Coastal wetlands, especially tidal marshes, are some of our most productive and threatened ecosystems. To better understand these threats and people's attitudes about them, we surveyed wetland scientists, managers, educators and environmentalists for an overview of their concerns and perceptions. The results are varied and interesting, and when compared to the data on wetlands losses reported from various state and federal agencies, indicate a high level of understanding of these threats by respondents. The results also revealed some interesting trends and attitudes in different regions.
Coastal wetlands, according to Ralph Tiner (US Fish and Wildlife Service) and others, are low-lying areas periodically flooded by tidal waters for varying lengths of time. They are associated with barrier beaches, salt water embayments and tidal rivers along the coastline. They generally include tidal flats, salt and brackish marshes and tidal freshwater marshes, shrub and scrub areas and swamps, mangrove swamps, salt barrens or flats, intertidal rocky shores, beaches and aquatic beds. Although there are a great variety of coastal wetlands types, and many are regional in nature, flooding by tidal water is the common denominator of all of them.
NOAA, looking at the "big picture" expands this definition somewhat, including wetlands within the Estuarine Drainage Areas (EDA) as part of a Coastal Wetlands Area (CWA) stretching from upstream, freshwater areas downriver to the sea-grass beds. This is important for proper management since even those of us that are uninformed about the complicated issues involved in managing an ecosystem, understand that water (And the problems associated with it) flows downhill.
Perhaps the best example is Chesapeake Bay, North America's largest estuary, with a watershed that encompasses six states, nearly 22,000 square miles, and accounts for about 45% of the EDA of the Middle Atlantic coast. However just three percent of it is wetlands, only about a fifth of which is classified as coastal. These limited wetland resources are greatly affected by the urban, agricultural and forestry activities that occur on about half of the land area. They are also at the receiving end of over a thousand pounds of pesticides and fertilizers that are applied each square mile every year, hundreds of industrial and wastewater "point" sources of water pollution, and innumerable sources of "non-point" source pollution from millions of residents.
Although coastal wetlands comprise 30% of the wetlands types in the contiguous United States (about 27 million acres) they are not distributed evenly. Eighty-one percent are found in the Southeast, with more than half (51%) concentrated on the Gulf coast, and the remainder (30%) in the Southern Atlantic region. Nationally, the states with the most coastal wetland acreage are (in order of acreage): Florida, Louisiana, South Carolina, Texas, North Carolina, Georgia, Alabama and New Jersey. More than three-quarters of coastal wetlands in the contiguous states are associated with the wider, shallow estuaries of the East, and the largest concentrations are found in the Everglades-Ten Thousand Islands system in Florida, the Mississippi Delta region, and Albemarle-Pamlico Sound in North Carolina.
Despite their great size, Washington, Oregon and California, account for less than two percent of coastal wetlands. This apparent incongruity is related to the ruggedness of their coastlines, but human activities weigh heavily too and California leads the nation in wetlands loss, with a 99% reduction.
Alaska, because of its size, geography, remoteness and limited development, is an exceptional case with more than half of the nation's remaining wetlands; over 170,000,000 acres -- much of it in the Yukon and Kuskokwim river deltas. Despite having a coastline longer than the rest of the coastal states combined, estuarine and marine intertidal wetlands are a small percentage of the entire wetlands acreage in Alaska. About 2.18 million acres are classified as estuarine, including 48,000 acres of marine intertidal wetlands.
Coastal wetlands are elastic ecosystems thriving in a dynamic geologic province. They move, disappear and reform at a natural pace that is for humans, barely perceptible, but biologically and ecologically, is quite acceptable. Natural processes like shifting shorelines and changing sea level constantly alter them.
In spite of the great biological and economic importance of wetlands, most states have sacrificed significant acreage to development during the last two centuries. Nationally, about 58,500 acres have been lost annually in past decades. There is little data documenting the early rates of destruction during Colonial times, but as with most other wetlands, what remains is less than half of what existed in the 1700's.
In New Jersey, for example, more than 85,000 acres of tidal marsh disappeared since 1925. Much of it was filled at a tremendous rate, over 3,000 acres a year, typically for vacation homes at the shore, until the state passed the Wetlands Act of 1975. Today, losses are reduced to about fifty acres a year, mostly for public works projects like utility right-of-ways, highway construction and causeways out to barrier beaches in the southern part of the state. (Where we shouldn't be doing anything to encourage more development!)
