Professors Teegarden and Green discuss effects of shoreline development runoff.
To many people, the Atlantic Ocean is simply vast, open water. To Greg Teegarden and Mark Green - professors of marine and environmental science - it is a vibrant world with a complex ecology. And the Gulf of Maine is their neighborhood.
"As a boy I spent my summer vacations on Cape Cod, walking around tide pools, fishing, digging for clams," Green says. "The passion never left me." For decades, both men have explored the Gulf of Maine, a stretch of sea that lies between Cape Cod and the southern tip of Nova Scotia, including the historically rich fishing grounds of Georges Bank. As boys, both Green and Teegarden played along the shore and fell in love with the sea.
As young men, both became intrigued with the ocean, its creatures and its importance to human well-being. Now, as scientists and fathers of young children, both are working to safeguard the Gulf of Maine so the next generation can continue to swim, fish, sail and work there.
"People are going to have to decide if they want to risk something they rely heavily on," Teegarden says.
The Gulf of Maine's water is cold and rich with nutrients, making the Gulf the perfect home for myriad kinds of marine life, including algae, clams, lobsters, ground fish and whales.
The region draws fishing and commercial industries, which look to the Gulf for income. The rocky, scenic coastline draws tourists, who sail the water or build homes on the shore. People have depended on the water for hundreds, and perhaps thousands of years. But that dependence - which sometimes leads to overuse and abuse - can harm the Gulf, say Green and Teegarden.
Dr. Mark Green conducted a 4-year research study on sediments in Casco Bay. Green points to the Casco Bay Estuary.
An estuary is a partially enclosed body of water that has an open connection with the ocean and is diluted by fresh water that feeds into it. As part of the Gulf of Maine, Casco Bay covers 578 miles of shoreline and includes the port of Portland. More than 850 species live there.
For hundreds of years, the estuary has proved valuable to fishermen, who make their livelihood from the water's world-renowned lobster, shellfish and fish. In the last century, Portland became attractive to tanneries, paint manufacturers, canneries and other industries. By the 1950s, the area had fallen into jeopardy because of that attention, Green says. The industries emitted air- and water-born pollutants, including heavy metals and untreated human waste. Parts of Casco Bay, and the rivers that fed into it, looked like an open sewer. The pollution altered the ecosystem and forced some marine life to seek better waters.
"When conditions on the sea floor degrade too much, you end up with less valuable species like worms," says Green, whose National Science Foundation-funded research on juvenile clam survival focused on Casco Bay.
In the 1970s, the Clean Water Act brought some relief. But as late as 1988, the Bay's toxin levels still rivaled those of America's worst city harbors.
In 1990, Casco Bay was recognized by the federal government as a "national treasure" and was included in the National Estuary Program. Residents, fishermen, environmental groups and others have worked since to improve Casco Bay. Maine officials recently said they would try to help by seeking to prohibit boats and ships from dumping their waste overboard.
The estuary has gotten healthier over the last 15 years, and a ban on sewage dumping from boats would help even more, Green states. But after so much abuse, it wouldn't take much to send the estuary and its marine life into an ecological tailspin again, making the water all but unfit for fishing or recreation, he adds.
"The Casco Bay Estuary needs to be taken care of," Green says. "It's an integral part of Maine."
Teegarden, who is intrigued by the very tiniest marine life in his National Oceanic and Atmospheric Administration-funded research on red tide algae, sees other possible dangers to the Gulf of Maine. He cites polluted runoff, over-fishing, introduced species and global warming as real threats that must be reckoned with.
Dr. Greg Teegarden studies red tide algae in the Gulf of Maine.
Intensive fishing has affected the ecosystem, according to Teegarden. Fishermen drag nets across the bottom of the sea floor to catch ground fish, such as cod and haddock. Those nets mow across fish habitats, kicking up the bottom and disrupting the habitat the fish rely on for food. While drag nets affect habitats, overfishing decimates the fish stocks themselves. Traditional regulations have not successfully protected fish stocks, and many species are at dangerously low levels, affecting both the ecosystem and the fishing industry that relies on the Gulf of Maine.
