Periodic Reporting for period 2 - SYMBIOSIS (A Holistic Opto-Acoustic System for Monitoring Marine Biodiversities)
Reporting period: 2019-05-01 to 2020-12-31
The SYMBIOSIS system detects, classifies and estimates the biomass of six key fish species: albacore tuna, dorado, swordfish, Atlantic mackerel, Mediterranean horse mackerel and greater amberjack. These were chosen based on social and ecological criteria, such as their commercial importance and availability within the study areas. Additional considerations included catering for a variety of body size and type, swimming velocities and schooling behaviours. The SYMBIOSIS stand-alone, optical-acoustic solution operates autonomously, conserving energy for more than a month thanks to a design based on a chain of progressive steps. Periodically the system transmits a short, narrowband underwater acoustic signal. Signal processing and a neural network pick up any reverberations, indicating possible moving targets. If a target is detected, 20 wideband signals are then emitted with their reverberations analysed by a combination of dynamic programming and machine learning techniques. Within a detection radius range of up to 500 m, these tools verify the moving target is a fish, calculate its size, and estimate its location and trajectory. If targets are moving towards the SYMBIOSIS mooring, multiple cameras and strobes are triggered to collect images for neural network detection and classification. The information about the number, size and fish species is compressed and sent to shore via a combination of acoustic and radio links. Each system component was tested separately in over 50 sea experiments. A prototype underwent 10 sea experiments before being deployed in 3 test locations: 1 month below a surface buoy in coastal waters 125 m deep in the Mediterranean Sea; 2 days at an offshore Mediterranean site in 1400 m deep water and 2 weeks in shallow water in a Red Sea reef. While SYMBIOSIS achieved most of its goals, it was unable to classify fish based on their acoustic signature. To achieve this the team are now building a larger database of acoustic signals from different fish, alongside new algorithms to accommodate greater diversity.
Hydroacoustic components developed by Evologics, such as an ultrashort baseline acoustic positioning system, are now being commercially produced. Demonstrations and sales already under way and optical components are being further developed. The system will be smaller to make it more marketable. Further improvements will include better energy efficiency and more powerful neural networks.
The methodology chosen for the project is a combination of underwater acoustic technology and underwater optical technology.
The objectives of SYMBIOSIS were
Objective #1: Developing an autonomous energy-independent opto-acoustic marine biomass estimation prototype with the following capabilities:
1. Detection: Remote, non-invasive detection of fish stocks at distances of up to 500 m (acoustically) and 2-3 attenuation lengths (optically) with a false alarm rate less than 0.001 and a detection rate of 90%. The detection scheme will be robust
to different marine environments and will operate continuously.
2. Classification: Determining the type of the detected fish with a miss-classification rate of less than 5%.
3. Biomass Evaluation: Determining the biomass of the detected fish with an error of up to 10%.
4. Data Telemetering: Transmission of the processed acoustic and optical data from deep to surface to shore with 95% communications availability.
At the end of the project, system is fully developed including the acoustic-optic detection, classification and target characterization algorithms Modeled simulations. The different algorithms were verified by a series of more than 50 sea experiments.
Objective #2: Integration of the developed units and implementation of a prototype system that is fully autonomous under the points of view of power supply, information processing and data telemetering.
At the end of the project, a prototype system was implemented and tested in parts and as a whole in realistic conditions. TRL6 level of readiness was achieved.
Objective #3: Demonstration of the capabilities of the developed prototype on-board three mooring platforms representative of different sea and ocean environments.
At the end of the project, three long term deployments were performed involving three different platforms: ship, over mooring, and from own mooring. During these deployments, the system was fully operated and obtained tracks of hundreds of pelagic fish.