Table of Contents

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

This dataset contains experimental and survey biogeochemical and microbial data from samples collected at the Moorea Coral Reef LTER site (French Polynesia). Goals of the study were to investigate how benthic primary producers directly affect seawater chemistry (DO and DOC) and to examine impacts of released DOC on reef bacterioplankton growth and respiration. Rates of photosynthesis, respiration, and DOC relsease were assessed for several benthic reef organisms (Haas et al. 2011).

2010 and 2011 Data Acquisition:
Sampling from small boats occurred along transects at the Moorea Coral Reef LTER sites during September 2010 and September 2011. Benthic producers were collected from water depths of 1.0 to 1.5 meters at back and fringe reef locations. Bacterioplankton abundance was determined using flow cytometry (Nelson et al. 2011). DOC was measured by a high-temperature TOC analyzer according to methods of Carlson et al. (2010). To assess DOC release by primary producers, each benthic species was incubated using the method of Herndl and Velimirov (Haas et al. 2011). To determine if DOC released by primary producers affects mirobial populations, ~48 hour dark dilution culture incubations were performed to measure changes in concentration of DO, DOC, and bacterioplankton over time (Haas et el. 2011).

For more details on methodology, quality assurance and control procedures, and precision and accuracy of methods used, see the following references (full citations are below):
Bacterioplankton flow cytometry methods: Nelson et al. 2011.

Experimental designs, dissolved oxygen, pH, temperature, and specimen surface area methods: Haas et al. 2011, Herndl & Velimirov B. 1986.

Dissolved organic carbon method: Carlson et al. 2010.

Chlorophyll method: Smith et al. 1981.

Dissolved inorganic nutrients, particulate organic nutrients, and isotope ratios methodological references, calibrations, precision, and accuracy are detailed at the UCSB MSI Analytical Lab Website.

BCO-DMO made the following modifications: changed parameter names to conform with BCO-DMO conventions; replaced blanks and 'NA' with 'nd' to indicate no data; calculated month_gmt, day_gmt, and time_gmt from the local dates and times provided (local to French Polynesia (Papeete, Tahiti; UTC/GMT -10 hours; Time Zone Code TAHT)); rounded the following to 4 decimal places (originally submitted in Excel file with 11 decimal places): POC, PON, d13C, d15N, algal_area_O2, algal_area_C; replaced '<' with 'lt_' (less than) and '>' with 'gt_' (greater than) in depth_bottom column; removed parameters defined as 'internal reference code'.

From http://www.lternet.edu/sites/mcr/ and http://mcr.lternet.edu/:
The Moorea Coral Reef LTER site encompasses the coral reef complex that surrounds the island of Moorea, French Polynesia (17°30'S, 149°50'W). Moorea is a small, triangular volcanic island 20 km west of Tahiti in the Society Islands of French Polynesia. An offshore barrier reef forms a system of shallow (mean depth ~ 5-7 m), narrow (~0.8-1.5 km wide) lagoons around the 60 km perimeter of Moorea. All major coral reef types (e.g., fringing reef, lagoon patch reefs, back reef, barrier reef and fore reef) are present and accessible by small boat.

The MCR LTER was established in 2004 by the US National Science Foundation (NSF) and is a partnership between the University of California Santa Barbara and California State University, Northridge. MCR researchers include marine scientists from the UC Santa Barbara, CSU Northridge, UC Davis, UC Santa Cruz, UC San Diego, CSU San Marcos, Duke University and the University of Hawaii. Field operations are conducted from the UC Berkeley Richard B. Gump South Pacific Research Station on the island of Moorea, French Polynesia.

MCR LTER Data: The Moorea Coral Reef (MCR) LTER data are managed by and available directly from the MCR project data site URL shown above.  The datasets listed below were collected at or near the MCR LTER sampling locations, and funded by NSF OCE as ancillary projects related to the MCR LTER core research themes.

