Xinhua reported on the 22nd of July (2017) that a rare rough-toothed dolphin (Steno bredanensis), named Jiangjiang, was released back to sea earlier this week, two months after it beached itself and was rescued in Guangdong Province.
The 2.2-meter male dolphin was found stranded on the coast of Heisha Bay near the city of Jiangmen (200 km west of Hong Kong) on May 3. It was suffering breathing troubles, according to Yang Naicai, a vet who joined the rescue operation.
Rescuers checked the dolphin’s breathing, gave an injection of antibiotics, and provided food and medicine to help it regain its strength.
The animal was housed in a pool designated for dolphin rescue at the Pearl River Estuary Chinese White Dolphin National Nature Reserve.
“We maintained round the clock monitoring, hoping for a miracle,” said Chen Hailiang, from the reserve.
The dolphin, which weighs around 100 kg, was released back to the sea on Thursday as its physical condition had returned to normal.
Although the rough-toothed dolphin, a national second class protected species, can be found in deep tropical, subtropical and temperate waters around the world, it is a rare visitor to Chinese coastal waters.
In 2014, a rough-toothed dolphin stranded in Guangdong died despite rescue efforts.
On the morning of the 2nd July (2017), a man fishing at Kat Tsai Wan, off the west coast of Lamma Island, found a 2.5 meter long pink dolphin washed up on the beach. The man told Apple Daily that he could tell from his boat that the animal was dead.
The Ocean Park Conservation Foundation Hong Kong (OPCFHK) response team visited the site and conducted a necropsy on the beach. The dolphin was an adult female and was carrying an unborn calf at full term.
The male calf measured 1.02 m in length, was also dead. The foundation said in a statement that no net entanglement or evidence of physical trauma was found on either carcasses, and both were severely decomposed.
The OPCFHK team said the mother dolphin’s organs and flesh indicated that she was very healthy prior to her death. The team has took organ, blubber, and tissue samples for further testing, inlcuding for microplastics.
According to a Marine Department notice, acoustic monitoring stations will be temporarily established on the seabed at Lung Kwu Tan (NW New Territories near Tuen Mun) and Siu Ho Wan (N. Lantau) for the next 9 months.
The acoustic monitoring stations will collect data on dolphin vocalisations in the area. They are structures of pyramid shape with a height of about 0.8 m and a square base of 1 x 1 m. Its bottom will be embedded in the seabed.
Regular diving operations for inspecting and retrieving data from the acoustic monitors will be carried out by a work boat in the above locations every month.
Source: Government of Hong Kong SAR Marine Department Notice No.12 of 2016 dated 22 January 2016
In May of this year CNOOC reported a mid-sized oil field discovery, the Liuhua 20-2 field, in the Eastern South China Sea. Liuhua 20-2 is located in the Pearl River Mouth basin of the South China Sea, at an average water depth of about 390 m. The discovery well (LH20-2-1) was drilled to a depth of about 2,970 m.
This is only the latest South China Sea oil and gas field to be opened. In the last decade a large number of fields have been discovered, explored and commercially exploited. Hong Kong in fact receives some of its gas via a direct pipeline from a gas field southeast of Hainan Island.
Oil and gas prospecting, however, relies on seismic surveys. This involves sending powerful sound or shock waves through the water to the seabed to measure and analyse the echo received back. For the echo to give valuable data on lower rock layers they must be powerful enough to penetrate through thick sediment and into the rocks below. There are a few ways that can be done some including TNT or electricity to create imploding plasma bubbles. But the result is always a loud sound or explosion.
In the last few years Hong Kong has seen a number of more unusual whale strandings including deep-water species like sperm whales, Pygmy sperm whales and short-finned pilot whales, as well as other whales normally rarely if ever seen in Hong Kong such as Omura’s whales. Toothed whales rely heavily on echolocation (seeing by sound) for navigation, so the idea arises whether increased seismic survey activity in the South China Sea is part of the cause for these strandings.
Unfortunately, I am not aware of any scientific investigations into the effects of seismic surveys on whales and dolphins in the South China Sea. Research in this area is very difficult because it is hard to track whales and dolphins in the first place, and because their navigation sense is poorly understood. There are also multiple possible reasons for strandings, including disease and injuries so making a causal link between seismic surveys and whale strandings is very difficult even in the best of circumstances. However, intuitively, it seems right to restrict the use of loud explosions in the habitat of rare marine animals with very sensitive hearing organs that are also essential for their navigation. Particularly as sound conducts much better in water than in air.
