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| griddap | Subset | tabledap | Make A Graph | wms | files | Accessible | Title | Summary | FGDC | ISO 19115 | Info | Background Info | RSS | Institution | Dataset ID | |
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| log in | [Benthic community composition] - Benthic community composition from a field experiment manipulating consumer pressure and nutrient availability on a coral reef in Moorea, French Polynesia from 2018 to 2022 (Collaborative Research: Tipping points in coral reefs and their associated microbiomes: interactive effects of herbivory, nutrient enrichment, and temperature) | Here we experimentally test the relative importance of alterations to top-down and bottom-up processes in driving community development and variability after a simulated disturbance on a coral reef. We use a factorial experiment manipulating consumer pressure and nutrient enrichment for four years on a coral reef in Moorea, French Polynesia. Our experiment consisted of plots (~1.25 m2 each) that manipulated access by consumers via different size openings that allowed different size fishes access to the benthos, creating four levels of consumer pressure (Very Low, Low, Medium, High). These four levels of consumer pressure were crossed with manipulations of nutrient availability with either ambient or nutrient enriched conditions. At the start of the experiment, we removed all live corals and fleshy macroalgae from the plots to mimic the effects of a severe cyclone. We quantified the abundance of benthic organisms (e.g., corals, macroalgae, etc.) for four years to assess how experimental treatments affected community development. At three time points each year (April, July/August, November - except for two time points missed due to the COVID-19 pandemic, April 2020 and November 2020), we quantified benthic cover in each exclosure via point contacts on orthorectified photomosaics. Using Olympus TG cameras, we took ~64 individual photographs of each exclosure and then generated photomosaics by stitching photographs together using Agisoft Metashape software (Agisoft Metashape Professional Version 17.0). These photomosaics generate high-resolution imagery that allows identification of benthic space holders to the lowest taxonomic level possible (genus for most corals and macroalgae). It was not possible to reliably distinguish among filamentous turf algae, bare space, and very small encrusting algae (including small CCAs and other encrusting algae) from photographs, therefore these taxa were categorized as one group. We used these data to generate percent cover estimates for each exclosure at each timepoint. Percent cover of benthic space holders was estimated via 225 random points per m2 exclosure using CoralNet software.\n\ncdm_data_type = Other\nVARIABLES:\nTime_point (unitless)\nTimepoint (unitless)\nunitless (Date)\nBlock_Plot (unitless)\nBlock (unitless)\n... (51 more variables)\n | BCO-DMO | bcodmo_dataset_1000908_v1 | ||||||||||||
| log in | [Coral bleaching and mortality] - Coral bleaching and mortality data from a field experiment manipulating herbivore pressure and nutrient availability on a coral reef in Moorea, French Polynesia from 2018 to 2022 (Collaborative Research: Tipping points in coral reefs and their associated microbiomes: interactive effects of herbivory, nutrient enrichment, and temperature) | Here, we used a large-scale field experiment on the forereef of Moorea, French Polynesia to directly test how different levels of simulated fishing impacted the dynamics of coral reef communities before, during, and after a major MHW that caused significant coral bleaching and mortality. We used 16, ~1.25m2 exclosures to create four different levels of consumer pressure (Very Low, Low, Medium, and High) by altering the hole sizes in the exclosures to allow access to fishes based on body size. These treatments created a gradient of access for important herbivorous fishes (e.g., parrotfishes, surgeonfishes), as well as corallivorous fishes, and allowed us to examine how reductions in consumer pressure, as would happen with intensifying fishing, impact benthic dynamics. At the beginning of the experiment in 2018, coral cover across treatments was 57%, and we assessed the temporal dynamics of coral and macroalgae in response to altering consumer pressure. In 2019, Moorea experienced one of the most intense MHWs on record resulting in widespread coral mortality. Thus, we were able to directly test how varying consumer pressure impacted coral reef communities during the months prior to the MWH, during the MHW, and then for three years after the immediate impact of the MHW.