Sediment accumulation rates and constituents in Culebra, Puerto Rico from sediment trap monitoring surveys conducted from 2022-08-30 to 2024-02-06

This record provides sediment trap monitoring data collected periodically between 30 August 2023 and 6 February 2024 at 13 nearshore monitoring stations on the island of Culebra, Puerto Rico, as part of Culebra's Ridge-to-Reef Monitoring and Evaluation Framework to assess the effectiveness of the NOAA strategies and actions in priority watersheds to reduce land-based sources of pollution (LBSP) impacts to the nearshore marine ecosystems of the island.

Monitoring stations were co-located with nearshore water quality monitoring sties and long-term seagrass monitoring transects. Monitoring stations were selected to identify watershed discharge points, coastal hydrodynamics, as well as the existing level of LBSP exposure and anticipated changes to LBSP exposure due to management actions. Nearshore monitoring stations were designated based on their land based sources of pollution management implementation status (LBSP Treatment Group), as follows: 1) LBSP Restoration stations: Located downstream where land-based pollutant management has or is being implemented. 2) LBSP Control stations: Represent a range of land-based pollutant impairments, including sites with no LBSP management, no known direct discharge of LBSP but are representative of the range of external factors that may be encountered at the LBSP Restoration stations. 3) Negative Reference stations of know significant -anecdotal and quantified- LBSP impairment. 4) Positive Reference stations of low LBSP impairment.

Two replicate sediment traps were deployed at each monitoring station. Traps were constructed and installed following Storlazzi et al. (2011) with an added honeycomb baffle at the top to reduce turbulence in the trap and prevent sample disturbance by aquatic organisms. Traps were retrieved and redeployed periodically (30-Aug-22 to 6-Feb-23; 6-Feb-23 to 1-May-23; 1-May-23 to 07-Aug-23; 07-Aug-23 to 6-Nov-23; 6-Nov-23 to 6-Feb-24). In the lab, the accumulated sediment from one trap was dried and weighed to estimate accumulation rates (mg/cm2/day). The contents of the second trap were separated into coarse (<2 mm-63 um) and fine (<63 um) fractions, dried and weighed to the estimate accumulation rate, followed by a sequential loss on ignition procedure (following Edmunds & Gray 2014, Heiri et al. 2001) to assess the terrigenous, carbonate, and organic composition. Laboratory analyses were conducted at University of Puerto Rico at Rio Piedras. Please review the Culebra Sediment Trap Monitoring Work Plan (Vargas-Angel 2024) for a complete methodological description.

The data presented herein was collected with financial support from NOAA Restoration Center and NOAA Coral Reef Conservation Program, and the National Fish and Wildlife Foundation (NFWF). The research questions, survey design and monitoring localities were specific to this study and the associated water quality data is unsuitable in a regulatory framework.

References:

Edmunds, Peter & Gray, Sarah. (2014). The effects of storms, heavy rain, and sedimentation on the shallow coral reefs of St. John, US Virgin Islands. Hydrobiologia. 734, 143-158. https://link.springer.com/article/10.1007/s10750-014-1876-7

Heiri, O., Lotter, A. F., & Lemcke, G. (2001) Loss on ignition as a method for estimating organic and carbonate content in sediments: Reproducibility and comparability of results Journal of Paleolimnology, 25, 101-110. https://doi.org/10.1023/A:1008119611481

Storlazzi, C. D., Field, M. E., & Bothner, M. H. (2011). The use (and misuse) of sediment traps in coral reef environments: Theory, observations, and suggested protocols. Coral Reefs, 30(1), 23-38. https://doi.org/10.1007/s00338-010-0705-3

Vargas-Angel B (2024D) Culebra Sediment Trap Monitoring Work Plan: Developing a nearshore sediment trap monitoring program to evaluate changes in LBSP exposure in Culebra, Puerto Rico. Available at: https://www.ncei.noaa.gov/data/oceans/coris/library/NOAA/CRCP/NMFS/OHC/Projects/30033/Culebra_LBSP_RidgeToReef_Monitoring_Program/Vargas-Angel2024d_Sediment_Trap_Monitoring_WorkPlan.pdf

