# Aquasafe: A Remote Sensing, Web-Based Platform for the Support of Precision Fish Farming
## 2 Materials and Methods
### Indicators
According to the \"Manual for the Wellbeing of Mediterranean Fish\", the appropriate threshold for dissolved oxygen saturation in water for armed fish is generally considered to be between 70% and 90% [43,44]. However, this can vary depending on the species of fish and the specific conditions of the farm. For example, some fish species may require higher levels of oxygen saturation than others, and certain conditions such as high water temperature or low water flow can also affect the oxygen requirements of fish. Gilthead seabream and European seabas are tolerant to lower dissolved oxygen levels, but it has been reported that a long exposure to such conditions may have negative effect on their immune system [45,46]. At a 40% oxygen saturation level, they may suffer from a decrease in feed intake and growth, as the low oxygen levels impede their ability to properly absorb nutrients and support their overall development [47,48]. That being said, saturation levels alone may be misleading for assessing danger at the farm level. For example, due to the solubility of oxygen correlating negatively with temperature, it is possible that the same low saturation levels that are detrimental at a high temperature may be sufficient for normal fish respiration at a lower temperature. In that regard, it has been reported that if dissolved oxygen levels fall below 5.5 mg/L, negative impacts on fish at all life stages occur [44]. Given the information mentioned above, we have established three levels of dissolved oxygen: safe levels, which are above 70%; critical levels, which fall between 40 and 70%; and danger levels, which are below 40%. Additionally, any values falling below 5.5 mg/L are considered critical. 4. Fish growth and target weight: The appropriate marketable weight of farmed fish varies depending on the species and consumer preferences. For example, in the case of gilthead seabream and European seabas, the typical marketable weight is generally considered to be portion sized (300-400 g), but demand for larger sizes (600-800 g) also exists [49, 50, 51]. However, this can vary depending on the specific farming conditions and the market demand. For gilthead seabream, it is expected to reach the marketable weight within 12-18 months of farming, while European seabas takes slightly longer,typically reaching the marketable weight within 18-24 months [33]. On the other hand, meagre, an emerging species in Mediterranean aquaculture with high commercial potential, grows faster and reaches market size of 700 g within a year, while its weight may exceed 2 kg in only two years at sea [52]. It is important to note that reaching the marketable weight is not the only consideration when determining the harvesting of the fish. Other factors that should be taken into account include the fish's health, growth rate, and the overall condition of the farm [49]. Additionally, the market demand for a certain size of fish also affects the appropriate marketable weight. Overall, appropriate marketable weight of farmed fish is a crucial aspect of the fish farming industry. It ensures that the fish are of good quality and are ready for market and also affects the profitability of the farm. The relevant alert is triggered based on a user-defined threshold and the predicted change in weight (\(\Delta\)Weight) as forecasted by the growth model. * Wind Speed/Gusts: Wind speed and gusts can have a significant impact on fish farms, as they can cause damage to the infrastructure and equipment, as well as stress and injury to the fish. Strong winds can cause waves and currents that can damage nets, pens, and other equipment, leading to costly repairs and potential loss of fish via direct mortality or escapees [53]. Additionally, high winds can also create difficult conditions for fish farmers, making it difficult to work and maintain the farm.