Cruise Report Tuamotus & Line Islands August 21 – September 2, 2017 Contributing Authors Dr. Stuart Sandin1 Dr. Brian Zgliczynski1 Lindsay Bonito1 1Scripps Institution of Oceanography www.100islandchallenge.org Report prepared on 22 August 2017 1 Expedition Team Scripps Institution of Oceanography Dr. Stuart Sandin, Professor Dr. Brian Zgliczynski, Postdoctoral Researcher Nicole Pedersen, Staff Researcher Chris Sullivan, Staff Researcher Waitt Institute Joe Lepore, Diving Safety Officer Shayna Brody, Social Media & Outreach, Photographer Cook Islands Korero O Te 'Orau Dr. Teina Ronga, Marine Ecologist James Kora, Research Assistant Center for Insular Research and Observatory of the Environment (CRIOBE) Charlotte Moritz, Postdoctoral Research Scholar The Nature Conservancy Hank Lynch, Scientific Diver 2 Executive Summary Members of the 100 Island Challenge team (Nicole Pederson, Chris Sullivan, Stuart Sandin, and Brian Zgliczynski) returned from an expedition this past August to survey coral reefs at a subset of atolls in the Tuamotu Archipelago, French Polynesia, as well as re-visit several islands in the Southern Line Islands, Republic of Kiribati. This expedition was supported by the Waitt Institute and represented a collaborative effort between the Scripps Institution of Oceanography, Waitt Institute, Center for Insular Research and Observation of the Environment (CRIOBE - French Polynesia), Korero O Te ‘Orau - Cook Islands, and The Nature Conservancy – Hawaii. The goal of the 14-day expedition was to characterize coral reef communities as part of the 100 Island Challenge. The coral reefs of the Tuamotu Archipelago and Southern Line Islands are remote and relatively free of direct human influence. Therefore, they provide researchers with an opportunity to study intact ecosystems with thriving coral and fish communities. Although this was the first opportunity to visit sites in the Tuamotus as part of the 100 Island Challenge, our team has conducted multiple survey efforts to the Southern Line Islands over the past several years. This expedition was particularly important because it provided our team with an opportunity to investigate the status of coral reefs of the region in conjunction with reports of widespread coral bleaching across the Pacific. By establishing new survey sites and re-visiting long-term sites are team will contextualize changes in coral reef communities through time and gain invaluable information on how these diverse ecosystems respond to recent warm water events. The team was excited to visit these sites but there was some apprehension over what they would find. Would the coral reefs of these islands be another casualty of the global mass-bleaching event? Upon entering the water, the team was filled with mixed emotions. Preliminary observations revealed that the reefs had been impacted by the warm water events. However, the magnitude appeared to be species-specific and variable across islands. For example, fast growing species appeared to be hit the hardest while slower-growing species appeared to be impacted to a lesser extent. While the observed mortality was discouraging the team was excited to see evidence of recovery and regrowth. Corals that had recently died were being overgrown with coralline algae, an important reef builder that strengthens the reef and provides substrate for new corals to settle and attach. Additionally, the team observed healthy populations of reef fishes including predatory species like jacks, snappers, and sharks as well as abundant populations of smaller-bodied species that are important food sources for predators. Overall, the expedition represented a successful collaborative effort and the team gained valuable insight into the structure and function of coral reefs in the two regions. During the 14-day expedition, the team conducted over 300 scientific dives across 8 islands (Millennium, Flint, Vostok, Takapoto, Tikehau, Rangiroa). These dives were comprised of 47 total photomosaic benthic surveys (14 resurveys of permanent sites) and 59 reef fish surveys. This high level of productivity could not have been possible without the hard work and efficiency of the crew of the Plan B. 3 100 Island Challenge Description: This research initiative employs novel approaches for studying coral reef community dynamics through the application of underwater photomosaic technology. Working with colleagues from the University of Miami, we have built a camera system that allows us to capture images of large swaths of the reef surface. Further, by re- visiting exact locations multiple times and replicating photography, we have an unprecedented opportunity to track the dynamics of corals and algae. In particular, with advanced image analysis, we can track how a reef community