Dolphins & Porpoise Found Dead During Lunar New Year

A dolphin concern group published on its social media page that one chinese white dolphin (Sousa chinensis) and four finless porpoises (Neophocaena phocaenoides) were found stranded between Saturday the 17th and Monday the 19th of February. Autopsy scans found food remains in the dolphins, showing they were not starved to death. However, they showed multiple fractures. It is feared they were hit by motorboats as they had injuries on their heads and necks.

One finless porpoise was almost cut in half by what is thought to have been a boat propeller.

The adult Chinese white dolphin was found stranded at Mo To Chau. It was a 2.5-meter female, at least 10 years old, and with signs of choking, bone fractures and serious bone dislocation. The death of an adult female is a great loss to the species’ population growth, with numbers in Hong Kong down from over 120 some years ago to 47 at present.

In the past three years there have only been 3-4 stranded cetaceans in tyhe months of January and February. This year, more than 10 dead cetaceans have been discovered in the same period.

High-speed boats are always a big threat to dolphins and some might be hit by propellers and never be discovered. The Dolphin Conservation Society of Hong Kong (HKDCS) has urged the government to launch a speed restrictions on boats around dolphin and porpoise habitats or even ban them from entering these areas.

According to the HKDCS only one new-born Chinese white dolphin was recorded last year. With the loss of another adult female dolphin, there is a dwindling chance of recovery of the local population.

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Pearl River Oil Spill Not Affecting Hong Kong

An oil spill reported in the Pearl River estuary close to the Qingzhou Island and Guishan Island has so far not entered Hong Kong waters. A few vessels were either stranded or sank in the wake of typhoon Hato.The Hong Kong Maritime Rescue Coordination Centre was informed of the spill by the Guangdong Search and Rescue Centre. Mainland maritime authorities have undertaken a cleanup and the HK Marine Department has begun patrols southwest of Lantau Island. Aerial surveillance carried out has so far not shown the spilled oil drifting into Hong Kong waters.

Rescued rare dolphin released back to sea

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.

Chinese White Dolphin Stuck in Pearl River Tributary

Wildlife experts in south China are trying to rescue an endangered Chinese white dolphin (Sousa chinensis) that is in worsening health after swimming into a tributary of the Pearl river a week ago. The dolphin is approximately 30 years old and swam into the Baisha Rivernear Jiangmen in Guangdong Province on the 1st of February. It is now in a stretch of water about 100 km from the sea. “[…] the skin of the dolphin is festering and its health is deteriorating … its moving area is shrinking,” said Feng Kangkang, a worker with Jiangmen Chinese White Dolphin Nature Reserve, on Thursday. The team is watching the dolphin around-the-clock and recording its health condition, according to the Guangdong provincial ocean and fishery department. Dubbed the “giant pandas of the sea” by some, the Chinese white dolphins are mainly scattered in a few coastal areas where they exist in small numbers. About 2,000 are known from areas around the Pearl River, including HK which at the last count, was down to about 60 dolphins. (Photo/Xinhua)

Chinese White Dolphin spotted in Pearl River near Guangzhou

As reported by several news outlets this week, a Chinese White Dolphin (Sousa chinensis) – aluas Indopacific Humpback Dolphin or ‘pink dolphin’ – was spotted near Guangzhou in the Pearl River on Wednesday the 21st of October. This drew some crowds as the dolphin stayed for about an hour. Conservation staff later used sonar equipment to try to herd it back out towards the sea -apparently with some success.

  
This story is however quite hyped-up, because these dolphins live near estuaries and previous studies have shown they move further into the estuary in the dry winter months when less freshwater is flushed into the sea by the Pearl River. In summer when the heavy rains come and the river swells the dolphins range extends further out. This is likely because they are following fish stocks that themselves track a line of salinity which mobmves in and out of the estuary with the seasons. Some fish like the flathead mullet (Mugil cephalus) commonly sold in fish markets also move in and out of fresh and seawater depending on their stage in life.

Speaking of which, I saw another prize catch of a mullet on the central waterfront yesterday. It’s a bigger fish than I have seen in any market at about 40 cm and probably 2+ kg – it drew a small crowd and plenty of mobile phone cameras. congratulations to the lucky angler!

  

The Stingrays of Hong Kong

I have just added a page about all the different species of ray that are found in Hong Kong. Here is a little preview on just the stingrays. Check out the full list of rays here.

