DOI: 10.5061/dryad.4tmpg4fnx
title: A physiological crisis drives the coral recruitment bottleneck

description: Recruitment failure is a leading cause of population decline for tropical
 corals. Because the causes of death for small corals are unclear, it is
 challenging to predict how recruitment bottlenecks will change in the
 future. We tested the hypothesis that depletion of biomass causes high
 mortality of small corals under thermal stress. The biomass of small
 colonies (&lt; 30 mm diameter) of genetically identified broadcast
 spawning Pocillopora from Moorea, French Polynesia, was manipulated using
 elevated temperature to increase respiration, and reduced day length to
 decrease photosynthesis. Corals with high or low biomass were incubated at
 ambient summer (28°C) and elevated (31°C) temperatures. Small P. meandrina
 with high biomass were six times more likely to die at 31°C versus 28°C,
 but corals with low biomass were 48 times more likely to die at 31°C
 versus 28°C. When small Pocillopora were grown in seawater augmented with
 bicarbonate to reduce the energetic expenditure on skeletogenesis, growth
 rates were not affected but energy expenditure was reduced by 20%.
 Resource-limitation of small corals therefore can affect their response to
 elevated temperatures, supporting the hypothesis that a physiological
 crisis initiated by resource limitation mediates the stringency of
 recruitment bottlenecks and the rate of coral community recovery. Data in
 support of this publication are supplied in 11 files.
description: # A physiological crisis drives the coral recruitment bottleneck Dataset
 DOI: [10.5061/dryad.4tmpg4fnx](10.5061/dryad.4tmpg4fnx) ## Description of
 the data and file structure These data come from experiments completed in
 2024 in which the first experiment used incubations in tanks to alter the
 biomass of corals and then exposed them in tanks to temperature treatments
 to test the effects of biomass manipulation. In the second experiment
 corals were grown in tanks in which bicarbonate concentrations were
 manipulated and growth and respiration were recorded.  README: A
 physiological crisis drives the coral recruitment bottleneck This
 submission includes 17 files that contains all the data published in the
 paper **1_Coral_sizes:** These data describe the size of the corals used
 in the survivorship experiment • Coral # = unique ID • Diameter = planar
 diameter of corals (mm) • Used for = how the corals were used in the
 experiment **2_Phase_1_tank_conditions_temperature:** These data describe
 the conditions in the treatment tanks during Phase I of the survivorship
 experiment • Date = day the measurements were recorded • Time of day =
 when the records were made • Tank = tank and treatment in which
 measurements were made  • Temperature = Temperature recorded in Tank (°C)
 **3_Phase_1_tank_conditions_light:** These data describe the conditions in
 the treatment tanks during Phase I of the survivorship experiment •  Date
 = day the measurements were recorded •  Time of day = when the records
 were made •  Tank = tank and treatment in which measurements were made  •
  Light = PAR recorded in Tank (µmol photons/m2/s)
 \**4_Phase_2_tank_conditions_temperature:** These data describe the
 conditions in the treatment tanks during Phase I of the survivorship
 experiment •  Date = day the measurements were recorded •  Time of day =
 when the records were made •  Tank = tank and treatment in which
 measurements were made  •  Temperature = Temperature recorded in Tank (°C)
 **5_Phase_2_tank_conditions_light:** These data describe the conditions in
 the treatment tanks during Phase I of the survivorship experiment •  Date
 = day the measurements were recorded •  Time of day = when the records
 were made •  Tank = tank and treatment in which measurements were made  •
  Light = Light recorded in Tank (µmol photons/m2/s)
 **6_Size-biomass_initial**: These data describe the relationship between
 biomass and area of corals collected from the reef in April 2023 •  Coral
 ID = unique number •  Area = area (cm^2) by wax dipping •  Biomass =
 biomass (mg) by fixing, decalcification and drying •  These data reported
 in Fig. S3A **7_Size_area:** These data describe the relationship between
 diameter and area of corals used in the survivorship experiment •  Coral
 ID = unique ID •  Area by wax = area determined by wax dipping (cm^2) • 
 Diam = planar diameter (mm) **8_Biomass_end_Phase_1**: These data describe
 the biomass of corals at the end of Phase I of the survivorship experiment
 •  Coral ID = unique number •  Species = species identified by genetic
 approaches •  Biomass = biomass (mg) •  Size Diameter = planar diameter
 (mm) •  Phase 1 treatment = phase I treatments, temperature (cool or hot)
 and day length (long or short) •  Tank = tank into which corals were
 placed •  These data reported in Fig. 1 **9_Survivorship_Phase_II:** These
 data describe the survival of corals in Phase II treatments •  Coral ID =
 unique number •  Species = coral species by genetic approaches •  Days to
 death = days in treatments until death occurred •  Censore_death = score
 as alive (0) or dead (1) •  Phase I treatment = either thick tissues or
 thin tissues •  Phase II treatments = either hot or cold •  Phase II tanks
 = tank into which corals were placed •  Size = planar diameter (mm) of
 corals •  These data reported in Fig. 2
 **10_Cost_of_growth_tank_conditions_temperature:** These data describe
 tank conditions in the August growth experiment •  Date = date of
 measurement •  Tank = tank into which corals were placed •  Temperature =
 temperature in tank (°C) **11_Cost_of_growth_tank_conditions_light:**
 These data describe tank conditions in the August growth experiment • 
 Date = date of measurement •  Tank = tank into which corals were placed • 
 Light = light recorded in tank (µmol photons/m2/s)
 **12_Cost_of_growth_tank_conditions_salinity:** These data describe tank
 conditions in the August growth experiment •  Date = date of measurement
 •  Tank = tank into which corals were placed •  Salinity = salinity
 recorded in tank (ppm) **13_Cost_of_growth_tank_conditions_pH:** These
 data describe tank conditions in the August growth experiment •  Date =
 date of measurement •  Tank = tank into which corals were placed •  pH =
 pH recorded in tank **14_Cost_of_growth_tank_conditions_TA:** These data
 describe tank conditions in the August growth experiment •  Date = date of
 measurement •  Tank = tank into which corals were placed •  AT = total
 alkalinity µmol/kg **15_Growth_August_Experiment:** These data describe
 the growth of corals in the August growth experiment •  Coral ID = unique
 ID number •  Tank_number = tank into which coral was placed •  Treatment =
 ambient or elevated total alkalinity (AT) •  Area = area of corals (cm^2)
 •  Growth = growth rate of corals mg/d/cm2 •  These data reported in Fig.
 3B **16_Respiration_August_Experiment:** These data describe the
 respiration of corals in the August growth experiment •  Coral ID = nique
 ID number •  Tank_number = tank into which coral was placed •  Treatment =
 ambient or elevated total alkalinity (AT) •  Respiration = respiration
 rate of corals µmolO2/cm2/h •  These data reported in Fig. 3C **17_Biomass
 August:** These data describe biomass of corals freshly collected in
 August 2023 for the growth experiment •  Coral ID = unique number •  Area
 = coral area (cm2) •  Biomass = biomass (mg) •  These data reported in
 Fig. S3