|van Woesik, Robert||Florida Institute of Technology (FIT)||Principal Investigator|
|Rauch, Shannon||Woods Hole Oceanographic Institution (WHOI BCO-DMO)||BCO-DMO Data Manager|
Details of field methods and data analysis are published in van Woesik & Cacciapaglia (2021).
A stratified random sampling approach was used to survey the reefs of Majuro (7.0667° N, 171.2667° E) and Kiritimati (1.8721° N, 157.4278° W), by randomly selecting 24 study sites at each island using the package 'sp' in R. In both locations, a stratified random sampling approach was used to survey the reefs for carbonate production by randomly selecting 24 sites on each island, with the exception of Kiritimati where only 22 of the 24 sites were surveyed because of inclement weather. At both locations, the sites were stratified as either (i) outer reefs, or (ii) patch reefs in lagoons. The number of sites sampled per habitat varied according to the area of available habitat at each location. The investigators were particularly interested in determining the potential of shallow-water reef carbonate production, and therefore focused surveys between 2–5 m. Majuro was surveyed from 6/17/2019 to 7/6/2019 and Kiritimati was surveyed from 7/10/2019 to 7/22/2019.
(ZIP Archive (ZIP), 20.70 MB)
Data files and R scripts associated with dataset 856943. PI: Robert van Woesik. Also available from BCO-DMO Github at https://github.com/BCODMO/Pacific Description of .zip contents: Data: Within the excel files are both data from literature and the field. Excel files containing the country and the sites at which the data were collected. These include urchin data, fishes data, and coral data. The files on coral density, coral extension rates, coral species info, and fish species data are files used for both Majuro and Kiritimati. R scripts: The numbers and letters in front of the R scripts represent the order they were created and used in, and the country they correspond to. Our study started with a random stratified sampling of the two countries, so in Rscripts 1M and 1K, are our methods for the sampling. The output from our sampled runs were recorded in the excel files: study sites Majuro (M) and study sites Kiritimati (K). 2M and 2K are the reef growth models, where all the collected data from the field and literature are used to determine the reef accretion rates at each site within the specified country. 3M and 3K use the output of 2M and 2K site specific reef accretion to Krige the geographic space in between the study sites. 4M and 4K use the output of 2M and 2K to Krige bioerosion by fishes in the geographic space between the study sites. 5M and 5K are used to krige individual fish species in the geographic space between the study sites. 6M and 6K use the output of 2M and 2K to Krige bioerosion by urchins in the geographic space between the study sites. 7M and 7K use collected data from the field and literature as well as output from 2P and 2Y to gain information used in the tables within the manuscript and supplementary document. 8 is used to make other plots not covered within scripts 3-7 including nMDS.
|country||country of site||unitless|
|state||state of study site||unitless|
|locat||Reef habitats stratified as either 'outer', 'inner', or 'patch' reef||unitless|
|NP||Net carbonate production including all erosion, sedimentation, and production of carbonate at each site||kilograms calcium carbonate per year (kg CaCO3 yr-1)|
|GP||Gross carbonate production, excluding all sedimentation and erosional forces, at each site||kilograms calcium carbonate per year (kg CaCO3 yr-1)|
|BFj||Biological erosion caused by parrotfishes at each site||kilograms calcium carbonate per year (kg CaCO3 yr-1)|
|BUj||Biological erosion caused by sea urchins at each site||kilograms calcium carbonate per year (kg CaCO3 yr-1)|
|lon||longitude||decimal degrees East|
|lat||latitude||decimal degrees North|
NSF Award Abstract:
Increases in ocean temperatures and sea-level rise are threatening coral reef ecosystems worldwide. Indeed, some island nations are no more than 1 m above modern sea level. Yet, building sea walls on tropical coasts, to keep out the ocean, as they do in the Netherlands, is a substantial economic burden on small-island nations. Healthy coral reefs, however, have the capacity to lay down sufficient calcium carbonate to grow vertically and keep up with sea-level rise, as they did in the geological past. By contrast, damaged coral reefs do not have the capacity to keep up with sea-level rise, making the coastal communities vulnerable, and inflicting a large economic burden on the coastal societies to build sea walls. In addition, and very recently, coral reefs are being subjected to high water temperatures that are causing considerable damage to corals. This study will ask some critical questions: Are coral reefs in the western Pacific Ocean keeping up with sea-level rise? Where are reefs keeping up with sea-level rise, and what is preventing reefs in some localities from keeping up? This study will also examine whether geographical differences in ocean temperatures influence the capacity of reefs to keep up with sea-level rise. Where coral reefs cannot keep up with sea-level rise, these natural storm barriers will disappear, resulting in the loss of habitable land for millions of people worldwide. The broader impacts of the study will focus on training a post-doctoral researcher, and developing and running one-week training workshops in the proposed study locations in Palau, Yap, Chuuk, Pohnpei, Kosrae, Majuro, and Kiribati. The investigators will work with local stakeholders on the various islands, focusing on connecting science to management practices to reduce local stressors to coral reefs.
Coral reefs are one of the world's most diverse and valuable marine ecosystems. Since the mid-Holocene, some 5000 years ago, coral reefs in the Pacific Ocean have been vertically constrained by sea level. Contemporary sea-level rise is releasing these constraints, providing accommodation space for vertical reef expansion. Yet recently corals have been repeatedly subjected to thermal-stress events, and we know little about whether modern coral reefs can "keep up" with projected future sea-level rise as the ocean temperatures continue to increase. This study will examine whether and where coral reefs are keeping up with sea-level rise across a temperature gradient in the Pacific Ocean, from Palau in the west to Kiribati in the east. The spatial differences in the capacity to keep up with sea level will be explored, and it is hypothesized that differential rates of coral growth and capacity to keep up with sea-level rise will be a function of regional temperatures, local water-flow rates, and land-use. One of the major tasks of this study is to determine the contribution of the various components of each reef to potential carbonate production, across the geographical temperature gradient. The investigators will quantify the rates of carbonate production, by corals and calcareous algae, and the rates of carbonate destruction, by reef eroders, by measuring the space occupied by each benthic component at each study site. The team will then sum that information to interpret the overall capacity of the reef to produce carbonate. At each study site mobile benthic eroders will be estimated, as counts and size measurements of echinoids and herbivorous fishes. The investigators will measure the densities of the different coral species, from different habitats, and develop models that relate the coral morphologies with the potential rate of carbonate deposition. This study will assess the contribution of sea surface temperature, flow rates, and land-use practice to the capacity of reefs to keep up with sea-level rise. Two different approaches will be used to predict the relationship between carbonate production and sea-level rise. The first model will assume that the capacity of vertical reef accretion is directly related to the extension of Porites microatolls at the various island locations. The second model will take a hierarchical Bayesian approach to examine reef growth, which depends on the presence and density of calcifying organisms, and on physical, chemical, and biological erosional processes.