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Stranded Hong Kong sea turtles full of plastic garbage

2021-02-09T13:43:20.003Z


Turtles play an important role in the marine ecosystem. They eat the seaweed that shields the sun and spreads germs; the seaweed that eats the belly is digested into manure, which provides nutrients for the animals and plants that inhabit the ocean. This size is big


World Topics

Written by: Luo Baoxi

2021-02-09 21:30

Last update date: 2021-02-09 21:30

Turtles play an important role in the marine ecosystem. They eat the seaweed that shields the sun and spreads germs; the seaweed that eats the belly is digested into manure, which provides nutrients for the animals and plants that inhabit the ocean.

This large, fast swimming and hard tortoise-shell animal lives in nature during the adult tortoise stage and has few natural enemies.

Unfortunately, due to the greed and selfish behavior of human beings, the habitat of marine life is seriously polluted, and some sea turtles are fatal by swallowing marine garbage by mistake.

The main sea turtles in Hong Kong are the green sea turtle and the leatherback turtle, the world's largest sea turtle species, both of which are endangered and protected animals. The Deep Bay Beach on Lamma Island was once the place where green sea turtles lay eggs.

Every year, about 10 to more than 20 sea turtles stranded and died in Hong Kong waters.

In addition to human factors such as fishing and being hit by a boat, some scientists have found a large amount of marine debris in some sea turtles.

Since August 2019, the Department of Clinical Animal Medicine and the State Key Laboratory of Marine Pollution, City University of Hong Kong have been approved by the Agriculture, Fisheries and Conservation Department to assist in the dissection and study of sea turtles stranded in Hong Kong waters, conduct comprehensive health assessment studies, and even analyze the cause of death .

They are also the first

team

in the world to use

*image anatomy technology to

study stranded sea turtles.

The team had studied 17 stranded sea turtles, including eight live cases and nine dead cases, involving two species of green sea turtles and leatherback turtles.

*Note: Image anatomy involves forensic radiology applications, such as computer scanning, magnetic resonance, ultrasound diagnosis, optical 3D surface scanning, and 3D photogrammetry to study living and dead organic matter without cutting muscles and bones.

The habitat of marine animals is seriously polluted, and the City University Marine Animal Imaging and Anatomy Research Group found a large amount of marine debris in the body of stranded sea turtles.

(Provided by CityU Marine Animal Imaging Anatomy Research Group)

In the first batch of seven corpse cases, six green turtles and one leatherback turtle were all under ten years old and underage. Most of them were found in the waters of eastern or southern Hong Kong.

Except for one sea turtle with obvious traces of being hit by a ship, a large amount of marine debris was found in five of the seven sea turtles, including fish shreds, fish hooks, plastic bags and wrapping paper.

"There is a sea turtle that has marine debris from the throat, esophagus, stomach to the large and small intestines, and even a complete surgical glove." Ge Zhanrong, visiting assistant professor in the Department of Clinical Animal Medicine of the City University of Hong Kong, who is in charge of the research project, told "Hong Kong 01" because The carcass of sea turtles is so decomposed that it is difficult to determine the cause of death, but the problem of marine debris is worthy of attention.

He added that sea turtles have the ability to remove small garbage from their bodies, and live turtles can even discharge plastic gloves.

If the trash accumulated in sea turtles is too large or too large, their intestines may become blocked, ulcers, or cause indigestion, nutritional deficiencies, and eventually chronic death.

Marine debris found in part of a beached turtle.

()

Ge Zhanrong pointed out that Hong Kong is not a big place, but a lot of marine debris has been found in sea turtles, reflecting serious marine pollution and that the problem is not limited to local waters.

He said that the wrapping paper in the turtles has traditional and simplified characters, and the source of the garbage needs further study.

"Sea turtles are migratory animals and do not only live in Hong Kong. We have tracked some sea turtles before and found that their activities range from Dongsha, Nansha, Hainan Island, and even the waters around Taiwan's Xiaoliuqiu Islands." He emphasized that if there is no regional cooperation , It is difficult to solve the problems of sea turtle ecology and marine pollution.

Ge Zhanrong pointed out that Hong Kong is not a big place, but a lot of marine debris was found in sea turtles, reflecting serious marine pollution.

(Provided by interviewee)

Microplastics enter the sea from small fish into the food chain

Since the large-scale production of plastics in the 1940s, it has had a catastrophic impact on marine life.

Studies have pointed out that 52% of sea turtles in the world have eaten marine debris, especially plastic bags that look and smell similar to jellyfish or seaweed.

A study by the University of Tokyo in Japan pointed out that when loggerhead sea turtles encounter plastic, they have a 17% chance of mistakenly identifying them as jellyfish, while green sea turtles have 62% of them eating them as seaweed.

In 2018, a team of scientists from the United Kingdom, the United States, and Australia studied seven species of sea turtles from the Atlantic, Pacific and Mediterranean, a total of 102 sea turtles, and found that all of them had eaten plastic.

The report said that more than 800 plastic products were found in the intestines of sea turtles. The actual number is more likely to be 20 times higher because they only sampled a small part of each turtle's digestive system for research.

(Hong Kong 01 drawing)

Eating plastic is a high-risk behavior for sea turtles, because 22% of sea turtles have the chance to be fatal after ingesting plastic. Not only the sharp plastic will damage the internal organs, but also the plastic bag will block the intestines, making the turtles unable to eat.

