.
This year, the Legislature appropriated $3.8 million -- $2 million from state lottery proceeds and $1.8 million from Legacy Amendment clean-water funds -- to renovate the facility and get the center up and running with a basic staff. While research experiments are making progress in the existing facility, which is on the U's St. Paul campus, they are limited.
For example, there are no zebra mussels. Because larval mussels are so small, the facility's water filtration system will be upgraded to ensure that none escapes. (The sensitivity of the research subjects is so great that the U asked media not to report the lab's exact whereabouts on the St. Paul campus.)
Next year, lawmakers will consider an additional $8.7 million in lottery proceeds, which would fund the center's research through 2019, including hiring Ph.D. candidates and top-tier researchers. One goal, Sorensen said, is to hire a "world-expert" zebra mussel researcher.
The center's goal is to become a national, if not global, leader in researching how Minnesota's invaders operate and how to thwart, control or kill them.
The center will coordinate with the government and nonprofit agencies that fund and conduct similar research, including the Minnesota Department of Natural Resources and Army Corps of Engineers, as well as local watershed and park districts, the groups often on the front lines of infestations and public dissatisfaction over them.
"Hopefully, at the end of six years, we'll have a major impact, but we're not going to solve everything," Sorensen said.
"There's so much emotion, people are very confused. We need to do a lot more science so that everyone can have a basic set of information to talk about."
One example of that is environmental DNA, or eDNA, testing. Data released last year showed positive results for DNA of silver carp farther upstream in the St. Croix and Mississippi rivers than the fish were believed to be. The results splashed huge question marks into a legislative debate about whether -- and where -- to build barriers to stop the fish's advance.
Since then, researchers scrutinizing eDNA have confirmed not only that eDNA testing can lead to false positives -- a finding of the fish DNA in a stretch of water where the fish do not live -- they've also pinpointed how long the DNA of a silver carp can survive on the hull of a barge (three weeks) and how much of it can remain intact in the excrement of a bird that ate one.
One of the center's projects aims to figure out how to use eDNA testing more effectively by, say, testing not just for traces of DNA but for DNA segments that could not have survived digestion.
Beyond that, Sorensen said he hopes to use eDNA to revolutionize the way fisheries biologists study fish populations. Sophisticated eDNA testing could allow researchers to know not only if a fish is present, but how many fish are in a body of water. Currently, that is done by setting nets or driving around a boat that stuns fish.
"Going out and actually catching these fish is ridiculously primitive," Sorensen said. "The data is so bad that it can be scientifically unusable."
Sorensen's team has outlined four steps to advance eDNA testing to the point where it might be able to replace electro fishing.
"We're halfway there," he said.