Interest in conducting this survey was motivated by several factors. Certainly, the primary reason is that these are interesting ecosystems. (And what is more remarkable than a wetland?). Another was the opportunity to tap into a national audience -- members of the National Marine Educators Association gathering at their annual meeting. Third, is the lingering menace from efforts started by the Bush administration ("Bush the Elder") to redefine "wetlands" in a way that might result in further losses, despite his "No net loss" pledge. (A goal that the nation has yet to achieve.)
The information about wetlands presented here is a snapshot of the attitudes and concerns of a wide assortment of individuals from around the country. To develop some relevant questions and a list of knowledgeable people to pose them to, local wetland scientists and advocates were consulted for their opinions and ideas. Some especially helpful individuals who assisted and guided us include: Ken Thoman and Sue Draxler (Monmouth County Parks System) Linda Stefaniak (Allentown High School), Owen Hatteras (American Littoral Society) and Dr. William Niering (University of Connecticut and Humbolt Field Research Institute, Maine).
Predictably, because of their biological and economic importance, many people have strong feelings about wetlands protection and it was easy to generate survey questions. Our target "audience" was wetlands scientists, regulators and marine educators at the local, state and national level from all of the coastal states. They were contacted by direct mailings. In addition, we were able to fill in many blanks by surveying participants at the annual conference of the National Marine Educators Association.
Over 325 questionnaires were returned and evaluated. Any that were incomplete or had confusing responses were rejected. I'm compelled to share a few anecdotes to illustrate how interesting it can be to undertake such an endeavor.
Surprisingly, many of the respondents one might classify as environmental activists and advocates (Self-described bunny-huggers and the like) proved to be the most difficult to retrieve timely responses, and as a result, several mailings were done. Perhaps not too astounding, efficient administrators at the middle levels of government needed little encouragement to return the survey or pass it to a subordinate for action. (And, as they say, it wasn't even an election year.)
We received a particularly memorable deep throat phone call from a government employee of one state (Let's just say it has oil, deltas; and shrimp dishes and politics that are hot and spicy.) in which he cautioned us that he "could not get the approval of his superiors to participate" so he was passing along the questionnaire to a local environmental group.
Perhaps the most insightful response came from a Middle Atlantic bureaucrat who felt compelled to write a review of the questions and reorganize them and the choices into the "proper (alphabetical) order." (That was one destined for the circular file.) Regardless of their responses, all were thanked for their participation.
The occupational breakdown of respondents is as follows: Government and regulatory agencies (73.4%), Educational institutions (15.3%), Environmental and Advocacy groups (11.3%). Most respondents are paid staff (58.5%) and directors or supervisors (31.7%), and the remainder (9.8%) described as educators and naturalists.
Data was evaluated nationally then compared regionally, and ranked according to the number of first, second and third responses. The regions are: New England (ME, NH, MA, RI, CT), Middle Atlantic (NY, NJ, PA, DE, MD, VA), South Atlantic (NC, SC, GA), Gulf (FL, AL, MS, LA, TX), Pacific (AK, WA, OR, CA) and Islands (Hawaii, Guam and Puerto Rico).
The responses pertaining to the greatest threats to wetlands are divided into Human and Natural threats.
Wetland types are quite variable and are shaped by the environment according to location, hydrology, climate, soil and fire frequency. The ways that humans disturb wetlands are as diverse as the many types of wetlands that exist. Urbanization of coastal areas destroys wetlands and affects adjacent areas through: filling, dredging, the creation of impervious surfaces, increased runoff, sedimentation, nutrient loading and the introduction of toxic chemicals from point and non-point sources.
Home construction also affects wetlands through habitat loss, sewage disposal and the introduction of exotic or invasive species. Shoreline stabilization projects alter wetlands, especially in coastal areas, and isolates upland areas that wetlands can naturally "retreat to" as sea level rises. Roads and bridges can alter hydrology and affect the salinity of coastal wetlands.
