Tianjin sees improved marine biodiversity

Efforts to enhance marine environment and biodiversity are bearing in north China’s Tianjin municipality, a metropolis on the shore of the Bohai Sea.

In 2018, the municipality initiated a comprehensive treatment campaign for the Bohai Sea. It has restored 531.87 hectares of coastal wetland and 8.3 kilometers of coastline. In 2021, good water quality was observed in 70.4 percent of Tianjin’s offshore areas, up 53.8 percent from 2017.

Nearly 10,000 four-gilled perch fries are released into the Bohai Sea during an activity held by Tianjin Port Second Container Terminal Co., Ltd., June 2021. (Photo courtesy of the convergence media center of Tianjin's Binhai New Area)

To offer a sound habitat for seabirds, the municipality has grown Suaeda salsa, reed and other plants on waterfront. Its coastal landscape is now attracting a considerable number of visitors.

However, things were not like this in the past.

“In late 1980s, local aquatic products such as fleshy prawns and swimming crabs were still available on the market, but later they gradually disappeared,” said a citizen surnamed Ye who has been running a seafood restaurant in Tianjin’s Heping district for nearly 40 years.

The Bohai Sea was once one of the four major fisheries of China. However, overfishing, pollution and other issues led to decreasing biodiversity in the region. According to statistics released by the Ministry of Agriculture and Rural Affairs in 2018, the types of fish spawning in the Bohai Sea was only around half of those 40 years ago, and the resource abundance was less than 1/10 of the 1980s level.

The decline in biodiversity was caused by a multitude of factors, but marine ecology generally determines marine biodiversity.

“The marine ecology is the foundation for biodiversity. Only by making this foundation solid can we improve marine biodiversity,” said Tu Jianbo, head of the pollution monitoring station of Tianjin's monitoring center for marine environment.

As the comprehensive treatment campaign for the Bohai Sea came to an end, Tianjin has basically contained the eco-environment degradation in offshore areas.

“Smallhead hairtail fish, baby croakers, and Spanish mackerels, which once disappeared in the waters, are now seen here. Syngnathus and other rare species are also observed. It indicates that we are making steady progress in building a sound eco-environment,” said Dr. Zhang Dajuan, an expert of offshore biological studies with Tianjin Agricultural University.

To further facilitate the recovery of biodiversity and improve biocoenosis structure, Tianjin is releasing aquatic fingerlings into the Bohai Sea each year.

This year, the municipality has put 20 types of juvenile fish, shrimps, crabs, and shellfish, which add up to 1 billion, into the Bohai Sea and important inland fisheries.

Dongjiang Park is a remarkable outcome of a comprehensive treatment campaign for the Bohai Sea launched by north China's Tianjin municipality. Wetlands and ecosystem along the coastline in the park have been restored. Viewing platforms, sports fields, playgrounds and other leisure and entertainment facilities have also been built there. (Photo courtesy of the convergence media center of Tianjin's Binhai New Area)

Besides, Tianjin has extended its three-month summer close season by another 30 days. As a result, the total marine capture is down by 25 percent from that in 2015.

On this year’s national fish releasing day, which falls on June 6 each year, Tianjin held a releasing activity in its Binhai New Area, during which more than 1 million juvenile fish and shrimps were released.

“These fries were all bred by the Tianjin Aquatic Products Research Institute,” Liu Kefeng, deputy director of the institute, explained.

“Fish releasing is similar to ploughing. It relies on breeding,” Gao Yinfu, an official with Tianjin Municipal Commission of Agricultural and Rural Affairs, told People’s Daily.

According to him, Tianjin has launched a number of fish breeding projects and fostered a batch of breeding enterprises, cooperatives and breeders. Currently, the municipality produces 30 premium varieties of juvenile freshwater and marine fish, shrimp and crab, which play an important role in optimizing the culturing structure, improving profitability of the fishery industry and safeguarding fishery germplasm resources.

Photo shows the Nanwan ecological park in north China's Tianjin municipality. (Photo courtesy of the convergence media center of Tianjin's Binhai New Area)

Gao introduced that apart from releasing fries, Tianjin is also building marine ranches to improve the marine ecology. So far, the municipality has established a national-level demonstration marine ranch, launched over 30,000 artificial fish shelters, and built a reef area covering around 13 square kilometers, which have prominently expanded local marine carbon sink and purified the sea water.

Thanks to the improved biodiversity in the Bohai Sea, fishermen’s capture today is 20 percent to 30 percent more than that before, said fisherman Li Yongquan. According to him, Tianjin also encourages fishermen to join marine ecological conservation, offering 30 percent subsidy for those who install an emission purification system on their fishing-boats.