Abstract:
Unlike the commonly practiced Underwater Visual Census (UVC), the
potential of using video for reef fish assessment is still not widely acknowledged. A
study was designed to analyse the optimal dive time required in a video census
survey, to investigate the advantages and disadvantages of utilising transect strip for
video survey, and to identify the appropriate techniques of video census for coral reef
fish survey. When transect is applied, a strip instead of a line was created (50 m x 2 m
framework). For without-transect method, video were captured in a random line.
Detectability curves showed that the transect method requires more sample (four to
five samples) to obtain the maximum number of species than the no-transect method
(two to three samples). The total abundance of species observed with the no-transect
method is substantially higher and it gave more precise species counts than the
transect method. Both within-site comparisons are highly correlated (Spearman's rho
=
0.866 and 0.825).
