Human Impacts on Tidal Wetlands: History and Regulations (Part 2) (Part 1)

 In 1985, Connecticut abandoned maintenance ditching in favor of a lower impact and more ecologically sound approach known as open marsh water management (OMWM). Mosquitoes are now controlled by Fundulus and other native minnow species which live in newly created, permanent, deep water ponds. The ponds are constructed only at those locations where mosquitoes regularly breed, and act as reservoirs to keep the fish on site and alive during low tide periods. The small fish leave the pond during high spring tides to feed voraciously on mosquito larvae on the high marsh. In some situations ditches are plugged with a sill to maintain a continuous source of water for the minnows. In addition to controlling mosquitoes, OMWM is also a simple yet effective marsh restoration technique. The abandoned ditches will slowly fill, allowing restoration of pre-ditching hydrology, and the construction of ponds replaces those that existed prior to their draining by the ditching.

Tide gates were also used in an attempt to control mosquito breeding by draining the salt marshes. Unfortunately, this caused significant impacts to tidal wetlands and eliminated the critical tidal link between marshes and the adjacent estuary, and thus limited productivity. Ironically, the only effect of tide gates on mosquito populations was to replace breeding by salt marsh mosquitoes with breeding by freshwater mosquitoes.

Flood Reductions and Landfills
Tidal gates have also been used to reduce coastal flooding in locations such as Pine Creek in Fairfield. Several thousand hectares of Connecticut wetland have been degraded in this manner. Draining causes the soil salinity to become fresh or nearly fresh and soil moisture to decrease. This creates ideal conditions for the replacement of the native marsh grasses by the tall Phragmites or Common Reed (Phragmites australis). This grass not only reduces plant and animal biodiversity, but creates a fire hazard (Fig. 5). Drainage enhances peat decomposition and leachate from this process and can also have negative effects on water quality (see the Tidal Wetland Restoration chapter).

Tidal wetlands were often a preferred location for municipal landfills. Examples include Farmill River in Shelton, Fletchers Creek in Milford, Pine Creek in Fairfield, Seaside Park in Bridgeport, Short Beach in Stratford, Sybil Creek in Branford and North Cove in Old Saybrook. On a positive note, a landfill proposal for Nells Island in Milford led to the protection of this, the largest unditched salt marsh in Long Island Sound, and its designation by the State of Connecticut as the Wheeler Wildlife Management Area.

 Fig. 5 Drained tidal marshes favor Phragmites, which is very flammable. (T.J. Steinke) (109K)
 

  TIDAL WETLAND LAWS

Level terrain, proximity to coastal water, saturated soil conditions and inexpensive purchase prices made tidal wetlands an easy target for development and alteration, especially in the twentieth century (Fig. 6). As early as the 1930s, wildlife biologists and hunters recognized the ecological value of tidal wetlands for species groups such as waterfowl and shorebirds, which led to the first concerted effort to protect tidal wetlands through acquisition. Examples include Barn Island, Great Island, Great Harbor Marsh, and Nells Island. Later, in the 1950s and 1960s, scientists and conservation groups began to recognize the ecological significance of tidal wetlands and the alarming rate at which these wetlands were being filled or dredged. In 1965, the Connecticut General Assembly appropriated $100,000 for marshland acquisition. In the same year, Massachusetts passed protective salt marsh legislation, and a group of concerned Connecticut citizens formed the "Save the Wetlands Committee," with the goal of providing similar legal protection for Connecticut marshes.

 Fig. 6 Projects like this salt marsh filling in Old Saybrook, 1970, are no longer permitted thanks to the Tidal Wetland Act. (W.A. Niering) (110K)

A look at the actual loss of wetlands helps put the push for legal protection of wetlands in perspective. Present day estimates place the total tidal wetland acreage for all of Long Island Sound at just over 8,456 hectares (20,895 acres ) with Connecticut's portion 84 % or 7,126 hectares (17,608 acres). Historic tidal wetland area in Connecticut around the turn of the century is believed to have been from 9,000 to 10,725 hectares (22,265 to 26,500 acres). Unfortunately, none of these historic estimates are accompanied by a methodology that explains exactly which wetlands were included in the calculations. The Connecticut Department of Environmental Protection (DEP) recently completed a wetland trend analysis by calculating wetland acreage for the same areas on both the 1880's Coast and Geodetic Charts and the DEP's 1970 wetland maps. Table 1 shows a clear trend from Fairfield, the most urbanized county, to more rural New London. Towns with over 60 percent tidal wetland loss include Stamford, Fairfield, Bridgeport, Stratford, New Haven and New London, many of which were major port areas in the past. Based on this new analysis, the average annual loss rate for the State over this 90 year period was approximately 28 hectares/year (70 acres/year). The total loss of wetlands State-wide was 30%.

Table 1- The amount of tidal wetland, by counties, in the 1880s and the 1970s, and the difference (losses) in hectares. One hectare equals about 2.5 acres.

The long-term loss and destruction of tidal wetlands ceased with the adoption of the Tidal Wetlands Act in Connecticut in 1969 (see Appendix) and in New York in 1973. These laws do not prohibit development in tidal wetlands, but rather require individuals proposing to conduct activities in wetlands to obtain authorization from the DEP (or the Department of Environmental Conservation in New York). In order for authorization to be issued in Connecticut, an applicant must demonstrate, and the Commissioner must find, that the proposed activity is consistent with all applicable statutory standards and criteria. Chief among these standards is to "preserve the wetlands and prevent the despoliation and destruction thereof in order to maintain their natural functions." Accordingly, activities which destroy and degrade wetlands, such as filling and dredging, cannot be authorized. The Connecticut standards further require an analysis of alternatives, which is used to identify means to mitigate any wetland impact. That regulatory programs can result in wetland protection is shown by the fact that in Connecticut permitted wetland losses currently average less than one-tenth hectare per year.

In both Connecticut and New York, detailed maps showing the boundaries of wetlands were initially used to identify regulated areas. Under regulation are the traditional tidal salt marshes found near the shore of Long Island Sound, tidal brackish marshes in areas where salt water mixes with freshwater, and tidal freshwater marshes, which on the Connecticut River may occur some 65 kilometers (40 miles) inland of the Sound. Lack of funding to update tidal wetland maps, and the need to regulate wetlands of fact regardless of mapped status, led to an amendment to the Connecticut Tidal Wetlands Act in 1990. The amendment eliminated the mapping requirement and clarified that the boundary of regulated tidal wetlands includes that area which is identified as meeting the statutory tidal wetland definition on the ground at the time an application is filed.

The Connecticut Coastal Management Act (CMA) provides supplements to the State's direct regulatory authority by requiring application of the same preservation oriented standards through municipal planning and zoning, and by requiring State review of federal activities. Specifically, any federal activity, and activities within coastal towns subject to planning and zoning review, must be found consistent with the tidal wetlands standards of the CMA in order to obtain authorization.

SUGGESTED READING

Tedone, D., editor. 1982. A History of Connecticut's Coast: 400 Years of Coastal Industry and Development. Coastal Area Management, Hartford, Connecticut. 75 pgs.

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