Page 16: of Marine Technology Magazine (April 2020)

FEATURE TONGA REEF dardized collection methodology provides point intercept surveys. In this sampling robust data that can be compared across technique, a scientifc diver used a 1 m × sites locally, regionally, and globally. 1 m quadrat, fipping it over a total of 10

The underwater surveys were completed times per transect to capture detailed pho- using a ‘rapid reef assessment’ methodol- tographs of a full 1 × 10 m photo transect. ogy. A rapid reef assessment is a sampling Analyzing photos of the underwater land- technique that maximizes bottom time scape required using computer software (amount of time a person can safely stay at called Coral Point Count with Excel Exten- depth below 10 m on SCUBA) to collect sions (CPCe), which was developed by our as much in situ data as possible. partners at Nova Southeastern University’s

Coral communities were recorded using National Coral Reef Institute (NCRI). The the point intercept method to record spe- images were imported into the software, cies of corals, algae, sponges, and other where 50 random points were overlaid on invertebrates. This method required two each photograph. A scientist then defned scientifc divers using SCUBA to lay out a the organism and substrate type directly 10 m transect line and record the organism underneath the point. For the Kingdom of and substrate type at every 10 cm mark Tonga, KSLOF analyzed over 3,000 pho- (total 100 points per transect). Belt tran- tos for a total of 41,000 points digitized. sects were used to count and measure reef Photo transects are an excellent record of fsh assemblages. This was completed by what the coral community looks like at a several scientifc divers who would swim point in time. The data derived from these 30 meters and record the species of fsh methods yielded important metrics that and its approximate size. quantifed how much live coral cover was

Perhaps one of the more critical data sets found on the reefs of Tonga, which is a collected was the photographic assess- metric that is linked to the overall health ment (photo quadrates) to supplement the of a coral reef ecosystem.

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