100 Island Challenge
Cruise Report
Windward Caribbean| Nov 6-16, 2016
Contributing Authors
Dr. Stuart Sandin, Scripps Institution of Oceanography Dr. Brian Zgliczynski, Scripps Institution of Oceanography Lindsay Bonito, Scripps Institution of Oceanography
Report prepared on 29 November 2016 Photo credit: Ralph Pace
Expedition Team
Ruleo Camacho, Department of Environment, Antigua & Barbuda Amelia Bird, Department of Environment, Antigua & Barbuda Melanie Meijer zu Schlochtern, St. Maarten Nature Foundation Erik Houtepen, St. Eustatius National Parks Foundation (STENAPA) Tadzio Bervoets, Nature Foundation of Sint Maarten
Jens Odinga, Saba Bank National Park Andy Estep, Waitt Institute
Ramón de León, Reef Support BV, Bonaire Dr. Mark Vermeij, Carmabi Foundation, Curaçao Ralph Pace, Photographer
Lindsay Bonito, Scripps Institution of Oceanography Nicole Pedersen, Scripps Institution of Oceanography Dr. Brian Zgliczynski, Scripps Institution of Oceanography Dr. Stuart Sandin, Scripps Institution of Oceanography
Collaborators
Executive Summary
The Waitt Institute and Dr. Stuart Sandin’s laboratory at Scripps Institution of Oceanography collaborated to organize an expedition to conduct a rapid scientific assessment of the coral reefs around the windward Caribbean islands, namely Sint Maarten, Sint Eustatius, Saba, Redonda, and a submarine atoll, Saba Bank. To
complement these efforts, the expedition was supported by the Government of Antigua and partners in the nearby Dutch-affiliated islands (St Eustatius, Saba, and St Maarten).
The collaboration is part of a larger effort to establish a regional scale perspective of coral reef health, investigating how reefs are structured, how they change over time, and how we can better manage them in the face of global change.
The research conducted during thiscruise aimed to investigate the independent and interactive effects of oceanography and human activities in affecting the structure and dynamics of coral reef communities. The survey design controls for within-island
variables by conducting the core surveys within the same habitat type – forereef habitat at 7-15m depth. To assess the benthic and reef fish communities, the GCRMN
methodology was utilized in conjunction with large-area ‘photomosaics’ to quantify the structure and the workings of each coral reef community at 1-2 km intervals surrounding each island.
To complement the ecological data colelcted, two sea temperature recorders (HOBO Pro v2 Logger) were deployed around each island. The temperature recorders were programmed to record the seawater temperature at an interval of thirty minutes. We expect to retrieve these recorders and download the temperature record in
approximately 2 years.
Across the 4 islands and submarine atoll, 65 sites were surveyed. This effort resulted in a total of 325 fish and benthic transects, following the GCRMN guidelines. Additionally 38 photomosaics were imaged: 6 on Redonda, 11 on Sint Eustatius, 11 on Sint
Maarten, 8 on Saba, and 2 on the Saba Bank.
The Windward Caribbean Islands
Figure 1. Map of the windward Caribbean islands surveyed in November, 2016.
Surveyed islands include Sint Maarten, Sint Eustatius, Saba, Saba Bank, and Redonda.
Island Highlights
The Lesser Antilles, also known as the Windward Islands, extend in a curve about 500 miles between Puerto Rico and Trinidad. Most of the islands were formed by volcanic activity, and when combines with the Greater Antilles and Lucayan Archipelago, are known as the West Indies.
Redonda
Island Type: High island; remnant of an ancient extinct volcano Island Size: 1.6 km long and 0.5 km wide (between 1.6 and 2.6 km2) Population: uninhabited
Sint Maarten
Island Type: High island Island Size: 34 km2
Population: ~39,000 (2011 census)
Sint Eustatius
Island Type: High island, dormant volcano.
Island Size: 21 km2
Population: ~4,000 (2013 data)
Saba
Island Type: High island, potentially active volcano Island Size: 13 km2
Population: ~2,000 (2013 data)
Saba Bank
Island Type: Submarine atoll Size: ~ 2200 km²
Population: uninhabited
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. Particularly, 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 the Windward Caribbean: 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
Survey Metadata
Table 1. Sites surveyed to assess and monitor the fish and benthic communities (GCRMN) and collect photomosaic imagery (Mosaic).
