NSWC/WOL/TR 76-161 



of fish. It was decided to continue testing in shallower water 

 at the mouth of St. Leonard's Creek, about 6.2 km upstream from 

 Solomons, where fish were known to be more prevalent. 



3.4 Shot 3 



Shot 3 was also a 9.1 kg Pentolite charge, but it was 

 fired at a depth of three meters in 6.1 meters of water. The 

 shallower water depth, and the location near St. Leonard's Creek, 

 provided a higher fish population density than the site used for 

 Shot 2. 



The dead fish were distributed uniformly in the pool after 

 the shot, and samples were collected with a dip net from 60 to 495 

 seconds after the explosion. The data are summarized in Table 3.3. 

 Distances from surface zero are based on visual estimates and have 

 a possible 25% error. The area of fish kill extended about 320 

 feet (98 meters) from surface zero. 



A bottom trawl was run from about 20 to 29 minutes after the 

 shot. Trawling was difficult because of the 7 m/sec wind speed 

 and the 0.5 m swell. The data are summarized in Table 3.4 and a 

 comparison between the results of the two sampling methods is given 

 in Table 3.5. The times are listed in Table 3.6. 



Although the number of fish collected and the times reguired 

 are comparable in both cases, the percentages at each damage level 

 differ. This may not be significant because of the small number 

 of fish in each collection. It should be noted however, that only 

 a bottom trawl would provide data on crabs and oysters. The trawl, 

 of course, covers only a small fraction of the area of possible 

 fish kill. 



During the bottom trawl, ranges and bearings of the boat were 

 recorded from the experimental platform. These readings were not 

 very accurate because the eguipment was difficult to handle, but 

 the feasibility of the method was shown. The readings indicated 

 a trawl distance of about 1000 feet (305 meters) and an average 

 trawling speed of about 0.8 m/sec. 



3.5 Shot 4 



Shot 4 was fired at the deep site as a multi-purpose test. 

 The charge was 39.5 kg of TNT with a 1.8 kg Pentolite booster, which 

 may be treated as 41.3 kg of TNT for the purpose of this report. 

 The charge depth was 6.1 meters and the test took place in water 

 that was 25 meters deep. About 0.9 kg of fluorescein dye was used 

 to assure a clearly visible pool. 



Water samples were collected in the pool immediately after 

 the shot and the weight of suspended solids was determined at the 

 White Oak Laboratory. This was done because TNT usually leaves 



16 



