Senior Scientist Christopher Neill has been named director of the Ecosystems Center. Chris is also the Phyllis and Charles M. Rosenthal Director of the Brown-MBL Partnership and director of the Brown-MBL Graduate Program in Biological and Environmental Sciences.
He received a B.S. from Cornell University, and a M.S. and Ph.D. from the University of Massachusetts Amherst. He first came to MBL as a student in the summer Marine Ecology course in 1983. He joined the MBL as a post-doctoral research associate in 1991 and later established a research program in the Amazon. Chris directs the Hands-on Environmental Laboratory for the MBL’s Logan Science Journalism Program, and has written a column on ecology and the environment for The Falmouth Enterprise newspaper. He was awarded a Bullard Fellowship by Harvard University in 2010 and a Fulbright Fellowship to Brazil in 2007. He is a member of the American Association for the Advancement of Science, The Ecological Society of America, The American Institute for Biological Sciences, and the American Geophysical Union. He currently serves as the president of Falmouth Associations Concerned with Estuaries and Saltponds and as a board member of BiodiversityWorks.
Chris succeeds Hugh Ducklow, who held the post since 2007, and has moved to the Department of Earth and Environmental Sciences at Columbia University.
Led by senior scientist Anne Giblin and postdoctoral scientist Inke Forbrich, Ecosystems Center scientists have built a 40-foot instrumentation tower at the Plum Island Long Term Ecological Research site in northern Massachusetts to allow them to make year-round measurements of net ecosystem carbon exchange.
The particular site was chosen to ensure that measurements can take place even during winter. Due to potentially harsh climate conditions and ice drift, measurements so far have been restricted mostly to the growing season.
Salt marsh ecosystems are among the most productive ecosystems worldwide and these data will help to understand and quantify the ecosystem carbon uptake and release. While marsh grasses take up considerable amounts of carbon during the growing period, the marsh is expected to release CO2 during winter.
The long term goal of these measurements is a better understanding of carbon cycling in the Plum Island Estuary and how the system can adjust to the projected sea level rise. Sea level is predicted to increase, and the scientists are interested in how these changes affect the salt marsh ecosystem. "The major question here is whether the marsh can keep up with a rising sea level by both sedimentation and peat accumulation. Since previous studies have shown that the sedimentation rate at Plum Island is relatively low, we will have a closer look at the carbon cycling in the salt marsh," Inke Forbrich said.
A long-term, large-scale study by Ecosystems Center scientists of salt marsh landscapes in an undeveloped coastline section of the Plum Island Estuary in Massachusetts has shown that nutrients such as nitrogen and phosphorus can cause salt-marsh loss.
Center scientists Linda Deegan, David Johnson and Bruce Peterson and four other scientists are authors of an article that appeared in the journal Nature on October 18, showing results of their nine-year research study. Septic and sewer systems and lawn fertilizers are often the sources of the nutrients that are causing the disintegration.
“Salt marshes are a critical interface between the land and sea,” Deegan says. “They provide habitat for fish, birds, and shellfish; protect coastal cities from storms; and they take nutrients out of the water coming from upland areas, which protects coastal bays from over-pollution.” Losses of healthy salt marsh have accelerated in recent decades, with some losses caused by sea-level rise and development.
“This is the first study to show that nutrient enrichment can be a driver of salt-marsh loss, as well,” says Johnson, a member of the team since the project began in 2003.
This conclusion surprised the scientists, who added nitrogen and phosphorus to the tidal water flushing through the marsh’s creeks at levels typical of nutrient enrichment in densely developed areas, such as Cape Cod and Long Island.
A few years after the experiment began, wide cracks began forming in the grassy banks of the tidal creeks, which eventually slumped down and collapsed into the muddy creek. “The long-term effect is conversion of a vegetated marsh into a mudflat, which is a much less productive ecosystem and does not provide the same benefits to humans or habitat for fish and wildlife,” Deegan says.
Until this study, it seemed that salt marshes had unlimited capacity for nutrient removal, with no harmful effects on the marshes themselves. “Now we really understand that there are limits to what salt marshes can do,” Deegan says. “And in many places along the Eastern seaboard—such as Jamaica Bay in New York, where marshes have been falling apart for years—we have exceeded those limits.”