Project
Island Site ID Latitude Longitude Local Name
GCRMN Redonda RED_00 16.944853 -62.346535 GCRMN Redonda RED_01 16.9422 -62.34229 GCRMN Redonda RED_02 16.93814 -62.34099 GCRMN Redonda RED_03 16.9351 -62.342133 GCRMN Redonda RED_04 16.93192 -62.345428 GCRMN Redonda RED_05 16.934392 -62.348748 GCRMN Redonda RED_06 16.938763 -62.348186 GCRMN Redonda RED_07 16.942964 -62.348807 Mosaic Redonda RED_00 16.94539 -62.3456 Mosaic Redonda RED_02 16.93927 -62.34187 Mosaic Redonda RED_04 16.93183 -62.34527 Mosaic Redonda RED_05 16.93417 -62.34909 Mosaic Redonda RED_06 16.93871 -62.34834
Mosaic Redonda RED_07 16.94269 -62.34898
GCRMN Saba SBB_01 17.65119 -63.2407
GCRMN Saba SBB_02 17.6379 -63.216495
GCRMN Saba SBB_03 17.63875 -63.22038
GCRMN Saba SBB_04 17.62315 -63.22055
GCRMN Saba SBB_05 17.6125 -63.23643
GCRMN Saba SBB_6B 17.61701 -63.25806
GCRMN Saba SBB_07 17.63116 -63.25766
GCRMN Saba SBB_08 17.6462 -63.25296
GCRMN Saba SBB_A 17.639 -63.25515
GCRMN Saba SBB_B 17.64917 -63.24608
GCRMN Saba SBB_C 17.6486 -63.23065
GCRMN Saba SBB_D 17.63116 -63.21763
GCRMN Saba SBB_E 17.61768 -63.22633
GCRMN Saba SBB_G 17.62468 -63.25955
Mosaic Saba SBB_01 17.65025 -63.23861
Mosaic Saba SBB_02 17.637 -63.25581
Mosaic Saba SBB_04 17.62315 -63.22055
Mosaic Saba SBB_05 17.61252 -63.2367
Mosaic Saba SBB_6B 17.61773 -63.25913
Mosaic Saba SBB_07 17.63116 -63.25766
Mosaic Saba SBB_08 17.6461 -63.25283
Project Island Site ID Latitude Longitude Local Name
Mosaic Saba SBB_8B 17.64671 -63.25513
GCRMN Saba Bank SBB_73 17.48067 -63.23009 GCRMN Saba Bank SBB_08 17.47138 -63.22876 GCRMN Saba Bank SBB_09 17.46317 -63.22559 Mosaic Saba Bank SBB_73 17.481317 -63.228267
Mosaic Saba Bank SBB_09 17.46323 -63.225415 GCRMN St Eustatius STE_01 17.5261 -62.9972
GCRMN St Eustatius STE_10 17.47691 -62.94706
GCRMN St Eustatius STE_101 17.466767 -62.990917 Barracuda Reef GCRMN St Eustatius STE_102 17.52515 -63.000067 Safety First GCRMN St Eustatius STE_103 17.46265 -62.977617 Mushroom
Gardens GCRMN St Eustatius STE_104 17.464967 -62.983267 Five Fingers GCRMN St Eustatius STE_11 17.47099 -62.94954
GCRMN St Eustatius STE_12 17.46683 -62.95893 GCRMN St Eustatius STE_13 17.4644 -62.96658 GCRMN St Eustatius STE_14 17.46289 -62.97644 GCRMN St Eustatius STE_15 17.47067 -62.98295 GCRMN St Eustatius STE_17 17.51249 -63.00091 GCRMN St Eustatius STE_18 17.51691 -63.00123 GCRMN St Eustatius STE_02 17.52032 -62.99123 GCRMN St Eustatius STE_03 17.517 -62.9842 GCRMN St Eustatius STE_04 17.51131 -62.97941 GCRMN St Eustatius STE_05 17.5047 -62.9765 GCRMN St Eustatius STE_06 17.50233 -62.96881 GCRMN St Eustatius STE_08 17.49205 -62.95195 GCRMN St Eustatius STE_09 17.4878 -62.94607 Mosaic St Eustatius STE_01 17.52643 -62.99715
Mosaic St Eustatius STE_100 17.47956 -62.99461 Double Wreck Mosaic St Eustatius STE_102 17.52553 -62.99962 Safety First Mosaic St Eustatius STE_11 17.47057 -62.94862
Mosaic St Eustatius STE_13 17.4624 -62.96883 Mosaic St Eustatius STE_15 17.46778 -62.98346 Mosaic St Eustatius STE_19 17.52122 -63.00087 Mosaic St Eustatius STE_03 17.50745 -62.97453 Mosaic St Eustatius STE_05 17.50723 -62.97472
Mosaic St Eustatius STE_07 17.50107 -62.96205
GCRMN St Maarten STM_102 18.018717 -63.020617 Pelican Reef N GCRMN St Maarten STM_103 18.018717 -63.020617 Pelican Reef S GCRMN St Maarten STM_104 18.022683 -63.000667 Molly Beday
Project Island Site ID Latitude Longitude Local Name
