Table 1 . — Comparison of raw and recirculated water in the Tiburon sea water system . ' 



Salin- Tempera- 

 ity ture 



Sample C/oo) ( °C ) 



PH 



Total Recircu- Open 



phosphate Nitrate Nitrite latingflow flow Biomass 

 (mg/1) (mg/1) (mg/1) (l/min) (1/min) (kg) 



300 



240 



320 



400 



60 



55 



45 



200 



20 



30 



40 



340 



' Mean values, N = 2. Total system volume = 65,000 liters. 



30%o. Control can be maintained with up to 150 1/min 

 open flow. With an average bay salinity of 18%o and open 

 circulation of 75 1/min, a level 10 %o higher can be 

 maintained for $270.00/week (salt cost $30.00/ton, de- 

 livered). The cost of salt makes it mandatory to 

 recirculate most of the flow and to monitor open 

 circulation during periods of low bay salinities. It is 

 recognized that the unnatural ionic balance of the salt 

 used to increase salinity could cause problems with 

 sensitive invertebrates or fish larvae, although no prob- 

 lems have been encountered to date. 



No maintenance has been required except routine 

 calibration. It is expected that the conductivity probes will 

 need cleaning and replatinization every 2 yr, and the brine 

 tank will need cleaning every 2-3 yr. 



This seawater system has allowed us to hold and 

 maintain a wide variety of organisms including adult and 

 larval Pacific herring, adult and larval northern anchovy, 

 juvenile striped bass, juvenile chinook salmon, and other 

 bay fish and invertebrates. Organisms have been held for 

 up to 8 mo and used for determining effects of petroleum 



components on their physiology. Pacific herring and 

 northern anchovy have been reared from eggs to 

 juveniles. We have achieved our goal of year-round 

 research with near-oceanic quality water. 



ACKNOWLEDGMENTS 



I thank Robert Brocksen, Reuben Lasker, and Jean- 

 nette Struhsaker for review of the manuscript. 



LITERATURE CITED 



HERALD, E. S., R. P. DEMPSTER, and M. HUNT. 



1970. Ultraviolet sterilization of aquarium water. In W. Hagen 

 (editor). Aquarium design criteria. Special edition of Drum 

 and Croacker. p. 57-71. U.S. Dep. Interior. 



HETTLER, W. F., R. W. LICHTENHELD, and H. R. GORDY. 



1971. Open seawater system with controlled temperature and 

 salinity. Prog. Fish-Cult. 33(1):3-11. 



LASKER. R.. and L. L. VLYMEN. 



1969. Experimental sea-water aquarium. U.S. Fish Wildl. 

 Serv.. Circ. 334, 14 p. 



ti U.S. GOVERNMENT PRINTING OFFICE: 1975-699-555 / 5 REGION 10 



