Suva, Fiji Sep 2015

Amanda measuring juvenile acropora colonies to assess growth and/or survival over the coming months

Amanda measuring juvenile Acropora millepora colonies to assess growth and/or survival over the coming months

Bleached skeletons of Porites and Acropora spp. preparing for microdensity analysis

Bleached skeletons of Porites and Acropora spp. preparing for microdensity analysis

 

 

 

Three weeks and 80 dives later, the benthic and fish teams are well underway with their projects. This time has been focused in three lagoonal reefs within close proximity to Suva, the capital city of Fiji. This part of the lagoon all belongs to one Qoliqoli (traditional fishing ground) under the governance of four villages. Despite their proximity to many drivers of poor water quality (i.e. large-scale sewage input, factory outlets and a large harbour), at first glance, the reefs seem to be doing relatively well with coral cover of around 30-40%. Furthermore, there are many juvenile corals and surprisingly low amounts of fleshy macroalgae. However, coral cover is predominantly Porites rus colonies, there are many dead juvenile corals, and the skeletons of corals appear very brittle. Furthermore, though Acropora spp. seem to be recruiting successfully, and some reaching mature sizes, every adult colony is disappearing under a thick layer of turf algae and the integrity of the skeleton is being destroyed leading to colonies falling apart.

We are interested in exploring these metrics further in order to establish reef trajectories in the area as simple status indicators (e.g. coral cover, macroalgal cover) may lead to misinterpretations of reef health. To achieve this, we have labelled specific Acropora-turf interactions to assess how they develop over time, as well as many juvenile Acropora millepora colonies to measure growth and survival. Skeleton samples have been collected for us to measure microdensity, as we expect that these reefs are highly vulnerable to storm damage. These metrics will be compared to reefs in more pristine water quality around Beqa Island. At each site we are also measuring both the biomass as well as the function of herbivorous fish using GoPro cameras positioned over naturally occurring patches of turf algae. Furthermore, we will investigate algal productivity and coral recruitment with tiles in this area over the coming months. For algal productivity, the team has shared the load drilling 196 shallow holes in 64 sandstone tiles to create microstructure for algal propagules.

Working in this area is super convenient due to the close proximity to our home, and we have been sharing the boating between local village boats and Suva Scuba center. Our assistant (Joe) from Waiqanaki Village is brilliant and has given us huge insight into changes in environmental conditions and fishing practices in the area. Now it is time to pack up the compressor and the dive gear, and move to a remote village on a small Island for a while…









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