All sites were sampled during daylight hours 

 about once a month. The depths sampled varied 

 among the areas, but all sites were sampled at 

 discrete depths between 10 and 70 m, several were 

 sampled between 10 and 120 m, and one site be- 

 tween 5 and 150 m. When considering seasonal 

 changes, winter was defined as January-March, 

 spring as April-June, summer as July-September, 

 and fall as October-December. Sampling effort was 

 essentially the same at a given site and depth over 

 all seasons. 



Diel (24-h) studies were conducted at West Point 

 in central Puget Sound (Figure 1) on 4 Nov. 1975, 

 13 Feb. 1976, 15 May 1976, 20 Aug. 1976, 19 Nov. 

 1976, and 5 May 1978. These six studies involved 

 sampling at depths of 5, 15, 25, 35, 45, and 55 m 

 every 4 h. The data were grouped into six time 

 periods (Pacific standard time): 0400-0800, 0800- 

 1200, 1200-1600, 1600-2000, 2000-2400, and 

 2400-0400 h. 



In addition to the major sampling effort at the 

 seven sites, a 24-h study was conducted at Eagle 

 Cove (San Juan Island) in northern Puget Sound, 

 and some daytime sampling was conducted in Port 

 Townsend Bay (Figure 1). 



All ratfish were counted, and length (measured 

 to the end of the second dorsal fin ), weight, and sex 

 recorded. 



Results 

 When all months were combined, data from the 



seven principal sampling sites indicated that 

 ratfish were most abundant in the 55-95 m depth 

 range. Hauls from depths <50 m and >100 m 

 generally had a lower catch per unit effort of 

 ratfish than those made at intermediate depths 

 (Figure 2). 



Port Townsend Bay was an exception to this 

 pattern. Ratfish from this shallow-depth area (< 

 30 m) were sampled during June, August, and 

 September 1978. In a total of 60 hauls at depths 

 from 3 to 27 m, 182 ratfish were caught. This 

 relatively high abundance of ratfish (3.03 fish/ 

 haul ) in shallow water was in direct contrast to the 

 scarcity of ratfish in <30 m at the other sites (1.31 

 fish/haul). (Actually, this latter average may be 

 inflated by a few abundant hauls at Port Madison 

 in the spring. If the Port Madison hauls are omit- 

 ted, the average drops to 0.70 fish/haul). Not only 

 was there an unusually large number of ratfish in 

 shallow Port Townsend Bay, but the fish seemed to 

 be selecting shallower water within the bay, be- 

 cause peak catches occurred in water only 10 m 

 deep. 



With the exception of the Port Townsend Bay 

 samples, the basic depth distribution pattern was 

 similar at the seven major sites. However, the pat- 

 tern was subject to seasonal and diel variations. 

 Catch per unit effort of ratfish was generally high- 

 est in spring, declined during summer and fall, 

 and increased again in winter (Figure 3). This 

 pattern was matched by a minimum average 

 depth of capture in spring (70.5 m) and a maximum 



3 

 < 



X 



X 



< 



cc 



3 



o 



1 : MUKILTEO 

 2- PORT GARDNER 

 3= PORT MAD ISON 

 4^ DUWAMISH HEAD 

 5= POINT PULLY 

 6= WEST POINT 

 7= ALKI POINT 

 8= PORT TOWNSEND 

 BAY 



Figure 2. — Daytime depth distribution 

 of ratfish at eight sites in Puget Sound, 

 Wash., throughout the year. 



60 90 



DEPTH (M) 



818 