\n \nUsing Olympus TG cameras, we took ~64 individual photographs of each exclosure which were then stitched together using Agisoft Metashape software. The creation of these photomosaics generates high-resolution imagery that allows identification of benthic space holders with high taxonomic resolution. The photomosaics allowed us to track the fates of individual corals across our time series. At the first time point in our time series (Aug 2018), we gave each individual Pocillopora and Acropora a unique identifying number. During the peak of coral bleaching, in May 2019, we took additional top-down photographs of each exclosure, allowing us to quantify whether each individual coral had bleached and, if so, what proportion of the colony surface area (to the nearest 5%) was bleached or dead. Because corals undergo natural, seasonal variation in Symbiodiniaceae density that can affect their coloration, we defined bleached tissue only as tissue that had lost all pigmentation. Bleaching severity was bimodal, with most corals either 0 or 100 percent bleached. However, approximately 36% of corals with some bleaching had less than 100% of their tissue bleached. For analyses, we defined 50% bleached as a severe bleaching threshold. Using our photomosaics, we then tracked the annual survival or mortality of each coral in August of each year (Aug 2019, Aug 2020, Aug 2021, Aug 2022). Corals frequently had partial mortality, with colonies sometimes having small amounts of remnant tissue which would remain for many months. Therefore, we used a threshold of the loss of 90% of live tissue to define a coral as being dead since we never observed recovery from this level of tissue loss.\n\ncdm_data_type = Other\nVARIABLES:\nBlock (unitless)\n... (30 more variables)\n | BCO-DMO | bcodmo_dataset_1000902_v1 | ||||||||||||
| log in | [Water column nutrient data 2018-2022] - Water column nutrient data from a 4 year experiment (2018-2022) manipulating consumer pressure and nutrient availability on a coral reef in Moorea, French Polynesia (Collaborative Research: Tipping points in coral reefs and their associated microbiomes: interactive effects of herbivory, nutrient enrichment, and temperature) | Here we experimentally test the relative importance of alterations to top-down and bottom-up processes in driving community development and variability after a simulated disturbance on a coral reef. We use a factorial experiment manipulating consumer pressure and nutrient enrichment for four years on a coral reef in Moorea, French Polynesia. Our experiment consisted of plots (~1.25 m2 each) that manipulated access by consumers via different size openings that allowed different size fishes access to the benthos, creating four levels of consumer pressure (Very Low, Low, Medium, High). These four levels of consumer pressure were crossed with manipulations of nutrient availability with either ambient or nutrient enriched conditions. At the start of the experiment, we removed all live corals and fleshy macroalgae from the plots to mimic the effects of a severe cyclone. We quantified the abundance of benthic organisms (e.g., corals, macroalgae, etc.) for four years to assess how experimental treatments affected community development. At three time points each year (April, July/August, November - except for two time points missed due to the COVID-19 pandemic, April 2020 and November 2020), we quantified benthic cover in each exclosure via point contacts on orthorectified photomosaics. \n \nTo evaluate the effectiveness of our nutrient treatment, we collected water samples using 50-ml syringes ~3cm above the benthos in each of our High consumer pressure exclosures (i.e., our open 1.25m2 exclosures). We collected water samples in 2021 and 2022 across a range of days after we swapped the nutrient diffusers (4-158 days). We filtered samples (GF/F) into falcon tubes, placed on ice and once back in the lab frozen until analysis. We analyzed inorganic nitrogen (nitrite + nitrate) and soluble reactive phosphorus concentrations using an autoanalyzer at the Marine Science Institute Analytical Laboratory at the University of California, Santa Barbara. For both nitrite + nitrate and phosphate, we averaged across time and our High consumer pressure exclosures to evaluate the average nutrient conditions in our experimental treatments.\n\ncdm_data_type = Other\nVARIABLES:\nBlock_plot (unitless)\nNutrient_TRT (unitless)\nDate_taken (unitless)\nDays_since_nutrient_swap (Days)\n... (5 more variables)\n | BCO-DMO | bcodmo_dataset_1000890_v1 |