The disintegration of the nutrient-enriched marsh in this study happened in several stages, the scientists report. In the first few years, the nutrients caused the marsh grass (primarily cordgrass Spartina spp.) along the creek edges to get greener and grow taller, “just like when you add fertilizer to your garden,” Deegan says. This taller grass also, however, produced fewer roots and rhizomes, which normally help stabilize the edge of the marsh creek. The added nutrients also boosted microbial decomposition of leaves, stems, and other biomass in the marsh peat, which further destabilized the creek banks. Eventually, the poorly rooted grass grew too tall and fell over, where the twice-daily tides tugged and pulled it. The weakened creek bank then cracked and fell into the creek.
By year six of the experiment, the scientists started seeing impacts at higher marsh elevations, above the lower creek banks. Three times more cracks, and bigger cracks, emerged at the top of the banks parallel to the creeks, than in a control marsh where no nutrients were added. Eventually, parts of the higher marsh also broke off and slid down toward the creek (which the scientists call the ‘toupee effect,’ because it leaves behind patches of bare, unvegetated mud). All told, at least 2.5 times more chunks of marsh fell into the creeks in the nutrient-enriched marsh than in the control system.
“We honestly did not anticipate the changes we measured,” says Deegan. “Based on prior small-scale experiments, we predicted nutrient enrichment would cause the marsh grass to grow better and remain stable. But when we allowed different parts of the ecosystem to interact with the nitrogen enrichment over time, the small process changes we saw in the first few years resulted in the creek banks later falling apart. This could not have been extrapolated from the smaller-scale, shorter term studies.”
Nutrient enrichment of coastal areas is known to cause harmful algae blooms, which create low-oxygen conditions that kill off marine life. “Now we understand that nutrient enrichment also causes a very important loss of salt marsh habitat for fish and shellfish,” Deegan says. “This is one more reason why we need better treatment of household waste in our towns and cities.” Individuals can help by not using fertilizers on their lawns and gardens. “If you have a green lawn because you are fertilizing it, you are contributing to loss of salt marshes and ultimately of fish,” Deegan says.
This study could not have been accomplished without the cooperation and fore-sightedness of officials from the towns of Ipswich, Mass., and Rowley, Mass., and the Essex County Green Belt Association, the scientists say.
“They recognized the importance of the work,” Johnson says. “They understood that our work would not affect the much larger Plum Island Estuary, since the area manipulated was small relative to the large area of the sound and the marsh is able to process a lot of the nutrients before they get anywhere near the sound. They realized that whatever we discovered would help their towns, and society in general, make better decisions about treating the excessive nutrient enrichment of our coast.”
This study is part of the Plum Island Ecosystem Long-Term Ecological Research (PIE-LTER) program, supported by the National Science Foundation (NSF). The PIE-LTER conducts basic science and provides information to coastal managers to help them make more informed decisions.
"This is a landmark study addressing the drivers of change in productive salt marsh ecosystems, and a stellar example of the value of supporting LTER sites," says David Garrison, program director in NSF's Division of Ocean Sciences, which supports the LTER program along with NSF's Division of Environmental Biology.
In the next phase of research, the scientists will study the recovery of the nutrient-enriched marsh. “After we stop adding the nitrogen, how long does it take the system to rebound to its natural state?” Deegan asks. This information will be important in reclaiming the health of salt marshes that are currently suffering from nutrient enrichment.
In addition to Deegan, Johnson, and Bruce J. Peterson of the MBL, co-authors of this study in Nature include: R. Scott Warren of Connecticut College; John W. Fleeger of Louisiana State University; Sergio Fagherazzi of Boston University; and Wilfred M. Wollheim of the University of New Hampshire.
Deegan LA, Johnson DS, Warren RS, Peterson BJ, Fleeger JW, Fagherazzi S, and Wolheim WM (18 Oct 2012) “Coastal Eutrophication as a Driver of Salt Marsh Loss” Nature.
