1996 Citizens Report: Rands Canal, Fiddler Cove, and Wild Harbor
Embayment: Rands Canal, Fiddler Cove, and Wild Harbor
Embayment and Watershed Characteristic
Rands Harbor, and Fiddlers Cove are two small embayments within Megansett Harbor. These two embayments have small watersheds, and the Buzzards Bay NEP has not evaluated watershed nitrogen loadings to these embayments which only have modest levels of development. Wild Harbor on the other hand, which lies between Megansett and West Falmouth Harbors in Falmouth, has a much larger watershed Rands or Fiddlers Cove, but smaller than most of the other Buzzards Bay embayments monitored. All three systems appear well flushed with offshore waters, although the upper reaches of Wild Harbor known as Wild Harbor River is probably less so.
In 1969, a tanker spilt fuel oil in Buzzards Bay which washed ashore primarily in Wild Harbor.
This was one of the larger oil spills to have occurred in Buzzards Bay and resulted in the closure
of Wild Harbor to shellfishing for more than two decades. Purportedly areas of marsh still
occasional release smells of fuel oil.
The Wild Harbor watershed includes densely built summer cottages in the Silver Beach area--many of which have now been converted to year round residences, and the less densely built and
older village of North Falmouth. Failed septic systems have been problematic, particularly in the
New Silver Beach area, and the town has sought to address this issue by draining wetlands and
has proposed to construct a small treatment facility to handle those homes that cannot meet Title
5 septic system requirements. The watershed for this embayment delineated by the Buzzards Bay
Project in the early 1990's shows that residential and commercial land covered a relatively high
45% of the watershed and accounted for 85% of the nitrogen loading to the estuary. The new
drainage basin delineated by the Cape Cod Commission based on more detailed groundwater
elevation data, suggests that the watershed is actually more than four times the size of the prior
estimate, but with more inland forested areas, so that residential and commercial land account for
only 38% of the landscape and 78% of the loadings. The larger watershed also results in more
than twice the nitrogen loading. Still, existing loading using this new land use data suggests that
Wild Harbor now receives only 36% of Project recommended nitrogen loading limits, and at
build-out conditions, would receive only 84% of recommended nitrogen limits.
Water Quality monitoring
In Wild Harbor, water samples were not collected for nutrient analysis so we have only the oxygen data to discuss. Oxygen was monitored at two sites in Wild Harbor. Site WH1 was monitored in all four years, but site WH2 was monitored only in 1992 and halfway through the 1993 season. This monitoring showed that oxygen saturation levels were generally very good, typically ranging from 70 to 90% saturation, with summertime means of 73% to 79% saturation, but in 1995, oxygen saturations showed a big drop, with many values in the 40% to 65% saturation range, and a summertime average of 59% saturation. The lack of data from station WH2 since mid 1993 could not account for the lower summertime mean oxygen saturations at WH1 and WH2 were comparable. Curiously, water transparency showed a slight improvement in 1995. Without other data such as nitrogen concentrations or phytoplankton pigments, it is difficult to interpret these results, but it is worth noting that several other embayments around Buzzards Bay also showed declines in oxygen saturations in 1995. It is possible that high water temperatures and overcast or other contributing weather conditions could have coincided with sampling days in 1995. Summertime salinities consistently ranged from 27.5 to 28.5 ppt (compared to 30 to 31 ppt offshore in Megansett for example), showing slight freshwater influence at these monitoring sites.Fiddlers Cove was monitored only in 1992 and 1993 for oxygen, and saturations observed there
were better than in most Buzzards bay embayments. In Rands Harbor, oxygen was monitored in
all four years, and like Wild Harbor, a big drop in oxygen saturations occurred in 1995 (mean
saturations for the four years were 82%, 81%, 89%, and 76% respectively).
Nitrogen Management needs
Because existing and future loadings to Wild Harbor appear to be well below recommended limits for Outstanding Resource Waters, nitrogen management action appears unwarranted. The declines in oxygen saturation in 1995 in Wild and Rands Harbors is intriguing and it is probably worthwhile to continue oxygen monitoring as well as to collect water samples for nutrient analysis once every several years to better put water quality conditions of these embayments in perspective.Back