In the blue aquaculture waters, an orange-colored marine monitoring buoys floating quietly. These seemingly ordinary devices, in fact, is the guardian of the fishery "intelligent sentinel", they are 24 hours open "electronic eyes", alert to the invisible killer in the water - red tide and hypoxia area! When red tide occurs, the seawater will be damaged. When red tide occurs, seawater is colored reddish-brown by hundreds of millions of harmful algae. Some of these algae release neurotoxins that kill fish within hours; some form mucus that clogs the gills of fish, as if the fish were wearing asphyxiation masks. The anoxic zone is more hidden - when the oxygen concentration in the bottom layer of seawater drops to less than 2 milligrams per liter (lower than the survival limit of fish), the whole piece of water will become a "no death zone". Last year, a bay was not detected in time due to anoxic area, resulting in thousands of tons of farmed fish overnight death, fishermen suffered heavy losses.
These ocean monitoring buoys are equipped with a variety of sophisticated sensors that can capture key data about seawater in real time. The water quality sensor can detect the chlorophyll concentration in the water body, when the red tide algae bloom, the chlorophyll content will be abnormally high, the buoy will immediately issue an early warning. Dissolved oxygen sensors monitor oxygen levels in the water at all times, and quickly transmit an alert message if they fall below fishery-safe thresholds.
The working principle of the ocean monitoring buoy is ingenious and efficient. Solar panels provide continuous power to the device, ensuring 24-hour operation. Data is transmitted to the monitoring center in real time via satellite or wireless network, so fishermen and the marine department can grasp the dynamics of the fishing ground at the first time. Some of the ocean monitoring buoys are also equipped with water temperature and salinity sensors, and these data can assist in determining the trend of red tide and hypoxia.
These data are having a more far-reaching impact. In an ecological fishing ground, a network of buoys, combined with a tidal model, directs intelligent gates to introduce oxygen-rich seawater at low tide; by analyzing historical data, fishermen plant kelp forests in areas prone to hypoxia-the oxygen released by photosynthesis during the day in these "underwater forests" is equivalent to building natural oxygen bars for fish. These "underwater forests" release oxygen from photosynthesis during the day, which is equivalent to building a natural oxygen bar for fish. When the marine monitoring buoys detect the first signs of red tide, fishermen can shift the breeding area in time; when they find the formation of anoxic areas, they can take measures to increase oxygen in advance. These buoys have been widely deployed in many coastal fishing grounds in China, and fishery losses due to red tide and hypoxia have dropped by 37% in the past five years.
When the setting sun reflects the buoys on the sea surface, fisherman Lao Chen pointed to the real-time monitoring map on his cell phone and said, "In the past, fish farming depended on the weather, but now there are these sentinels on watch, and I can finally have a restful night's sleep." Under the flashing lights of the buoys, the unseen data flow is being woven into the life defense line guarding the blue granary - every time the alarm sounds, it is science and technology injected into the breath of the sea.
