Table 2. — Sand dollar catches off the Oregon coast in kilograms per 10-min dredge haul and density (number of sand 



dollars) per square meter, September 1969. 



' Approximate midpoint of hauls. 



- Dashes ( — ) indicate that no haul was made at the station. 



3 Live specimens, all others were dead (empty tests). 



4 Catches which were sampled for width measurements. 



6 at 24-27 m, and 8 at 29-37 m. The second sur- 

 vey was conducted in September between Coos 

 Bay and Newport, Oreg. Eighty hauls were 

 made: 14 at 9 m, 16 at 14 m, 16 at 18 m, 17 at 

 23 m, and 17 at 27 m. The areas sampled were 

 uniformly spaced along the coast, approximate- 

 ly 7.4 km (4 nautical miles) apart. 



Sand dollar catches were weighed using a 

 dynamometer on the first several hauls of each 

 of the surveys. Weights of catches were estimat- 

 ed on the remaining hauls according to the por- 

 tion of the cod end and dredge that was filled. 

 During the Washington survey, which was 

 largely involved with development of dredging 

 techniques, no data were collected on the pro- 

 portion of live and dead specimens. On the 

 Oregon survey the incidence of live specimens 

 and "empty tests" (dead specimens) in each 

 haul was recorded. Also width measurements 

 were made on five samples of live specimens 

 taken at a depth of 9 m. Sample sizes varied 

 from 136 to 310 individuals. 



Results 



Washington. — Nearly all the D. excentricus 

 were taken in the two shallowest depth inter- 

 vals — 9-10 and 13-15 m (Table 1). No sand 

 dollars occurred in hauls made at depths greater 

 than 18 m. The largest single catch, 1,209 kg 

 (2,666 lb), occurred in a depth of 15 m off Ocean 

 City (lat. 47°05.0'N), and catches of up to 454 

 kg (1,000 lb) were taken in 9-11 m just south of 

 the Willapa Bay entrance (lat. 46°34.5'N). The 

 average density in each ofthe above two sampling 

 areas was over 26 sand dollars per m-.'^ 



Oregon. — There was a consistent pattern in 

 the incidence of live and dead (empty test) sand 

 dollars with increasing depth in Oregon waters 

 — only live animals were taken in the shallower 

 water and only dead animals were taken in 

 the deeper water (Table 2). The largest catch 



^AU estimates of numbers of sand dollars from weight 

 of specimens based on an average weight per specimen of 

 30 gm (15.1 specimens per lb) . 



1108 