Agricultural practices on existing and former wetlands can have significant impacts on adjacent wetlands. Although the "Swampbuster" provision of the 1985 Food Security Act discourages the conversion of wetlands to agricultural production, many "permitted" practices by farmers, like maintaining roads, ditches and drainage systems, timber harvest (silviculture), livestock grazing, and the application of fertilizer and pesticides, can interfere with wetlands function and impact wildlife.
In our survey, urbanization received the most first-choice responses nationally (23%); followed by non-point pollution (16%), vacation homes (10%), and agricultural development and dredge-and-fill activities (9% each). Other activities that are of concern include: commercial development (7%), shoreline stabilization (6%), agricultural and forestry practices (4%), industrial runoff (4%), sewage (3%), transportation corridors (3%), and two percent each for oil spills and primary residences.
Responses making up less than one percent of the tally were: industrial development, tidal flow restrictions, bulk-heading, fertilizer, land-filling and leaching of contaminants, pesticides and sedimentation.
Not surprising, some of these threats are more significant in different regions. For example: In the Gulf region, dredge-and-fill ranked highest among respondents. In New England and the South Atlantic, non-point pollution ranked highest. And in the Middle Atlantic States, vacation homes ranked second to urbanization. The threats presented by region are:
These opinions about threats to wetlands reflect some departure from the most recent USF&WS survey of documented losses from 1986-1997. Urbanization also topped that list with 30% of the acreage lost, but it was followed closely by agriculture (26%), silviculture and forestry (23%) and rural development (21%). This most recent data illustrates a continuing trend regarding wetlands loss. The previous surveys (1975-1985) found agriculture leading the list for wetlands disturbance and accounted for 54% of the acreage lost that decade. This is a decline from the previous two decades when agriculture accounted for 87% of the losses of coastal wetlands.
The population distribution of people near the coast is often cited as a major threat to wetlands; and indeed, more than half of Americans live in coastal counties and these areas have five-times the population density of inland areas. However, this distribution is not that different from observations made over 200-years ago by Thomas Jefferson. What is significantly different is the size of the population today. This, and society's needs, determines the impact on wetlands. Urbanization is simply the most recent chapter in our exploitation of these valuable ecosystems.
Coastal wetlands are altered by many natural processes like erosion and accretion, sea-level changes, grazing by wildlife, ecological succession, climate change and geological upheavals. In an undisturbed setting they are able to endure by migrating, responding to change and continually being re-established. Their ability to develop and thrive can be severely impeded by human activities like development along the coast.
In our survey, erosion (35%) received the most first choice responses nationally, followed by rising sea level (22%), exotic species (11%), storms (10%), invasive species (7%), subsidence (6%), accretion (2%), and overgrazing by wildlife (2%). Fires, flooding, groundwater depletion and soil loss received 1-2% each.
Louisiana loses between 16-25,000 acres of wetlands (an area larger than Manhattan) each year because of a combination of human activities like dredging, levee construction and dams reducing the amount of sediments that reach the Mississippi Delta. It is also subject to natural processes like subsidence and rising sea level, which also may be influenced by human activities. Not unexpectedly, among Gulf state respondents, erosion, subsidence, storms, and rising sea level are listed more frequently than in other regions. Surprisingly, respondents most areas listed exotics and invasive species as major concerns.The threats presented by region are:
Participants were asked to list invasive and exotic species that threaten wetlands in their state and the responses reflect the current regional distribution of just a minute fraction of the 4,300 alien or exotic species that are now thriving in the U.S. Some species listed have not yet reached any state (Brown tree snake in Guam). Another, Spartina alterniflora, is considered an exotic because it is an eastern species and has been crowding out western species where it is introduced in Washington and Oregon.
The impact of exotic species on native biodiversity can be especially pronounced in wetlands. Exotic and invasive species are often very aggressive and not only threaten the integrity of native communities and functions, they can completely replace them, as Phragmites (reed grass) has done in parts of the Middle Atlantic. This can reduce habitat and endanger local species, alter hydrology, and even have direct socioeconomic impacts, like increasing fire hazards.