GCRMN St Maarten STM_106 17.99867 -63.0562 Mike's Maze W GCRMN St Maarten STM_108 17.989867 -63.055833 Coralita GCRMN St Maarten STM_109 17.988233 -63.051217 Fishbowl GCRMN St Maarten STM_11 18.018561 -63.073623
GCRMN St Maarten STM_111 18.04676 -63.142118 Long Bay SE GCRMN St Maarten STM_112 18.04352 -63.14388 Long Bay NW GCRMN St Maarten STM_113 18.041817 -63.1411 Gregory GCRMN St Maarten STM_114 18.016317 -63.093767 Moonscape GCRMN St Maarten STM_115 18.01775 -63.09485 Frenchman GCRMN St Maarten STM_116 18.010633 -63.007917 Hen & Chicks E GCRMN St Maarten STM_13 18.012146 -63.059273
GCRMN St Maarten STM_17 18.010078 -63.035792 GCRMN St Maarten STM_18 18.015807 -63.028671 GCRMN St Maarten STM_20 18.031349 -63.01928 GCRMN St Maarten STM_21 18.03998 -63.016033
Mosaic St Maarten STM_100 18.023333 -63.012367 Cow & Calf Mosaic St Maarten STM_101 18.010633 -63.007917 Hen & Chicks Mosaic St Maarten STM_104 17.98816 -63.05154 Molly Beday Mosaic St Maarten STM_105 17.99127 -63.05611 Mike's Maze E Mosaic St Maarten STM_107 17.98897 -63.05897 Proselyte Reef Mosaic St Maarten STM_109 17.98799 -63.05172 Fishbowl Mosaic St Maarten STM_110 18.02117 -63.11266 The Bridge Mosaic St Maarten STM_16 18.00523 -63.04025
Mosaic St Maarten STM_19 18.02314 -63.026315 Mosaic St Maarten STM_22 18.050654 -63.011356
Survey Methods
Fish & Macro-Invertebrate Surveys
Fish Assemblage Survey Methods
Estimates of fish abundance and biomass were completed using methods consistent with the Global Coral Reef Monitoring Network - Caribbean (GCRMN) guidelines for ecological monitoring. In summary, All fish present (of all species) are counted and sized within a belt transect (30m length x 2m width), with the survey time limited to approximately 6 minutes per transect. At each site, at least 5 transects are surveyed and the data are pooled to provide an average estimate of the density and size structure of all fishes at the site. Fish are classified by size to the nearest 5cm bin.
Key Macro-Invertebrate Survey Methods
The densities of the long-spined sea urchin (Diadema antillarum), other sea urchins, and all sea cucumbers were recorded in situ by the fish diver. Within 3 of the benthic transect lines, the diver counted invertebrates in the first 10m along the transect, within a 2m wide belt, giving a total area of 60m2.
Benthic Surveys
Benthic Survey Methods
Similar to the fish survey methods, Benthic communities were characterized using a photoquadrat method, consistent with the Global Coral Reef Monitoring Network - Caribbean (GCRMN) guidelines for ecological monitoring. Digital photographs of the reef surface were taken in standardized quadrat areas (0.9m x 0.6m). Photographs are taken along each of the 5 transect lines set for counting fish, with 15 images captured per 30m transect line (i.e., one image taken at every 2m on the transect tape). In total,
75 benthic photographs were collected at each site (5 transect lines x 15 photographs per line). Images will be analyzed by overlaying 25 random points and identifying each organism or habitat feature associated with each point to the finest level of resolution possible (genus level for hard and soft corals, functional group for algal turfs and crustose coralline algae, and species level for macroalgae and macroinvertebrates when possible). Photoquadrat images will be analyzed for coral disease as well, in addition to in situ presence/absence surveys of disease within the transects.
