Dongting Lake Field Trip – Day 2

On November 14, 2019, we arrived at Yueyang, Hunan, for the second day of our study tour. Here is Dongting Lake, the birthplace of traditional Chinese culture. Our group boarded a yacht to get close to the Yangtze finless porpoise, a Class I nationally protected animal.

The Yangtze finless porpoise is an endangered species in the world, and only about 300 remain in Dongting Lake. But under the protection of the goddess of luck, we were fortunate enough to see the porpoises and to record the moment they surfaced.

On the yacht, with the sea breeze blowing, blue sky and white clouds overhead, we unexpectedly spotted two black arcs on the water. "Those are porpoises!" the classmates shouted with delight. In the instant the porpoises broke the surface, several classmates took out their cameras and captured their graceful posture.

On the small island where the lookout tower stands, the classmates met two "guardians." They were two dogs adopted by the staff. While feeding them, several classmates, all for the great cause of "study tour," sank into the marsh and sacrificed their shoes. After these small mishaps, we prepared to head back.

Suddenly, a huge vessel appeared. Brother Dao said, "Look over there. Ahead is probably illegal sand dredging. Sand dredging is strictly prohibited across the entire Dongting Lake waterway." Hearing this, we were indignant yet helpless. All we could do was report it to the relevant national authorities. But then I thought: the witness of the public is the best deterrent to illegal sand dredgers. Through us, they felt society's attention, and we truly contributed to the cause of protecting the porpoises!

The sound of a siren rang out. We knew the maritime safety staff had arrived and believed the lawbreakers would be severely punished. However, the maritime staff explained to us: "That is a dredging vessel with legal permits." We only held our cameras, said nothing, and quietly recorded this scene: sand shoveled up bucket by bucket, money banked bundle by bundle. All we could do was this.

Human nature is complex, and merchants pursue profit. But the world is not always dark. That ray of light will be lit by us. In the darkness, we light a lamp to illuminate the darkness and warm people's hearts.

After lunch we rested briefly, cleaned the mud off our shoes and clothes, and began the two experimental surveys of the afternoon.

The first experiment was on benthic organisms. We used the professional instrument Mr. Liu brought along, the Peterson grab sampler. After we hauled up the bottom sediment, we went through layers of filtering and multiple procedures to screen out samples suitable for collecting organisms. Then we used tweezers to collect snails, freshwater snails, dragonfly larvae, and other organisms into bottles. In this way, we could judge whether the water quality was good based on the organisms collected.

Through Mr. Liu's explanation, we learned that when dragonfly larvae appear in a body of water, it indicates good water quality, while leeches appearing indicates severe pollution. In the experiment, our group was lucky enough to collect dragonfly larvae, along with some shells and freshwater snails. This shows that the water quality of Dongting Lake is relatively good.

The second experiment was to judge water quality by using pH test strips and data on ammonia nitrogen and potassium permanganate in the sample water. We compared samples from a sewage discharge point and from the lake's surface water, and found that the water at the sewage outlet was seriously polluted and far exceeded the standard. This shows that it is no wonder some factories cause such harm to the environment. Unfortunately, even though we discovered this problem, we could not stop the polluting behavior and could only return the samples to the lake.

After dinner, we drove back to the hotel and went to the second-floor conference room for the summary meeting of the day. First, Mr. Liu introduced the plan for tomorrow: visiting the Institute of Hydrobiology and the translocation protection area, and told us the goals and precautions for tomorrow. Then he summarized today's schedule. Through this meeting we realized that a study tour emphasizes "study" rather than "tour." We must look through phenomena to the essential problems and offer suggestions on the corresponding issues. Finally, today's itinerary came to a close with a documentary Mr. Liu had made earlier, on his survey of the porpoises during the Yangtze River cruise.

Tomorrow is both a new beginning and the day we return home. We will surely cherish the opportunity to visit the Institute, and we hope there will be no regrets tomorrow!