UC Berkeley, U.S.G.S. Scientists Discover Microscopic Invader Of San Francisco Bay, The First Known Marine Microbe Invader Of U.S. Waters

October 31, 1996

Denver -- While there are many known cases of exotic creatures invading the country's rivers and estuaries, scientists have for the first time documented the invasion into U. S. coastal waters of a type of marine microorganism.

In a talk to be given on Thursday, Oct. 31, at the annual meeting of the Geological Society of America in Denver, Doris Sloan and Andrew N. Cohen of the University of California at Berkeley, and Mary McGann of the U.S. Geological Survey in Menlo Park, Calif., report the introduction of a single-celled amoeba-like organism, the foraminifer Trochammina hadai.Foraminifera or forams, microscopic marine creatures with shells of calcium carbonate, are best known from their abundant fossils, which are found in such profusion and diversity they are used to date sedimentary rocks going back as far as half a billion years.The organism apparently arrived within the past 10 years from Japan, probably hitching a ride in the ballast tanks of a ship that took on water in a Japanese port and emptied its tanks into western U.S. waters, the scientists say. This exotic foraminifer is a common inhabitant of estuaries and bays in Japan, where it lives in the mud in shallow water.Alarmingly, the new resident in San Francisco Bay has spread widely throughout the bay and is now found in large numbers at many sampling sites.The introduction of an exotic organism that spreads as rapidly as T. hadai is a matter of considerable concern, Sloan says. In particular this invasion raises questions about the extent to which other microorganisms are invading the world's ports and estuaries.It is too early to tell what the impact of this introduction will be on the ecosystem, Sloan says, but at the population levels currently found, it is likely to have a large impact on the native species of foraminifer.The introduction of exotic species to the estuaries and inland waters of the United States is now a well known problem. Invaders such as mussels, clams, crabs and other invertebrates crowd out native species, and if they have no natural predators, can cause major damage to our harbors and waterways. A prime example is the zebra mussel which has clogged water pipes in the Great Lakes region, causing millions of dollars of damage. Cohen, who works with the Energy and Resources Group at UC Berkeley, has previously reported the introduction of more than 200 exotic macroscopic species, both plants and animals, to San Francisco Bay in the past 150 years, suggesting that the bay is the most invaded estuary in the world.T. hadai's presence in San Francisco Bay is probably not the first time one of these tiny organisms has traveled around the world, the scientists say. It is likely that there are a number of introduced microorganisms in the worlds' estuaries that just haven't been noticed yet.Some of the species previously reported as natives might in fact have been introduced before studies of shallow-water foraminifers became common in the 1950s. Cohen thinks that they could have arrived in the bay as hitch-hikers on ship hulls during the Gold Rush, in shipments of oysters from the Atlantic seaboard, in ballast water or by other mechanisms.T. hadai was first found in San Francisco Bay sediment by McGann in 1995 while examining samples taken near the San Francisco airport. She recognized that this organism was not one of the common native species of foraminifers that lives in the bottom of the bay.At about the same time Sloan, a geologist and lecturer emerita in environmental sciences at UC Berkeley, also found it in samples taken further north in Marin County waters. Sloan and McGann then looked at many sediment samples collected in earlier years from the bay, to see if they could determine when it first arrived.While they did not find it in any sediment samples which had been collected between 1964 and 1981, they did find it in samples collected from the bottom of the bay in 1987. Evidently this organism was introduced to the bay sometime between 1981 and 1987, though no samples from this period are yet available to date its arrival more closely, Sloan says.Since they first found it, the scientists have sampled bay sediments twice a year and have now found that T. hadai has spread throughout the entire bay ecosystem. At many sampling sites it makes up over 50 percent of the foraminifer population and in one case over 90 percent. The mud and water found in ballast tanks of ocean-going ships is probably one of the most common current mechanisms by which species travel from port to port today, Cohen says. Over 68 million gallons of ballast water are released by ships in San Francisco Bay annually, yet there currently is no regulation of such dumping to prevent invasions by exotic species.
For further information, contact Doris Sloan at (510) 642-3703 or dsloan@violet.berkeley.edu; Mary McGann at (415) 329-4979 or Andrew N. Cohen at (510) 848-1029.

University of California - Berkeley

Related Water Articles from Brightsurf:

Transport of water to mars' upper atmosphere dominates planet's water loss to space
Instead of its scarce atmospheric water being confined in Mars' lower atmosphere, a new study finds evidence that water on Mars is directly transported to the upper atmosphere, where it is converted to atomic hydrogen that escapes to space.

Water striders learn from experience how to jump up safely from water surface
Water striders jump upwards from the water surface without breaking it.

'Pregnancy test for water' delivers fast, easy results on water quality
A new platform technology can assess water safety and quality with just a single drop and a few minutes.

Something in the water
Between 2015 and 2016, Brazil suffered from an epidemic outbreak of the Zika virus, whose infections occurred throughout the country states.

Researchers create new tools to monitor water quality, measure water insecurity
A wife-husband team will present both high-tech and low-tech solutions for improving water security at this year's American Association for the Advancement of Science (AAAS) annual meeting in Seattle on Sunday, Feb.

The shape of water: What water molecules look like on the surface of materials
Water is a familiar substance that is present virtually everywhere.

Water, water everywhere -- and it's weirder than you think
Researchers at The University of Tokyo show that liquid water has 2 distinct molecular arrangements: tetrahedral and non-tetrahedral.

What's in your water?
Mixing drinking water with chlorine, the United States' most common method of disinfecting drinking water, creates previously unidentified toxic byproducts, says Carsten Prasse from Johns Hopkins University and his collaborators from the University of California, Berkeley and Switzerland.

How we transport water in our bodies inspires new water filtration method
A multidisciplinary group of engineers and scientists has discovered a new method for water filtration that could have implications for a variety of technologies, such as desalination plants, breathable and protective fabrics, and carbon capture in gas separations.

Source water key to bacterial water safety in remote Northern Australia
In the wet-dry topics of Australia, drinking water in remote communities is often sourced from groundwater bores.

Read More: Water News and Water Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.