. Conclusions
The foregoing findings revealed that, despite unclear spatial
variation, heavy metal pollution in Nansha mangrove was very
serious probably owing to the discharge of industrial sewage in the
region of the PRE. Consequently, the ecological risk of heavy
metals, largely due to Cd, in Nansha mangrove was very high.
The core sediment samples revealed that heavy metal pollution,
except Mn, in Nansha mangrove has been deteriorating at a
relatively constant rate from 1979 onwards. Unfortunately, the
dominant plants in Nansha mangrove, including C. malaccensis and
S. apetala, had limited capability to immobilize, extract and
translocate the heavy metals. Therefore, inspection of the potential
sources should be enforced immediately, whereas environmental
policy, such as regulating the discharge standards of industrial
sewage, should be implemented to alleviate the heavy metal
pollution so that the public health and integrity of Nansha
mangrove can be maintained sustainably