○ Mysterious deaths of two expert divers at an underwater section of Great Wall shock China’s diving circle.
○ Illegal electrofishing speculated as possible cause of death
○ Incident complicated by authorities denouncing divers’ surveying and mapping activities as illegal.
The divers, Xu Haiyan and Sun Hao, belonged to Global Underwater Explorers (GUE), an international NGO of divers that aims to conserve the world’s aquatic environments.
At the time they went missing, Xu, a female aged 39, and Sun, a male aged 34, were said to be carrying out a surveying and mapping mission of the Panjiakou Reservoir Scenic Area, where sections of the Great Wall are submerged.
Although no official announcement has been made on what happened during their dive, many are speculating that illegal electrofishing in the area caused their deaths. An autopsy and police investigation are underway.
The underground section of the Great Wall of China, approximately 50 kilometers long, was submerged in the late 1970s when a dam was constructed across Panjiakou Pass. Later named Panjiakou Reservoir, it provides water for nearby cities including Tangshan and Tianjin, which at the time were plagued by water shortages.
The reservoir resulted in the complete immersion of a section of the Great Wall as well as an old village, creating a unique underwater landscape that has attracted many recreational divers over the decades.
It also inspired GUE divers to survey and map out the hydrogeological characteristics of the area.
A hydrogeological map, which reflects a water area’s aquatic environment, is essential to future divers who hope to explore the area and also an important source for aquatic, geological and historical studies.
If Xu and Sun’s mission had been completed, images, videos and maps of the submerged sections of the 500-year-old Great Wall would have been made available to the public for free by GUE, according to the organization.
Each diver was loaded with over 50 kilograms of equipment. According to their plan, the first pair, Xu Haiyan and Sun Hao, would dive for two hours and then surface at 2:30 pm. The other pair of divers, Hai Jun and Jin Hui, would ascend at 3 pm.
Compared with previous missions that these same divers had undertaken, the difficulty of the Panjiakou mission was deemed relatively low. The depth of their dive, a maximum of 50 meters, was much less than the distance these divers are capable of reaching; both Xu and Sun have obtained Tech 2 certificates, meaning they’re capable of diving as deep as 75 meters.
The open-water area is also safer to explore compared with underwater caves or shipwrecks. The length of their mission, about 2.5 hours, was also relatively short.
At around 3 pm, Hai and Jin surfaced as planned. But Xu and Sun, who were supposed to have surfaced before them, were nowhere to be seen. Nor could the team find Xu and Sun’s surface marker buoys, used by scuba divers to indicate their position.
On September 7, GUE’s official WeChat account posted a message officially announcing the disappearance of the two divers.
The search: A search and rescue mission for Xu and Sun was launched soon after the announcement. Although there was little hope that the divers had reached the shore, drones were deployed and fishing boats sailing along the coast were also asked to keep a look out for the divers.
But authorities knew it would be difficult to locate two people in a 72-square-kilometer reservoir. What’s more, a dense thicket of derelict fishing nets and cages in the water presented additional challenges for the search teams.
“My left shoulder became entangled. There were so many fishing nets, horizontal and vertical, that it was like a trap,” one rescue diver said after surfacing from the water.
The rescue team were thus forced to rely on navigational sonar systems to create images of the underwater area; when a suspicious shadow appeared, divers were immediately deployed into the water to identify it.
But over the following days, every shadow turned out to be nothing but a fallen tree or an entangled mess of old fishing nets.
On September 17, 10 days after Xu and Sun first went missing, rescue teams turned to remote-control operated underwater vehicles (ROV) to continue the search. At 5:10 pm on September 20, at a depth of 62 meters, an ROV spotted the body of Sun. At 10:50 am the next morning, Xu’s body was also found.
Speculation and theories: Family members of the two divers now speculate that one diver might have encountered an accident, and the other diver might have died while trying to help his partner.
But professional divers say this rarely happens to skilled divers. Xu herself once wrote an article about scuba rescue training. “Never panic when a diving partner is in danger. Accept the fact that the person you’re trying to rescue is probably dead already, and your job is just to recover his or her body,” she wrote.
Professional divers speculate that illegal electrofishing activity in the reservoir might have caused the divers’ deaths. Fishing with electricity is banned in China due to its potential detriment to biodiversity and the surrounding environment, but many local fisheries nonetheless illegally use the method due to its higher efficiency.
In April, during a trial of a fisherman who was caught illegally fishing with electricity in Chaohu, East China’s Anhui Province, prosecutors cited a report by the Fisheries Research Institute, Anhui Academy of Agricultural Sciences.
According to the report, electric fishing often results in the death of all creatures in the surrounding underwater area; any that happen to survive the shock will suffer from permanent injuries to their sexual glands, resulting in a loss of reproductive functions.
Furthermore, fish that die from electric shock, if not immediately trawled, fall to the ocean floor or lakebed and rot, befouling the water and resulting in disease among the surviving fish.
“I saw a lot of dead fish in the water, their bodies intact and not yet decayed. They looked like silver speckles when our flashlights lit up the deep water,” said Hai Jun, GUE’s first instructor in China, who participated in the search for his teammates.
Electrocution seems to be the most plausible theory for the two divers’ deaths, as it explains why their bodies were found at 62 meters deep in the water even though their working depth was only 30 meters, as the shock would have left the divers negatively buoyant.
Who is responsible? Local police have not yet revealed any information on their investigations. The actual cause of death will be confirmed during an autopsy. In the meantime, netizens and diving professionals are now arguing about whether the two divers were qualified to conduct the survey and mapping mission.
An officer from the Hebei Bureau of Geo Information told Red Star News that, according to China’s Surveying and Mapping Law, underwater surveys require special qualifications and applications, as it is illegal to map the Great Wall without approval from relevant organs.
Some netizens are also arguing that GUE, as a “foreign organization,” are responsible for their “illegal activities” in China, including the deaths of the two divers.
But others say it is normal for Chinese divers to possess international certificates as diving has only just entered China in the past decade. The team is no more than a private diving club, whose members have certificates from the same organization. GUE has not responded to media inquiries so far.
— Global Times
The 68th Anniversary of the Founding of the People’s Republic of China.
— The Daily Mail - People's Daily