19 

 18 



17 



_i 



<16 



X 



x15 



CO 



-14 

 < 



LU 



o 



11 



10 



SP 



W 



Figure 3. — Seasoned relationship between ratfish abundance 

 (CPUE, catch per unit effort) in Paget Sound, Wash, (data aver- 

 aged for the seven principal sites). 



average depth of capture in the fall (76.5 m). These 

 two trends indicate that ratfish move shallower in 

 the spring and deeper in the fall, perhaps beyond 

 the sampling range of this study. 



The 24-h studies gave evidence of a nocturnal, 

 onshore movement. Within the sampling depths of 

 5-55 m, the number of fish per haul ranged from 

 0.69 in the 1200-1600 sample series to 5.42 in the 

 2400-0400 series ( Figure 4). Although the samples 

 were taken at different times of year, sunrise was 

 always between 0415 and 0715 h, and sunset was 

 between 1615 and 1930 h on the dates when the 

 sampling was done. The data from the 24-h study 

 at Eagle Cove also showed a peak in nearshore 

 abundance after sunset and before sunrise, consis- 

 tent with the West Point data. 



The 24-h studies also provided evidence that 

 large and small ratfish were not behaving alike. 

 Although large fish were caught at night, there 

 was a decrease in average length (Figure 4) indi- 

 cating that the nocturnal onshore migration was 

 composed principally of small fish. 



Analysis of the combined monthly data from 

 West Point, Alki Point, and Point Pully indicated 

 that fish caught in shallow water were larger than 

 those caught in deeper water (Figure 5). This 

 trend was also apparent for the West Point 24-h 

 and Port Townsend Bay data as well. The samples 

 at Port Townsend Bay were from water <30 m 



=3 

 < 



x4 



I 



C/3 



< 



LLI 



u 



300 

 280 

 260 I 



X 



I- 

 240 ^ 



220 



IX 



200 



TIME OF DAY 



Figure 4. — Die! changes in abundance (CPUE, catch per unit 

 effort) and average size of ratfish caught in shallow water (5-55 

 m) at West Point, Puget Sound, Wash.; data averaged from six 

 24-h studies. 



O 



400 



370 



340 



310 



280 



IX 250 



220 



1 - POINT PULLY 

 2- ALKI POINT 

 3: WEST PO I NT 



20 



40 60 



DEPTH(M) 



80 



100 



Figure 5. — Relationship between depth of capture and ratfish 

 length in samples from three sites in Puget Sound, Wash. 



deep, and the average length was 360 mm (±74 

 mm SD), and no ratfish were <200 mm long. 



Sex ratios of ratfish at West Point, Alki Point, 

 and Point Pully were significantly (chi-square) 



819 



