The climate of the region is characterized by prominent seasonal temperature changes that produce distinct winters and summers; precipitation is evenly distributed throughout the year. The project area is also strongly influenced by the proximity of Long Island Sound, which modifies both summer and winter temperature extremes. The mean annual temperature of the area is about 51oF (10.5oC). Average winter temperature is about 32oF (0oC) with a mean monthly minimum of 23oF (-5oC) in the coldest month. Mean annual minimum temperature is approximately 0oF (-18oC). The average seasonal snowfall accumulation is generally around 76 centimeters (30 inches), with lesser amounts closest to the coast (river mouth). Frost-free season averages between 180-190 days. Average summer temperature is about 21oC (70oF); the warmest month has a monthly mean maximum temperature of about 28oC (82oF). Annual precipitation ranges from 109-117 centimeters (43-46 inches) (Brumbach 1965).
MOSQUITO DITCHING:
Throughout much of the northeastern U.S. during the first half of the twentieth century, nearly all salt and brackish tidal wetlands, including the project area marshes, were ditched for mosquito control purposes. While ditching did not destroy tidal wetlands, it did drain the marsh of standing water and in so doing reduced or eliminated pool, panne, and stunted smooth cordgrass (Spartina alterniflora) habitats. Stunted Spartina habitat is now known to be a critical habitat for seaside sparrows (Ammodramus maritimus). Presently, seaside sparrows are listed as a species of special concern in the state and a Federal species of management concern in the Northeast. The sparrows' low abundance probably reflects the reduced acreage of stunted smooth cordgrass associated with past ditching practices. There are virtually no natural pools and ponds occurring on ditched marshes in Connecticut. Studies have shown that wildlife diversity is greatest on those natural marshes containing pools and ponds, even through these critical habitat types originally covered only a small percentage of the total wetland area during prior to ditching.
WATER QUALITY:
Over the last few decades there have been tremendous improvements in the water quality of the Connecticut River. Many of these improvements are due to the establishment of secondary sewage treatment plants (STPs) for the major metropolitan areas, particularly Hartford in the late 1960's and Springfield in the late 1970's. Coupled with this were improved treatment for and sewage treatment tie-ins by industrial facilities. On a more localized basis, the establishment of STPs in Chester in the early 1980's and Deep River in the late 1980's and combined sewer overflow (CSO) corrections in Middletown and Portland, have improved the water quality in those estuarine segments of the river. Long-term water quality monitoring has shown reductions in turbidity, total organic carbon, total phosphorus, dissolved iron, dissolved zinc, dissolved nickel, and fecal coliforms. Oxygen levels have improved and nitrogen concentrations have increased slightly.
