Captain Tama`s Lagoon Cruizes - Takitumu Lagoon Day 2009 24/08/2009 Saving the Reef - By Simon Spinola The focus of environmental concern on Rarotonga has in recent weeks been directed towards the quality of the water found in the lagoons. The release of the results of testing conducted in 2009 on the Water quality report card showed that many lagoon sites on the Island secure only a very low “pass” rate for nutrient levels in the water. These findings, published by the Ministry of Marine Resources last month, are of grave concern. So what does increased nutrient levels actually mean? According to the report card: “Nutrients such as nitrogen and phosphate, found in fertilisers and human and animal waste, are normally in seawater in very small amounts and are needed for the growth of algae. If concentrations become high, the algae will grow, potentially damaging coral reefs.” It therefore follows that as nutrient levels are now positively recorded as high in several areas, that algae growth rises exponentially, severely damaging the coral formations within the lagoon. It also follows that the word nutrient in itself attempts to beautify the source of origin of these pollutants, namely human and animal faecal matter running off into the lagoons. The south and west coasts of the Island are the hardest hit regions with the area around Arorangi School and the Public works being particularly affected. If the lifeblood of the lagoon is its water, then the lagoons skeleton is it’s coral, which in turn supports all other life in the water. Much has been said about the degrading water, but what is this actually doing to the coral? A few weeks ago I learned of a coral transplantation scheme taking place in Muri lagoon necessitated by the dearth of coral in that area. As the coral brings fish and the fish in turn provide both food and a tourist attraction through snorkelers, this scheme is hoping to turn the tide. It’s a technique new to these islands but much tested abroad, being utilised in lagoons and open seas around the world in an attempt to revitalise coral growth. The hope here is that in the face of this algae invasion, caused by increasing nutrient levels, coral can be grown which will in turn encourage fish back into the lagoon. My interview took place upon the lagoon itself where I caught a few words with Sonny Tatuava who works at the Ministry of Marine Resources, and was at the time conducting tours of the lagoon from a glass bottomed boat in aid of Lagoon day. On my brief voyage aboard the vessel it visited a site in Muri where branching corals were being cultivated in a joint effort with tourist resorts in the area to increase the amount of Coral cover. Tatuava specifically told me that one of the main reasons why there is low fish density in the lagoon is due to a lack of coral and that this coral transplantation technique, which has proven successful in other nations such as Fiji, hopes to remedy that problem by providing the fish with the shelters and hiding places they need. Fast growing branching corals have been chosen for transplant here, these small sections are glued to wooden pallets and placed in the lagoon to grow, these thriving cuttings are then attached to sections of deceased coral where they take hold and continue to grow. As for the scope of this cultivation Tatuava related that currently- “There are only two islands where we are developing (the coral), here and in Aitutaki.” he went on to say that the main reasons for the development are to “...maintain a healthy environment and to encourage tourism.” Growing and transplanting branching corals has many potential benefits both ecologically and economically, but certain agencies abroad place its use only as a last resort for coral re-growth. Expected benefits of the scheme are short term increases in coral cover in specific areas, it replaces corals, to some extent, that have been destroyed by pollution or sewage and can enhance the underwater environment from a touristic viewpoint. It can however, as the method used here focuses on fast branching corals, lead to a monoculture situation where these fast growing corals propagate massively and slower growing corals are neglected leading to an imbalance in coral species and species that feed on the corals, which affects the biodiversity of a given area. Coral transplantation is seen as a “last resort” technique by some marine scientists, the methods’ use here is in itself perhaps cause for alarm. Maybe a more concerted effort to clean up the lagoons and utterly minimise the amount of organic pollutants entering these once pristine waters will have a greater long term impact, and future generations of Cook Islanders and visitors can enjoy the natural beauty of these unique eco systems. In essence, focusing on alleviating the cause of this degradation and not merely treating the symptoms of this diseased water.