When I took part in a research cruise to the Weddell Sea in Antarctica (back in 2005) there was actually a restriction on even the scientific use of small seismic surveys for marine geological baseline research. Special permits had to be applied for from the relevant government ddepartments of participating nations – in the end the only country that granted a permit was Russia.
There are also (as far as I am aware) reasonable restrictions on using seismic surveys in the North Atlantic by Europe, the U.S. and Canada, that require observers to check (as far as possible) that no whales are in the area before the survey starts.
I am not aware of any such restrictions in the South China Sea, although my knowledge of PRC laws and regulations is poor and perhaps such rules exist after all (feel free to point out any errors in the comments below).
A team from the Ocean Park Conservation Foundation (OPCF) yesterday (24/3/2015) examined the dead body of a Chinese white dolphin found in waters near the Hong Kong airport.
The carcass was first spotted floating off of the Brothers, a pair of islands to the northeast of the Hong Kong International Airport.
The team was unable to determine the cause of death since the body was severely decomposed, but samples were collected for further study.
“Unfortunately, we can only confirm the cause of death in less than 10 percent of cases, mainly because most of the carcasses are badly decomposed when discovered,” said Shadow Sin, the assistant manager of scientific projects for OPCF.
It’s the third cetacean stranding case reported so far this year. This month also so the death of the injured dolphin nick-named ‘Hope’.
Hong Kong’s Chinese white dolphins, widely known as pink dolphins, are threatened by habitat loss and marine traffic.
The range of pink dolphins in Hong Kong has shrunk substantially since the construction of the Hong Kong International Airport at Chek Lap Kok.
If you spot a dead or distressed animal you should immediately call the Hong Kong government hotline at 1823.
The animal, nicknamed ‘Hope’ , was found off Shek Pik, on southern Lantau Island, by experts from Ocean Park (amusement park) and the Agriculture, Fisheries and Conservation Department who had been searching for the dolphin since January 20.
The team captured it using a specially adapted net and a sedative to slow the dolphin down. The preliminary health assessment found multiple serious wounds with three exposed vertebrae in front of its tail. Also the caudal (tail) vertebrae in front of its fluke was cut through and Hope suffered at least 4 deep transversal wounds on its tail stock, extending back from its dorsal fin toward the tail.
Over the next few days Hope will have 24-hour care and undergo a thorough examination – including X-rays, ultrasound, bacterial swabs and blood tests – and receive medical treatment at the hands of experts from the park, the conservation department and the Society for the Prevention of Cruelty to Animals.
The dolphin is a male, 2.3 metres long and weighs 135 kg. It was first spotted by a group of University of Hong Kong students off the Lantau village of Tai O on January 16. They saw severe cuts on its fin and back, probably caused by the propeller of an outboard motor.
Some marine conservation specialists argued that it should be left to recover in the wild. Images of the wounded animal were circulated on the internet, causing widespread concern and pressure that probably led to the current capture.
Chinese white dolphins are a protected species in the city, with only 60 of them living in Hong Kong waters.
Hong Kong Dolphin Conservation Society chairman Dr Samuel Hung Ka-yiu, who inspected the dolphin after its rescue, said there was no immediate threat to its survival, but judging from its condition it faced a long road to recovery.
Yesterday’s success was the sixth attempt to capture the animal. The society provided a boat for the search team to use in the operation, and sent its own team to observe the process. Asked whether the rescue procedure had caused any further injury to the dolphin, Hung said his society had shot a video of the rescue process for the park to release and it was better to leave that judgment to the public. Watch the capture of the dolphin posted by Apple Daily here.
HK Marine Life’s Opinion:
It is questionable whether the dolphin can recover from such severe injuries. Only the veterinarian and experts can judge that. But the public should know that Ocean Park for many years ran a so-called captive breeding program for dolphins that in reality managed to kill 10 times more dolphins than were born. In fact the survivorship of healthy dolphins in captivity is preety poor. A study published in 1994 examined survivorship of dolphins and whales at Ocean Park (article online here), and showed that Ocean park was not unique – all captive dolphins and whales have relatively poor survivorship.
The dolphins injuries look extremely severe. A severed or partially severed vertebrae in front of the fluke would deprive it of proper locomotion and condemn it to early death. Now if the dolphin were to die as a direct or indirect result of these injuries, the humane question to ask would be how and where should it die? In the wild where it grew up where its social contacts are? Or alone in a clinical tank at Ocean Park.
Dr Hung has been very cautious in his statements. Part of the reason may be his well-founded opposition to Ocean Park’s dolphin facilities which serve to foster public appetite for dolphin shows and captive dolphins (see SCMP articel here).