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BIOLOGICAL REPORT 31 



contamination by human wastes (Gale Associates 

 1989inSAIC 1991). InasimilarstudyforButteirnilk 

 Bay, most of the bacterial loading could be 

 accounted for by dog waste (Heufelder 1988). In- 

 puts from agricultural activities, notably dairy and 

 beef industries as found within the Westport River 

 watershed, may be locally important as an addi- 

 tional source of coliform bacteria, as increased lev- 

 els of coliform have been observed in the Westport 

 River. Without quantitative assessment of sources, 

 management can focus on the wrong sources, but 

 within the Buzzards Bay system determination of 

 the importance of surface runoff has led to a prior- 

 ity to address surface-water discharges through 

 rapid infiltration beds and is already showing posi- 

 tive results. New methodologies to deal with 

 stonnwater are being considered by several towns 

 around Buzzards Bay. The town of Bourne recently 

 installed an innovative filtration system that treats 

 initial road runoff (about the first few centimenters 

 of stormwater runoff, which contains most of the 

 pollutants) before it reaches bay waters, the first in 

 what is planned to be many stormwater remediation 

 projects around the bay. 



The difficulties in identification of specific sources 

 of coliform bacteria have led researchers and regu- 

 lators to also consider other potential direct dis- 

 charges. Discharge of untreated boat waste, while 

 not significant to nutrient loading baywide (cf Chap- 

 ter 6), is an important potential coliform and patho- 

 gen source. Although there has been an increase in 

 the use of pump-out facilities for boat wastes, el- 

 evated levels of coliform bacteria are still evident in 

 many marina areas. Recognition of the impact of 

 direct discharges is leading to zero discharge regu- 

 lations for Buzzards Bay; in 1992 the town of 

 Wareham had its coastal waters designated as a 

 Federal "no discharge area" by the EPA, the first 

 such designation on the East Coast. This designa- 

 tion prohibits discharge of untreated and treated 

 boat wastes and involves increasing boat pump- 

 out facilities and providing an expanded boater edu- 

 cation program. 



Regardless of the source of bacterial contami- 

 nation in Buzzards Bay waters, it is clear that there 

 has been a significant increase in shellfish bed 



closures around the bay over the past few decades. 

 These closures affect the recreational and commer- 

 cial shell fisheries and restrict many water-based 

 activities such as swimming and snorkeling. Increases 

 in restriction of shellfishing and swimming with in- 

 creased growth of the nonurban population within 

 the watershed are resulting in increased attention to 

 land use and management objectives to protect both 

 the public health and shellfishing, one of the most 

 important economic resources Buzzards Bay has 

 to offer. Fortunately coliform contamination, while 

 restricting resource use (swimming, fishing, etc.), 

 does not seriously impact the ecosystem and ani- 

 mal species of the bay waters. The consequence is 

 that finding and preventing future inputs will result in 

 rapid "recovery" of the bay's resources. 



7.3. Nutrient Loading 



The primary sources of anthropogenic nitrogen 

 inputs to Buzzards Bay are sewage treatment facili- 

 ties, on-site septic treatment of waste, and fertiliz- 

 ers added to lawns, golf courses, and agricultural 

 land (Fig. 6.4; Table 6.2). This nitrogen enters bay 

 waters through direct discharge, groundwater trans- 

 port, or stream flow (which often are supplied by 

 groundwater). Overall. Buzzards Bay is well-flushed 

 and at present maintains high levels of water qual- 

 ity. The smaller coves and embayments surround- 

 ing the bay, however, are the most sensitive to ad- 

 ditional nutrient inputs due to their shallow nature 

 and generally low-flushing characteristics (Table 

 1.3). These subsystems are of the greatest concern 

 as they support most of the commercial and recre- 

 ational shellfishing industries as well as much of the 

 recreational activity around the bay. and most of 

 the increasing population is settling in these areas 

 (Fig. 1.5). New Bedford Harbor and Buttermilk 

 Bay are examples of embayments that have experi- 

 enced high nitrogen inputs and are therefore con- 

 sidered to be relatively impacted, New Bedford via 

 its point source outfall and Buttermilk Bay via 

 groundwater-transported inputs. 



At present, only about 53% of the area in the 

 Buzzards Bay watershed suitable for building has 



