AUTOMATED BIOFOULING CONTROL OF AQUACULTURE OYSTER CAGES AND CROP

The  Aquaculture  industry  provides  essential food to  the growing world population, especially in the supply of protein to low-income and food deficient countries

. Biofouling is a major problem in a quacultural production  as both the target culture species and/or infrastructure are exposed to a diverse array of fouling organisms.  This problem has been partially mitigated  over the years by manually lifting or flipping  infrastructure like oyster cages periodically above the waterline though it is labor-intensive and costly.  This is to expose the cro p as well as the  farm equipment in  the air and sun to minimize biofouling. Automated oyster cage operation would help in the reduction of manual labor and increase productivity. It  will address these challenges by providing remote control that can vertically move farm structures  based on user input or predefined rules  which can be  based on any combination of time of the day,  wave height,  air  temperature, humidity , wind, precipitation , and other weather conditions.  Such flexibility allows optimizing the desiccation cycles for maximum farm production.  An automated control unit has been  developed  that is  comprised of  low-cost air pumps,  solenoid  valves, solar cells, microcontrollers,  and  other electronics,  as shown in Figure 1. The pumps  allow automatic desiccation of the oyster cage  by moving air into  the side  floats and bottom floats . This process lifts the cage above the water line into the desiccation position.  The valves allow the air inside the floats  to escape  and water to re-enter the floats to sink the cage . As bottom floats are filled with water, top floats hold the cage right below the water surface in the feeding position . The s ide floats stabilize the cage during the transitions between  feeding and desiccation  position. T he sinking and raising of the system are controlled via an IoT (Internet of Things) microcontroller, i.e. , the cage  is connected to the internet for remote operation. All electronics are powered by solar energy.  The  performance of the system is monitored via telemetry, which includes  the Wi-Fi strength , cage state, pumps, and valves states,  and battery voltage level .  The telemetry also includes local  environmental parameters like temperature and humidity inside the control unit . This study currently advances towards the development of a cellular data link to a  master cage at the  remote farm site and a local mesh network  between  the rest of the oyster cages. This will allow the far mer to adjust the desiccation times to the oysters' growth stage and react to weather events based on the local conditions and forecasts from internet-based weather services.  Future research will focus on the refinement and ruggedization of the system and the optimization of the desiccation cycle.