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NSF & Congress


Dr. Rita Colwell

Dr. Rita Colwell
National Science Foundation

Before the House Science Committee
Basic Research Subcommittee
September 28, 1998

Mr. Chairman, members of the subcommittee, thank you for allowing me the opportunity to testify on the use of remote sensing technology in the sciences.

Before I begin, let me say how pleased I am to be appearing before this subcommittee again. While I have testified before this subcommittee several times in the past, this is my first appearance in my new capacity as NSF Director.

The Science Committee and the Basic Research Subcommittee have worked hard over the years to promote policies that have helped keep the United States a world leader in science, space and technology. The Committee is unique in that its work has been marked largely by bipartisan cooperation in pursuit of common goals. This tradition has been maintained by you Mr. Chairman, along with Full Committee Chairman Sensenbrenner, Ranking Member Brown, Vice Chairman Ehlers and especially the late Steve Schiff, the former chairman of the Basic Research Subcommittee.

The subject of the hearing today -- remote sensing -- is a special one for me, both as Director of the National Science Foundation and as an active researcher as well. Remote sensing is an wonderful example of the many exciting developments in science. First, it exemplifies how scientists across disciplines are work and collaborate on complex global scientific problems in new exciting ways. Second it demonstrates how the next generation of computer and communications technology is able to organize, transmit, and disseminate massive amounts of data collected by satellites and remote sensing devices in ways that create benefits for scientists and citizens. Third, it shows how federal agencies like NSF, NASA, NOAA and DoD - each with their own expertise and missions - collaborate effectively to solve fundamental and complex scientific problems.

Remote sensing technology -- whether from satellites, radar facilities or other types of sensors -- is now an important tool for researchers in many disciplines. For many years, development of sophisticated remote sensors were driven in large part because of scientific and national security needs. In the 1980's and early 1990's the United States -- led by NASA -- made a major commitment to improve our ability to gather data about the Earth's systems from satellites.

Now a new generation of advanced sensors allow scientists to study the earth's biochemistry and ecology on a fully global scale. Today, at NSF, we regard remote sensing as an indispensable research tool in many disciplines we support, including geosciences, physical science, biology, and social and behavioral sciences.

I have seen the power of remote sensing technology first hand during my research. As an aquatic microbiologist I have spent over 30 years studying the microbial disease, cholera. In recent years, use of satellite data by myself and my students has led to a greater understanding of how global environmental change influences the spread of this deadly disease. We have found, through the use of remotely sensed data, that cholera epidemics can now be related to climate and climate events, including ocean warming events such as El Niño. Further refinements of these studies could allow us to save thousands of lives each year through effective monitoring and prediction of conditions conducive to cholera epidemics.

Cholera is a disease caused by drinking water contaminated with a bacterium known as Vibrio cholerae. Cholera can cause severe diarrhea and dehydration, and in some cases may be fatal - especially to those with weakened or less well-developed immune systems, such as the elderly and young children. Before the advent of modern water treatment facilities, cholera was once the source of major epidemics in European and American cities. Today cholera remains a serious problem in developing countries that lack sources of clean water.

The link between clean water and reduced outbreaks of cholera has been known since the nineteenth century. For centuries, cholera was associated with the sea as well, since outbreaks of the disease followed the ocean coastlines. Cholera also tends to spread in erratic but massive pandemics that ravage parts of several continents over long periods of time. Despite these tendencies, we have known little about how exactly the cholera bacterium was spread until recent decades.

The key breakthrough in the early seventies came when we discovered that the cholera bacterium lives in the gut of microscopic aquatic animals, the zooplankton, This pivotal discovery occurred only through years of fundamental research by myself and my fellow researchers and students, both in the laboratory and in the field.

Proving the link between plankton and the cholera bacterium allowed my colleagues and I to develop a simple and inexpensive solution to help reduce the presence of cholera bacteria in water obtained from untreated sources.

The low technology solution to combat cholera that we came up with was to filter untreated water through cloth, trapping the plankton and, thereby, the attached bacteria. This low technology approach is critical, since during the monsoon flood season in areas of India and Bangladesh, living conditions deteriorate to simple survival. Building a fire to boil water is not possible. Luckily, inexpensive cloth - used to make a women's dress called a sari - is readily available. Filtering water through three or four layers of sari cloth has been proven to remove plankton and other particulate matter and this reduces the numbers of disease-causing cholera bacteria in the water. Field studies are underway that will soon test our hypothesis that cholera outbreaks will decrease in villages using this new filtering technique.