Jerry Melillo and Gus Shaver of the Ecosystems Center have been named Fellows of the Ecological Society of America (ESA). They are in the first group to be named to the new Fellows program by the 10,000-member society, the world's largest organization of professional ecologists. A total of 40 Fellows were named. At the same time, ESA also established an Early Career Fellows program honoring young scientists.
“The Fellows and Early Career Fellows programs will recognize the many ways in which our members contribute to ecological research and discovery, communication, education and pedagogy, and to management and policy,” said ESA President Scott Collins.
Both Jerry and Gus have conducted research at the Ecosystems Center for more than three decades. Jerry, distinguished scientist and former co-director of the Center, is also a professor of biology at Brown University. In his research, he studies the impacts of human activities on the biogeochemistry of terrestrial ecosystems. He has studied carbon and nitrogen cycling in ecosystems across the globe, including arctic shrublands in northern Sweden, temperate forests in North America, and tropical forests and pastures in the Amazon Basin of Brazil. Jerry served as ESA’s President in 2004-2005.
Gus is a senior scientist at the Center and a professor at Brown. He studies plant growth and nutrition and the role of plants in ecosystem element cycle, focusing his research on Alaskan tundra ecosystems, where low temperatures, low light intensities, low nutrient availability, and a short growing season all interact to limit plant growth. He is lead principal investigator of the Arctic Long Term Ecological Research program, based at Toolik Lake, Alaska. Gus was ESA’s Vice-President for Science 2004-2007.
The 2011 Ecosystems Center Annual Report features stories on nutrient pollution, climate warming and fisheries. Ed Rastetter writes about the models of nutrient cycling that he has developed, which he uses to predict the effects of thermokarst scars in the Arctic, as shown in the photo (on left). Thermokarst occurs when permafrost thaws and the land surface collapses. Joe Vallino writes about bacteria that control denitrification, the conversion of fixed nitrogen compounds back to nitrogen gas, an important part of the global nitrogen cycle. Linda Deegan tells about the use of new acoustic fish tagging technology to track the coastal migration of "schoolie" striped bass.
The report has updates on our many educational and outreach programs. The Semester in Environmental Science had its largest class ever in 2011, and students in the Brown-MBL Graduate Program in Biological and Environmental Sciences conducted research with their MBL advisors. Ecosystems Center staff also mentored local junior high and high students and judged science fairs, provided guidance to undergraduate interns at the center and in remote field sites, and participated in a mentoring program to encourage diversity in the science community.
Check out the new annual report web site, which also features an update from Ecosystems Center Director Hugh Ducklow, and then sign up for email updates from the Ecosystems Center throughout the year.
If you pay attention to a New England salt marsh in the summer you can see emergence. The greenhead that emerges from the grass. The dragonfly that emerges from the pond. The snail that emerges from the flooding waters. In Plum Island, if you're patient, you can see young scientists emerging from the marsh.
These young, intrepid marsh-minded scientists are part of the the Ecosystem Center's TIDE (Trophic cascades and Interacting control processes in a Detritus-based aquatic Ecosystem) Project, which is nestled within the Plum Island Long Term Ecological Research site. TIDE is a large-scale fertilization project in the salt marshes of the Plum Island Estuary in northern Massachusetts that is currently in its 10th field season.
The project is led by Ecosystems Center senior scientist Linda Deegan, and many center scientists have participated in the project. More importantly, the TIDE Project has provided opportunities for young scientists to get their feet wet (that is, wet, muddy, and mosquito-bitten) in science.
These young researchers write about their experiences in the TIDE blog. From the frontlines of the field, it gives first-hand accounts of the science being conducted.The most recent posting is by David Johnson, a research associate at the center who has been a part of the TIDE Project for 10 years. While greenheads and snails and dragonflies come and go, some who emerge on the marsh stay for a while.
Land of Extremes Is Colorful Guide to Natural History of the Arctic Tundra
John Hobbie and Alex Huryn, long-time principal investigators on the Arctic Long Term Ecological Research project at Toolik Lake, Alaska, have just finished a book about the natural history of the North Slope of Alaska, the only Arctic tundra in the U. S. The book, Land of Extremes, A Natural History of the Arctic North Slope of Alaska, will be published this September by the University of Alaska Press.
