62 
Fishery Bulletin 109(1) 
157°40'0"W 157°40'0"W 
Figure 3 
Distribution of (A) Etelis coruscans and (B) Pristipomoides filamentosus seen on the BotCam video 
at Penguin Banks, Hawai'i, between June 2006 and February 2007. Shown is the MaxNo (maximum 
number in a single frame) of each species seen at each camera deployment site, and the location of all 
82 successful deployments. 
Table 2 
Measurement statistics for testing the precision and accuracy of the stereo-video camera system. A BotCam video camera 
was used to measure four different models of fish of varying length (469.9 mm, 581.0 mm, 628.7 mm, and 997.0 mm) and 
body depth. The fish models were filmed in approximately 10 m of water off the South Shore of Oahu, Hawai’i, at distances 
of 3 m and 6 m from the cameras. The BotCam was rotated by a diver so that the fish traversed the field of view to simulate 
swimming. The models were moved vertically to obtain coverage throughout the fields of view of the two cameras and were 
measured at haphazard angles. Length measurements on each fish were made by three scientists (user 1, 2, and 3) using Vision 
Measurement Software (Geomsoft, Victoria, Australia). Error is defined by the following: Error = actual fork length-fork length 
measured by stereo-video (also called residual). 
User 1 
User 2 
User 3 
Total 
3 m 
6 m 
3 m 
6 m 
3 m 
6 m 
3 m 
6 m 
Number of measurements 
193 
113 
192 
134 
249 
0 
634 
247 
Average error (mm) 
-2.3 
-6.2 
-0.8 
-17.0 
-7.5 
na 
-3.1 
1 
CO 
bo 
Standard deviation of average error (mm) 
22.2 
50.8 
25.6 
42.0 
30.8 
na 
27.7 
51.6 
Percent error (%) 
-0.3 
-1.2 
0.0 
-2.2 
-1.1 
na 
-0.5 
-1.3 
