Involved Members: Dr. Siu Gin CHEUNG, Dr. Chun Kit KWOK, Prof. Kenneth Mei Yee LEUNG, Prof. Jianwen QIU

This study provides up-to-date the distribution and abundance of amphioxus at 23 sites spanning the eastern, southern and southwestern waters of Hong Kong. Amphioxus is classified as a Class II protected species in China. This study also elaborated the relationship between amphioxus abundance and environmental factors. The results show that amphioxus strongly prefer shallow seabed with coarse sandy sediment and low organic matter content, indicating that subtle changes in substratum and water quality may alter the distribution and abundance of amphioxus in Hong Kong. It is suggested that cautious planning in coastal development is required so as to minimize anthropogenic disturbance and pollution in the core habitats of amphioxus. The study also reveals seasonal differences in population size structure, with higher percentages of juveniles in the dry season, indicating reproductive seasonality in amphioxus.

Reference:
Au, M.F., Au, H.M., Chu, W.K., Kwok, C.K., Cheung, S.G., Leung, K.M.Y., Qiu, J.W., (2023). Spatial distribution, abundance, seasonality and environmental relationship of amphioxus in subtropical Hong Kong waters. Regional Studies in Marine Science, 57, 102726. (impact factor: 2.166)