Tag Archives: cetacean

Fourth Dead Cetacean Found in 1 Week

A dead finless porpoise (Neophocaena phocaenoides) was found in Discovery Bay on Sunday afternoon, the fourth dead marine mammal discovered in four days after the bodies of three dolphins were discovered on Thursday.
It was found in the water and handed over to the Ocean Park Conservation Foundation for an autopsy. The OPCFHK said that the porpoise was a 1.55 metre long female and the body had reached the fourth stage of decomposition. Its cause of death has yet to be determined.

On Thursday, the bodies of three Chinese white dolphins (Sousa chinensis) were found – one entangled in fishing wire near Lido Beach in Sham Tseng, one in waters near Lamma Island and another in Fan Kwai Tong off Lantau Island.

The Hong Kong Dolphin Conservation Society (HKDCS) estimate that there has been a decline since 2014, when 61 dolphins were estimated to be in Hong Kong waters.

Sai Wan Ho Dead Dolphin Turns Out To Be Dwarf or Pygmy Sperm Whale

The dead dolphin I posted about yesterday has been reclassified as either a dearf or Pygmy sperm whale by AFCD and Ocean Park Conservation Fund staff. The two-metre-long decomposing whale was found a few metres from the marine police base at Tai Hong Street in Sai Wan Ho.

It is believed it was a male dwarf sperm whale, but a genetic test is needed to confirm its species. The other possibility is its relative, the pygmy sperm whale. Both species are rare in local waters.
Dwarf sperm whales and pygmy sperm whales are extremely similar and usually indistinguishable when spotted at sea. They are widely distributed in tropical and temperate zones of all the world’s oceans.

The first and only recorded local sighting of a dwarf sperm whale was in 1991. There were four previous local discoveries of pygmy sperm whales, with the most recent in 2014.

Young Dolphin in Tuen Mun Marina

A young pantropical spotted dolphin was seen swimming in the Gold Coast Marina in Tuen Mun. The dolphin is estimated to be about 1 m in length, has apparently been in the area for over a day, with Apple Daily reporting that it had been stuck for 27 hours at around 2pm yesterday (27/1/16).
The Agriculture, Fisheries and Conservation Department (AFCD) was then notified, and sent three officers to observe the situation.

While Apple Daily maintains that the young cetacean is trapped by the boats in the harbour, President of the Hong Kong Dolphin Conservation Society, Hung Ka-yiu, told Hong Kong Animal Post that he believes the dolphin was simply lost and would not require human assistance at the moment.

Hung identified the dolphin as a young pantropical spotted dolphin (Stenella attenuata), a species often seen in Taiwan, but not common in Hong Kong’s waters, and the second most abundant dolphin species in the world. Hung also theorised that the dolphin was only in Hong Kong by mistake, and said he hoped it would eventually find its way back out to the ocean.

The AFCD said it would discuss future measures with dolphin experts at Ocean Park, and reminded yachtowners not to disturb the animal.

Dead Finless Porpoise Off Shek O

A locally-rare finless porpoise (Neophocaena phocaenoides) was found dead in the waters off Shek O, last week (19th November 2015).

The adult female finless porpoise was discovered on Wednesday at Tai Long Pai, bringing the total number of cetacean strandings this year up to 35. It measured 162 centimetres in length and was already severely decomposed. Dissection revealed a fishing rod in its stomach, but the cause of death is still unknown.

Marine Police received information that the corpse of a finless porpoise had been spotted floating near Shek O. The porpoise was then collected and brought to Marine Police Regional Headquarters at Sai Wan Ho, where Ocean Park Conservation Foundation’s Cetacean Stranding Response Team took on the cadaver for autopsy.

Elsewhere in China the Global Times reports another finless porpoise washed up dead in Poyang Lake in Jiangxi Province. Poyang Lake is a freshwater lake which along with the Dongting Lake is host to an estimated 500 finless porpoises. This stranding brings the total for Poyang Lake for 2015 to 5.

