From this study, the level of tourist intensity aligns with the le-
vel of pollution and, with seasonal variability, strongly affects
water quality parameters and condition of nearby coral reef com-
munities. The effect of anthropogenic sources of pollution was
not localised around the pollution source. It appeared to be trans-
ported to unpolluted sites by currents, especially in the wet season,
when secondary treated wastewater with high levels of nutrients
and particulate matter, because of poor maintenance standards,
adds to background levels.
Wastewater disposal and changed land-use related to tourism
activities are linked to marked spatial contrasts in water quality,
and these changes in environmental conditions propagate upwards
to cause significant shifts in the density and diversity of algae, per-
centage cover of corals, and fish abundance in coastal coral reef
communities.Accordingly, plans to improve and sustain the status of water
quality through effective sewage treatment as well as the long
term monitoring are necessary to ensure that marine environ-
ments are maintained to continue supporting Phuket, Phi Phi and
Surin asmajor tourist destinations. The immediate need is tomain-
tain existing sewage treatment plants so that effluent discharge
has a minimum of suspended solids. The longer term approach in-
volves the requirement for new plants to tertiary treat effluent and