Preventing the introduction of these pest species is critical because management programs for many of them are labor intensive and expensive, and have had only limited success. Estimates of the cost of controlling exotic species in the U. S. range as high as $138 billion (about $500. per person) each year. Louisiana is trying a novel approach to deal with the nutria or Argentine swamp beaver (Myocaster) by developing new recipes that encourage residents and tourists to sink their teeth into the problem and serve that South American rodent in new dishes. Unfortunately, few other target species are likely to be exploited this way.
The invasive, reed grass (Phragmites) topped the list in nine Northeastern states (CT, DE, ME, MD, NY, NJ, PA, RI, VA). Considered a probable native by some authorities, Phragmites (or an aggressive cultivar of the native) colonizes disturbed sites and crowds out more valuable wetland plants in others. Cattail (Typhus), a valuable wetland plant in many parts of the world is blamed for crowding out other marsh plants in Alabama and California.
Exotics reported as problem species in other states include: Annual grasses in California; Brazilian Pepper (Schinus), Melaleuca and Australian "Pine" (Casuarina) in Florida; Autumn olive (Elaeaguus) in New Jersey; Chinese tallow or Popcorn tree (Sapium) in Alabama and Texas; Pampas grass (Cartaderia) in California; Purple loosestrife (Lythrum) in Maine, Connecticut, Oregon, Washington, Pennsylvania and New Jersey; Reed canary grass (Phalaris) in Oregon and Washington; and Tamarisk tree or Salt-bush (Tamarix) in California.
Two bothersome plants are particularly interesting to me. One, because it is a good example of the complexity of the issue of exotics, and the other because it hits close to home. Water hyacinth (Erichhornia), labeled by some as the "world's worst aquatic plague", clogs waterways and is a nuisance to boaters. It has no enemies in Florida and Louisiana, except the manatee, which will graze on it. The manatee is threatened from habitat loss and because it is frequently injured by boat traffic.
The other plant of interest, Scotch broom (Cytisus), crowds out many native species in Oregon and the Pacific Northwest, and has little value to native wildlife. It was introduced to the West Coast by an expatriate Scotsman, a Captain Walter Grant (!) who also opened the first lumber mill in Vancouver.
The protection of wetlands is carried out at the national, state and local levels, and individuals have a significant impact by taking a proactive role in wetlands protection. Participants were questions about which protection and management methods they felt were the most effective in their state.
Nationally, 55% of respondents feel there is sufficiently strong public support for continued wetlands protection in their state. Regionally the responses ranged between 45% (Islands) and 75% (New England).
When asked if changes are proposed in their state's wetlands protection laws, 44% responded "Yes" nationally. Regionally the responses ranged between 25% (Islands) and 60% (Pacific). Of those who answered, "Yes", 67% felt that changes proposed in their state laws would make wetlands protection more difficult.
Some wetlands advocates still express concern about short-sighted "No net loss" policy and wetlands classification changes proposed by the Bush Administration, and 76% of respondents indicated such proposed changes in federal laws would make wetlands protection more difficult in their state. The highest level of concern expressed is from respondents of the Gulf, Pacific and New England states (85%, 84% and 65%, respectively).
When asked what programs are most effective in protecting coastal wetlands in your state, 37% of respondents nationwide rank state regulatory programs (state wetland protection laws) the highest; followed closely (35%) by federal regulatory programs like the Clean Water Act, River and Harbor Act of 1899, etc. Eastern regions tend to favor state programs whereas in the Gulf, Pacific and Island regions (Which also tend to have greater proportions of government-owned land) federal programs received higher praise.
Private programs like Ducks Unlimited and The Nature Conservancy also received high marks from respondents and ranked third nationally (9%), followed by federal acquisition programs (U.S. Fish &Wildlife Service, National Wildlife Refuges, etc.) with eight percent. Local and municipal regulatory programs (Ordinances, transfer of development rights, etc.) ranked fifth (6%). Surprisingly, state acquisition programs (open space bond issues, etc.) were last with four percent.
