Press Release

HKBU PhD student Yixuan Li participated in a deep-sea research cruise


Figure 1 R/V "Xiangyanghong 01" and ROV "Pioneer" in the South China Sea (Photographed by Yixuan Li)

Figure 2 Underwater sampling by ROV “Pioneer” in the Haima cold seep region (Photographed by Yixuan Li)

Figure 3 Sorting specimens sampled by ROV "Pioneer" on board (Photographed by Qintao Yin from FIO)

Figure 4 Group photo for all involved in this cruise (Photographed by Qintao Yin from FIO)


Yixuan Li, a Year 3 PhD student from Prof. Qiu Jianwen's Lab, Department of Biology of HKBU embarked on a journey to the deep sea in the South China Sea earlier. Read below to discover her amazing sea journey and sharing.


“As a PhD student studying deep-sea biology, I have always been dreaming that I could see the vivid animal communities on the sea floor. In July 2022, I was informed that there was an exciting chance for me to participate in an expedition on the Haima cold seep in August aboard one of the most advanced research vessels - R/V “Xiangyanghong 01” in China from the First Institute of Oceanography, Ministry of Natural Resources. This cruise was special because this was also the first exploration journey in the deep sea for the new ROV (Remotely Operated Underwater Vehicle) named “Pioneer” manufactured in mainland China by SMD company (Shanghai, China).


Haima cold seep, our research region, locates in the southeast direction of Hainan Island, South China Sea, China. It is a large area containing the typical chemosynthetic ecosystem with methane gas leakage from the sea floor. It is called a cold seep because the water temperature here is around 3°C at ~1400m depth, lower than the water at the hydrothermal vents-another type of chemosynthetic ecosystem – which releases boiling water. From 2018 to 2022, my supervisor Prof. Qiu Jianwen and collaborators participated in several expeditions in this region to study the ecology and biodiversity of this ecosystem. So as a freshman in deep-sea research, I was curious to see how thriving benthic communities exist below 1400m depth and how to sample these animals.


I spent a total of one month at sea and witnessed multiple ROV dives. I observed the thriving mussel beds, clam beds, swimming scallops, crustaceans, sea anemones, echinoderms, and benthic fish, that comprise the complex, beautiful, and vulnerable community. We measured the environmental parameters and collected water and biological samples, and conducted field experiments. Apart from using ROV, we also deployed box corer and gravity core from the ship to collect samples.


My work mainly involved the biodiversity of cold-seep community. I have found some exciting new animals during this cruise, such as deep-sea hermit crabs, and many new worms and molluscs. At HKBU, I am identifying them using an integrated molecular and morphological approach. Overall, I have gained first-handed experience in deep-sea research through this journey. The invaluable samples will greatly enhance the quality of my PhD thesis.”