Shorebird Hg project

Baseline characterization of mercury levels and its potential toxicity in shorebirds in Mai Po Nature Reserve and Deep Bay

Environmental Research, Technology Demonstration and Conference Project funded by Environment and Conservation Fund (#92/2022)

Research Summary

In view of the paucity of mercury (Hg) data in shorebirds along the East Asian-Australasian Flyway, this project was initiated and funded by ECF (#92/2022) to examine the Hg levels among different commonly encountered shorebird species in Mai Po Nature Reserve and Deep Bay. In short, our team worked with Hong Kong Waterbirds Ringing Group to conduct multiple shorebird sampling in Mai Po Nature Reserve (at Gei Wai), and all bird sampling was conducted at night time and our team collected the feathers for subsqeunt Hg analysis using thermal decomposition method:

Research Results

From 2023-2025, our team has collected a total of 189 shorebird individuals. Among the collected, we have a total of 16 shorebird species but 5 shorebird species (see below) represent ~87% of those collected. Thus, the following diagram shows the relative contamination risk of Hg in these common shorebirds based on knowledge about Hg toxicity from other studies. Overall, we can see that only a portion (up to 25%) of 3 shorebird species have members under moderate to severe risk. The underlying reason why other species are at no/low risk at all is unknown and will be researched in future studies. Furthermore, our team examined Hg levels among the lower trophic level organisms in Mai Po Nature Reserve and so far did not observed elevated Hg levels, and thus high levels of Hg in shorebirds may potentially not obtain from feeding on local prey items in Mai Po Nature Reserve:

Research Outreach

So far, we hosted a variety of outreach programmes under the project "Baseline characterization of mercury levels and its potential toxicity in shorebirds in Mai Po Nature Reserve and Deep Bay". We have partnered with non-government nature education organisations to develop and deliver educational activities and social media materials to promote our research findings. We wish to enhance the public's awareness on heavy metal contamination and its implications to our ecosystems and human wellbeing. Below are our new video promoting mercury and mangrove ecosystems (in Cantonese with English subtitle):

Our newly designed pamphlet can be downloaded below (in English and Traditional Chinese):