Staring out to sea only a few short kilometers from the hustle and bustle of Denpasar Indonesia, it would be easy to miss what is going on beneath the surface. Above, you would notice surfers paddling between crashing waves and fishermen wading out at low tide, but below what you might not see are the rows upon rows of metal racks growing perfectly manicured corals.
The coral farm we visited at Serangan is one of several coral mariculture farms operated by Bali Aquarium and the corals grown here are destined for wholesales and reef tanks around the world. The variety and abundance of corals here is staggering with Montipora, and 
Pocillopora found shallower leading to a truly jaw dropping selection of Acroporas. This was Reefbuilders’ third visit the Serangan farm and we were impressed to see how much it has grown since our first trip to Bali.
The farm is best accessed at low tide where you can swim between the racks, making working with the various corals easier, most being 1m (3 feet) or less from the surface. There are also some Euphyllia corals growing a bit deeper close to the surf, and to work efficiently with these rack scuba equipment is required. This particular area has a 4m (12 foot) tidal variation creating plenty of flow and changing light conditions throughout the day.
We spent just over two hours snorkeling around the farm which is situated on the inside of a coral reef lagoon and is between a small channel in the larger reef. This made for some interesting thermoclines going from bathtub hot water to chilly ocean currents, however the corals we saw didn’t seem to mind the few hours of hot shallow water each day.
Although the corals at Serangan we adapted to the hot bright environment, there are some species of coral which will not grow in these conditions, for example deep water Acroporas which need to be kept in darker water. This is one of the reason Bali Aquairum has farms set up around the island in different environment
Each day at low tide, workers from Bali Aquarium visit the farm to collect, plant and care for the corals. On this particular day they were busy fragging colonies of Royal blue Acropora tenuis. This brilliant blue coral is popular in the aquarium hobby and has been growing and propagated here for six years.
We counted two racks of freshly fragged corals, two racks of establish frags and another three racks of larger brood stock colonies. It was really incredible to see all these Acropora tenuis, as Vincent from Bali Aquarium told us they had all originally come from two medium sized mother colonies!
It is interesting to think about the active propagation of corals, especially in this case the Royal blue tenuis Acro. If left to grow in the wild, the tenuis colony would only be able to reach a certain size before the growth rate slowed. Larger corals can actually begin to self shade themselves and branches growing on the underside or inside of the colony compete for space and nutrients.
From only two colonies there are now hundreds of potential colonies alive and doing well. With all this doom and gloom talk about coral dying, maricultured corals and the professionals who grow them seem to have found a recipe to not only help corals survive but thrive.
