By Kevin Lino
Among shoals of damselfishes, Andrew Gray of the PIFSC Coral Reef Ecosystem Division on June 16 reels in a transect line at the end of a reef fish survey in Oecusse, Timor-Leste. NOAA photo by Kevin Lino
Researchers from the PIFSC Coral Reef Ecosystem Division (CRED) recently completed a successful mission to assess coral reef fish assemblages in nearshore (<18 m), coastal waters off the northern coastlines of Timor-Leste—in conjunction with the Timor-Leste Ministry of Agriculture and Fisheries and the Coral Triangle Support Partnership (CTSP) of the U. S. Agency for International Development (USAID). From June 4 to 27, they completed 311 dives and collected survey data at 150 sites in the districts of Dili, Manatuto, Baucau, Bobonaro, Lautem, Liquiça, and Oecusse and at Atauro Island.
A vast school of golden sweeper (Parapriacanthus ransonneti) aggregates near a coral ledge off the northern coast of Timor-Leste on June 11. NOAA photo by Kevin Lino
Also highly successful were secondary projects to (1) record acoustic data on seafloor depths for use with WorldView-2 satellite-derived data to create accurate shallow-water bathymetry for the area and (2) collect water samples to complement existing ocean acidification projects in the region. The team completed 14 water sampling arrays for carbonate chemistry analysis: 35 samples for dissolved inorganic carbon (DIC) concentration and 28 samples for salinity.
This mission involved immense data gathering, but its greatest achievements were the activities in which CRED researchers shared their knowledge and expertise with local partners and agencies to increase their technical capacity in monitoring of the marine environment to which they are so closely connected. Looking back at our accomplishments now, about a month after our return, these experiences stand out as not only some of the most memorable but also the most rewarding for us.
The team worked from chartered platforms—the Sundancer NT catamaran and its tender boat during the live-aboard portion of our mission and from the Lancet during shore-based operations. CRED divers used the stationary-point-count method to collect underwater visual census information on the reef fish populations and benthic composition at each of the 150 survey sites. The locations of survey sites were indiscriminately selected with a stratified random sampling design.
Sundancer NT crew member Ian Brown collects bathymetric data aboard the tender boat in transit to another survey site on June 16. NOAA photo by Andrew Gray
Despite thorough mission planning and some great local information used in determining potential survey locations, the final selection of exact sites during this mission was affected by logistics, weather, and many other conditions. In several areas, finding the targeted habitat of hard-bottom reefs proved to be a difficult and time-consuming process. Evidently, the acoustic mapping data collected during this trip was in great need and will begin to alleviate this lack of information on seafloor depths. The variety of habitats encountered during this mission was often surprising and quite unpredictable. We learned that The Dry (aka dry season) does not mean that there will be no rain but rather that it will be less rainy than it is during monsoon season—a bit of knowledge that will be helpful for future research in this region. Because of the rain we encountered during this mission, we limited the number of survey areas associated with river basins, where runoff and particulates in the water column resulted in visibility that was not optimal for our surveys.
Figure 1. Total fish biomass (g m-2) by district or area from stationary-point-count surveys conducted at 150 sites off the northern coast of Timor-Leste in June 2013.
Kaylyn McCoy, who served as our database manager during this mission, rapidly produced a summary of initial survey results, including many figures to help illustrate them, and shared these results with partners and local agencies before departing the country (see Fig. 1). These preliminary results closely reflect the general impressions of CRED divers of the various habitats surveyed and provide a respectable representation of the northern coastline. With more than 500 fish species identified during our surveys, as expected, biodiversity and complexity were much higher than the levels observed in other regions in the Pacific that have been surveyed by CRED. Although we did not encounter as many large-bodied fishes as we anticipated, the abundance and diversity of fishes were adequate compensation (see Fig. 2). Also promising was an observation that several remote areas, which have been recognized by local agencies as potential locations to establish some form of protection in the future, appeared to hold levels of fish biomass that were higher than the levels we observed in other areas off Timor-Leste. Hopefully, further analysis will produce more detailed information that can aid local agencies in making their management decisions.
Figure 2. Total fish biomass (g m-2) by district or area and size class from stationary-point-count surveys conducted at 150 sites off the northern coast of Timor-Leste in June 2013. Error bars indicate ±1 standard error of the mean.
It was clearly a collaborative effort to educate, inform, and collect data by all parties involved. Not only did we pass on the data we collected and the methods we used to collect them, but also our partners returned much more in local knowledge, information, and way of life. We would like to especially thank CTSP and Rui Da Silva Pinto for his immeasurable service in logistics and communications and his overall constructive attitude. Robert Crean and the team at Compass Charters were fantastic to work with and very accommodating, especially in arranging our use of the Sundancer NT, with its captain, Peter Herden, and highly skilled crew members Ian Brown and Kym Hamilton. There are too many individuals to thank here, but our team appreciates everyone involved in this mission, both in Timor-Leste and within NOAA, who made everything possible. Obrigado!
A blue-spotted fantail ray (Taeniura lymma) rests on the seafloor while a tailspot squirrelfish (Sargocentron caudimaculatum) swims overhead on June 25 at a coral reef off the northern coast of Timor-Leste. NOAA photo by Kevin Lino
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