METHODS 



Field work was carried out during September 4-7 1985, 

 September 8-0ctober 3 1986, and July 7-8 1987. Field work in 

 1985 was limited primarily to video documentation with the Mini- 

 Rover , but also included field observations of sediment samples 

 collected inside and outside egg beds at sites A and D (Figs. 2 & 

 3). Field work in 1986 was more intensive and included, in 

 addition to video observations, visual evaluation and analysis of 

 egg and sediment samples collected with a Ponar bottom grab 

 sampler deployed from the surface and, in depths of 25 m or less, 

 by SCUBA divers. Detailed bathymetric surveys were conducted at 

 sites F and K in 1986 with a depth recorder and, in July 1987, 

 with a side-scan sonar. A few additional sediment samples were 

 also collected with a Smith-Maclntyre benthic sampler at these 

 same two sites in July 1987. Although these samples were not 

 collected during the spawning season, information from the 

 previous fall was used to differentiate samples from inside and 

 outside the two spawning sites. 



The ROV was used in both years for reconnaissance purposes 

 and for surveying egg beds and spawning habitat. Reconnaissance 

 dives were of short duration (10-15 minutes or less) and were 

 used to confirm reports of egg deposition received from the 

 fishermen, to precisely locate where eggs were deposited, and in 

 1986, to locate bottom areas that were suitable for sampling and 

 to obtain video documentation of precise locations where samples 

 were taken, both with the Ponar grab sampler and by SCUBA divers. 

 In some cases, the ROV operator directed the grab sampling 

 operation from the vessel by observing where the grab was in 

 relation to the bottom and giving instructions for its final 

 descent into the substrate. The ROV was also used to determine 

 the extent of egg cover and to document changes in depth, bottom 

 topography and general substrate type at different locations 

 inside and outside of the egg beds. Special attention was paid 

 to the perimeters of the egg beds in order to determine whether 

 distinct changes in egg abundance could be related to changes in 

 bottom topography and/or substrate. A total of 43 dives were 

 made in 1986 in depths of 15-50 m, 12 at Libby Island and 25 at 

 the Little Machias Bay ( LMB ) site (Fig. 4). Thirty-one dives 

 were made in 1985 in depths ranging from 22 to 55 m at a variety 

 of locations. 



All dives were made from an anchored vessel using a 40 lb. 

 down-weight and either a short (10 ft) or long (100 ft) tether to 

 the ROV, depending on the state of the tide. Extreme tides in 

 this part of the Gulf of Maine produce maximum current speeds 

 along the coast of 2 knots at the surface and 1-1/2 knots at the 

 bottom (Townsend et al . , 1985). Transects as long as 1000 ft 

 were successfully made in strong bottom currents by simply 

 orienting the ROV downstream and maintaining visual contact with 

 the bottom as anchor line was paid out. One to two hour dives 

 with a long tether were made at slack water, using the down- 

 weight as a central reference point. Visibility in eastern Maine 



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