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rate of siltation, and associated turbidity. 



Plankton Production 



One of the most marked contrasts betvreen the clear and turbid reservoiis 

 was in volume of plankton production. Samples were taken at 15-foot intervals 

 once each second or third week through both sunaners. The samples obtained 

 from Upper Spavinaw were not unusually rich for Oklahoma reservoirs, a fact 

 which further emphasitts Heyburn's deficiency. In 1954, the average volume 

 (Oo0085 milliliters per liter) of net plankton from the surface waters of 

 Upper Spavinaw was 13.5 times greater than the average (0.0006) from Heyburn. 

 Differences at both the 15- and 30-foot depths were similar, and the average 

 volume from the 60-foot depth at Upper Spavinaw was greater than txie combined 

 total from the surface, 15- foot, and 30-foot depths at Heyburn. The contrast 

 was less marked in 1955, the surface samples from Upper Spavinaw having approx- 

 imately three times the volume of samples from Heyburn surface waters, and the 

 15- and 30-foot depths ^aly approximately twice as great. 



Fishing Success 



Fishing at the two reservoirs differed distinctly in quantity and quality, 

 as well as in the methods used. Heyburn received quite heavy use from pic- 

 nickers and boating enthusiasts but very little fishing. It provides neither 

 the natural beauty nor the fishing opportunities to attract the vacation angler 

 and is utilized chiefly by local residents vrtio fished the creeks with pole and 

 line before the dam was constructed and who still employ much the same methods. 

 Bait casting for bass was occasionally rewarding in the upper creeks when the 

 streams were low and relatively clear, but bait fishing with cane poles, bank 

 and trotlines predominated. 



