top of page

Successful Collection of Hong Kong Estuary Samples in Both Dry Season and Wet Season

By Xitong Fu

The sampling campaign for the first phase of the Global Estuaries Monitoring (GEM) Programme, launched in July 2023, has been progressing smoothly. To date, over 120 estuaries have been approved for sampling, and samples from more than 60 global estuaries have been sent to the State Key Laboratory of Marine Pollution (SKLMP) at City University of Hong Kong for further analysis.

During the dry season of Hong Kong in March 2024, the GEM Research Team from SKLMP successfully completed the second round of sampling in six rivers and estuaries within the region. Following the first round of sampling during the wet season in August 2023, all samples required for the first phase of the GEM Programme have been collected.

Figure 1 A sampling site located in a mangrove wetland. The GEM team was sampling and recording.

The selection of sampling locations in Hong Kong was conducted with careful consideration to enhance the representativeness of the monitoring data. The campaign covered the selected rivers, including Kai Tak River, Shing Mun River, Lam Tsuen River, Tuen Mun River, Kam Tin River, and Shan Pui River, from their upstream areas to the estuaries. The standardized method of water sampling, utilizing the GEM sampling kits, was strictly adhered to during the collection process.

Figure 2 The filtration was conducted before transferring the water from the sampling bucket to the glass bottles.

Additionally, we are pleased to confirm the effectiveness of our filter kit. For turbid water, we recommend allowing a settlement time of three minutes before filtration.

Figure 3 Comparison of sampled water before settlement and after settlement and filtration, from one of the sites in the dry season.

Following sample collection, the GEM Team promptly initiated the pre-treatment process. Similar to the samples collected by our global partners, our samples underwent standardized and robust solid-phase extraction for further analysis.

During our sampling and recording activities, we had the opportunity to engage with local residents who expressed their concern for water quality. Some elders shared their insights into the history of the rivers and how these water bodies have influenced their lives. We also interacted with enthusiastic young students who displayed a keen interest in our work. It was a valuable experience for our team to exchange ideas with these important stakeholders - the citizens residing around the estuaries. We believe that this concept of stakeholder engagement is spreading among our global partners as well.

As the first phase of the GEM Programme is set to conclude by the end of this year, we encourage partners who have not yet submitted their sampling proposals to take prompt action. For inquiries or further information, please contact us via email at

Stay tuned for future updates as GEM continues its vital work in safeguarding our estuaries for future generations.


Editor’s Note:

The Global Estuaries Monitoring (GEM) Programme aims to monitor and assess the health of estuaries worldwide. Through international collaboration, GEM seeks to provide reliable and transparent data for supporting informed decisions on water quality management.


bottom of page