Go Green: Fish regain way home when oyster migrants settle down at Pinglu Canal

As of August 29, the Pinglu Canal has completed a total investment of approximately 38.67 billion yuan. This key project of the New Western Land-Sea Corridor is moving closer to realizing the original vision. The world's top inland river water-saving locks include the Madao Hub Lock and the Qishi Hub Lock. Additionally, there is the largest domestic mutual irrigation and drainage water-saving lock, the Youth Hub Lock. All of them are in full swing now. The goal for this world-class canal is to achieve a “smooth river, clear water, fish-friendly zone, green bank, beautiful scenery, and low carbon” environment. This canal is dedicated to becoming an optimal ecological protection model for the integration of engineering and natural protaction.

Oyster migration

The Pinglu Canal starts at the Pingtang River-mouth in Xijin Reservoir, Hengzhou City of Nanning, and it flows into the Beibu Gulf along the Qinjiang River through Luwu Town, Lingshan County of Qinzhou. It has a total length of 134.2 kilometers, with the downstream section being approximately 114.5 kilometers. All three major hubs and the estuary are located within Qinzhou.

Qinzhou is famous for being the home of the Chinese oyster, scientifically known as Ostrea rivularis Gould. The sight of the ten-mile oyster farm in the Maowei enclosed sea is truly spectacular. How can we ensure the sustainable development of the local oyster farm and minimize the impact of canal construction on marine ecology?

He Junhui, the Minister of the Engineering Management Department at Pinglu Canal Group Co., Ltd., stated that before the construction of the project, they ensured that the oyster farm was maintained at a safe distance to prevent pollution. They worked closely with local oyster farmers to optimize the pipeline layout, specifically keeping the mud drainage pipeline away from the oyster growing areas.

He Xiaowen, Chief Engineer of Pinglu Canal Waterway 15 Project, CCCC Tianjin Waterway Bureau Co., said, “We moved the natural oyster germplasm resources around the shipping lane of the Maowei enclosed sea to temporarily raise in the waters nearby the Longmen Bridge. This was an oyster migration. We collected a total of 20,771 oyster parents and kept their survival rate of more than 90% through careful management.”

“We are currently working on oyster ecological restoration. We plan to carry out an oyster ecological resources restoration project in the other waters of the Maowei enclosed sea. This project aims to significantly improve the ecological environment and restore oyster resources by creating suitable habitats, replenishing the oyster population, establishing reefs, and enhancing and releasing to minimize the impact of canal construction on the oyster population.”

Fish regain way home

In the Youth Hub Lock, a way home for the fish is being built after a 65-year interruption.

Minister He Junhui stated that a Youth Lock was constructed in 1959 to address seawater intrusion and make it drinkable. However, the lock also prevented seawater from reaching certain areas, causing fish such as marbled eels to lose their way back home. In order to protect the migration and breeding of fish and improve the ecological environment, the Youth Hub Lock was intentionally designed to create a green and cost-effective path for migrating fish.

“This is a special path for mitten crabs and marbled eels.” said Chief Engineer Liu Fei. After fully investigating the habits of local fish, they constructed a 480-meter-long vertical fishway and a passage for the eels to meet the migratory needs of different fish.

“The fishway inlet is located at the tail of the hydropower station and utilizes flow velocity to attract fish. It will soon undergo testing for use.” The fishway consists of 120 separate rooms and the Qingjiang River flows through it continuously. Looking at the fishway, the chief engineer Liu Fei informed the journalist that migrating marbled eels, perches, and mitten crabs, which originally inhabited the area 65 years ago, would be visible along the fishway.

To protect animal migration along the Canal, customized passages for animals have been created in the Yue Ling section and there are dual passages at the Jintang Village Bridge, located upstream of the Madao Hub Lock. The area has been planted with a variety of vegetation to recreate the natural habitat for animals such as squirrels, wild boars, and leopard cats. This aims to facilitate the movement of local wildlife between both sides of the Canal.

Transplant the Ocean Escort

The Pinglu Canal flows through the Guangxi Maowei Mangrove Nature Reserve, which is the second-largest mangrove nature reserve in China.

From the Youth Hub along the Qinjiang River, numerous factory ships roar upon the river. The vast cutter suction dredger Tianhua at the estuary forges ahead to crush sand and gravel, then sends them through the mud pump to a temporary waste disposal site 1200 meters away. Contrasting with the bustling scene, the mangrove forests stretching for hundreds of meters along the riverside thrive and live in peace.

Mangrove forests, also known as Ocean Escorts, play a crucial role in purifying seawater, reducing wind and wave impact, preserving biodiversity, and storing carbon. Minister He Junhui stated that to protect this valuable ecological resource, the project has installed anti-fouling curtains around the construction area to prevent suspended materials from entering. Furthermore, the project has undertaken mangrove transplantation and off-site recovery, with a total of 9,572 mangrove trees transplanted and 275,000 planted in the vicinity.

"The project has established a dedicated team for mangrove protection. This team conducts daily field patrols and regularly uses drone aerial photography to closely monitor changes in the mangrove environment," said the chief engineer He Xiaowen. In addition to these measures, they also regularly or frequently clean the dirt attached to the roots, stems, and leaves of the mangrove trees. On the other hand, they collaborate with the Forestry Bureau of Qinzhou City to carry out mangrove pest control and jointly protect this ecosystem."

The project involves relocating 37 ancient trees to protect them within the designated area of the Canal land acquisition. Additionally, it includes implementing in-situ protection and monitoring for 128 ancient trees within a one-kilometer buffer of the Canal boundary. Protection files have been created for those trees. (End)