From the Forest to the Ocean
Interdependence and Human Action
by Ben Wildrick
As the poet John Dunne observed, no man is an island. Yet, in our specialized world, we run the danger of becoming experts in a narrow field, isolated from others. It is easy to focus on our own areas of expertise, or our own plot of earth, to the point that we ignore a broader perspective.
My elementary science students, grades one through four, work to achieve a wide-angle perspective of the ecology that surrounds our small, suburban school campus. As these students grow, they follow the movement of water from an upland forest through our schoolyard and eventually to a salt marsh. By following a small stream, my students gauge the impact of the school community on downstream habitats. In addition, they recognize (and are often surprised) that the tiny headwaters in our forest wind their way to the ocean!
One habitat at a time
When I ask where these headwaters go, my students usually respond, "Away." At their age, this ingenuous reply is honest and appropriate. Yet many adults continue to apply the concept of "away" to their world. Curbside trash is taken "away." Wastewater goes "away."Herbicides and pesticides applied to our yards go "away." Fortunately, people are learning that there is no place called "away." As inconvenient as it is, all our actions have downstream effects. As teachers we need to introduce the concept of a global ecology to our students. And this happens one habitat at a time.
In my classes, the journey starts in first grade as students examine the layers of the forest. In the leaf litter they discover the precursors to soil. Under layers of shed leaves, decomposers are hard at work composting. Like a crowded hotel, rotting logs provide shelter for a veritable soap opera of interdependent organisms. After a fall rain, my students notice a series of "big puddles.""Where did they come from?""This one is moving!" And with those questions our journey continues.
Toward the pond
Most of us have dropped a stick in a stream for the simple satisfaction of watching it float. It gets tossed by rapids and lulled by the deep, quiet sections. I have used the motion of a cork in our small stream to teach second-grade students about the movement of water. It doesn't really feel like teaching. We're having too much fun! The kids drop their corks into the stream and race to a still section. Their cries of joy and anguish increase as the corks either survive the rapids or get shot to the side of the creek, into a swirling no-man's-land. My students love to race. I wonder sometimes how far their corks would go if we didn't scoop them up with a net.
The stream leads to a small human-made pond, about 50 meters away. In addition to my second graders' boats, this stream carries sediment from the upland forest, dropping it in our pond as the waters slow.
Our entire school is drawn to the pond that over the years has sustained a varied community of organisms. My third-grade students frequent these waters in the fall and spring. They scream with glee when a green frog is sighted and are amazed at the large numbers of tadpoles that suddenly wriggle into view as they are touched by shadow, then just as magically disappear in the mud. Each fall these student chroniclers document our pond's cycles. They splash, slip, spy, measure, interview, predict, guess, share and imagine. This is the work of budding scientists.
Three years ago our pond faced an environmental catastrophe. A snowplow punctured a heating fuel pipe. The resulting spill flowed into our creek, pond and beyond. Owing to the quick action of our physical plant staff and an equally speedy response by the Coast Guard, the environmental damage was minimized.
The following day we were greeted by men in yellow suits and respirators in our pond, laying squares of absorbent material on the surface! This potentially disastrous accident turned into an important and novel learning experience for our students. Based on their knowledge of our watershed, my students concern first went to the pond, and then spread to the wetland and finally the salt marsh.
Because of health concerns immediately after the spill, we couldn't spend much time at the pond. However, we were able to use our noses (home heating oil has a distinctive odor!) and followed the flow of the accident. When my students found signs of oil in the salt marsh they were devastated. Back in the classroom discussions revolved around the effect of heating oil on pond, stream and salt marsh organisms. "How long will the oil stay around?" "How do they clean it up?" "Where do they take those 'diapers' in the pond once they're full of oil?" "How did this happen?"
To the salt marsh
As the rich waters of our pond continue their journey they pass through a wetland. The water spreads out and intermingles now with the earth, more intimately than before. Soil here smells different. Tree roots grow up and outwards to brace themselves in the mushy land. Plants like skunk cabbage and red maple thrive.
Imperceptibly the waters leave our wetland, purified, ready for the next destination. These waters collect and flow, under a roadway and into a salt marsh. Here the landscape changes radically. Trees and grass are replaced by salt hay and spartina. It's harder to move through this grass. There are no lawnmowers here, and boots are required. The flow that my students have followed seems to end. The muddy stream my first graders poked and prodded has gone through many transformations. Yet in a sense, the story of this flow is just beginning.
