Between the Communications Workshop and Turtle Workshop I attended a couple of weeks ago I had the pleasure of diving the Great Sea Reef with WWF colleagues in order to retrieve two temperature loggers from the sea bed.
We took a taxi from Labasa, where our hotel was, to a beach near a small village where we could get a fisherman to take us the hour or so across to an island resort where we were to suit up for the dives.
The resort that was helping to facilitate this project was incredible – apparently a couple of years ago it was voted one of the ten best island resorts in the world! Unfortunately we didn’t have time to enjoy it for long as we soon were on another boat heading out to the reef.
The devices that we recovered from the sea had been recording the temperature of the water every hour for the past six months and the data was to help understand the relationship between a coral reef’s health and its proximity to mangroves.
Coral is very sensitive to water temperature fluctuations. An annual variation in water temperature is normal but prolonged periods of high temperature, which causes coral damage, has been witnessed in recent years.
Although coral has shown that it can adjust to increases in water temperature, they can only do so with enough time – the current rate of sea temperature increase doesn’t provide them with this.
What the WWF wanted to explore by placing the temperature loggers, was to what extent mangroves aid the corals in resisting sea temperature rises.
Our first dive was over a part of the reef that was totally exposed – about an hours boat ride offshore. The water was warm and although the coral was reasonably healthy, the concentration of marine life was not what I have come to expect form reefs of this size.
Our second dive was about 500 meters from a large mangrove island and the difference was noticeable. Below five metres the water temperature was noticeably COLD, not cool but cold! The health of the reef and the level of biodiversity was also clear to eye.
The problem is that in Fiji tourism is a big industry and increasingly areas of mangroves are being removed in favour of holiday resorts. This not only harms coral but also Fiji’s protection against major storms and tsunamis, which, it appears, are in the future to increase in ferocity.
Since this project the WWF in Fiji are now planning work to increase their effort to promote mangrove appreciation, so you can expect me to be writing about it again soon.