Surveys
of sessile benthic communities
using the video technique
Standard
operational procedure 2
TRAINING
Training personnel in the field
video technique can be achieved by following the instructions
in this manual and supervising trainees as they prepare the
equipment and conduct trial video transects in the field.
Competency with the video technique, requires familiarity with
the video camera and housing and experience at filming at a
constant height and speed along the transect. Proficiency in
SCUBA diving (especially buoyancy control), is necessary to
enable the filming technique to be rapidly acquired.
Extensive training is required
for consistent analysis of video footage. Analysis requires an
understanding of AVTAS software and proficiency in the
identification of sessile reef benthos. This is facilitated by
discussing and scrutinising video images in the laboratory
with the trainee. Training should cover the following
components:
1.
Preparation of the video equipment
- Care and maintenance of
camera equipment before and after field work.
- Operation of video camera
and housing.
- Maintenance of the camera
equipment during field work.
2.
Sampling reef benthos using the video technique
- Learning the correct
sampling protocol.
- Practice to attain constant
swim speed and camera position.
- Practice to choose best
filming path along the transect.
3. Data
entry
- How to time-code and
catalogue tapes.
- Use of the AVTAS database.
- Use of training software to
standardise identification of benthic lifeforms.
Most of these objectives are
met by supervision of new personnel in the field and the
laboratory. While training software is still being developed,
the procedure followed to obtain consistency between observers
is for the experienced person and the trainee to duplicate
tape analysis for different reef environments. Where
discrepancies occur, observers should confer to resolve
difficult areas until an acceptable degree of precision is
acquired.
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