The relationship between plankton and cholera bacterium also has caused us to study how significant changes in climate such as ocean warming may be a factor in cholera epidemics. The use of ocean climate data generated by satellites has been critical to this research link. As the ocean warms during global climate events like El Niño, we know that large plankton blooms become more prevalent. Given that cholera bacteria was proven to be present in plankton, we felt that there would be a strong correlation between ocean plankton growth and cholera outbreaks. If such a link is verified, it will hopefully lead to direct monitoring and prediction of cholera epidemics in the future.

To correlate cholera cases with changes in ocean climate, we needed enough historical data on cholera cases along with sufficient ocean climate data for a particular region. We have weekly cholera case histories for Bangladesh. Earlier studies using ocean color were valuable in developing the research. Directly collected data on ocean temperature and sea surface height -- usually made by water sampling from research ships -- has been sparse and infrequent up to this point and for the most part been very expensive and time consuming. However, archived remotely sensed data from NASA and NOAA supported satellites on global ocean temperature and height are now publicly available on the Internet.

Comparing the number of cases of cholera with changes in sea surface temperature and ocean height obtained from remote sensing, showed a strong link between changes in ocean climate and incidences of cholera. If verified, this would bring the potential of predicting conditions conducive to cholera outbreaks closer to reality. This would have enormous implications for improvements in human health worldwide. Recent cholera epidemics have swept through Latin America and Africa in the early 1990's. These recent epidemics - part of a larger cholera pandemic that began in the 1960's - killed thousands of people.

This work in developing models to enable prediction of conditions conducive to cholera epidemics...that is, to allow proactive, not just reactive, measures against cholera would be difficult if not impossible without remote sensing. But satellites represent only half of the picture. Only through advances in high speed computing and communications technology has the data from remote sensing become readily available and usable. These advances have been supported by the National Science Foundation at their earliest stages for many years.. Continued NSF support for fundamental research on information science and technology - through our investment in the Next Generation Internet and other initiatives -- will continue to play a vital role in scientists' ability to effectively use our remote sensing resources.

While remote sensing now is viewed primarily a tool for NSF-funded scientists, it is clear that development of this important tool must proceed hand-in-hand with the development of scientific questions requiring its use. This is one area where NSF and the academic research community can cooperate effectively with mission agencies like NASA and DoD that manage remote sensing resources. Continued design and implementation of higher resolution satellite technology will be critical for improved physical, biological and chemical understanding of our land, sea and atmosphere.

It is clear also that developments in remote sensing technology will have important commercial applications as well. While I will leave it to other witnesses to discuss the details of this important area, I would like to include one or two points.

It has been known for several decades -- ever since the Gemini and Apollo astronauts brought back the first photographs of the earth -- that observations from space would have tremendous use in areas such as forestry, hydrology, agriculture, and fisheries management. However, use of remotely sensed data for commercial applications - as well as many scientific ones -- lagged for many years.

The reasons for this have little to do with the sophistication of remote sensing technology. Rather it has to do more with the ability to store, manage, access and use the massive data produced by satellites, radar facilities and other remote sensing instruments.

Without advanced information processing, it would take decades to compile and analyze the incredible amounts of information that produced by many of these instruments We still have enormous amounts of stored earth climate data from remote sensors that will require additional developments in vast database handling. This research must occur before we can understand fully how our planet's ecosystem works. Since the advent of the Internet and other advances in computing and information sciences, the use of data gathered from remote sensing increased profoundly in a few short years.

Several congressionally-mandated reports on unlocking the potential of remote sensing were written during the 1980's and early 90's. Let me conclude with a quote from the first sentence of one:

"If the United States is not prepared to manage efficiently the increase in quantities of remotely sensed data, it will not be able to reap the full benefits of its investment in its satellite systems. In order to use remotely sensed data efficiently, scientists and other users will require adequate data storage and computer systems capable of managing, organizing, sorting, distributing, and manipulating these data at unprecedented speeds."

This prophetic statement is just as true now as when it was written just four short years ago. Nevertheless, the year 1994 is ancient history in terms of the Internet's development - we have come a long way from the days of the 14.4 modem. Advances in computational power, instant communication, vast databases, and extensive analytical capability have brought us to a new era of discoveries in many fields of science and engineering. Now we can explore the universe with powerful tools that unlock knowledge from the subatomic to the super-celestial level.

Some of the contributions of information systems and remote sensors will be like the seafaring ships of earlier eras -- transporting huge quantities of commodities from distant places. Other contributions from information science and technology will be to create whole new disciplines and fields of knowledge, to trigger new industries, and to find new worlds, literally and figuratively.

The NSF is poised to lead those diverse expeditions. As the new Director of NSF, I'm excited to be a part of these efforts and look forward to working with you Mr. Chairman and this subcommittee to lead this country forward into the next century.

Thank you.