Re ECF Project: 2015-15

Project Title: Juvenile fish resources and nursery function of macroalgal beds in Hong Kong waters – a habitat-based study

Applicant: Professor LAM Kwan Sing Paul, State Key Laboratory in Marine Pollution (SKLMP), City University of Hong Kong

Total Approved Grant: $500,000

Duration: 1/7/2016 to 31/12/2017

Project Status/Remarks: Completed

This study aims to document a holistic picture on the associated juvenile fish resources and the nursery roles of local macroalgal beds (i.e. sargassum beds) in Hong Kong waters and to identify potential nursery hot-spots associated with these sargassum habitats. The findings of this study can provide comprehensive baseline information for future conservation, management and education purposes.

Summary of the Findings/Outcomes:
The research team studied the biodiversity and habitat-based pattern of juvenile fishes associated with local Sargassum beds. They collected a total of 146 species (52 families) of juvenile fish from different littoral habitats. During the vegetation period of the Sargassum fronds (January to May 2017), Sargassum beds were present in 24 of the 42 sampling sites. Of those 106 species (46 families) reported in the peak season, more than 70% (i.e., 75 species from 39 families) of juvenile species can be found in the Sargassum beds. Juvenile fishes collected in this study also exhibited strong seasonal and habitat-based patterns in terms of their species compositions, species richness (species number), abundance, and biomass. The results highlight that the seasonal Sargassum beds are an important juvenile habitat not only for local fish species but also for temperate deepsea species. Results were disseminated in a conference in October 2017. An education booth and presentation was held at the 7th Hong Kong Marine Life Carnival held from 30 September to 1 October 2017 in Sai Kung. The event aimed to introduce to the public the diversity and nursery habitats of juvenile fish in local waters, and attracted more than 500 local participants. A pdf flyer providing a species checklist of juveniles collected from the Sargassum beds and a map showing some potential nursery hot spots has been posted on the SKLMP website.