Net pen aquaculture systems are intimately connected to the local environment. Significant benefits from ecosystem services are obtained such as removal of wastes, provision of well oxygenated water, and maintenance of a relatively stable temperature, but these are natural processes and they are subject to fluctuations. It is critical for farmers to monitor environmental conditions to ensure the health of their fish and to make sure operations are optimized for current conditions. Tools that provide live data streams wirelessly are the most suitable to create the spatial and temporal resolution necessary to apply the data and get the most value from it.
Temperature does not usually vary significantly over the spatial scale of a typical net pen farm, but it can change significantly on a temporal scale relevant to farm operations. A temperature change as small as 2°C has a significant impact on total feed intake and feed intake rate making it important to have live temperature data streams recorded hourly or faster to optimize feeding operations. Adjusting feeding rates and target feed amounts based on temperature can reduce feed wastage to the environment, particularly in low visibility environments when cameras are less useful. Additionally, extreme temperature events can be stressful for fish, compromising immunocompetence and even causing mass mortality.
Dissolved oxygen levels can vary significantly on very small spatial and temporal scales. During feeding or bathing, dissolved oxygen levels can drop by over 1% per minute. Regular measurements are essential to ensure that fish are maintained in safe conditions. Aside from farm operations, there are environmental events that can reduce dissolved oxygen content to sub-lethal levels within hours.
An environmental monitoring system that populates data onto a cloud allows for automated analysis and reactionary steps to be taken. These can be as simple as automated emails or text messages that are sent out when a parameter crosses a certain threshold, or entire systems can be automated to react to a changing environment. For example, an air diffuser system can be turned on automatically in response to low dissolved oxygen readings or high temperatures. This level of automation can improve fish performance and avoid critical issues which can lead to mass mortality events.
Live, uninterrupted data streams that report at a spatial and temporal resolution appropriate for the parameter that they measure, should be considered essential aquaculture tools. They enable farmers to achieve higher levels of efficiency and can also reduce the risk of critical issues leading to mass mortality events.