Figure 14. — Streaming net just before lowering (see 

 text). This is a 1-m net only. 



acidity of plankton in Formalin is added — 

 20 ml per quart — (saturated solution of so- 

 dium borate in seawater). The jar is iilled 

 almost to the top with seawater, capped, 

 and shaken to insure a good mixture of pre- 

 servative and plankton. 



Note: Full-strength formaldehyde aboard ship is 

 kept in 5-gal polypropylene carboys (see Table 1 

 for source of supply). With the carboy moored 

 securely above the sink (Fig. 16), the preservative 

 is drawn by siphon action. A further safety mea- 

 sure now adopted is to draw the formaldehyde via 

 a teflon tube into a 50-ml plastic syringe through 

 an automatic double valve (Fig. 17) — see Table 1 

 for source of supply. The buffer is added with a 

 20-ml plastic syringe fitted with cannula (a 

 "needle" without a point) . 



11. Inside and outside labels are filled out. (The 

 greater part of these might be filled out be- 

 fore a station is occupied. ) Inside and out- 

 side labels are illustrated in Figure 18. If 

 more than one jar is used for a sample, la- 

 bels are so designated — 1 of 2, 2 of 2, or 1 

 of 3, 2 of 3, etc. The number of jars used 



is noted in the proper space on the tow sheet 

 (see 14d below). 



12. The cod end(s) is washed (it may be left 

 everted) and replaced on the net(s) in 

 preparation for the next tow (Fig. 6) . 



13. Before leaving station the meter(s) is read 

 and recorded as the final reading at item 13, 

 and the initial reading, item 14, is sub- 

 tracted from item 13. 





Figure 15. — Rinsing dovm plankton after net tow, before 

 removing cod end with sample. Note: Cod end should 

 be removed after it is hung from the ship's rail as shown 

 in Figure 6. 



16 



