Hainan, a tropical island province in southern China and a major hub for marine aquaculture, has experienced two “red tide” outbreaks since late June. According to Caixin, this was one of the largest and most damaging red tide events recorded in Hainan in recent years. Satellite monitoring suggested some extended 20-30 km out from the coastline.
Lv Songhui, chief expert of Hainan’s marine disaster emergency response team, told Caixin that while the two outbreaks involved the same type of algae, these were two separate events: one occurred in western Hainan, the other in the south.
The dominant species was identified as a close relative of the harmful (and typically red) algal bloom species, Margalefidinium polykrikoides. This is the first time it has been detected in Hainan. Lv says the algae can be highly toxic to fish, damaging their gill tissues and causing farmed fish to die.
The causes of the outbreak are still under investigation. Hainan has recently experienced an extended period of hot, dry weather. Lv suggests prolonged high temperatures, seawater stratification, and changes in ocean currents and nutrient conditions may have jointly contributed to the bloom.
The outbreak has caused heavy losses for Hainan’s marine aquaculture sector. According to Caixin, some aquaculture farmers and companies in the towns of Chengmai and Changjiang, and in the city of Sanya, reported large-scale fish deaths: one aquaculture co-operative in Chengmai lost approximately 60,000 kg of cobia, resulting in losses of more than a million yuan; a company in Changjiang lost approximately 3.2 million golden pompano juveniles, with losses estimated at nearly RMB 10 million; while some companies in Sanya reported losses of more than RMB 10 million.
In response to the disaster, financial institutions have begun providing support for recovery efforts. According to Phoenix New Media, Hainan Rural Commercial Bank has launched a dedicated support mechanism, visiting key affected areas to assess losses and understand the funding needs. The bank has introduced special credit quotas, emergency recovery loans, fast-tracked approval procedures and concessional interest rates. Its first round of emergency loans has provided RMB 10 million in support of purchasing new fish stocks and resuming production.
Related insurance discussions are increasingly prominent. In a 2025 China Finance article, researchers noted that aquaculture insurance pilot schemes dedicated to extreme weather have been launched in 29 provinces of China. Overall protection remains limited, with relatively low insurance coverage. Many farmers simply bear most disaster-related losses themselves.
Aquaculture involves diverse species and complex environments, says the article, making it difficult for insurers to accurately assess losses and settle claims. In addition, disasters such as red tides and typhoons often impact large areas – such concentrated risk puts pressure on traditional insurance models. The article calls for stronger monitoring and early warning systems to aid preventative action.
The article also says aquaculture insurance and risk-sharing mechanisms must be expanded, and that better collaboration between government agencies, researchers, financial institutions and producers will build a more resilient aquaculture sector.