A Chinese businessman who made a living off the ocean now spends his time and money on scooping trash from the waters.
With a rumble of engine noise, the garbage collection ship Canghai No. 9 returned from its 438th mission and moored in the port of Shengsi island in Zhoushan City in east China's Zhejiang Province.
Measuring 16.5 meters long by 3.6 meters wide, the ship has a loading capacity of 21 tonnes. Its deck held a big basket of trash, including plastic bags, bottles and disposable meal boxes.
Its owner, Yang Shichai, was busy moving trash collected from the ocean off the ship. Its final destination would be a garbage treatment plant on the island.
Designed by Yang himself, the trash-collecting ship cost him around 530,000 yuan (80,800 U.S. dollars) to build.
The ship has retrieved more than 2,000 cubic meters of garbage from the ocean since it was put into use in May 2016.
"I've earned some money because of the ocean. I just want to give back to it what I've gained," said Yang, who has tanned skin and scars on his hands from working long hours outdoors every day.
Growing up along the shore, he started a refueling service for ships at sea at the age of 18. Later, he set up a company dedicated to recycling the oil residue.
But his focus shifted from profits to the ocean itself because of a video.
"A dead whale was found in the Pacific. Its belly was full of trash after being opened," Yang recalled. "The horrible scene from that video sticks in my mind."
Yang said that he is not well educated, but he understands one principle: if you live near the ocean, you must protect it because you rely on it to raise your family.
A study published in Science in 2015 estimated that 8 million tonnes of plastic waste are dumped in the ocean each year. Plastic waste affects marine wildlife such as sea birds and fish, which can become entangled or choked by it.
Yang recalled that the water surrounding Shengsi island was crystal blue 20 years ago. However, swarms of tourists and overdevelopment of coastlines have posed a serious risk to local marine ecology.
"If the situation continued, the fish and shrimp would disappear one day. A trash-collecting ship was what we needed most," he said.
But local shipbuilding workshops did not know how to build the ship he wanted, so Yang had to design it himself.
"If it's too big, it cannot enter the harbor; If it's too small, it can't resist strong wind and waves," said Yang, who changed his design many times.
After the "Canghai No. 9" was built, Yang employed three crew members to clean up the ocean trash within a 90-plus-km radius of Shengsi island. The ship goes to sea every day except when there is extreme weather or the crew is on leave.
His expenses reach at least 700,000 yuan each year for the crew's wages, diesel and maintenance fees.
"It's big money," said Yang. He set himself a target -- collecting trash in the ocean for another 10 years, as long as he can afford it.
China has adopted a string of measures to ease environmental strain, ranging from coral restoration campaigns and clamping down on illegal wastewater discharge to treating polluted rivers and launching public education activities.
It's difficult to find a good way to collect and manage the garbage in the ocean, he said.
"Encouraging people to throw their trash into the right place is the most important thing," said Yang.