KAPLAN, WELKER, and KRAUS: EFFECTS OF DREDGING 



In 1966-1967 salinities ranged from a mean 

 low of 26.79 7cc to a mean high of 28.34,^^0. The 

 pH ranged from 7 to 8. The dissolved oxygen 

 levels varied seasonally and from station to 

 station from a low of 4.50 ml 02/liter to a high 

 of 9.95 ml 02/liter. Readings were always at 

 saturation. The mean temperature range was 

 between -1.0°C and 26.18°C over the 2 years; 

 the bay is too shallow to exhibit a pronounced 

 thermocline. Portions of the surface were frozen 

 solid during parts of the months of February and 

 March, 1966, and January, February, and March, 

 1967. 



The tidal currents were relatively rapid in the 

 eastern section of the bay, reaching a velocity 

 of 56.7 cm/sec at station 1, at the confluence of 

 the three channels, but they rapidly lost velocity 

 until negligible readings were recorded in most of 

 the western half of the bay. 



Yearly rainfall (1967) amounted to 126.09 cm. 

 Pollution by effluents from cesspools along the 

 southern periphery of the bay consisted of fecal 

 material, other organic material, and detergents 

 as indicated by coliform bacteria and phosphate 

 levels. 



Previous Dredging of Goose Creek 



Goose Creek was chosen for this investigation 

 because of its unspoiled nature. This is a relative 

 term, however, and on Long Island, with its high 

 population density, it is unlikely that any bay 

 or inlet has escaped some form of dredging 

 operation. 



There have been a number of private drag-line 

 dredgings in Goose Creek reported by local 

 residents. The earliest incident described was a 

 dredging operation along channel A in 1930; a 

 1904 map of the region reveals, however, that the 

 general contours of the bay remained unchanged. 



The first officially recorded dredging in the 

 environs of Goose Creek performed by Suffolk 

 County occurred in November, 1959. A channel 

 approximately 500 m long and 30 m wide was 

 dredged from the bridge east by southeast into 

 Southold Bay as an aid to small boat navigation. 

 The depth of the channel was increased from 

 approximately 0.5 m to 3 m mean depth below 

 mean low water, and 35,653 m^ of spoil were 

 placed along the southeast shore of the inlet, 

 covering 20,920 m^ of Spartina marsh. 



Another area, smaller in size, received some 

 spoil from this dredging. It was contiguous 

 with what was to become spoil area C. 



The second dredging operation began on 27 

 June 1967 and ended on 2 August 1967. The 

 effects of that operation are the subject of this 

 investigation. 



A channel 23 m wide by 825 m long was 

 dredged from the bridge at the inlet to the bay in 

 an easterly direction along Channel B. A total of 

 57,383 m^ of spoil was removed and placed on 

 spoil areas A, B, and C. Spoil area A covered 

 approximately 6,000 m^ of Spartina and Phrag- 

 mites marsh adjacent to a previously used spoil 

 area of approximately 26,000 m^ covered to a 

 maximum height of 3 m above mean low water. 

 Spoil areas B and C in the southwest corner of 

 Goose Creek covered 44,640 m^ and 23,250 m^ 

 of Spartina marsh respectively. 



A third dredging took place from 22 December 

 1967 to 12 April 1968. A 15.25-m wide channel 

 was dredged to extend the previously constructed 

 channel across the bay to the cut opening into 

 the eastern shore. A small extension to an 

 existing channel was also dredged through the 

 center of Thyone Cove. The combined dimensions 

 of these extensions were 427 m x 15.25 m and 

 8,508 m^ of substratum were removed and placed 

 on spoil area B. 



During the spring and summer of 1970, drag- 

 line operations in the northwest corner of Goose 

 Creek obliterated 13,950 m^ of Spartina marsh 

 along a frontage of 152 m as site preparation for 

 a housing development. This was part of the 

 largest portion of the original peripheral marsh 

 which remained after the dredging operations 

 of 1967-1968. The only remaining marsh in Goose 

 Creek at the time of this writing was an area 

 approximately 16,000 m^ bordering the north- 

 western edge of the bay (see Figure 2). 



Estimates of the areas of marsh covered by 

 dredge spoil along the periphery of Goose Creek 

 can be seen on Table 1. 



An estimate of the remaining marsh in Goose 

 Creek comes to 43,826 m^ (islands) plus 23,715 m^ 

 (peripheral) or a total of 67,541 m^. This is 31.4% 

 of the total acreage covered by marsh in 1959. 

 Excluding the islands, only 10.7% of the 1959 

 peripheral marsh remains. Examination of a map 

 of the Goose Creek area drawn in 1904 reveals 

 that the entire periphery of the bay was sur- 

 rounded by extensive marshes. Probably less than 



447 