The idea for the book came up in the dining hall at Toolik. Says Hobbie, “I was sitting at the dinner table with Alex, and was struck by the diversity of the expertise there. Scientists who were world experts on birds, mammals, microbes, plants, geology and so on. What an opportunity to bring together all that knowledge about one small region of the Earth – and a very interesting region it is too.”
The first section is devoted to climate, geology, landforms, and ecology; the second provides a guide to the identification and natural history of the common animals and plants and a primer on the human prehistory of the region from the Pleistocene through the mid-twentieth century. The appendix provides the framework for a tour of the natural history features along the Dalton Highway, the road that runs from the Brooks Range to Prudhoe Bay and the Arctic Ocean.
John Hobbie, currently senior scholar the Ecosystems Center, was instrumental in setting up Toolik as a research station in the mid 1970s. He has been going to the North Slope, in fact, since he began conducting his doctoral research in the late 1950s. Like Hobbie, Alex Huryn, professor at the University of Alabama, has carried out research in the Arctic year-round. “Alex is an excellent naturalist, and provided hundreds of color illustrations for the book,” said Hobbie.
Students from the New York Harbor School visited Woods Hole and the Ecosystems Center last month. JC Weber explained the work that he and Maureen Conte conduct in the Oceanic Flux program. He told students about one aspect, using organic chemical biomarkers extracted from deep sea particulate matter to learn about processes in the mesopelgaic zone of the deep Sargasso Sea.
Matthew Erickson gave an overview of the Palmer Station Long Term Ecological Research project in Antarctica. Research there is focused on the Antarctic pelagic foodweb.
The Harbor School is a small college preparatory school on Governor's Island in New York City. All students must choose a career and technical education program of study from one of these maritime related areas: marine technology, marine science, marine policy or SCUBA diving.
The Ecosystems Center staff plays an active role in community outreach and education. Every year, scientists and research assistants volunteer to mentor students from the middle school and high school levels, helping them to refine ideas for their science fair projects. Many of the staff are also involved in judging projects at both the local and state science fairs.
Mentoring of seventh and eighth grade students at Lawrence School is organized by the Woods Hole Science and Technology Educational Partnership (WHSTEP). In 2012, Ecosystems Center researchers JC Weber, Sam Kelsey, Lindsay Scott, Suzanne Thomas and Kate Morkeski spent several hours with the students, helping them develop their science project ideas and organize their approach and methods. Other Ecosystems staff, eager to help the next generation of scientists, also mentored several motivated high school students who approached them independently with their scientific interests.
This year, three Falmouth High School students who were advised by Ecosystems Center scientists went on to win top awards at the Falmouth Public Schools Science Fair on March 3. The following week, all three won prizes in the South Shore Regional Science Fair at Bridgewater State University and will next compete in the Massachusetts State Science and Engineering Fair at MIT in May.
Vincent Lin, a junior at Falmouth High School who was mentored by Ecosystems Center scientist Jim Tang, won first prize at the Falmouth fair. He also received the Mary Sears Scholarship from the Woods Hole Oceanographic Institution as well as an award from the National Marine Fisheries Service. His project was "Effects of Fertilization and Temperature on Greenhouse Gas and Nitrogen Oxide Emissions from Soils." Jim commented on the project, "The results will inform us how to appropriately fertilize lawns and agricultural crops in order to decrease greenhouse gas emissions and increase carbon stocks in soils." Vincent will represent Massachusetts at the International Science and Engineering Fair in Pittsburgh this May. This was Vincent's third year winning of first prize at the science fair.
Another FHS junior, Ted Price, received first prize for his project, "Light Attenuation in West Falmouth Harbor." Melanie Hayn, research assistant at the Ecosystems Center, was his advisor. In addition, Ted was awarded a prize from Hydroid, Inc. His project looked at the factors that affect light penetration in West Falmouth Harbor. "He was interested in why you could see further below the water surface at some locations than others, and wanted to figure out what was responsible," noted Melanie. Ted looked at many factors, including chlorophyll, colored dissolved organic matter, suspended solids, salinity, and tidal state.
