Ha Long Bay (Viet Nam) Sediment and Microfaunal Background Assessment for Future Monitoring Actions

In order to assess the quality of the Ha Long bay environment we performed sampling campaign in April 2003, January 2004 and more recently in August 2018. Sedimentological, microfauna and calcareous nannofossil analyses have been conducted on samples collected in different location of the bay. This allowed obtaining preliminary description of the sedimentary environment and a census of the benthic microfauna to assess the biodiversity and to start to create a database in order to monitor the change in time of the organism distribution. In fact, the identification of indicators that, based on the knowledge of past events, can reveal in advance the changes to come in such a way as to proactively prepare the instruments for their mitigation. These are bio geological indicators whose use in environmental analysis is expected to be very interesting. In particular, a group of protozoa with a calcareous shell (Foraminifera) seems very promising. The fact that these organisms leave an imprint in the ancient sediments (but also simply “old”) allows to reconstruct the “pre-impacts”, and to compare them with the “impacted” modern conditions therefore to recognize a baseline condition to obtain useful information about possible actions suitable for the protection of the environment. This chapter illustrates the result of our analyses and is a base for future, more detailed studies.