Somewhere in its soil and water, Merrymeeting Bay holds answers to questions generated by decades of human influence, and a group of Bowdoin researchers are out to find them.
On a late summer afternoon, Merrymeeting Bay looks pristine and peaceful: a bald eagle perches on a telecommunications tower, and a few seals poke their heads up out of the water near the Chops, the narrow channel where water moves between the Bay and the Gulf of Maine. If you didn't know it, you couldn't tell that only a few decades ago the waters feeding the Bay were among the most polluted in the country. Many who grew up near its shores remember the sights and smells of raw sewage and tell stories of fumes so caustic they caused paint to peel off nearby buildings.
Though memorable, pollution wasn't the only harmful force: construction of dams, overfishing, hunting and other aspects of human life and industry took their toll on the Bay. Fish populations were greatly reduced, and by 1979 there was only one known nesting pair of eagles left. Eventually the problem became too big to be ignored. State, then Federal, efforts reduced pollution, and, left alone, the Bay began to heal itself. Now the eagles are back, the smell is just a memory, and rafts and swimming platforms attest to the fact that swimmers no longer fear the water. The legacy of those generations of human influence aren't yet fully understood, but the earth doesn't forget. Somewhere in its soil and water, Merrymeeting Bay holds answers, and a group of Bowdoin researchers are out to find them.
Members of the Bowdoin community have long been interested in study of Merrymeeting Bay. Former English professor Frank Burroughs has been writing essays about the Bay for years. In the early 1990s, the College's environmental studies program held a conference about the Bay and helped spark formation of the Friends of Merrymeeting Bay. In recent years, new faculty in the environmental studies program, along with an emphasis in service learning, have provided energy for a surge in research, and a $365,000 grant from the Henry Luce Foundation gave Bowdoin the money to put that energy into action. Now, ecosystem scientist John Lichter, geologist Peter Lea, environmental historian Matthew Klingle, political scientist and director of the environmental studies program DeWitt John, lab instructor Jaret Reblen, project manager Heather Caron and numerous Bowdoin students are studying the ecology, land use, environmental history, and legacy of that history in and around Merrymeeting Bay.
Located about five miles northeast of the College, Merrymeeting Bay is a freshwater estuary surrounded by marshland. Lichter, who leads the research program, said its large size could make it unique in the world. Six rivers converge at the Bay, which is made up of about 10,700 acres and 99 miles of shoreline. It's host to thousands of migrating birds each fall and spring and is an important fishery habitat. Whether it proves to be unique or not, the complex nature of the system and its history make it an important location for research. In general, aquatic and marine ecologists have overlooked such systems, since they exist somewhere between freshwater and marine environments, but Bowdoin researchers say there is much to learn from Merrymeeting Bay.
Oddly enough, pollution might have done a service to the Bay by protecting it from other human activity. "It used to be such a filthy place that nobody went there," Lichter said. "It's remarkably unaltered by development." By the time that the Bay was clean enough to be attractive, zoning and environmental regulation limited the amount and type of future development.
Even so, humans and the natural world have long interacted around Merrymeeting Bay. Native Americans lived there for thousands of years before Europeans first discovered it in 1605. Once the Europeans came, it took only a few centuries for towns to spring up around the area. By the 1800s, midcoast Maine had become home to shipbuilding, fishing, logging, pulp, paper and ice industries as well as agriculture. This history, combined with the complex nature of the ecosystem, make Merrymeeting Bay an ideal setting for interdisciplinary work.
"We tend to think of environmental problems in this country as technical problems with technical and scientific solutions," said Klingle, whose work is grounded in the idea that history can shed light on those problems and their solutions. Klingle and junior Samantha Farrell are compiling an annotated bibliography of sources to lay the groundwork for a comprehensive historical investigation of the Bay. He hopes the project will provide the background for a dialogue between history and science. That interplay is one of the elements that those involved find most exciting about the research program.
"Ecologists haven't always been able to, say, look at the past and consider that influence on what we're observing," Lichter said. "In most places you really just don't have a history to work with, and here we do."
Marshes and Mud
Reblin, junior Chrissy Souther, and senior Julie Grinvalsky meet outside Druckenmiller Hall on a sunny August morning. Among the tools they load into a Bowdoin van are boots, PVC pipe, and a box full of ceramic dog bowls. It's nearly low tide, and they are heading out to eight sites where they've marked transects, lines beginning at the high tide mark and moving out 50 meters, to study plant life in the marshes around the Bay. Their main focus is the growth of wild rice, an annual introduced to the Bay by Native Americans that now dominates its plant life. But they're also taking a census of the plants in square meter plots along the transects. The dog bowls should be heavy enough to resist the tide as they sit in the mud to collect rice seeds, and the PVC pipe will mark the plots to be counted. The survey will give them a sense of which plants are thriving, which are emerging, and if there are any struggling to survive.
"Ecologists use a lot of simple stuff," Reblin says as he loads. "It's amazing what you can do with Rubbermaid containers, duct tape and some dog bowls."
