Coral reef management requires a robust understanding of the state of the managed environment. For a long-term management plan to be successful, a monitoring scheme of the coral reefs has to be in place. To start with such a process, an initial survey trip, on-board the Blue Whale, was conducted to execute a baseline survey. Captained by the jack of all trades – Robert Edgar, and with a group of experienced surveyors including Sefano Katz, the BLI project manager, Muhammad Azmi Abdul Wahab (Zuzu) from the Australian Institute of Marine Science, Australia, and Katrina Bromhall from the Danish Technical University, Denmark; our project collaborators, we engaged a productive and enjoyable trip.
The purpose of the trip was to select sites that will be used to monitor the reefs inside and outside traditionally instated marine protected areas; Tabu areas. Six sites were selected within the Rukua Qoliqoli (fishing grounds), where surveys will commence from now and into the future. This enables us to monitor the changes in the state of the reefs over time. Finding representative sites, with the same depth and structural complexity inside and outside the tabu areas, is essential for making a comparison.
Therefore, a manta-tow survey (a surveyor pulled behind a boat attached by a rope to a hand held board) was initially carried out to facilitate the assessment of representative sites over a large area in a short period. Thereafter, a team of divers descend onto the site equipped with hammers, tape measures, and 50cm metal rods to mark the surveying sections of the reef. The tape measure is trailed along the reef to a length of 30m, and every ten meters a metal rod is hammered into the reef, being careful to select spots on the reef that are void of living organisms. Each site has three transects, with at least 30m between them. This makes a permanent survey site that will be revisited and monitored bi-annually.
Once sites were designated, surveys were carried out to create a baseline dataset for the state of the reef. Three divers carried out the surveys, each recording different aspects of the reef: A video-transect recorded the fish present along the surveyed section of reef, allowing scoring their abundance and diversity. In addition, the abundance and size of uncommon fish species were separately recorded. Digital images taken of a half meter squared quadrat above the reef substrate documented the benthic composition, i.e., the assemblage of living and non-living material on the floor of the reef. Furthermore, visual census carried out by trained specialists determined the health-state of the corals, assessing each individual coral colony and identifying the reason for its compromised-health.
Moreover, uncommon macro-invertebrate species’ (e.g., sea cucumbers, Trochus snails and urchins) composition was documented; scoring their occurrence, abundance and size.
Surveying the reef in this manner, and continuing to do so, builds up a time series of data; reporting on the health state of the coral reef ecosystem. It is crucial to have a baseline (initial status) for which data from years to come can be compared against. An abundance of information can be drawn from a time series dataset, allowing the assessment of whether management measures are successful or not. Thus, giving indication as to when management measures need to be reassessed. Furthermore, it can identify changes in species composition, such as increases in the crown of thorns sea star, a voracious coral predator, thought to be an indicator species signifying excess nutrients
We are optimistic that this is just the beginning of a successful and prosperous time series, which will later be carried out by trained Champions from Rukua village. The work carried out to date was only made possible by the kind donation of Blue Whale Adventures, which allowed us to use the Blue Whale as a research vessel; traveling between sites, compress air for dive tanks and, have an office to keep up to date with ongoing data analysis.