# Aquasafe: A Remote Sensing, Web-Based Platform for the Support of Precision Fish Farming
## 3 Results
### Real-Life Cases
#### 3.3.1 Fish Growth Model Performance  
The following figures show selected outputs from the three study areas. Reference cages of 300 m\({}^{3}\) volume were created for the three study areas and were stocked with either of the three fish species at varying sizes. Next, the entire 1 April 2022-1 October 2022 growing season was simulated taking into account the respective environmental parameters. As seen in Figures 11 and 12, the tool performed well, not only realistically depicting the seasonal growth patterns of the considered species but also capturing quantitative differences across the study areas. Specifically, growth predictions of both European sea bass and meagre from the Souda pilot farm closely matched the corresponding field measurements regarding fish weight, thus corroborating the validity of the models. Moreover, some notable differences were observed among the aquaculture sites. The weight increase was the fastest at the Souda site and the slowest in Agrilia, with Astakos exhibiting intermediate values. While data for validating such differences are not provided, their interpretation is intuitively found in latitudinal differences among them. Namely, the area exhibiting the highest growth rates (Souda) is also the southernmost, thus corresponding to higher temperatures which are beneficial for growth.  
Figure 10: The map shows the three areas that were used as case studies to validate the performance of Aquasafe web-based platform: (a) HCMR pilot aquaculture farm (Souda), (b) PLAGTON S.A. commercial fish farm (Astakos), and (c) AVRAMAR S.A. commercial fish farm (Agrilia).  
Another output related to fish that the platform generates is fish respiration, which is a useful metric for evaluating the oxygen requirements at the farm level. Taking the example of gilthead seabream, we show that the model captures the typical seasonal patterns in oxygen consumption across the three aquaculture sites (Figure 13). In particular, respiration is predominantly affected by temperature and body size, and this is reflected by the steady increase in the oxygen consumption rate as the simulation progresses through spring (days 0-60), eventually reaching the highest values during the summer months (days 60-150). Quantitative differences exist here as well, with the southernmost and warmest area (Souda) exhibiting higher oxygen consumption values compared to the other two--a pattern similar to that of growth rates.  
Figure 11: Mean weight progression for European sea bass during the period 1 April 2022–1 October 2022. The lines represent the Aquasafe platform’s outputs at the three study areas, while the points denote field measurements.  
Figure 12: Mean weight progression for meagre during the period 1 April 2022–1 October 2022. The lines represent the Aquasafe platform’s outputs at the three study areas, while the points denote field measurements.  
Finally, the platform generates alerts when oxygen availability is low, which typically occurs in densely stocked populations. Here, this platform capability is explored by simulating biomass changes for cages with low (<10 kg/m\({}^{3}\)) and high (>30 kg/m\({}^{3}\)) stocking densities. As seen in Figure 14, in a low-density scenario the fish continue to grow uninhibited throughout the season resulting in increasing biomass without the appearance of oxygen alerts. Conversely, in high stocking density scenarios the oxygen availability reduces and eventually becomes critical for the fish as they progressively increase in size with analogous increase in their oxygen requirements. Specifically, in all three sites the platform generated oxygen alerts once the simulation entered the summer months. Moreover, the alerts appeared sooner for the site that showed the fastest increase in biomass (Souda, day 67) compared to the other two, for which they appeared one month later (days 84-89). This feature may be of great value for aquaculture operators in regard to managing the cage populations.