Out in the marsh, they lay out a PVC square, and Reblin and Grinvalsky begin counting, fingering plants down at the bases to make sure they get each one. Souther takes down the numbers as they shout them out, "339 three-squared sedge...15 biden...2 goldenrod." They count everything-down to the moss that forms a lacy carpet over the mud. The only sounds other than their counting are the wind rustling the plants and the buzzing of a bee on a nearby purple flower Ñpickerel weed, Grinvalsky says.
Only about 10 feet out from the first transect, it starts to get gloppy. Each time someone takes a step there's a loud splurching sound, and each footprint becomes a small pond. At high tide, the water would completely cover many of the smaller plants. Part of what this census will show is what plants prefer what level of inundation - once they determine what each plant is.
Identification is easier now than when they began last spring, but it's still a challenge. Identification manuals show mature plants, not what a plant looks like when it's only an inch high. Gerry LaRoche, a retired botanist who works in the lab, is growing many of the plants from seed to allow the researchers to see what the young plants look like. Then they'll build a database to make the information available to other scientists.
Grinvalsky keeps thinking she's seen water starwort, but it's an endangered species, and there seems to be so much of it out by the Bay that she's not sure it's the right identification. "But that can be the case with rare plants," Reblin reminds her. "They can be really locally abundant in some places."
Grinvalsky's seen the same thing happen in Parker's pipewort, which she's studying under a grant from The New England Wildflower Society. Though it's endangered, it's dense around the Bay. In addition to counting the pipewort, she's also trying to determine how it's pollinated.
"Overall, all this gives you information on how the plant community is structured and hopefully the relationships between the species," she said.
They arrive at the second set of plots they're counting, and it looks like they've stumbled onto crop circles. Wild rice grows tall but has a very small root system, so the plant eventually becomes too heavy for its roots to hold up and falls flat. They dig under the plants and begin counting.
After a few minutes, they hear voices and a metallic thump somewhere beyond the rice. Though they can't see anything for all of the plants, they determine that it's Peter Lea, taking soil cores. They exchange a few shouted pleasantries, then it's quiet again and back to counting.
"It's nice to be out here," Grinvalsky says, and she's speaking for all of them. "The counting gets a little tedious, but then you look up, and..." She looks around her, drinking in the sun and trees and a glimpse of water in the distance. That says it all, really, why Merrymeeting Bay is something so many people treasure and are working to understand.
"It's fun to be looking at something that's been in your back yard all these years, and realize that there's all this interesting and exciting stuff happening," Lea said of his work at Merrymeeting Bay. "It really is a fascinating system, with a lot of different twists."
Lea and junior Chris Proctor have been taking soil cores from the mud flats. They pound a three- to five-foot-long metal tube into the earth to collect the soil, then analyze the samples to see how the history of the Bay is recorded in the sediment.
"People envision the sediment accumulating sort of like page by page in a book," Lea said. That's not exactly true, though. "You can have a sedimentary surface in which nothing happens for 20 years, and then a storm deposits a lot of stuff....The challenge is to piece together the entire story, if you will, recognizing the information you have is incomplete."
Back at the Bowdoin lab, they'll test for the amount of organic material in the sediment, and do some pollen and fossil analysis, but they'll send it out to commercial labs for radiocarbon dating and metals analysis. In the upper part of the cores they've taken, they can see a definite change in color and texture of the soil, so even before the analyses, Lea can tell that there's a record of environmental change. But they don't know yet whether that change was natural or caused by humans.
"We're seeing changes in the cores and patterns from site to site that lead us to believe we're going to have some kind of story, although until we get the data back, we're not exactly sure what that story is," Lea said. The results of those analyses, combined with insight from the environmental history, will help them determine the next step in their research.
Working on Water
But plants and soil are only a part of the Bay's story. Perhaps even more important is water.
At 8:30 on a September morning, Reblin and Souther arrive at the Brunswick boat launch and begin to rig the boat donated by Mel Weiner '45 for research on the Bay. They load the usual equipment and set up a crane Reblin constructed to lower their tools into the water. They put in and motor out onto the Androscoggin, passing under the old, rusted railroad bridge, then the newer bridge connecting Brunswick and Topsham. Rays of sun slant down through the clouds, and the reflections of the trees, shore, and clouds, look up from below.
They have five transects at the Androscoggin - the Chops, Abagadasset Point, the Abagadasset River, and the Cathance River - where they pull samples from across the width of the water and at a number of different depths. They've done this so often that there's very little conversation. Most of the communication is understood, or brief. At each point Souther lowers a collection bottle and sonde, which instantly measures salinity, temperature, pH, dissolved oxygen content, turbidity, and fluorescence of the water. Later, they'll analyze the water they collect for total carbon, inorganic carbon and nitrogen content.
When it isn't being used to collect water, Lea takes the boat and an Acoustic Doppler Current Profiler (ADCP) out for all-night drives around the Bay to log data on water flow. The Luce grant allowed the College to purchase the ADCP - a pretty nifty gadget for a geologist and one that Lea is thrilled to have.
"You get just an incredible wealth of information from this thing," he said, "so it's kind of fun."
