Seminar on ‘two sessions’ held

Hairy crab report clarified

The Environmental Protection Department today clarified that dioxins found in hairy crabs in Ha Pak Nai crab farm were unrelated to the surrounding environment.


The department made the clarification in response to a recent media report on dioxins found in hairy crab samples from a Ha Pak Nai crab farm exceeding the limit suspected to be due to nearby rivers contaminated by the New Territories West (WENT) Landfill.


It noted that sampling and testing results showed that the river water was not polluted, while detailed dioxin composition analysis further confirmed that the source of dioxins in hairy crabs was not from the environment or landfill near the crab farm.


Upon receiving complaints last year, the department collected water and sediment samples along Tai Shui Hang between the WENT Landfill and the Ha Pak Nai crab farm for testing in September and October.


The analytical results showed that no dioxins were detected in the water sample, and the levels of dioxin and dioxin-like polychlorinated biphenyls (DL-PCBs) in the sediment samples were also very low, similar to those of normal environmental background levels.


The department explained that it conducted a detailed comparison of the compositions of dioxins in hairy crab tissue samples from the crab farm and that of sediment samples from Tai Shui Hang.


It was found that the composition of the two sets of samples was completely different, indicating that the source of dioxins contaminating the hairy crabs was not from the environment or the landfill near the crab farm.


The WENT Landfill has been designed and constructed as a secure containment facility incorporating multilayer composite liner systems covering the entire surface area of the site. All contaminated effluent within the landfill is collected and treated to ensure that there will not be any contaminated discharge from the landfill to the rivers nearby.


The department also conducts regular river water quality monitoring at Tai Shui Hang. The results showed that the water quality has been maintained at an excellent level, the aquatic ecosystem remained normal, and there were no signs of pollution.

Since hairy crabs have a high fat content and are bottom dwellers, it is comparatively easy for their meat to accumulate dioxins.


During the culture period, if hairy crabs are affected by other human factors, such as using dioxin-contaminated feed or introducing dioxin-contaminated organisms to the culture environment, the farm and its hairy crabs will be exposed to dioxin contamination.


The Government will continue supporting local farmers in hairy crab culture. To reduce the possibility of the above-mentioned situation, the Agriculture, Fisheries, & Conservation Department will strengthen the monitoring of local hairy crab farms, including increasing the sampling and testing of feed as well as requiring the farm operators to implement biosecurity measures strictly.