Coral recruitment was data in situ, with the goal of estimating the density of young corals that are likely to contribute to the next generation of adult corals on the reef.
Coral recruits are defined operationally for this assessment as any stony coral that is greater than 0.5 cm and up to 4.0 cm. Estimates of coral recruit density were recorded from replicate 25cm x 25cm (625 cm2) quadrats. A total of 3 quadrats were surveyed along each transect used for benthic and fish surveys. The coral recruit quadrats will be placed at 10-meter intervals along the transect line, resulting in a total of 15 quadrats surveys per site (5 transect lines x 3 quadrats per line. Within each quadrat, each stony coral within the target size range ( 0.5 - 4.0 cm) were recorded to the finest taxonomic level possible (family, genus, or species). Additionally, in each coral recruitment quadrat, average turf height was also measured four times in the quadrat.
Benthic Photomosaic Survey Methods
To complement the transect-based benthic surveys, benthic photomosaics were completed to collect a permanent record of reef habitat on a larger scale (100m2). The benthic photomosaic system consists of a diver operating a camera system including dual SLR cameras and video camera mounted to a custom frame. The first still camera is setup to use a wide-angle 18 mm focal length lens to sure high overlap among adjacent images while the second still camera uses a 55 mm focal length lens to capture images with sub-cm resolution. The high-resolution wide-angle video camera serves as a backup in the event that images from the still cameras are compromised. To obtain the large image covering 10m x10m the diver operating the camera system
swims a gridded pattern approximately 1.5 m above the benthos recording images at 1
sec intervals throughout the plot. A pair of lasers is mounted within the frame of the 55 mm camera to provide scale in the high-resolution imagery. Images are later stitched together analytically using custom algorithms to create a single image file representative of the 100m2 plot.
Figure 2. Photomosaic Data Collection Method. Each mosaic is stitched together from
~2000 photos acquired by swimming back and forth over the reef in the pattern on the left.
Figure 3. Photomosaic Processing Method. Once stitched, each mosaic is ecologically post-processed by tracing individual coral colonies and algae species of interest. Once individual colonies are traced and identified (E), data is exported and run through custom algorithms to evaluate both standard metrics including percent coral cover and more complex spatial statistics.
Summary Findings
Figure 4. Sites surveyed during the November 2016 expedition.
Fish Survey Results
Fish Abundance
Figure 5. Fish abundance (individuals per m2) by trophic group in Redonda.
Figure 6. Fish abundance (individuals per m2) by trophic group in Saba.
Figure 7. Fish abundance (individuals per m2) by trophic group in Saba Bank.
Figure 8. Fish abundance (individuals per m2) by trophic group Sint Maarten.
Figure 9. Fish abundance (individuals per m2) by trophic group in Sint Eustatius.
Figure 10. Fish abundance (individuals per m2) by trophic group across all islands.
Table 2. Abundance of fishes by species in Redonda (individuals per m2) and trophic level classifications.
Figure 11. Fish biomass (g/m2) by trophic group in Redonda.
Figure 12. Fish biomass (g/m2) by trophic group in Saba.
Figure 13. Fish biomass (g/m2) by trophic group in Saba Bank.
. Figure 14. Fish biomass (g/m2) by trophic group in Sint Maarten.
Figure 15. Fish biomass (g/m2) by trophic group in Sint Eustatius.
Figure 16. Fish biomass (g/m2) by trophic group across all islands.
Table 3. Biomass (g/m2) of fishes in Redonda by species and trophic level classifications.
Benthic Survey Results
Mean Density of Juvenile Corals
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
Mean Density of Juvenile Corals (# per m2)
Saba & Saba Bank
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
Mean Density of Juvenile Corals (# per m2)
Sint Eustatius
Figures 17-20. Mean and standard error of density of juvenile stony corals per site (number of individuals per m2). Survey site covers an area of 56.25m2.
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
Mean Density of Juvenile Corals (# per m2)
Sint Maarten
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
RED_00 RED_01 RED_02 RED_03 RED_04 RED_05 RED_06 RED_07 Mean Density of Juvenile Corals (# per m2)
Redonda
Figure 21. Mean and standard error of density of juvenile stony corals per island (number of individuals per m2). Island survey area covers 93.75m2.
