I would like to correct some of the misconception that local SG seawater is not optimal to do aquaculture...
I've observed that from Chek Jawa to Woodlands mud flats and that at end of Lim Chu Kang, partially around the whole of Sentosa and even along some part of West Coast to the Keppel Bay Club area (near to Vivo), there are plenty of LPS, some SPS and various algae in these areas. Today I've even spotted 2 small clumps (baby's fist size) of brightly Sun Corals growing from the pontoon of the Keppel Bay Club where the leisure craft are moored. Sometime back in Oct/Nov 2011 when I was at Keppel Bay Club, I've also seen hard corals (SPS plates) growing out along those pontoons. Some are as huge as 30cm by 30cm.
So it's not really true that our local sea water is not good enuf rather it's that the focus and awareness of such LS ard SG (both on land and in the water) are not sufficient. Our culture is one that talks abt "monies and profit opportunities"... so all these talk abt Aqua-culturing and nature preservation are not really that "important" to the authorities. Unless these items can bring in the "big cash flow" if not, no one is really going to care abt them.
Oh BTW, it was also my first time to see a super big sea urchin (in the wild) clinging on the sea wall outside the Caribbean condo. It's size is really as huge as 30cm in diameter... not kidding.