SEA-WATER SYSTEMS AT THE FRIDAY HARBOR 

 LABORATORIES OF THE UNIVERSITY OF 

 WASHINGTON 



By Robert L. Fcrnald, Director 



Friday Harbor Laboratories, University of Washington, San Juan Island, Wash. 



Abstract. — The Friday Harbor Laboratories are on San Juan Island, Wash., in an 

 area where the sea water is relatively free from industrial pollution and fresh-water 

 runoff. Three separate sea-water systems are in operation. Two have glass piping 

 over the span of 1,500 feet from pumps to laboratories ; the third has polyethylene 

 piping. Each has a hard-rubber centrifugal pump ; a 250-gallon, glass-lined receiving 

 tank maintains a constant head of pressure in the laboratories. The water enters the 

 laboratories with little or no change in temperature, or fauna. 



The field laboratories for marine sci- 

 ences at the University of Washington, 

 the Friday Harbor Laboratories, are lo- 

 cated on some 484 acres of shore property 

 on San Juan Island, Wash., approxi- 

 mately 80 miles to the north of Seattle. 

 The Laboratories were established in this 

 general area in 1904, and development on 

 the present site began in 1924, In recent 

 years, the past 12, we have had some expe- 

 rience in the design, construction, and 

 operation of sea-water systems which may 

 prove of interest to similar laboratory 

 operations. 



At present we have in operation three 

 more-or-less separate and independent 

 sea-water systems. However, two w^ere 

 designed in such fashion that the lines 

 may be interconnected and the water 

 mixed in delivery to the several smaller 

 laboratory buildings. The three systems 

 have a number of features in common. 

 All draw water from a single location 

 marked by the "cantilever pier" shown in 

 figure 1, on a point at the entrance to Fri- 

 day Harbor proper and projecting into 

 San Juan Channel along the east side of 

 San Juan Island. The sea water at this 



site is highly stable in temperature, is 

 well mixed, and is free of pollution and 

 fresh-water runoff. The intakes are in 

 the rapidly moving current of sea water 

 just below extreme low water level. It 

 is anticipated that in the near future the 

 intakes will be lowered an additional 5 

 feet to reduce clogging by free-floating 

 Ulva and other algae in late summer. 

 Each intake by w\ay of a 3-inch hard-rub- 

 ber foot valve is protected by a screen of 

 polyethylene. 



In addition the water in each system is 

 pumped by a hard-rubber-lined centrifu- 

 gal pump powered by an electric motor. 

 Both 5-hp. and Ti/o-hp. motors are in use 

 and are operated continuously when the 

 system is functioning. The suction lift is 

 approximately 15 feet at low water. In 

 each system the water is carried some 1,500 

 feet to the laboratory area wliere it is de- 

 livered to a 200-gallon glass-lined tank 

 outside the laboratories. The three receiv- 

 ing tanks are of the same small size to 

 avoid holding the water for any appre- 

 ciable period of time and thus risk marked 

 change in temperature of the water on un- 

 usually cold or hot days. Each receiving 



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