This project is supported by continuing grants with slight name variations:

• LTER: Long-Term Dynamics of a Coral Reef Ecosystem
• LTER: MCR II - Long-Term Dynamics of a Coral Reef Ecosystem
• LTER: MCR IIB: Long-Term Dynamics of a Coral Reef Ecosystem
• LTER: MCR III: Long-Term Dynamics of a Coral Reef Ecosystem
• LTER: MCR IV: Long-Term Dynamics of a Coral Reef Ecosystem

This project is part of the ETBC (Emerging Topics in Biogeochemical Cycles) program.

From NSF award proposal:
The proposed research will investigate the coupling between primary producers and the utilization of dissolved organic matter (DOM) by marine heterotrophic microbes on coral reefs. Previous metagenomic studies of the microbial communities associated with near-pristine and degraded coral reefs demonstrated a shift from a microbial food web similar to the open ocean (Prochlorococcus spp. and SAR11-like bacteria) to a community dominated by "super-heterotrophs", most closely related to known pathogens like E. coli, Staphylococcus spp., Streptococcus spp., Enterobacter spp. and Vibrio spp. This shift is associated with a decline in coral cover and an increase in coral disease prevalence. Our previous research has also shown that dissolved organic carbon (DOC) concentrations are lower on coral reef platforms compared to measurements of offshore waters (60-80 µM). On degraded reefs, we have observed DOC measurements as low as 30 - 40 µM, a value similar to concentrations observed in the deep Pacific Ocean. The observation of low DOC measurements on degraded reefs is decoupled from the high abundance of macroalgae, which one might expect would raise levels of DOC through the release of photosynthate into the water column.

The data generated from the proposed research are key to understanding the microbial, chemical, and ecological dynamics on today’s coral reefs. The proposed research plan will consist of five inter-related objectives that will use a combination of field surveys, molecular characterization (microbes and DOM) and experimental approaches to assess the overall hypothesis. We propose to use a combination of archived samples from previous reef expeditions as well as conduct two field visits to reefs in French Polynesia (Moorea) and the Line Islands (Kiritimati) for focused sampling and experimentation. The biogeochemistry, local physical oceanography, and detailed reef ecology has been well characterized and continues to be monitored as part of the MCR-LTER program at Moorea. This environmental context will be useful in interpreting our experimental and field results at Moorea. We will also compare two field sites, Moorea and Kiritimati to ensure that our results are not specific to one region.

adapted from http://www.lternet.edu/

The National Science Foundation established the LTER program in 1980 to support research on long-term ecological phenomena in the United States. The Long Term Ecological Research (LTER) Network is a collaborative effort involving more than 1800 scientists and students investigating ecological processes over long temporal and broad spatial scales. The LTER Network promotes synthesis and comparative research across sites and ecosystems and among other related national and international research programs. The LTER research sites represent diverse ecosystems with emphasis on different research themes, and cross-site communication, network publications, and research-planning activities are coordinated through the LTER Network Office.

2017 LTER research site map obtained from https://lternet.edu/site/lter-network/

The original call for proposals for Emerging Topics in Biogeochemical Cycles (ETBC) was issued in September 2007 by the US NSF Directorate for Geosciences (NSF 07-049).

The Geosciences Directorate (GEO) is substantially augmenting our past funding sources to explicitly support emerging areas of interdisciplinary research. We seek to foster transformational advances in our quantitative or mechanistic understanding of biogeochemical cycles that integrate physical-chemical-biological processes over the range of temporal and/or spatial scales in Earth’s environments. We encourage submission of proposals that address emerging topics in biogeochemical cycles, the water cycle or their coupling, across the interfaces of atmosphere, land, and oceans. Proposals must cross the disciplinary boundaries of two or more divisions in Geosciences (e.g. ATM, EAR, OCE) or of at least one division in Geosciences and a division in another NSF directorate.

Although funding programmatic disciplines continues to provide a robust and adaptable framework to build our understanding of the geosciences and the earth as a system, there are classes of emerging and challenging problems that require integration of concepts and observations across diverse fields. Our goal is to enhance such integration. Successful proposals need to develop intellectual excitement in the participating disciplinary communities. Also encouraged are proposals that have broader educational, diversity, societal, or infrastructure impacts that capitalize on this interdisciplinary opportunity.