Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

This dataset contains Acropora cervicornis calcification data from experiments conducted in tanks at Summerland Key, Florida (24.6616,-81.4538) between 2016-09-02 and 2016-09-10 with corals from a nursery located near Looe Key Reef (24.5636, -81.2786).

Physiological Methods

Photosynthesis, respiration, and calcification measurements were performed on each fragment using 300 mL temperature-controlled respirometry chambers filled with seawater from the treatment aquaria that was continuously stirred with a magnetic stir bar.  The chambers were used to assess the rates of respiration (Rd) in the dark and rates of photosynthesis (Pn) and calcification in the light.  Light was supplied by a series of blue and red LEDs with adjustable intensity (150 uMol quanta m-2 sec-1).  Water samples were taken from each chamber prior to a cycle and also at the end of both dark and light incubations (60 minutes each) for measurements of pHT (pH on the total scale) and total alkalinity (AT) as described in Martin and Gattuso (2009).  

Calcification - Total alkalinity (TA) values were measured using an automatic potentiometric titrator (Metrohm 807 Titrando, Riverview, FL) to the second end point of a 15.3-g accurately weighed seawater sample.  Total alkalinity values were then computed using the Gran equation (DOE, 1994) with pH values lower than 3.9 for creating the Gran plot. The pH electrodes (Metrohm 807 Titrando) were calibrated daily as described above.  The acid titrant concentration was 0.05N HCl (JT Baker, Phillipsburg, NJ).  Alkalinity was calculated using the first derivative of the curve for the evaluation of the exact end point.  Standards for total seawater alkalinity and provided by Dickson were run daily (Dickson, 2007).  The differences between duplicate samples and standards were less than 5 uEq kg-1 (for calibration of the titrator, differences were measured between triplicate samples).  Water samples were analyzed immediately or stored in darkness at 4C and processed within 24 hours of collection.  

Dickson AG, Sabine CL, and Christian JR (2007) Guide to best practices for ocean CO2 measurements: PICES Special Publication. 3, 191 p.

Martin S and Gattuso J-P (2009) Response of Mediterranean coralline algae to ocean acidification and elevated temperature. Glob Change Biol 15:2089-2100. 
Marubini F and Thake B (1999) Bicarbonate addition promotes coral growth. Limnol and Oceanogr 44: 716-720.

Riebesell U, Fabry VJ, Hansson L, and Gattuso JP (2010) Guide to best practices for ocean acidification research and data reporting. European Commission, European Research Area. Brussels. 258 p

Calcification values were calculated using the alkalinity anomaly method (Riebesell et al., 2010).  Calcification rates were normalized to surface area.

Riebesell U, Fabry VJ, Hansson L, and Gattuso JP (2010) Guide to best practices for ocean acidification research and data reporting. European Commission, European Research Area. Brussels. 258 p.

BCO-DMO Data Manager Processing Notes:
* added a conventional header with dataset name, PI name, version date
* modified parameter names to conform with BCO-DMO naming conventions
* calcification values rounded to three decimal places

NSF Award Abstract:
Caribbean staghorn coral was one of the most common corals within reefs of the Florida Keys several decades ago. Over the last 40 years disease, bleaching, overfishing and habitat degradation caused a 95% reduction of the population. Staghorn coral is now listed as threatened under the U.S. Endangered Species Act of 1973. Within the past few years, millions of dollars have been invested for the purpose of restoring the population of staghorn coral within Florida and the U.S. Virgin Islands. Significant effort has been placed on maintaining and propagating corals of known genotypes within coral nurseries for the purpose of outplanting. However, little is known about the individual genotypes that are currently being outplanted from nurseries onto coral reefs. Are the genotypes being used for outplanting resilient enough to survive the three major stressors affecting the population in the Florida Keys: disease, high water temperatures, and ocean acidification? The research within the present study will be the first step in answering this critically important question. The funded project will additionally develop a research-based afterschool program with K-12 students in the Florida Keys and U.S. Virgin Islands that emphasizes an inquiry-based curriculum, STEM research activities, and peer-to-peer mentoring. The information from the present study will help scientists predict the likelihood of species persistence within the lower Florida Keys under future climate-change and ocean-acidification scenarios. Results of this research will also help guide restoration efforts throughout Florida and the Caribbean, and lead to more informative, science-based restoration activities.

Acropora cervicornis dominated shallow-water reefs within the Florida Keys for at least the last half a million years, but the population has recently declined due to multiple stressors. Understanding the current population level of resilience to three major threats - disease outbreaks, high water temperatures, and ocean acidification conditions - is critical for the preservation of this threatened species. Results from the present study will answer the primary research question: will representative genotypes from the lower Florida Keys provide enough phenotypic variation for this threatened species to survive in the future? The present proposal will couple controlled laboratory challenge experiments with field data and modeling applications, and collaborate with local educators to fulfill five objectives: 1) identify A. cervicornis genotypes resistant to disease, 2) identify A. cervicornis genotypes resilient to high water temperature and ocean acidification conditions, 3) quantify how high water temperature and ocean acidification conditions impact disease dynamics on A. cervicornis; 4) determine tradeoffs in life-history traits because of resilience factors; and 5) apply a trait-based model, which will predict genotypic structure of a population under different environmental scenarios.