Microbiologists Investigate “Lake Crime”

For UWM microbiologists John Berges and Erica Young crime is nothing new; millions of criminals go unnoticed each day.  Most of those criminals, however, are not visible to the naked eye, yet they form an essential part of aquatic life.

For roughly a year, this topic has governed CSI: Lake Michigan, Berges’ and Young’s ongoing, interactive lecture series at UWM.  The focus this month centers on invasive species in freshwater environments.  Not surprisingly, Milwaukee’s proximity to Lake Michigan makes it an interesting case study for the duo.  On Friday night, Berges and Young demonstrated why, scientifically, in front of 70 people at UWM.

“We don’t work well the metric system in America,” Berges said.  “But don’t leave the math behind,” he added.  The comment came after an audience poll indicated most had not studied math for several years, a point of concern for both presenters.

Essential to their presentation, though, is the city’s own past.

Milwaukee’s history with commercial cargo is an integral part of CSI’s research.  In fact, that history predates the Civil War; thus it’s hard for Milwaukeeans to imagine shipping boats as a “culprit” with regard to damaged freshwater food chains.

Those ships carry heavy cargo, but it is largely the water itself that causes problems – which Berges and Young have researched extensively.  One of the foci of the evening’s presentation was ballast water exchanges, which Young equated to “germ factories.”

Among other things, sediment, salt, and critters become lodged in ships’ ballast systems, forming a breeding ground in which numerous invasive species (ex: zebra mussels, Asian carp) can take root.  Thousands of invasive aquatic species are transferred around the world every day in ships’ ballast systems, and Milwaukee’s lakefront is certainly part of this process.

The Lake Effect

Professor Berges sidestepped the lecture to give a local example of their research.

“If you told [Milwaukee residents] they’d have to give up salmon to repopulate the lake trout,” Berges said, “they’d have a fit.”

“There may not be much real science at these lectures,” he added. “Yet week after week, it’s findings like those that reel people [into the lectures].”

With billions of dollars needed for Lake Michigan’s cleanup, CSI’s hosts have their doubts about the real, tangible impact of their studies.

“It’s hard to counteract these issues when those with the means to change them are ill-equipped to respond in the first place,” Young said, nothing the continued effects of the economic downturn.

Young explained that viruses are one of Lake Michigan’s ongoing problems (“very small bad guys”) like viral hemorrhage septicemia (VHS) — an infectious fish disease known to claim humans.

“Even with good ballast exchanges, it’s hard to get rid of these species,” Young said.

To reinforce this, Berges and Young broadened the focus of their presentation to include concepts of fluorescence.

Seeing is believing

The ability to see (literally) the problems caused by invasive species is perhaps part of the problem itself.  According to Professor Berges, the issue is not as complex as it appears, though the math it involves is.

As mentioned, much of what catalyzes the impact of invasive species cannot be seen with the naked eye.  To this effect Berges joked that this is “something [audience members] may recognize in [their] relationship with a financial institution,” an allusion to the fine print that accompanies signed agreements in this category.

Extending the theme of “invisible criminals” – in this case viruses — both biologists asked the audience how far humans could see with their own eyes.   The two hosts then put it in perspective.

“The sun is roughly 93 million miles away, whereas the horizon is only 26 miles away,” Berges said.  “Our research is mostly conducted on the algal, microscopic level, though it’s important that people understand how small these organisms are,” he added.

Not all viruses are bad

Professor Young alluded to the important viruses play in the microbial food chain by saying, “Not all viruses are bad, per se…”

As one of the program’s more kid-friendly examples, the team brought young children up front to administer tests on a teaspoon of Lake Michigan water.  The sample contained over 200 viruses, a number that is “not unheard of” for a freshwater source of its kind (Young).

Berges and Young then proceeded to show audience members how nano-size (14,000X scale) viruses can be illuminated (i.e. “glow”) using a fluorescent indicator.  Fluorescence is partly accomplished through the exchange of photons (light particles), with blue and red corresponding to more or less energy, respectively.  Those in attendance watched as the pair illustrated the color spectrum to younger crowd members, as the shade of red (or blue) fluctuated amidst energy transfers.

Berges compared the naturally unequivocal exchange(s) of photons to that of an ATM withdrawal experience.  In other words, ATM fees essentially strip people of what’s rightfully theirs on some degree.  In the case of their presentation, those “people” are photons.

The duo also made an example of other another species: The spring water flea.

As a zooplankton predator, the spring water flea disrupts a considerable portion of the microbial food chain (a “smaller bad guy”).  Zooplankton are essential to the processing of food sources in aquatic food webs, but are also – at times – carriers of disease.  Zooplankton and photosynthesis are key research areas for Barges and Young, but their profession has led them to other, less kid-friendly conclusions.

An age-defying experience

“We talk a lot about ‘growing our economy,’” Berges said.  “But Americans have innately associated that with government non-regulation of important, particularly environmental issues.  As you can see, that’s not always a good thing.  For an issue like this, the government’s help is absolutely vital.”

Beyond the numerous CSI parodies, there are sobering insights involved for both professors.  In addition, a glance into the audience of these events reveals a tuned-in, age-defying crowd.  To this end, Elisabeth Karron, 15-year-old daughter of UWM biologist Jeff Karron, is in agreement.

“These two do a really nice job of talking to different age groups,” Karron said.  “They have enough activities to engage the younger children, but there’s also enough science to engage high school students, college students and older adults.  And that, to me, is very impressive.”

In this same realm, Berges is hesitant to include what influences these topics have outside of labs and classrooms into the CSI presentations.  He carries a perspective made worrisome by discussion of climate change, the recycling of endangered minerals, and the impact of plastic (and plastic derivatives) on the Lake Michigan ecosystem and beyond.

“It’s difficult not to be cynical about these issues, as well as legislation that protects our ecosystem(s).  But when most of our opportunities to reverse these effects were shrugged off nearly 20 years ago, the present situation is rather concerning.”

Berges is also frustrated by deniers of global climate change.

“Our country’s libertarian ethos will pay backfire heavily in the years to come.  Some researchers claim that it’s too late to correct problems like climate change.  But in the end our country’s aversion to government intervention now equates to…the right to poison ourselves?  This is scary stuff.”

CSI: Lake Michigan returns for its final installment on Friday, April 29.  This marks the end of the Science Bag lecture series until this fall.