changes, addressing questions of coral growth, death, and competition that are currently unresolved. We have field-trialed this photomosaic equipment and are developing a reliable image analysis protocol. We are now poised to apply this tool to generate the large-scale data of reef community dynamics that have to date been unavailable. Further, by combining these image-based data with reliable information about the composition of the fish community, the general oceanography, and the human situation of each location, we can begin to elucidate the conditions that are more (or less) conducive to the maintenance of growing and so-called ‘healthy’ coral reefs. Application to French Polynesia & Line Islands: By linking the fates of these reefs to the oceanographic conditions and to the local activities of people, we will be able to start understanding cause-and- effect pathways for reef change. Given that local-scale marine managers consistently seek information on the ‘state’ of their coral reef, looking for comparisons to help guide local management. Further, by making the data that describe each reef readily available and easy to visualize, there is a terrific opportunity to increase the dialogue between the science and management communities, as well as independently among the managers looking for tangible information to improve their self-management. By working side-by- side with regional managers and partners in local NGOs (e.g., the Nature Conservancy, Conservation International), we will expand the scientific insights into the state and future of their reef areas. For more information, visit www.100islandchallenge.org 4 Tuamotus & Line Islands Background Figure 1. Map of French Polynesia & Line Islands. The Tuamotu archipelago is a French Polynesian chain of almost 80 islands and atolls with a land area of 850 km2 and 16,000 inhabitants. Its major islands are Anaa, Fakarava, Hao and Makemo. The Line Islands is a chain of 11 atolls (with partially or fully enclosed lagoons) and coral islands (with a surrounding reef) spanning 2,350 kilometres. Of the 11 islands/atolls, 8 form part of Kiribati, while the remaining 3 are United States territories grouped with the United States Minor Outlying Islands. Only Kiritimati and Tabuaeran atolls and Teraina Island have a permanent population. 5 Survey Metadata Table 1. Sites surveyed to assess fish and benthic communities in 2017. Local Area Data Island Station ID Date Latitude Longitude Habitat Mosaic Divers1 Fish Divers1 Time (m2) Collected2 Tikehau TIK 29 2017-08-21 8:30 -14.98673 -148.27971 100 Forereef CS, NP, TR, JK NA M Tikehau TIK_31 2017-08-21 10:50 -14.97581 -148.27463 100 Forereef CS, NP, TR, JK NA M Tikehau TIK_33 2017-08-21 13:20 -14.94565 -148.24799 100 Forereef CS, NP, TR, JK NA M, T Tikehau TIK_30 2017-08-21 8:30 -14.97896 -148.27632 100 Forereef NA BZ, SAS, HL, CM F, B Tikehau TIK_32 2017-08-21 11:06 -14.95968 -148.26324 100 Forereef NA BZ, SAS, HL, CM F, B Tikehau TIK_34 2017-08-21 13:21 -14.93361 -148.23050 100 Forereef NA BZ, SAS, HL, CM F, B Tikehau TIK_24 2017-08-22 8:40 -15.10787 -148.25697 100 Forereef NP, TR SAS, HL F, B, M Tikehau TIK_25 2017-08-22 8:45 -15.09092 -148.26892 100 Forereef CS, JK BZ, CM F, B, M, 360 Tikehau TIK_26 2017-08-22 10:40 -15.07326 -148.27898 100 Forereef NP, TR SAS, HL F, B, M, T Tikehau TIK_27 2017-08-22 11:00 -15.05541 -148.28696 100 Forereef CS, JK BZ, CM F, B, M, 360 Tikehau TIK_28 2017-08-22 13:10 -15.03591 -148.29088 100 Forereef NP, TR SAS, HL F, B, M, T Tikehau TIK_CRIOBE 2017-08-22 13:20 -15.01405 -148.28525 100 Forereef CS, JK BZ, CM F, B, M, 360 Millennium MIL_C24 2017-08-24 8:30 -10.01105 -150.23424 100 Forereef CS, JK BZ, CM F, B, M, 360 Millennium MIL_C1 2017-08-24 8:30 -10.00463 -150.23869 100 Forereef NP, TR SAS, HL F, B, M Millennium MIL_16 2017-08-24 10:45 -9.99833 -150.23634 100 Forereef CS, JK BZ, CM F, B, M, 360 Millennium MIL_C25 2017-08-24 10:30 -9.99193 -150.23393 100 Forereef NP, TR SAS, HL F, B, M Millennium MIL_05 2017-08-24 13:30 -9.98814 -150.23267 100 Forereef CS, JK BZ, CM F, B, M, 360 Station ID Local Area Data Island Date Latitude Longitude Habitat Mosaic Divers1 Fish Divers1 Time (m2) Collected2 Millennium MIL 06 2017-08-24 12:30 -9.97930 -150.22855 100 Forereef NP, TR SAS, HL F, B, M, T Millennium MIL_C7 2017-08-25 8:30 -9.93995 -150.21213 100 Forereef NP, TR SAS, HL F, B, M Millennium MIL_04 2017-08-25 10:05 -9.95014 -150.21541 100 Forereef NP, TR SAS, HL F, B, M Millennium MIL_02 2017-08-25 12:45 -9.95460 -150.21555 100 Forereef NP, TR SAS, HL F, B, M, T Millennium MIL_C8 2017-08-25 8:30 -9.92806 -150.21010 100 Forereef CS, JK BZ, CM F, B, M, 360 Millennium MIL_C5 2017-08-25 11:00 -9.96098 -150.21771 100 Forereef CS, JK BZ, CM F, B, M, 360 Millennium MIL_01 2017-08-25 13:00 -9.97102