Steven Spall won second prize for his study of "Biomass Denitrification in Saltwater Estuaries." His mentor was Ken Foreman, director of the Ecosystems Center's Semester in Environmental Science. Steven won the Dr. Donald Zinn Award from the Salt Pond Area Bird Sanctuaries, Inc., and was selected as alternate to Vincent Lin for the International Science and Engineering Fair. The goals of his project, said Ken, were to use microcosms filled with wood chips to simulate a permeable reactive barrier designed to promote denitrification in the groundwater. Steven also evaluated the lifetime of the wood chips by measuring the decomposition of the wood via the release of carbon dioxide from the degradation of the wood in the outgoing water vs. the incoming water.
Ecosystems Center staff who judged at the Falmouth Public Schools science fair were JC Weber, Marshall Otter, Jim Tang, Suzanne Thomas and Miriam Johnston. Falmouth Academy's science fair, held in February, was judged by Hap Garritt. Marshall, Hap and JC also judge the science fair at the state level at MIT.
Volunteering in these educational initiatives gives the center staff an opportunity to share their own passion for science with the next generation of young scientists. “It’s an incredibly rewarding experience seeing the excitement and enthusiasm about science within the kids and the pride that they exude when presenting their final presentations,” noted Ecosystems research assistant JC Weber.
As part of his research on preserving healthy and productive salt marshes, James Nelson, postdoctoral researcher at the Plum Island Sound Long Term Ecological Research site, turned 28,500 mummichogs green last summer.
Dr. Nelson explains: "Salt marshes, such as the Great Marsh along the northern Massachusetts coast, are highly productive landscapes that provide a great number of ecosystem services. Some of the more well known ecosystem services provided by salt marshes are protection from storm surge and runoff filtration. There is another major service salt marshes provide that ecologist have long theorized about but rarely demonstrated and that is the export of food to adjacent habitats in the form of fish.
Each year in the spring the productivity engine of the marsh gets switched on and begins to produce enormous amounts of biomass in the form of small fish. These fish, primarily mummichog (Fundulus heterclitus), follow the pulse of the tides to feed on the abundant food in the relative safety of tidal creeks throughout the spring and summer. As the temperatures dip into the fall season these little fish must move out of the shallow tidal creeks and into deeper waters, where they become prey for larger fish such as striped bass (Marone saxatilis). Essentially, salt marshes act as food factories that package large amounts of production in a short period and then export that production to organisms in other systems. In fact, we have observed a strong correlation between the amount of mummichog produced and the number of striped bass. Therefore, maintaining healthy and productive salt marshes will help to maintain productive offshore fisheries.
"Human-caused nutrient pollution, however, is a major threat to the stability of this important ecosystem service. My work focuses on the effects of 'eutrophication' or human-caused nutrient pollution on the secondary (fish) productivity of salt marshes. To examine this I employ a number of techniques with the primary goal of answering two main questions: first, how does nutrient pollution change the number of fish the salt marsh can support? And second, what are the effects on fish growth from nutrient pollution? By knowing the number of fish and their rate of growth we can calculate the total production of fish in the salt marsh. Of course, actually determining fish growth in the wild can be quite difficult.
"This summer I utilized a new technique that marks the bones, and other hard parts, of fish with a fluorescent dye (Calcein) that can be used to determine a fish’s growth rate. The fish are marked by immersing them in a non-toxic solution of Calcein and salt water for two minutes. A major advantage of this method is the number of fish we can mark at one time. This summer I was able to mark 28,500 fish in a two-day period. The dye does not harm the fish and cannot be seen in normal light, so the fish’s natural behavior is not affected. Once marked with the Calcein the bony structures will glow green under ultraviolet light. The marked fish were released back into the creeks from which they were captured to grow during the summer. We conducted monthly sampling of the fish in these creeks to recapture the marked fish. In the lab an ultraviolet light will be used to illuminate the Calcein mark. We will then measure the additional growth beyond the calcein mark on several bony structures to determine the fish’s growth during its time at liberty. If we are successful we will be able to answer the question of how eutrophication affects the growth rate of these fish and draw conclusions about the overall effect eutrophication will have on the export of secondary production from marshes to fisheries species offshore."