UPPER NET 



MIDDLE NET 



LOWER NET 



s 

 o 

 o 

 o 



< 

 a: 



-PO 



lOll.. 



en 



^2ll_a 



hi -i, lll^ I ■nnl-t 



0600 1200 1800 0600 1200 1800 0600 1200 1800 



HOUR OF DAY HOUR OF DAY HOUR OF DAY 



Figure 11. --Average number of Pleuromamma , Neocalanus , and Candac la per 1,000 m. of water 



strained by the three nets on HMS-34. 



OBLIQUE HAULS AT TO 200 M. 



During HMS-34, hydrographic stations at 

 which zooplanliton was collected were occupied 

 on April 27 to May 7 and June 20-28, 1956 (fig. 

 17). At each station, a l/2-hour oblique haul 

 was made at to 200 m. with an open 1-m. net. 

 Collections were compared with those from 

 tows made at the same depths on CHG-24 (fig. 

 1) in November 1955. 



The data for this series are presented in 

 tables 15, 16, and 17 in the appendix. The av- 

 erage adjusted volume (cc. per 1,000 m."^) was 

 14.0 for the April-May stations and 15.4 for the 

 June stations of HMS-34; for the hauls at to 

 200 m. during CHG-24 in November 1955. it 

 was 12.4. The data from HMS-34 and CHG-24 

 are for different years and localities and there- 

 fore are not strictly comparable. As compared 



with the averages from similar tows for pre- 

 vious years (King and Hida, 1957; their fig. 7). 

 the averages for 1955 and 1956 were among the 

 lowest recorded for this type of tow (fig. 18). 



SUMMARY 



1. This report presents the results of a study 

 of the abundance and distribution of zooplankton 

 in Hawaiian waters in 1955-56. Collections 

 were obtained on eight cruises by vessels of 

 the Bureau of Commercial Fisheries and nine 

 cruises by the vessel Makua of the Hawaii Divi- 

 sion of Fish and Game. 



2. Two types of sampling gear were used: 

 three nets towed simultaneously at to 60 m., 

 70 to 130 m., and 140 to 200 m. (the middle and 

 lower nets had opening and closing devices), 

 and a single net (of the same type as the upper 



16 