When wetlands are disturbed by human activities, mitigation is often required by government agencies. Mitigation is a last resort, not a substitute for wetlands preservation, and is a process to attempt to alleviate impacts on wetlands through:
Not all mitigation attempts are successful. For example, in New Jersey, almost half of these projects have failed, and the result has been a net loss of wetlands. Tidal restoration projects have the best track record, especially when initiated adjacent to existing, functioning wetlands. Forested and other freshwater wetland mitigation projects have not demonstrated great success, and some enhancement efforts have been controversial. The least favored options are Contribution or Mitigation Bank programs, which allow the destruction of a wetland, as long as there is no net loss in an area. A major concern is the scope of that affected "area" since it may allow the substitution of wetlands some distance away, reducing the value of the replacement.
Nationally, only 39% feel wetlands mitigation is a successful program in their state. In New England and the South Atlantic, half of respondents (50%) feel their state programs are successful, but significantly fewer in the Islands (25%) and the Middle Atlantic (26%) approve of their state's mitigation efforts.When surveyed as to the type of mitigation required, 56% responded restoration, 20% reported creation and 5% reported enhancement. The respondents were split almost evenly regarding the replacement requirements for impacted acreage (1:1 or 2:1) for their state. The National Audubon Society recommends that in cases when damage is severe or a mitigation site is separate from an existing wetland, the ratio should be greater, as high as 3:1 or even 6:1.
It is said that "wetlands work 24 hours a day, seven days a week" and the value of wetlands cannot be overstated or detailed adequately here. Participants were asked what features of coastal wetlands make them most valuable to your state? Their responses are fairly consistent and are: Habitat (25%), Water Quality (19.9%), Flood Control (16%), Recreation (11.5%), Erosion Control (8%), Storm Protection (8%), Aesthetics (6.4%) and Natural Products (3.9%). All regions listed Habitat as the top value that wetlands provide to their state, although Flood Control moved into the number-two spot in the Gulf, Northeast and Pacific regions.
Finally, participants were asked: Are there any coastal wetlands types that are unusual or unique to your state, or particularly threatened? Again, the responses reflect interesting regional variations.
Many respondents from different regions included "tidal marshes" as threatened. A large number also listed vernal, ephemeral, or isolated wetlands, which are more difficult to identify and protect. Significantly, destruction of some isolated wetlands is permitted under wetlands protection laws, so these are areas of particular concern. (Most importantly, these responses also gave me a complimentary guide to interesting wetlands worth exploring on my next vacation!)
Starting in New England, one encounters unusual raised peatlands (Coastal bogs) along the coastal strip of Downeast Maine. Dominated by dwarfed shrubs, sub-arctic plants and orchids, some of these actually drain directly into saltwater at the seashore. They are threatened by development, rising sea level and peat harvesting. In Massachusetts, Coastal Plain Ponds (Ponds without inlets or outlets, and which are tied to the water table) and Cranberry bogs (Natural peatlands dominated by cranberries and bog plants) are threatened by development, pollution, and draw-down of water tables from too many private and municipal wells. These areas harbor a disproportionate number of endangered species, including some that are globally rare.
Coastal fens were listed too. These were a new one on me and a bit of a puzzle, until a reticent Cape Codder, responded to my inquiry with a curious answer: "Why don't you ask the Red Sox?" Persistence on my part paid off and I was rewarded with another enigmatic response, but it helped describe them and the threats to them: "Ever hear of Fenway Park?"
In Rhode Island, Connecticut and New York, tidal ponds were listed most frequently, and these are threatened by development, pollution, bulk-heading and shoreline protection structures. Also in Connecticut and in New Jersey, Pennsylvania and Virginia, freshwater tidal creeks are threatened by pollution, utility rights-of-way, development and changes in tidal flow and hydrology. These limited sites, dominated by non-persistent plants like wild rice and arrowhead, and cattails, are some of the most valuable habitat for fish and migrating waterfowl.
Also in the Middle Atlantic region, ephemeral and isolated wetlands were repeatedly listed. These tend to be peculiar little shrub bogs, wet meadows and vernal pools with local names like spongs, pingos and pocosins (In New Jersey) and whale wallows, sea level fens and Delmarva bays in Delaware and Maryland. Although their method of formation is poorly understood, these wetlands are another variation of a coastal depression, dominated by deciduous trees, shrubs, grasses and sedges, some of which are quite rare.
