Featured Research

from universities, journals, and other organizations

Microorganisms Are Cleaning Up Boston Harbor, UMass Study Finds

Date:
November 14, 2002
Source:
University Of Massachusetts At Amherst
Summary:
Microorganisms are cleaning up contaminants in the mud beneath Boston Harbor, and if humans prevent future fuel spills and leaks, the harbor could potentially cleanse itself within the next 10 to 20 years, according to research conducted at the University of Massachusetts Amherst. The findings are detailed in the Nov. 15 issue of the journal Environmental Science and Technology. The work was funded by the Office of Naval Research.

AMHERST, Mass. – Microorganisms are cleaning up contaminants in the mud beneath Boston Harbor, and if humans prevent future fuel spills and leaks, the harbor could potentially cleanse itself within the next 10 to 20 years, according to research conducted at the University of Massachusetts Amherst. The findings are detailed in the Nov. 15 issue of the journal Environmental Science and Technology. The work was funded by the Office of Naval Research.

Scientists had previously determined that these contaminants, called polycyclic aromatic hydrocarbons, or PAHs, could biodegrade if suspended in water. But it was also believed that once PAHs sank into the silt at the bottom of the harbor, they could not be oxidized or degraded – a theory that the new study challenges.

"This is important because it demonstrates that the self-purification capacity of the harbor is much greater than previously recognized," said UMass microbiologist Derek Lovley, a co-author on the paper. "Furthermore, if future spills of contaminants can be eliminated, the harbor may get cleaned up in large part due to natural activity without the requirement for expensive remediation strategies. It does give us hope for the longer term, if practices change."

Marine harbors are frequently polluted with contaminants from fuel spills, industrial waste, shipping activities, runoff, soot, and creosote-treated pilings, Lovley said. Although some chemical portions of these contaminants readily degrade, PAHs tend to accumulate in the sediment. "They're not very soluble in water, and they don't react chemically with many other compounds," said Lovley, "so they collect in the mud at the bottom of the harbor." Previous research has shown that PAHs accumulate in fish and other aquatic animals, and are often associated with cancers in some fish. Some PAHs are highly toxic, and are suspected carcinogens in humans.

The UMass team was prompted to study the issue after earlier research by Lovley found that benzene degrades in the absence of oxygen, in certain conditions. PAHs are essentially groups of two to five benzene rings, Lovley noted. His collaborators on the Boston Harbor project were Mary Rothermich, a former postdoctoral researcher at UMass who is now at Harvard University, and Lory Hayes, a former graduate student who now works in industry.

The key component in the microbial action appears to be the existence of sulfate in the water, said Lovley. "As long as there is sulfate in the water, the PAHs can degrade slowly." Sulfate is a salt of sulfuric acid, and is naturally abundant in seawater, according to Lovley. These microorganisms use sulfate the same way that humans use oxygen. Whereas we use oxygen to oxidize the food that we consume, these microorganisms can oxidize PAHs and their other food sources with sulfate. In this way they can remain active in the mud at the bottom of the harbor where there is no oxygen.

In addition to Boston Harbor, the team also studied marine contaminants in San Diego, Calif., and in Latvia. For the local portion of the project, Boston Harbor sediments were pulled from the harbor near a former coal-tar plant in an area of Everett known as Island End. Coal-tar works had been in production in the area from the late 1800s to about 1960, according to Lovley. The sediments used in the study overlaid the site of a leaking underground storage tank that had been removed in the 1980s, he said.

Scientists monitored the sediment samples in the lab, replenishing the samples with fresh harbor water roughly once a month. They found that the PAHs in the collected sediments broke down 20-25 percent over 338 days – a little less than a year. "In a way, it seems slow, but if you're thinking about the alternatives, it's not bad to have some patience," Lovley said.

He noted that other alternatives for removing the contaminants, including dredging, are expensive and disruptive to the marine environment. Dredging also creates the additional problem of how to dispose of the contaminated mud. "Of course, you don't want to say, 'Oh, it's okay to keep dumping this stuff.' The fact that it's even there shows that the spillage rate is too fast for nature to keep up with. You have to actively protect the environment."


Story Source:

The above story is based on materials provided by University Of Massachusetts At Amherst. Note: Materials may be edited for content and length.


Cite This Page:

University Of Massachusetts At Amherst. "Microorganisms Are Cleaning Up Boston Harbor, UMass Study Finds." ScienceDaily. ScienceDaily, 14 November 2002. <www.sciencedaily.com/releases/2002/11/021114072013.htm>.
University Of Massachusetts At Amherst. (2002, November 14). Microorganisms Are Cleaning Up Boston Harbor, UMass Study Finds. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2002/11/021114072013.htm
University Of Massachusetts At Amherst. "Microorganisms Are Cleaning Up Boston Harbor, UMass Study Finds." ScienceDaily. www.sciencedaily.com/releases/2002/11/021114072013.htm (accessed July 31, 2014).

Share This




More Earth & Climate News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) — Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Big Waves In Arctic Ocean Threaten Polar Ice

Big Waves In Arctic Ocean Threaten Polar Ice

Newsy (July 30, 2014) — Big waves in parts of the Arctic Ocean are unprecedented, mainly because they used to be covered in ice. Video provided by Newsy
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) — Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Weather Kills 2K A Year, But Storms Aren't The Main Offender

Weather Kills 2K A Year, But Storms Aren't The Main Offender

Newsy (July 30, 2014) — Health officials say 2,000 deaths occur each year in the U.S. due to weather, but it's excessive heat and cold that claim the most lives. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:  

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile iPhone Android Web
      Follow Facebook Twitter Google+
      Subscribe RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins