Skip to main content

Table 7 Results of best-fit dose–response meta-regression (DRMA) models for coral responses where sufficient data were available to assess the relationship between sediment exposure (‘dose’) and magnitude of the coral response of-interest (standardized effect size, Hedges’ d)

From: Effects of sediment exposure on corals: a systematic review of experimental studies

Coral age class Continuous coral response Deposited or suspended sediment* # Treatment groups* (controls included/excluded) # Studies/articles in DRMA # Species/genera in DRMA Dose–response I2 Statistic* Dose–response threshold* (DS: mg/cm2/day; SS: mg/L)
Gametes Fertilization success rate SS 110/86 10/6 4/2 82.3% 30.4 (p < 0.0001)
Larvae Larval survival rate SS 50/42 4/3 4/2 73.0% n.s
Settlement rate DS 71/61 7/6 2/2 84.6% 1.3 (p < 0.0001)
Settlement rate SS 26/20 6/3 3/2 88.3% n.s
Juveniles Recruit mortality rate DS 132/87 3/3 4/2 47.1% 13.8 (p = 0.025)
Adults P/R ratio DS 20/10 3/3 4/4 58.4% n.s
Photosynthetic efficiency DS 181/141 8/6 9/6 76.8% 3.2 (p = 0.005)
Photosynthetic efficiency SS 217/164 5/4 6/5 21.4% n.s
Growth rate DS 29/19 8/8 8/5 41.5% n.s
Partial tissue mortality rate DS 140/115 4/4 11/8 86.9% n.s
Total colony mortality rate SS 47/33 4/4 6/4 0.0% n.s
  1. Analyses using deposited or suspended sediment datasets are indicated as ‘DS’ and ‘SS,’ respectively. A ‘treatment group’ is an experimental unit of corals exposed to the same exposure conditions within a study—these may be control conditions (no sediment exposure) or treatment conditions of differing exposure concentrations and/or durations. The ‘Dose–Response I2 Statistic’ is a measure that indicates the percentage of variance in a meta-analysis that is attributable to heterogeneity among dose–response comparisons within study. Heterogeneity is substantial when I2 is above 75%. The ‘Dose–Response Threshold’ for a coral response significantly affected by sediment concentration was the minimum exposure value at which DRMA 95% CI no longer overlapped with zero (where zero indicates no difference between a treatment group and its control, see Fig. 2C). Rows in bold represent significant relationships (p ≤ 0.05) between sediment exposure and the effect size of the corresponding coral response and ‘n.s.’ indicates a non-significant relationship (p > 0.05)