In the South Atlantic region, Carolina bays and Maritime forests were listed. Carolina bays are unusual, elliptical ponds and shallow wetlands, dominated by evergreen "bay" trees, like sweetbay magnolia and redbay. Thousands exist on the coastal plains from Florida to Delaware, and some are quite large, but their origins are a mystery. Many have been filled for farmers or altered by timber harvesting. More than 97 percent of the Carolina bays once found in South Carolina have been destroyed or severely altered.
Dry and wet maritime forests are found on barrier islands and sea islands of the Carolinas, Georgia and Florida. Many oak and cedar maritime forests along the entire Eastern Seaboard were logged-out for ship building in Colonial times, and are today threatened by development, saltwater intrusion and erosion.
The Everglades or River of Grass (Emergent freshwater wetlands prevalent in South Florida) is threatened by agricultural development and runoff, freshwater diversion, saltwater intrusion, exotic plants, soil desiccation and fires. Florida mangroves (Forests of saltwater-tolerant trees with floating seeds) also are threatened by development. Although cutting mangroves is prohibited, some homeowners practice what is called locally, Midnight Blight to open their view to the water. Black mangroves along the south Texas coast (which grow farther north than other species) are threatened by coastal development on barrier beaches and die-off during severe winters.
In Alabama, there is concern for carnivorous plant bogs, peatlands with poor drainage, high acidity and insectivorous plants. Since they are isolated wetlands, they are threatened by farming and development. In Mississippi and Louisiana, concern was expressed for delta and riverine swamps and marshes. Besides problems like subsidence and rising sea level, lumbering is still an important industry along this part of the Gulf coast and threatens the remaining cypress and lowland forests.
On the West Coast, inter-dunal bogs were listed as threatened because they are restricted to a narrow band of coastline. These coastal peatlands are dominated by spruce and other bog plants. Wetlands in Alaska are the least threatened and most abundant in the country, but concern was expressed regarding oil development and transportation, and the inevitable spills that occur.
Island wetlands have not escaped threats from tourism and commercial development. Ephemeral wetlands were identified as threatened in Hawaii, and tourists should note that Waikiki beach (Which means "spouting waters" and referred to the many freshwater springs and seeps where taro was once cultivated.) has only hotel fountains remaining. Hawaii harbors many endangered plants and animals including freshwater species that have evolved there and rely on these threatened wetlands.
Respondents from Guam and Puerto Rico expressed concern over commercial development on the coast. In Puerto Rico, vacation home construction and agriculture, particularly sugar cultivation, threatens wetlands; and a proliferation of illegal houseboats threatens its mangroves, bioluminescent bays, and coral reefs.
Our attitude about wetlands has changed over the time. Once they were regarded as waste areas or valued only for the resources that could be extracted. George Washington devised a plan to try and drain the Dismal Swamp in Virginia to try and convert it to "productive" agricultural land. Wetlands were also feared as the lair of pirates, boogiemen like the Jersey Devil, or worse. The great ornithologist Frank Chapman wrote in 1895, "How many evenings have I tempted the malaria germs of the Jersey lowlands to watch the Woodcock perform his strange sky dance!"
Perhaps the first person to sound the alarm about wetlands loss was the Swedish botanist Peter Kalm, who in 1749, returning from a visit to North America, complained that colonists recklessly cutting 1,000-year old Atlantic white cedar would soon destroy the forests of New Jersey.
Because they are situated below the fall line and at the lower reaches of our rivers and estuaries, coastal wetlands will always be impermanent features on the landscape. Also because of their location, they were the first and some of the hardest hit wetlands modified and destroyed by human activities. They are usually the first casualties in the endless battle to tame our surroundings and because they are situated in our most densely populated areas, will always be impacted by our activities and natural processes.
After several centuries, we are still debating how to manage wetlands, although it should be apparent by now that they are our most valuable coastal resource and every effort should be made to preserve them. Addressing the issues and concerns presented here will influence the future of coastal wetlands, but in the long run it is necessary to increase the public's awareness of the value and threats to these special places. The best protection for wetlands continues to be public ownership and vigilance by individuals to insure that wetlands and the laws that regulate them are protected.
Note: Grant is the director of Brookdale College's Ocean Institute at Sandy Hook, and wrote the New Jersey version of Saving Wetlands: A citizens' guide for action, for the National Audubon Society.