Deep Dive Into Noninvasive Biometrics: A Pilot Journey Using Stereo-Video in a Public Aquarium

Area of Science:

• Marine biology
• Ichthyology
• Conservation science

Background:

• Accurate biometric data are crucial for marine organism biology and conservation.
• Traditional methods of data collection are invasive and stressful.
• Noninvasive techniques like stereo-video photogrammetry offer accurate measurements but are underutilized in aquariums.

Purpose of the Study:

• To pilot a low-cost, house-made stereo-video photogrammetry system in a public aquarium setting.
• To assess the feasibility and accuracy of this noninvasive technique for multiple marine fish species.
• To evaluate its potential for improving husbandry and ex situ conservation efforts.

Main Methods:

• A diver-operated stereo-video system (stereo-DOV) was adapted and deployed in a public aquarium.
• Biometric data (total and fork lengths) were collected for 31 teleost and 16 elasmobranch species.
• Measurements were estimated using specialized software and compared to actual measurements.

Main Results:

• Over 100 individuals across multiple species were measured in approximately one day.
• High root mean square (RMS) values (>20 mm) indicate technical limitations.
• Methodological discrepancies were minimal, ranging from 1.37%-5.5% compared to actual measurements.

Conclusions:

• Stereo-video photogrammetry is a viable, cost-effective, noninvasive method for marine fish biometrics in aquariums.
• Despite technical limitations, the technique provides accurate length estimations crucial for husbandry and conservation.
• Further refinement of the system can enhance its application in ex situ studies.