The Stingrays of Hong Kong:

 

Round ribbontail Ray / Black-spotted stingray (Taeniura meyeni)

Round Ribbontail Ray (via WikiCommons)
Round Ribbontail Ray (via WikiCommons)
A bottom-dwelling inhabitant of lagoons, estuaries, and reefs, generally at a depth of 20–60 m (66–197 ft). Reaching 1.8 m (5.9 ft) across. Generally nocturnal, the round ribbontail ray can be solitary or gregarious, and is an active predator of small, benthic molluscs, crustaceans, and bony fishes. Although not aggressive, if provoked the round ribbontail ray will defend itself with its venomous tail spine. In Hong Kong, it is found mainly in the relatively clear southern and eastern waters, but it has also been found in the northern part of Lantau and in brackish water near the Pearl River estuary. It is also one of the species that has been found on Hong Kong’s artificial reefs. Check out Eric Keung’s spooky photo of a this stingray in Hong Kong waters.
Between July 2005 and June 2008 there were two cases of people being stung by stingrays in HK – fortunately with mild outcomes. The sting and its venom can cause bluish or greyish discoloration around the wound, disproportionate pain, muscle cramp, weakness, seizure, hypotension, cardiovascular toxicity, deep wounds and lacerations. In other words, stingrays are dangerous! Just watch from a distance and don’t touch!


Blue-Spotted Stingray (Neotrygon kuhlii)

Blue-Spotted Stingray, Papua New Guinea (via WikiCommons)
Blue-Spotted Stingray, Papua New Guinea (via WikiCommons)
The body is rhomboidal and green with blue spots with a maximum width estimated at 46.5 centimeters (18.3 in). The rays coloration is a warning for the highly poisonous barbs, thus few animals attempt to overpower this ray. In HK, they are more easily seen in summer in the shallow water along the coast, on coral reefs and in mangrove areas. Because of the venomous sting observers should not get too close or try to touch it!


Pale-edged stingray (Dasyatis zugei)

Pale-edged Stingray (via WikiCommons)
Pale-edged Stingray (via WikiCommons)
A bottom-dwelling ray most commonly found over sandy areas shallower than 100 m (330 ft) and in estuaries. It measures up to 29 cm (11 in) across, has a diamond-shaped pectoral fin disc, a long projecting snout, small eyes, and a whip-like tail. It is chocolate-brown above and white below and feeds mainly on small crustaceans and fishes. In HK it is mainly found in the western Pearl River estuary south of Lantau Island.

Newborn dolphin dies at Ocean Park; 2 more found dead on Hong Kong beaches

 A newborn dolphin, a small marine cousin of the dolphin, died at Ocean Park last night, where it had been born just 73 hours earlier. Its death came on the same day that two other finless porpoises were revealed to have been found dead on the city’s beaches.

The dead calf’s mother was said to have had a difficult labour, and her baby, a female, immediately displayed an abnormal swimming pattern. The theme park said she also found it difficult to stay alongside her mother when she was not suckling.

Necropsy results show the calf’s stomach was empty, and about 25 per cent of her lungs were not fully expanded. The theme park said it was not uncommon for dolphins to die in infancy, citing a previous study of dolphins in Western Australia, which showed 44 per cent of calves do not survive to three years of age.

Meanwhile, Mui Wo resident Leslie Parker said her son and his friend found the body of what was initially thought to be a seal or sea lion on the rocks near Lower Cheung Sha beach on Wednesday.

Officers from the Agriculture, Fisheries and Conservation Department and Ocean Park’s Cetacean Stranding Response Team visited the site yesterday evening to conduct an autopsy. They removed the carcass for further examination.

A dolphin, which lacks a dorsal fin, may appear similar to a sea lion, said Dr Samuel Hung Ka-yiu, chairman of the Dolphin Conservation Society. However, the porpoise has a smoother skin, with no hair, and it has a tail, while the sea lion has flippers. The species is considered vulnerable by the International Union for Conservation of Nature.

“The six months between December and May have always been the time of the year when most strandings of dolphins are reported,” said Hung, adding that gillnet fishing was usually the cause of dolphin deaths in Hong Kong waters.

Yesterday morning, police received another report of a dead finless porpoise – this time a 158cm-long adult, which was discovered at a beach off Tai Wan Tau Road, Tseung Kwan O.

The Ocean Park response team were again sent to the scene and took a sample to find out the cause of death. A spokeswoman described it as “severely decomposed”, with signs of having been strangled by a fishing net. There were also bruises on its tail.

There were 32 reports of finless porpoise strandings last year.


Reported by the SCMP ON 2nd April, 2015