Greetings Islanders
I wanted to get a communication out to everyone in regards to the pond and our efforts to restore it to the beautiful feature we have all treasured over the years.
Since the pond was drained and the Koi removed during the water crisis, there have been numerous challenges to getting it back to its former glory. Firstly, a decision was made to try to create as natural an environment as possible with all effort made to use only indigenous flora and fauna, and to allow the feature, including the cascades, to create its own ecosystem with our help.
After the resealing and subsequent filling of the pond, the challenges compounded – the greatest of which was the quality, availability and cost of water from the municipality. We experimented with various treatments and methods of sterilization of effluent water, and tinkered with the reticulation of the water, and the mechanization of circulating and oxygenating the entire system. This took time and patience and a great deal of sweat and tears!!
When we finally had the system working and determined that the balance of the water was stable, we planted indigenous sedges and margin plants, while introducing and propagating indigenous aquatic plants to provide oxygenation and shade.
On April, 29th we were happy to introduce over 150 adult Tilapia fish into the pond and cascades, as our testing determined it stable enough to do so. We created shelter and gravel pits for breeding, and we are happy to say that despite the ups and downs of water quality over the last 6 months the fish are happy and breeding (despite the attentions of our friendly herons, cormorants and kingfishers!). Frog populations have also increased and we have had some fun nocturnal visitations from Cape Clawless Otters on a couple of occasions!
Recently you may have noticed a change in colour from an unpleasant orangey-brown to a pea-soup green. Both of these states are due to strong algal “blooms” when populations of microscopic algae multiply rapidly. The conditions that cause these blooms are; higher temperatures, longer days and stronger sunshine – as well as high levels of nutrients in the water. This last factor has unfortunately been exacerbated again by the quality of the effluent water that is used on the grass and gardens around the pond. The run-off into the water greatly increases the food available to the algae and the bloom continues.
Over the next two weeks you will notice our work to provide a long-term solution to prevent future algal blooms. In an effort to provide more shade and reduce the nutrient load to effectively “starve” the algae - we are increasing the number and species of plants, introducing Ultra-violet light filters, creating gravel and plant “reed filters” at strategic places in the circulation, and attempting to reduce run-off into the pond. We are hopeful that this central feature of our community will slowly be restored – but please know that the system is healthy and getting healthier as we work on it!
WILL TAYLOR
TRUSTEE: GARDENS, ESTATE AND DUNES