This work is an integral component of the Culebra Ridge-to-Reef Monitoring Program; a spatiotemporally coordinated effort designed to evaluate the effectiveness of the NOAA management strategies and actions in priority watersheds to reduce land-based sources of pollution (LBSP) impacts to the nearshore marine ecosystems of the island. This ridge-to-reef monitoring framework implements a Multiple Lines of Evidence approach consisting of: 1) Monitoring of LBSP stressors that are being managed through NOAA funding including sediment accumulation at unpaved road stabilization projects, water quality monitoring at key points throughout the watershed, and watershed modeling to estimate pollutant loads into the nearshore coastal environment. 2) Monitoring of LBSP exposure through nearshore water quality and sediment trap monitoring at nearshore fixed stations. 3) Monitoring of nearshore habitat responses that is co-located with the aforementioned nearshore water quality fixed stations and includes data collection via seagrass monitoring transects. Within this context, sediment accumulation rates and composition are characterized and tracked to quantify the land-based pollutant exposure levels in the receiving coastal environment and the associated seagrass and coral reef communities, which are ultimately the focal point of the NOAA LBSP management efforts on Culebra.

https://www.ncei.noaa.gov/data/oceans/coris/library/NOAA/CRCP/NMFS/OHC/Projects/30033/Culebra_LBSP_RidgeToReef_Monitoring_Program/Vargas-Angel2024_Culebra_LBSP_RidgeToReef_Monitoring_Program.pdf

https://www.ncei.noaa.gov/data/oceans/coris/library/NOAA/CRCP/NMFS/OHC/Projects/30033/Culebra_LBSP_RidgeToReef_Monitoring_Program/Vargas-Angel2024d_Sediment_Trap_Monitoring_WorkPlan.pdf

https://www.ncei.noaa.gov/data/oceans/coris/library/NOAA/CRCP/NMFS/OHC/Projects/30033/Culebra_LBSP_RidgeToReef_Monitoring_Program/Vargas-Angel2024c_Nearshore_WaterQuality_Monitoring_WorkPlan.pdf

https://www.ncei.noaa.gov/data/oceans/coris/library/NOAA/CRCP/NMFS/OHC/Projects/30033/Culebra_LBSP_RidgeToReef_Monitoring_Program/Vargas-Angel2024e_Seagrass_Monitoring_Transects_WorkPlan.pdf

These are processed data and include: average sediment accumulation rates in milligrams per centimeter square, per day (mg/cm2/day), and percent composition (i.e., carbonate, organic, and terrigenous) for each size fraction (coarse: <2 mm - 63um; fine: <63 um).

The temporal data for each survey include: sediment trap deployment and recovery dates.

While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.

We welcome the opportunity to collaborate on research issues contributing to the scientific basis for better management of marine ecosystems.

The following recommendations are for your consideration as you use this data:

1) Data analyses should take all field exigencies into account. The most effective way to do this would be active collaboration with principal investigators.

2) In all presentations, product releases, or publications using these data proper acknowledgement the funding agencies and individuals responsible for data collection is expected. Citing the DOI (if available) is preferred, a non-DOI example is listed below.

3) If you collect or generate data for the same study areas, NOAA requests that you share relevant information on complimentary data collections.

Data can be accessed online via the NOAA National Centers for Environmental Information (NCEI) Ocean Archive.

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Data were collected periodically between 2022-08-30 and 2024-02-06 and provide a quantitative baseline of sediment accumulation rates and composition at key nearshore sites selected to identify watershed discharge points, coastal hydrodynamics, as well as the existing level of LBSP exposure and anticipated changes to LBSP exposure due to management actions.

The same la instrumentation (i.e., analytical balance, drying oven, and furnace) was employed to process and analyze all samples. Handheld GPS units were used to locate sites and mark site locations.

Sediment samples were processed at the University of Puerto Rico at Rio Piedras. Laboratory technician turnover subtle sample processing inconsistencies are expected.

A few of sample processing and analytical computations inaccuracies were identified which required the removal of those data points.

Data gaps may originate from, but not limited to sample loss due to bioturbation, sample handling, and laboratory technician turnover.

Handheld GPS units were used to locate sites.

Survey and analytical methods were consistent across all samples.

The quality control occurred at three major stages - 1) instrument calibration; 2) data entry; and 3) data management. Data entry quality control included both review and manual error correction steps.

This data addresses Land Based Sources of Pollution exposure monitoring, specifically sediment trap monitoring, which together with LBSP habitat response monitoring represent the basis of Culebra's Integrated LBSP Monitoring and Evaluation Framework with which to successfully assess progress and effectiveness toward achieving NOAA LBSP management goals and outcomes on Culebra.