Lea drives back and forth across the Chops and then around in a circle for a 12-hour tidal cycle, the submerged machine gathering information about the currents all the while. The ADCP sends out an acoustic pulse along four beams, then listens for a return signal scattered back from particles that move in the water. For stationary sources, the frequencies come back the same; for sources that are moving, the frequencies are different depending on whether the object is moving toward the ADCP or moving away. A computer program uses the sound waves to display a three-dimensional picture of the current.
Though it's a long night out on the water, Lea finds it good for his creativity. "It was very useful for me to be out there for a full 12-hour tide cycle...as the stuff comes in, it just generates ideas," he said. "You're not just sitting back catatonically doing it, you're engaged in it."
Because the Bay is affected by both tide and river flow, the currents are quite complicated. Near the Chops, where water from the rivers and ocean converges, Lea has found that currents moving in from different directions hit each other, forcing some of the saltier water downward. Items like foam, logs and plants that aren't forced down collect on the surface. This flow structure makes water sampling more complicated, which is why Reblin and Souther collected samples at so many locations.
"Water flow on Merrymeeting Bay really underpins a lot of the ecological processes," Lea said. "We're essentially just trying to understand what drives that water flow." He's already learned that general perceptions of the Bay aren't necessarily accurate. Lea said many people tend to think of the Bay as the convergence of two big rivers, but the data show that river flow accounts for only about 10% of water moving through the Chops.
"The big message, I guess, for us is just that Merrymeeting Bay can be characterized as a tidal system that's influenced by river flow," he said, "as opposed to a river system influenced by tidal flow." This means the tides can actually change the direction of river currents. "It's not like they're just sort of slowing the river flow down on the way to the ocean, they're actually halting it and reversing it," Lea said. "It's a complicated system and we're just scratching the surface."
From their data collection near the Chops, they were able to distinguish three water masses - from the Kennebec, Androscoggin and the ocean - but the water from all sources mixed together, so there wasn't a lot of variation in the salt content. Sonde measurements also seemed to stay consistent at every depth, so they won't have to take water samples at every depth and every site in the future, which will make their sampling more efficient.
In addition to understanding water flow in the Bay, the researchers have discovered an important service it seems to be providing - protecting the Gulf of Maine from nutrient pollution.
Municipal and agricultural waste can put too much nitrogen in the water, which in turn leads to eutrophication - the growth of plants that suck the oxygen out of the water, harming other organisms. The Bay has many shallow, anaerobic places that allow bacteria to convert pollutant nitrogen to atmospheric nitrogen, and they've found that only about 89% of the nitrogen flowing into the Bay is flowing out into the Gulf. Over the course of a year, Lichter said, that 11% would translate to about 300,000 pounds of nitrogen kept out of the Gulf of Maine.
While the ADCP and sonde have allowed the researchers to get information on the move, they hope to set up a network of fixed locations to collect information over time. This will allow them to see the nutrients coming into and going out of the Bay, which will help them determine what's happening inside it. This would also enable them to see what happens when a storm hits the Bay. But for now, they're only a year into the work, and just getting started.
"A lot of it is just basic exploration and inventory of what's in the Bay, because no one's ever done it before," Lea said.
Though Merrymeeting Bay itself is an important local resource, it hasn't been methodically studied. In fact, Lichter has found only two articles dealing with the Bay in peer-reviewed journals in the last century. The Luce grant will support the work for three years, at the end of which Lichter hopes to have data to support an application for a National Science Foundation grant to fund the program for even longer.
"Understanding the legacies of Merrymeeting Bay's past would be cutting edge science in my view," Lichter said.
Some of the changes wrought by that past are evident, and permanent. For example, the Bay is shallower than it once was because of soil erosion caused by the cutting of forests. Others are less visible - like the pollution that still makes fish from the Bay unsafe to eat. But perhaps those effects can be reversed, if nature is given enough time. The Kennebec was upgraded last year to a Class B from a Class C river, demonstrating the vast improvement in its health. It was a Class E back in the '50s and '60s, Lichter said, which is as low as river classifications get. This means that pollution laws will now kick into effect to help ensure the river stays clean. The Androscoggin is still a Class C river, but it too was once an E.
Scientists working at Merrymeeting Bay aren't necessarily seeking a eureka moment at the end of the research. In fact, there won't necessarily be an end to the research. As part of what Klingle called the "buzzing, growling, biting, stinking world that surrounds us," the Bay is ever changing.
When the researchers talk about Merrymeeting Bay, you can sense the excitement they feel about this work. They often call it a "living laboratory," one that gives them a chance to work in a dynamic system with a complicated past, and to share that experience with students and colleagues.
"The world doesn't divide itself neatly into academic disciplines," Lea said. "For me, it's kind of a tangible project that gets at something I feel strongly about: that you have to approach these environmental and scientific problems from an interdisciplinary standpoint."
Merrymeeting Bay at a Glance
A. McCollum Algeo, a former member of Bowdoin's communications staff, is a freelance writer living in Los Angeles. She can be reached at firstname.lastname@example.org.