National Coral Reef Monitoring Program

Climate Monitoring Brief: Puerto Rico

Diver surveying Puerto Rico reef

Diver surveying Puerto Rico reef


NOAA/Atlantic Oceanographic & Meteorological Laboratory (AOML) Coral Program
University of Miami Cooperative Institute of Marine and Atmospheric Studies (CIMAS)


N. Besemer, A. Palacio, A. Webb, G. Kolodziej, T.Gill, I. Enochs - October 2023

Mission

The AOML Coral Program tracks the status and trends of coral reef ecosystems of the U.S. Atlantic and Caribbean as part of the National Coral Reef Monitoring Program (NCRMP). This summary brief provides an overview of the most recent climate monitoring efforts in Puerto Rico.

Expedition summary

Data collection summary

Subsurface temperature Subsurface temperature recorders (STRs) were recovered and redeployed at all 6 transects, each one composed by 4 depths (Fig. 1). In total, more than 10 million temperature observations were collected from 24 instruments (Table 1)

Table 1: Number of temperature observations collected by transect and depth
Location 1m 5m 15m 25m Total
Arecibo 105,139 557,457 298,970 568,609 1,530,175
Culebra 364,870 289,966 444,325 391,261 1,490,422
Fajardo 123,562 603,161 241,695 776,035 1,744,453
Jobos Bay 605,123 316,687 622,946 512,922 2,057,678
La Parguera 622,965 513,059 362,198 404,737 1,902,959
Rincon 453,283 286,086 270,786 384,289 1,394,444

NCRMP Climate fixed sentinel site monitoring: At La Parguera - 5m site, located in SW Puerto Rico, short term instruments (54h) were deployed to monitor daily fluctuations in:


Habitat persistence: Changes in bioerosion and accretion were monitored:


Figure 1: Study sites and depths in Puerto Rico.

Subsurface temperature

The temperatures that marine organisms experience are a function of local oceanographic conditions and vary with depth. To monitor subsurface temperature, six transects were established around the island. Each transect consists of STRs at four depths (1, 5, 15, 25m; Fig.2). Temperature was measured using SeaBird Electronics Subsurface Temperature Recorders (STR)s that collected data at 5-minute intervals. The instruments are usually swapped every 3 years for data collection but the COVID - 19 pandemic delayed field work in 2020. Local contractors were hired to swap the instruments as travel was not allowed and so gaps exist in the data as not all instruments survived the extended deployment time. The entire record from 2017 to 2023 is shown to aid with comparison.

Figure 2: Temperature conditions at six locations in Puerto Rico (Rincon, Arecibo, Jobos Bay, La Parguera, Culebra, Fajardo) representing a depth gradient (1m, 5m, 15m and 25m). Data were collected from June 2017 to July 2023 However, the COVID 19 pandemic caused a significant delay in collection of these instruments. Contractors were hired to complete the work in 2021 as travel was not allowed. Some instruments survived the entire deployment but others have not.

Mean temperature values were similar among the locations and depths. The lowest temperatures generally occurred in February (mean: 26.5\(^\circ\)C, min: 24.7\(^\circ\)C, max: 28.5\(^\circ\)C) and the highest temperatures in September (mean: 29.4\(^\circ\)C, min: 25.4\(^\circ\)C, max: 32.2\(^\circ\)C).

Diurnal suite deployment

Seawater carbonate chemistry can fluctuate diurnally, due to biological forcing processes such as photosynthesis and respiration, as well as calcification and dissolution. To characterize this, discrete water samples (Fig. 3) were collected at three-hour intervals (n=15) using Subsurface Automatic Samplers (SAS, www.coral.noaa.gov/accrete/sas).

These samples will be analyzed for Total Alkalinity (TA), Dissolved Inorganic Carbon (DIC), and SpectrophotometricpH (SpecpH), which will be used to calculate pCO2 and aragonite saturation state (ΩAragonite). A suite of instrumentswas deployed for a 54-hour period at the La Parguera 5m site. A SeaFET was used to log pH, an EcoPAR measured Photosynthetically Active Radiation (PAR), and a Lowell Tiltmeter measured current speed and direction. Each collected measurements at 15-minute intervals (Fig. 3).

Figure 3: Data from La Parguera diurnal suite monitoring from May 21st to May 23rd. Top panel: pH and temperature fromSeaFET. Bottom panel: Photosynthetically Available Radiation (PAR) and current speed from EcoPAR and Tiltmeter. Shading denotes nighttime throughout sequence of the plot. Instruments measured parameters every 15 minutes.

Habitat persistance

Carbonate budget assessments use transect-based surveys to quantify the abundance of carbonate producers (e.g., Corals and Crustose coralline algae), and carbonate bioeroders, (e.g., parrotfish and sea urchins). Abundances are multiplied by taxon-specific rates of carbonate alteration to determine if a reef is in a state of net accretion (habitat growth) or net loss (habitat loss; Fig. 4). At La Parguera, six transects were surveys in 2015, 2017 and 2023 to obtain carbonate budgets. These data show stable carbonate production over the monitoring timepoints. The transect results showed positive carbonate budgets in 2015, 2017 and 2023, which implies that this site supported reef accretion over the past eight years.

Figure 4: Total changes in net carbonate production and separated by the functional groups contributing to either calcification or bioerosion. PF represents parrotfish.

Calcification Accretion Units (CAUs) and Bioerosion Monitoring Units (BMUs) were used to investigate the balance between calcification and erosion. CAUs and BMUs were collected and redeployed for the next sampling cycle. CAUs are processed by the NCRMP Pacific Climate group and the data will be available within a year. BMUs will be dried and cleaned using a hydrogen peroxide solution. These samples will be weighed and scanned using a CT scanner and then compared to their pre-scans to quantify bioerosion. Data will be available in a year. Please reference previous datasets for more information.

About the monitoring program

AOML’s climate monitoring is a key part of the National Coral Reef Monitoring Program of NOAA’s Coral Reef Conservation Program (CRCP), providing integrated, consistent, and comparable data across U.S. Managed coral reef ecosystems. CRCP monitoring efforts aim to:

Point of Contact

Atlantic Climate team lead:

Principal Investigator:

NCRMP Coordinator:

For more information

Coral Reef Conservation Program: http://coralreef.noaa.gov

NCRMP climate monitoring: https://www.coris.noaa.gov/monitoring/climate.html

NOAA Atlantic Oceanographic and Meteorological Laboratory: http://www.aoml.noaa.gov/

Perto Rico Reef Status Report 2020

National Coral Reef Status Report 2020

Acknowledgements

These efforts were jointly funded by NOAA’s CRCP project #743 and OAP. We would like to sincerely thank the University of Puerto Rico Mayaguez campus particularly Milton Carlo for all of the mission support we received in La Parguera. We would also like to thank our other collaborators: Staff at Jobos Bay National Marine Estuary, PR Diving Services, Taino Divers and the University of the Virgin Islands for supporting our field efforts.

Our Team

Puerto Rico, 2023 Field team

Puerto Rico, 2023 Field team

AOMLs NCRMP Atlantic and Caribbean Climate Team: I. Enochs, N. Besemer, A. Palacio-Castro, G. Kolodziej, T. Gill, A.Boyd, M. Jankulak, K. Simmons, A. Webb, B. Chomitz