Total Number of Juvenile Corals
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2
Redonda Saba Saba Bank St Eustatius St Maarten Mean Density of Juvenile Corals (indivduals / m2)
0 5 10 15 20 25 30 35
Total # of Juvenile Corals (Per 56.25m2)
Saba & Saba Bank
0 5 10 15 20 25 30 35
Total # of Juvenile Corals (Per 56.25m2)
Sint Eustatius
0 5 10 15 20 25 30 35
Total # of Juvenile Corals (Per 56.25m2)
Sint Maarten
Figures 22-25. Total number of individual juvenile stony corals in site survey area (56.25 m2).
Figure 26. Total number of individual juvenile stony corals at the island level (survey area 93.75 m2).
0 5 10 15 20 25 30 35
RED_00 RED_01 RED_02 RED_03 RED_04 RED_05 RED_06 RED_07 Total # of Juvenile Corals (Per 56.25m2)
Redonda
0 50 100 150 200 250 300 350
Redonda Saba Saba Bank St Eustatius St Maarten
Total # of Juvenile Corals
Number of Juvenile Corals by Species
Figure 27. Total number of individual juvenile stony corals by species in site survey area (56.25 m2) in Redonda. Coral species: SSID- Siderastrea sidereal; SRAD-
Siderastrea radians; PPOR- Porites porites; PAST- Porites asteroids; MDEC- Madracis decactis; MCAV- Montastraea cavernosa; FFRA- Favia fragum; AGA- Agaricia spp.;
AAGR- Agaricia agaricites.
Mean Diameter of Juvenile Corals
0 5 10 15 20 25 30 35
RED_00 RED_01 RED_02 RED_03 RED_04 RED_05 RED_06 RED_07
# of Juveniles
SSID SRAD PPOR PAST MDEC MCAV FFRA AGA AAGR
0 5 10 15 20 25 30 35 40 45
Mean Juvenile Size (mm)
Saba & Saba Bank
0 5 10 15 20 25 30 35 40 45
Mean Juvenile Size (mm)
Sint Eustatius
0 5 10 15 20 25 30 35 40 45
Mean Juvenile Size (mm)
Sint Maarten
Figures 28-31. Mean size (diameter, mm) and standard error of juvenile stony corals in site survey area (56.25 m2).
Figure 32. Mean size (diameter, mm) and standard error of juvenile stony corals by island (survey area 93.75 m2).
0 5 10 15 20 25 30 35 40 45
RED_00 RED_01 RED_02 RED_03 RED_04 RED_05 RED_06 RED_07
Mean Juvenile Size (mm)
Redonda
0 5 10 15 20 25 30 35
Redonda Saba Saba Bank St Eustatius St Maarten
Mean Juvenile Size (mm)
Mean Turf Height
0 2 4 6 8 10 12 14 16 18 20
Mean Turf Height (mm)
Saba & Saba Bank
0 2 4 6 8 10 12 14 16 18 20
Mean Turf Height (mm)
Sint Eustatius
Figures 33-36. Mean height and standard error (mm) of turf in site survey area (56.25 m2).
0 2 4 6 8 10 12 14 16 18 20
Mean Turf Height (mm)
Sint Maarten
0 2 4 6 8 10 12 14 16 18 20
RED_00 RED_01 RED_02 RED_03 RED_04 RED_05 RED_06 RED_07
Mean Turf Height (mm)
Redonda
Figure 37. Mean height and standard error (mm) of turf by island (survey area 93.75 m2).
0 1 2 3 4 5 6 7 8 9 10
Redonda Saba Saba Bank St Eustatius St Maarten
Mean Turf Height (mm)
Photomosaic Results & Products
All mosaic products are available online both on the 100 Island Challenge YouTube Channel and through our public Google Drive. Below are links and URLs where you can find these products.
100 Island Challenge Google Drive | Link
https://drive.google.com/open?id=0BweQfAzx_6a0V2cwSkdKay11MW8
100 Island Challenge YouTube Channel | Link
https://www.youtube.com/channel/UCR6xc-3SFGmqdYthU8VrgsQ
Sample Photomosaic
Island: Sint Maarten
Site: SM105 (Mike’s Maze E) Date: November 2016
Habitat Type: forereef Protection Status: MPA
Landscape of the Windward Islands
