Instead of the normal report re the quality of the canal water, we are concentrating on water quality when the water is murky. The latest tests indicated that the water quality is still “excellent”. The following (extract from Newsletter) looks at the relationship between murky water and water quality:
Apart from the aesthetic appeal of the canal, the canal acts as a conduit to carry sea water from Seaworld back to the ocean. As such, the canal is a semi-closed eco-system and water exchange is limited to that returned from the aquarium. Due to the canal being semi-closed, nutrients are following the on-going cycle of feeding plankton (animal and plant), plankton die-off, decay and feeding new plankton.
During warmer and still weather conditions, plankton growth increases, resulting in reduced water clarity or murky water. During cooler weather conditions, the productivity is drastically reduced, resulting in clearer waters. During rains the water is cooled down, nutrients are flushed out and the salinity of the water may be reduced. All these factors contribute to lower plankton productivity and even the die-off of plankton, which in turn results in clear waters as dead plankton would sink to the bottom of the canal and subsequently, under the correct conditions, decay to form nutrients that will feed the new plankton.
The above cycles of clear and murky water do not affect the water quality in terms of suitability to support aquatic life as tests done by the CSIR indicate that the water quality remains ‘good to excellent’ under all conditions. Many sea-creatures are dependent on plankton in order to survive! Next time when you see murky water, imagine all the millions of microscopic plants and animals breeding and feeding the eco-system.