In some cases, the virtual lack of regulation has led to rapid changes in the ecosystem. It happened with sea urchins, creatures that were plentiful in the coastal waters of Maine until a market opened because of their popularity in Asian cuisine. "Nobody really worried about taking sea urchins. In little more than a decade, they were all but gone," Teegarden says. "We're affecting the food web. You can't remove a major component of the food web without affecting other species that either were preyed upon by that species, or that fed on that species."
Just as removing species harms the food web, so can introducing new species that shouldn't be there. It happened with the green crab, which 100 years ago came to the Gulf, multiplied and took food away from other species. Teegarden believes the same thing could happen with a number of species, including a new type of crab and foreign algae that have recently been found in the Gulf, both of which could invade and change the Gulf irreparably. "As a general rule, when you start removing sea life or adding, it has an effect on the overall health of the Gulf," he says.
Like Green, who worries about waste dumped into Casco Bay, Teegarden believes pollution is a concern for the entire Gulf of Maine. He says rainwater runoff from shoreline development brings chemicals and excess nutrients into the Gulf, which has many adverse effects, including potentially harmful blooms of algae and low oxygen conditions that can kill fish and shellfish. Other contaminants such as car exhaust residues, oil spills, and municipal sewage chip away at coastal water quality.
Then there are boaters who dump trash overboard.
"I've thrown a plankton net over the side of a ship hundreds of miles from shore, and found plastic in the sample. Plastic is everywhere," Teegarden says.
There's also the emerging threat of global warming. "The public has a general impression that there's a controversy over global warming, but the scientific community is overwhelmingly convinced, based on hard evidence, that the threat is real and considerable," says Teegarden. Although it's hard to predict what could happen specifically, warmer water on the surface generally means colder water is trapped deep down, making the area less productive. That could ultimately make it harder for fish to find food and for us to find fish.
Although Teegarden has concerns for the Gulf of Maine's future, he quickly points out that the all-out alarm bells aren't ringing yet. On a scale of 1-10, he puts the Gulf's health at a 6.5 - better than average, with room to improve.
He doesn't want to see it slide lower.
"The system can take some hits as long as you don't keep pushing it too far," he says.
Having spent their childhoods exploring the Gulf of Maine's shore and their adult lives researching its underwater dynamics, Green and Teegarden believe there are basic ways to safeguard its future. Green would like to see a law prohibiting boats from dumping their waste into Casco Bay. He also wants better public education about the area and how fragile it is.
Teegarden, who collaborates with the Friends of Casco Bay, believes better regulations on development and pollution would help reduce water contamination. He would like to see marine protected areas, similar to wildlife refuges, where fishing and industrial activities are restricted. Such marine protected areas currently exist in New Zealand, Canada and certain areas in the United States. He also notes that states like Maine are beginning to take the lead on greenhouse gas emissions and global warming.
Teegarden would also like fishermen and environmental scientists - historically adversaries - to work together to better manage the ecosystem.
"Although it's very difficult, we need to look at fish management from the ecosystem perspective, rather than looking at just individual stocks," Teegarden says. "The regulations we've been using for the past 50 years have adversely affected not just the fish stocks, but the fishermen themselves," he adds. "People have to fish harder for fewer fish, endangering the resource as well as the industry. We need to investigate new management approaches."
For the health of the ocean, for the future of the Gulf and its value to Maine, both scientists believe such things are a necessity, not a choice. "The Gulf needs to be protected and preserved to the very best of our ability," Green says.
• Editor's note: When it comes to which ocean fish to eat, Dr. Teegarden suggests avoiding swordfish and shark, which have the highest level of contaminants such as mercury and PCBs. He also recommends avoiding species that are dangerously over fished, like cod and haddock, or Chilean sea bass, which is being decimated. For more information, go to the MontereyBay Aquarium site at www.mbayaq.org. Click on Seafood Watch.
By Lindsay Day