Baseline surveys for monitoring the fringing reef of Rarotonga, Cook Islands

Coral reef systems globally are showing signs of increasing stress and that there is a general lack of understanding of the causes of this stress. In the face of global climate change and potential sea level rise, impacts caused by events such as coral bleaching and tropical storms, coupled with increasing human usage, there is a need for reliable information on the status of coral reefs. There are inadequate baseline data to provide rigorous scientific assessment of the nature and the extent of the problem. Such information is essential for the informed management and sustainable use of this vital resource.With this in mind, IOC-UNEP-SPREP sponsored a workshop in the Cook Islands, hosted by the Cook Islands Conservation Service at Rarotonga from 23rd February to 11th March 1994. Using sampling methods developed jointly by the ASEAN-Australia Living Coastal Resources Project as a basis for a global monitoring program, the workshop had two main aims, which were:1. To develop a monitoring program and provide baseline data on the status of the fringing reefs surrounding Rarotonga, Cook Islands.2. To train participants from the Pacific Islands (Papua New Guinea, Fiji, Solomon Islands and Cook Islands) in the use of standard sampling methods adopted for the global monitoring program. Logistical constraints and training commitments reduced the sites surveyed to Titikaveka, Ngatangiia and Avatiu Reefs. Two sites located approximately 500m apart were chosen at each reef. Where possible, the position of these sites was recorded using a hand-held GPS.1. Benthic SurveysEach site consisted of five fifty metre transects laid along the 10m depth contour of the reef. Shallower depth contours were impractical for survey due to high wave energy of the system. At each transect, reef benthos was surveyed over a length of 20m using the Line Intercept Transect (LIT) method. Only four transects were surveyed on site 1, Ngatangiia Reef.Surveyed reefs were also videoed to provide a permanent visual record of the transects.2. Fish SurveysFish were surveyed in a five metre wide belt along the entire 50m of each transect. A Visual Census Technique (VCT) was used. Absolute counts were made of all species from the families Acanthuridae, Chaetodontidae, Kyphosidae, Scaridae and Zanclidae. Log base 4 abundance categories where recorded for species of the Pomacentridae on all sites except Ngatangiia site 1. The families Lethrinidae and Lutjanidae were also targeted, however none were recorded.