By Xiong Zhang
Before my recent trip home to China, I discovered a folk tale that explains why seahorses are used as a traditional medicine. It goes something like this:
Once upon a time there was a fisher living on the coast of South China Sea. While fishing one day he saw a shiny body drifting away in the deep sea. He rowed his boat to the body and discovered that it was a mermaid who was badly injured. The fisher rescued the dying mermaid and cured her with some herbal medicines. In order to thank the fisher, the mermaid gave him a shiny pearl and told him that whenever he needed her help he could throw that pearl into the water with a message, and she would come to help him.
A few years passed. The fisher got married and his wife became pregnant. He was very happy. However, during childbirth his wife had a very difficult labor, and the fisher was afraid she might not survive. In that moment he recalled the mermaid and her promise. He rushed to the sea and sent the message with the pearl. Then the mermaid appeared with a magical medicine — a finger-length fish that has a horse-like head, a weird pouch, and a curved tail. The fisher brought the “medicine” home to his wife and she ate it. Soon after, she delivered a healthy boy.
The fisher visited the mermaid again to thank her. He persuaded her to drive these magical fishes into the shallow seas where they could be easily captured by fishers to help more women during childbirth. Since then, this magical fish — the seahorse — has lived in China’s shallow waters to ensure the safety of pregnant women and their babies.
I was surprised and amazed by this story, which I’d never heard before, even though I grew up in China and, as a PhD student with Project Seahorse, am now studying seahorses and their distribution patterns, their habitats, and their reaction to human pressures. The reality is that most Chinese people don’t know this story, either. They only know that dried seahorses are used as traditional treatments for infertility and obstructed childbirth (dystocia), and have been used this way for a very long time.
On my visit to Shanghai in June, I was struck by how little most people know about seahorses. At Shanghai Ocean Aquarium, one of the biggest aquariums in China, I spoke to some of the visitors at the seahorse display. I asked them what they knew about these charismatic animals and the threats to their conservation. Most people gave me a polite smile but they weren’t at all interested in learning more about seahorses.
I must admit that I felt a little frustrated by this at first. As a young scientist, I want my research to be more than just research. I want to inspire people to learn more about seahorses and rethink about what we should and can do for the sustainability of seahorse exploitation in China and all over the world.
But visiting Dr. Qiang Lin, a colleague in the Laboratory of Marine Bio-resource Sustainable Utilization, South China Sea Institute of Oceanology, has doubled my resolve. He is the leader of the only seahorse research team in China, conducting studies on seahorses in various fields including behavioral ecology, evolutionary biology, and conservation biology. He explained to me that the domestic production of cultured seahorses is around five million animals per year, while his preliminary research suggests the annual illegal domestic catch of wild seahorses could be as high as 12 to 15 million.
Under increasing pressure from overexploitation, seahorses are becoming very rare in many of China’s coastal waters. Based one of his early studies, the domestic demand for dried seahorses is about 600 tonnes per year, but only about 5% of the volume can be satisfied by China’s own seahorse populations. To meet this demand, China has become the largest importer on seahorse trade, importing dried seahorses from all over the world. Vietnam and the Philippines are among those major countries who export seahorses to China. Along with development of tonic and medicine industries and the increasing demand, the prices of seahorse products are rocketing. Dried seahorses can be sold at a price of $2,500 per kg in Hong Kong, for example.
Facing this pressing issue, Dr. Qiang Lin and his team have conducted impressive studies on seahorse conservation and sustainable use in China. They have completed the whole genome sequencing of seahorses, and are currently exploring the genetic diversity and evolution of wild seahorses in order to build a strong foundation for seahorse conservation in China. They are also conducting seahorse aquaculture and creating new breeding stocks as an indirect way to relieve the pressure on wild populations from overfishing.
They have also completed a decade-long survey (2004–14) on wild seahorse populations in China’s seas – Bohai Sea, Yellow Sea, East Sea and South China Sea. This is extremely important work that will influence my own research. We have agreed to cooperate on seahorse conservation in the future in order to uncover more about the “reality” of wild seahorses in China. I believe this cooperation will be rewarding and hope that it will be the start of a larger movement to raise awareness about seahorses and marine conservation in China.