Digital video techniques for assessing population size structure and habitat of greenlip and Roe’s abalone
To make more reliable projections on future catches of abalone, catch data needs to supplemented with an appreciation of what is coming into the fishery. This requires information on in-water stocks to allow predictions of new recruitment to be confirmed and recruitment failures to be identified.
Commercial divers have unequalled access to in-water stocks, particularly in remote regions. Although commercial divers regularly dive areas of interest, and could provide a cost effective means of monitoring stocks, this has been difficult to achieve because:
1) the traditional process for collecting data is considered non-independent (compromised) in the hands of commercial divers, and
2) divers perceive caliper and slate technology as slow, an undue interference and insufficient in coverage to supply representative datasets.
What is needed is an efficient, cost effective stock monitoring process that utilises commercial abalone divers, around the time of their normal fishing activities, to give fisheries managers and quota holders critical in-water information for the management of stocks. Recent preliminary trials, where researchers utilised digital video surveys filmed by commercial divers, clearly provides the potential for such a process.
Whereas researchers need such footage as a data source, the video also provides a mechanism for divers to 'ground truth' their own perceptions of change on surveyed reefs and convey what they are seeing to licence owners. Most importantly, such a system gives divers a further opportunity to contribute to stock management and reduce licence fees under cost recovery regimes.
Presently, video is played back and measurements are taken on two software packages. This process needs streamlining so that access to frames and measuring of abalone is time efficient. Measures and images generated from such a process need to be stored in an appropriate database, where they can be accessed through simple interrogation.