Even if it survives, eating plastic will cause turtles to float abnormally, or hinder growth, and slow down reproduction.

Based on the above background, the CityU Marine Animal Imaging Anatomy Research Group not only performed imaging anatomy for stranded sea turtles, but also cooperated with traditional anatomy to find out their cause of death and life history, calculate their age, species, and pathology, and explore whether they were injured by human activities. Wait.

The research results help to further understand the health status of marine animals and provide basic data for the management of Hong Kong waters, animal conservation and related policies.

They started a similar study on stranded cetaceans as early as 2014, and have so far performed imaging dissections on more than 221 cetaceans that have been stranded in Hong Kong and other waters around the world.

Ge Zhanrong and his team used anatomical techniques to analyze the life history and cause of death of stranded sea turtles.

(Provided by CityU Marine Animal Imaging Anatomy Research Group)

Summarizing the causes of death of these marine animals, Ge Zhanrong said that they can be roughly divided into three categories, namely, human factors such as ship strikes, natural factors such as diseases, and unknown causes (such as severe decay).

Ge Zhanrong said that marine pollution is roughly divided into "visible" and "invisible".

Visible pollution is large garbage. For example, "ghost nets" (discarded fishing nets) can entangle dolphins and sea turtles, making them unable to swim to the surface to breathe and cause death; or accidentally eating fish hooks, fishing lines and other sundries, which block the esophagus. And die.

Invisible pollution is small, or even invisible to the naked eye, such as microplastics and DDT pesticides, which may affect health in the long term after being absorbed by marine organisms.

Ge Zhanrong pointed out that after these compounds enter the ocean, they will be absorbed by small fishes, which are eaten by big fishes and then preyed by other larger marine creatures.

He emphasized: "These effects are not immediate. It may take years or even decades to see real effects. There are also opportunities to affect the next generation of these organisms, such as causing their immunity to decline, affecting the nervous system, etc., or reducing Their chances of survival."

Ge Zhanrong also carried out similar research on dolphins earlier.

(Provided by CityU Marine Animal Imaging Anatomy Research Group)

Related studies have found that dolphins are less affected by marine pollution than sea turtles. He believes that this may be related to many factors such as the species of dolphins in Hong Kong, their living habits, and the low water depth in Hong Kong.

He reiterated that dolphins are also affected by pollution, but it is still impossible to jump to conclusions from the cause of death, and more in-depth research is needed.

Ge Zhanrong and his team’s research revealed that plastics and garbage are a major problem of marine pollution.

These wastes may come from garbage dumped near the coast, they may also come from wind and rivers, or they may be brought by marine disasters such as shipwrecks.

In addition, some natural objects such as driftwood will also become marine debris.

Plastic is difficult to be biodegraded and easily eaten by marine organisms. It is a serious and major source of marine pollution.

Waste plastic often accumulates in ocean vortexes, forming garbage vortices.

One of the famous examples is the Great Pacific Garbage Patch, which is estimated to have an area of ​​1.6 million square kilometers in 2018, equivalent to 1,446 Hong Kong.

At present, plastic waste in the area accounts for about 80,000 tons, which is 4 to 16 times more than previous estimates.

Marine creatures such as sea turtles will mistake marine debris for food.

(Getty)

It is estimated that there are more than five trillion pieces of plastic debris floating in the ocean.

If we continue to produce plastic at the current rate, the amount of plastic in the ocean will exceed the total number of fish by 2050.

A 2019 report by the World Wide Fund for Nature (WWF) pointed out that a large amount of plastic is flowing into the ocean. Humans use about 500 billion plastic bags each year, which is equivalent to dumping a truckload of plastic into the sea every minute.

These rubbish seriously threaten marine life. In 2019, a dead sperm whale was found to contain up to 220 pounds of rubbish.

Restore the basic steps and go to the source of plastic daily to reduce waste

Ge Zhanrong touched and dissected a large number of marine organisms that died of pollution, and felt deeply: "We should start from the source to reduce waste. Most people can participate, such as daily "walking", reducing waste and avoiding the use of disposable products, and don’t mess around. Throw rubbish.” In addition, he reminded citizens to go hiking, going out to sea or going to the beach. If they see stranded marine life, they can immediately report to the AFCD or contact its research team.

Although it may not be able to save them, it can at least allow scientists to study their causes of death and living habits.

Reducing costs at the source may be something humans should do.

(Getty)

Ge Zhanrong and his team are collecting marine data and working with partners from mainland China, Japan, Thailand, New Zealand, and the United States to collect data on stranded marine animals and add them to the database after analysis.

However, he reiterated that these studies require long-term funding and support from people who are interested, otherwise similar studies may be unsustainable.

Under the concept of marine health integration, whether it is sea turtles, whales, or humans at the top of the food chain on land, protecting marine animals is also protecting ourselves, and it should be a part of the ocean.

In addition to avoiding waste, we should reduce the purchase of items that require ocean transportation, recycle them appropriately, and pay attention to chemicals that have the opportunity to enter the drainage system.

The above is excerpted from the 252th issue of "Hong Kong 01" Weekly (February 8, 2021) "The Silent Cry of Turtles Under Epidemic".

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Sea Turtle, Marine Pollution, Environmental Protection, Ecological Environment, Marine Ecology, World International Special 01 Weekly

Source: hk1

All news articles on 2021-02-09

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