The motion capabilities by ROVs provides new possibilities in surveying methodology not capable by other deep-water (>30 m) or video-based survey techniques. ROV-based sampling strategies often reflected the aims of the study, which could be classified into six major types (Study at the University of Tasmania, Australia https://www.utas.edu.au/):
- Surveys in natural habitats,
- Surveys on artificial structures,
- Surveys in marine protected areas
- Opportunistic/exploratory surveys without the use of transects,
- Studies that evaluate the effectiveness of ROVs, and
- Studies that compare ROVs with other survey methods
ROV can make fish react in different ways, (attraction or avoidance). Studies suggest that most species (68%) behaved neutrally towards the vehicles. But the other 32% Responses to ROV are related to the following factors:
- Fish species
- Size-specific
- ROV Illumination
- Thrusters sound emission
- Speed of the vehicle
During Fish Census apart from the Size and Number the most important factor to check is fish health.
- Regular observation allows farmers to monitor welfare for fish, feeding processes, water conditions and fish behavior.
- Healthy fishes are profitable farms.
- Finding symptoms early by monitoring fish behavior, can reduce big losses.
- Infectious diseases are one of the biggest causes of Loss.
ROV surveys allow for systematic inspection of the sampling area. It is potentially useful where rapid assessments of species diversity within a complex habitat are required.
For more information please go to http://www.24marine.com/, and for many articles check www.fisheries.noaa.gov