Marine “elves” face a crisis of survival (East Asian Finless Porpoise)

Marine “elves” face a crisis of survival (East Asian Finless Porpoise)
East Asian Finless Porpoise

Not long ago, ecologists paid attention to the death of the East Asian finless porpoise. The bodies of twenty East Asian finless porpoises, large and small, were found near the shore of the Daling River inlet in Panjin, Liaoning. Finless porpoises are a family-style lifestyle, which is likely to be a whole population or a family “outdoor” event.

China to rescue Yangtze finless porpoise
Yangtze finless porpise (Picture credit: globaltimes.cn)

Most of the finless porpoises that have been found have been rotten and stinky. The estimated time of death should be within a month or so; some have peeled off their skin and have scratches on their bodies; others have full flesh, which may have just died shortly after.

Stranded finless porpoise in Zhuhai, Jiangxi Province, China.
Stranded finless porpoise in Zhuhai, China

Several ecological studies released the news for the first time, which attracted the attention of relevant departments through various channels. Volunteer leaders of Local Wetland Conservation Association and established the “East Asia finless porpoise death cause investigation working group”. Marine zoologists, marine experts, environmental journalists, marine police, grassroots fishermen, and other parties at home and abroad participated in pay attention to the survival crisis of East Asian finless porpoise.

The current analysis pinpoints several causes of death:
A dead finless porpoise was found washed up on shore of Poyang lake in Central China's Jiangxi Province, China.
A dead finless porpoise found on the shore of Poyang lake in China (Picture credit: globaltimes.cn)
  1. Near-shore environmental pollution. A large amount of waste produced by industrial and agricultural production and human life is discharged into the sea. After spreading in the nearby sea area and offshore oil production, a large number of oily substances are generated, which causes environmental pollution near the shore.
  2. Natural changes, such as changes in temperature and climate or ocean currents, finless porpoises do not adapt to changes in the environment but are affected by diseases and virus outbreaks in the body.
  3. Fishing by fishermen. The finless porpoise was accidentally injured while fishing and was discarded. Such a finless porpoise may have string marks or regular wounds on its body. However, the local fishermen said that this reason is unlikely, because the recent fishing ban period, the concentration of so many deaths, is not in line with common sense.
  4. Underwater explosions. Another marine biology expert is more skeptical, that is, underwater blasting and reef explosions nearby. Such human activities will have a great impact on finless porpoises. It will be fatal to finless porpoises passing by, and finless porpoises who like to go together will also be killed collectively.
  5. The characteristics of finless porpoise may also cause the death of finless porpoise. The finless porpoise has very strong motherhood. If the cub is caught by mistake, the mother and father will “sacrifice” with the cub, so once the cub is injured, a whole finless porpoise family may die together.
Dissection and examination of East Asian finless porpoise
Shortcomings in researches:

At present, humans are still in the initial stage of understanding the marine finless porpoise population. The finless porpoise (Neophocaena phocaenoides) is a marine mammal, and it will surface to ventilate at intervals. It only operates in the northern waters of the East China Sea, the Bohai Rim and the Yellow Sea, and some waters in South Korea and Japan.

World's only freshwater finless porpoise
The Yangtze river finless porpoise (Picture credit: Peter Parks/AFP/Getty)

Therefore, the statistics of finless porpoises are mainly observed by the naked eye and some acoustic methods at sea. Because the ocean area is wide and the sea state has a significant influence on the observation, it is impossible to carry out observations above the quaternary wind, so it is quite challenging to assess the number of finless porpoises.

We know that the available data is that there are only more than 1,000 Yangtze finless porpoises, and the number of East Asian finless porpoises is also very small. Therefore, it is the right way to protect the finless porpoise by actively investigating and publishing the results as soon as possible.

Overview

According to the analysis of the degree of corruption of dead finless porpoises, they did not die at the same time; no dead fish were found, and the cause of seawater pollution was basically ruled out; many dead finless porpoise bodies were found concentrated in the South Xiaohe waters, which was caused by ocean currents and tides.

At present, government departments and environmental NGOs at all levels are paying close attention to the situation in the sea area. The specific cause of death is unclear, and it is difficult to make a conclusion. Ecologists will continue to pay attention.

Related stories:

https://aquaticmammal.blogspot.com/2020/01/finless-porpoises-neophocaena.html

Read more:

http://oceanfacts.net/chinese-white-dolphin-resource-protection-is-not-optimistic/

http://oceanfacts.net/one-of-the-dolphin-but-looks-like-a-killer-whale-ankylorhiza-tiedemani/

Photo and video source credit :

The videos and pictures in this article refer to You-Tube, aquaticmammal.blogspot.com, and New Scientist.

Rajitha Dissanayake

Researcher in the field of Marine Mammals and Bio-acoustic

I'm a Master’s student in marine mammals and bio-acoustic laboratory, Institute of Deep-Sea Science and Engineering (IDSSE), Chinese Academy of Sciences (CAS) and focusing on the sustainable environmental application, conservation, and exploring all aspects of the ecology and behavior of marine mammals.