Short-Finned Pilot Whale Washes Up Dead Near Nim Shue Wan, Lantau

It appears that shortly after the first sighting of a short-finned pilot in Hong Kong (see post from January 14th), we now have the first stranding of a dead short-finned pilot whale. Ocean Park’s Cetacean Stranding Response Team investigated an adult female short-finned pilot whale stranding case today at Cheung Sha Lan, Discovery Bay. It’s 365cm long and as the carcass was severely decomposed, the cause of death cannot be determined. The Team and a veterinarian have done a necropsy on site. The preliminary findings show:

• A 12cm superficial wound was found near the fluke, though it unclear if this is pre-mortem or post-mortem
• A thin blubber layer of 1.5cm (mean blubber layer thickness of adult female short-finned pilot whale is 1.91cm), indicating that the dolphin was relatively thin and weak

Image: OPCF
Image: OPCF
Image: OPCF
Image: OPCF

The team sent the head, flippers and dorsal fin to Hong Kong Veterinary Imaging Centre for Computed Tomography (CT) scanning, and collected tissue samples for further testing.

Many people asked if this short-finned pilot whale is the same one people sighted at Tsim Sha Tsui on January 13. The dorsal fins on cetaceans have unique characteristics that allow identification of individuals, but since the dolphin’s dorsal fin was severely decomposed, no identification can be made as yet. Yet, as short-finned pilot whales are rare in Hong Kong, and the length of the carcass is similar to the estimated length of the pilot whale sighted in Tsim Sha Tsui (about 3 meter), the possibility can not be ruled out that they are the same individual.

In case you are wondering how this white carcass could have come from a black short-finned pilot whale: this often happens to decomposing whales and dolphins. I once saw a 0.5 m Finless porpoise washed up dead at the Cape D’Aguilar Marine Reserve. Normally Finless Porpoises are black, but the carcass was also white.

Before and After Images of Dolphin Injured by Boat Propeller

The dolphin recently spotted with terrible dorsal fin and back injuries likely caused by an outboard motor has been identified as an individual frequently spotted in Hong Kong waters off Lantau Island (see map below). The individual designated WL212 was identified by cross-referencing against a photographic database of dorsal fin markings. This allows us to make the before and after comparison of the injuries in the featured image courtesy of the HKDCS (HK Dolphin Conservation Society).

2015/01/img_8462.jpg

All images from HKDCS

Chinese White Dolphin’s Back Slashed Likely Caused by Outboard Motor

A Chinese white dolphin was spotted off the coast of Tai O with slash injuries across its fin and back believed to have been caused by a collision with a tour boat’s outboard motor.

Despite the injuries – some of which appear to be several inches deep – a marine scientist who observed the dolphin believes it still has a fighting chance. But tour guides operating dolphin-spotting excursions were warned to steer clear of it.

The dolphin was found near Tai O village at around 4.30pm on Saturday (17th of January 2015). Video and photos taken by members of the University of Hong Kong Swire Institute of Marine Science, clearly show the dolphin swimming along with large gashes on its back and tail.

Dolphin Conservation Society chairman Samuel Hung suspected they have been caused by propeller cuts from the outboard engine of a walla-walla – a type of small motorboat common in local waters which are often seen in the area for dolphin-spotting tours.

“The injuries are very serious,” said Hung, but despite the cuts the dolphin appeared “surprisingly tough” and was seen swimming, rolling around and even feeding on fish near the water’s surface.

Many more motorised tour boats arrived at the scene to view the injured dolphin by late Saturday afternoon putting the animal at greater risk. Hung urged all tour boats not to get too close to the dolphin. He also said that at this point, based on its behaviour, the dolphin would not require further intervention such as rescue or rehabilitation. “The last thing we want to do is to disturb this animal further,” he said.

The 2013 survey estimate of the number of dolphins in west, northwest and northeast Lantau areas is 62 dolphins (similar to the 2012 estimate). That is the lowest of the past decade.