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Prof. Hellweger Researches Toxic Algal Blooms

September 21, 2012

Associate Professor Ferdi Hellweger and collaborators from three other universities have received a new research grant for $2M from the National Science Foundation to study theecology of cyanbacteria. Human activities have dramatically increased nitrogen inputs, causing algal blooms that threaten economic and recreational uses of lakes and rivers in North America and around the world. In this study, the identities, nitrogen processing capabilities, and activities of the algal blooms containing cyanobacteria and associated microbial communities will be examined to determine if nitrogen processing can be predicted from the genetic makeup of those communities. This research provides the capability for an ecosystem-scale systems biology approach to environmental management. The project focuses on blooms in Lake Taihu in China, but the findings will be relevant to many other lakes and reservoirs, including the Charles River in Boston.


Source: News @ Northeastern

Cyanobac­teria are among the oldest organ­isms on earth — they were the orig­inal oxygen-​​producing species and are thought to be respon­sible for the direc­tion life has taken on earth. Nonethe­less, they aren’t the friend­liest of species. Cyanobac­teria pro­duce neu­ro­toxins, which can kill mam­mals in a matter of hours if ingested.

With today’s changing envi­ron­ment, cyanobac­teria are becoming more pro­lific in water­ways as dis­parate as the Charles River in Boston and Lake Taihu in China, said Fer­di­nand Hell­weger, pro­fessor of civil and envi­ron­mental engi­neering.

Hell­weger, along with three other prin­cipal inves­ti­ga­tors from the Uni­ver­sity of North Car­olina, the Uni­ver­sity of Ten­nessee Knoxville and the Uni­ver­sity of Texas Austin, have col­lec­tively received $2 mil­lion in funding from the National Sci­ence Foun­da­tion to under­stand the fac­tors behind cyanobacteria’s increasing presence.

“We know there are links with tem­per­a­ture and nutri­ents,” Hell­weger said. “But exactly how those things work together to cause this trend is still a mystery.”

Lake Taihu is the third largest lake in China, span­ning more than 2,000 square kilo­me­ters. In recent years, cyanobac­teria have plagued the waterway, which serves as the fresh­water drinking supply for sev­eral mil­lion people. From both a health and an eco­nomic per­spec­tive, this pol­lu­tion has the poten­tial to cause sig­nif­i­cant damage to the society, Hell­weger said.

Hellweger’s col­lab­o­ra­tors, Hans Paerl (UNC) and Steven Wil­helm (UT Knoxville), have been working on Taihu for a long time, col­lecting data on nitrogen and phos­pho­rous levels, nutrient set­tling, and cyanobac­te­rial growth rates, for example. “Now it is time develop a model to put all the data together,” said Hell­weger, whose exper­tise is in mod­eling com­plex water sys­tems for pre­dic­tion purposes.

“We want to be able to make pre­dic­tions for nutrient reduc­tion sce­narios,” he con­tinued. For example, if new policy is geared toward spending mil­lions of dol­lars to cut nitrogen levels in half, you’d want to know for sure that the approach would have a sig­nif­i­cant ben­e­fi­cial impact. “But it’s very non­linear,” said Hell­weger, explaining that even small changes in nitrogen or phos­pho­rous levels could impact the species that call Taihu home, including cyanobacteria.

Much like the cli­mate system, he said, there is so much going on that simple rea­soning is not suf­fi­cient for deter­mining out­comes. One needs to model many com­plex mech­a­nisms and sys­tems. But, “a model is always a sim­pli­fi­ca­tion,” he noted. “So we put in what we think is important.”

The team will start work by devel­oping a gene expres­sion pro­file of all the organ­isms in the lake. “This will tell us who’s there and what they’re doing. It’s up to us here at North­eastern to put it all together in a model, and to try to make sense of it,” Hell­weger said.

If suc­cessful, the model of Lake Taihu could set a prece­dent for under­standing the cyanobac­teria infes­ta­tions of water­ways across the globe, including the Charles River in the Boston area. His­tor­i­cally, sewage runoff has been the main pol­lu­tant in the Charles; today, cyanobac­teria now shares equal blame in making the Charles River unswim­mable, according to research at Hellweger’s lab. “If cyanobac­teria are increasing in the Charles,” he said, “it would not be sur­prising to find other local water­ways next on the list.”

 

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