To the sea
Like the stream my students play and learn in, almost all rivers culminate in an ocean. While this may seem elementary, we are as a society ignorant of this fact and its implied consequences. A 2003 study by the Pew Oceans Commission clearly illustrated the link between ocean health and human activity along rivers. To study this link, the Commission focused on coastal Maine, the Gulf of Mexico and, oddly enough, the city of Des Moines, Iowa, some 1,000 miles from the nearest ocean! What the Commission discovered is startling: farm runoff has become the main source of pollution in the oceans.
Farmers in the mid-west use nitrogen to fertilize their crops. It's inexpensive and increases yield. But the fertilizer doesn't stay put. It seeps into groundwater and enters the Mississippi River as runoff. This process continues for over a thousand miles until the river dumps its load in the Gulf of Mexico. This is hardly a new issue. The National Oceanic and Atmospheric Administration (NOAA) studied this and issued a report in 1999. What are the consequences of this practice? The report's conclusions:
Nutrient overenrichment from human activities is one of the major stresses affecting coastal ecosystems. There is increasing concern in many areas around the world that an oversupply of nutrients from multiple sources is having pervasive ecological effects on shallow coastal and estuarine areas. These effects include reduced light penetration, loss of aquatic habitat, harmful algal blooms, a decrease in dissolved oxygen (or hypoxia), and impacts on living resources. The largest zone of oxygen-depleted coastal waters in the United States, and the entire western Atlantic Ocean, is found in the northern Gulf of Mexico on the Louisiana-Texas continental shelf. This zone is influenced by the freshwater discharge and nutrient flux of the Mississippi River system.1
The Gulf Coast region has already suffered wetland loss from oil and natural gas exploration and extraction. With the reduced storm-buffering effects of those wetlands, the coastal region is more susceptible to further damage from major storms. That the actions of a farmer in Iowa can influence the ecology of an ocean seems at first surprising. But the influence of ten thousand farmers?
In fact, all coastal ecosystems are threatened. According to the Pew Commission, more than half the U.S. population lives in coastal counties. The resident population in this area is expected to increase by 25 million people by 2015. Tens of thousands of jobs in fishing, recreation, and tourism in the U.S. depend on healthy, functioning coastal ecosystems. Clearly, this is a valuable resource worth preserving.
A fragile system
The Earth's oceans have always seemed limitless to humankind. Sailing and mapping them were the work of brave explorers who returned with tales that only heightened the awe and mystery surrounding these waters. The Pew report states with stark clarity, "What we once considered inexhaustible and resilient is, in fact, finite and fragile." (p.v)
Can racing corks in a stream help students develop a connection to the ocean? Did a fuel spill in our creek illustrate the precarious relationship we have with our downstream neighbors? Does squishy mud between your toes bring you closer to a relationship with your natural world? If the answer to any of these questions is, "no," I'd better start looking for another job! My aim is to help my students to, . . . recognize the interdependence of land and sea and how easily activities far inland can disrupt the many benefits provided by coastal ecosystems. (Pew Commission, p. vii)
We live in an age when the scientist and the poet have reached consensus: no man exists outside the natural systems that govern life on our planet. No man is an island.
©2007 Synergy Learning, Inc. All rights reserved.
Frashure, Kim. Estuary Trends and Conditions. Doctoral Dissertation (pending). University of Massachusetts.
Pew Oceans Commission, Leon E. Panetta, Chair, America's Living Oceans: Charting a Course for Sea Change, PDF from Pew Oceans Commission, 2003, http://www.pewoceans.org.
1. Rabalais, Nancy N., R. Eugene Turner, Dubravko Justice, Quay Dortch, and William Wiseman, Jr., Characterization of Hypoxia: Topic 1 Report for the Integrated Assessment on Hypoxia in the Gulf of Mexico, NOAA Coastal Ocean Program: Decision Analysis Series, no. 15, (May 1999), NOAA Coastal Ocean Program, http://oceanservice.noaa.gov/products/pubs_hypox.html.
Because of the benefits that estuaries provide, twenty-two of the thirty-two largest cities in the world are located on estuaries.
- Ben teaches science to first through fourth grade students at the Brookwood School. Located in Manchester, Massachusetts, Brookwood is a Pre-K-8 independent day school.