Greenland reef outlook
Estimated cold-water coral health over time
Each chart places its environmental driver on the left axis and the GACHE health estimate on the right. The health line now combines the temperature, acidification, and microplastic timelines using a nonlinear multi-stressor risk response.
Model v2: normalized logistic health = logistic(2.9 − cumulative risk), where risk combines thresholded thermal, acidification, and microplastic exposures plus their pairwise interactions. This structure follows coral prediction work that uses nonlinear thermal stress and multi-stressor effects; the Greenland-specific weights are transparent calibration assumptions, not field-fitted coefficients. NOAA heat-stress modelling ↗ and multi-stressor Bayesian-network study ↗.
Stressor selection is grounded in cold-water coral experiments showing reduced skeletal growth under microplastic exposure and altered calcification under unfavorable acidification conditions. Microplastic experiment ↗ and NOAA cold-water coral acidification study ↗.
Figure 01
Surface temperature → deep-reef temperature
NOAA surface observations are translated to an estimated 886–932 m reef-water temperature using a damped depth-transfer proxy.
Observed surface values: NOAA OISST ↗. Reef-depth temperature context: Meyer et al. ↗.
The health line includes all three stressor trajectories. 2026 onward is a linear warming scenario, not an NOAA forecast.
Figure 02
Microplastic contamination
Sparse reported water-column observations from Greenland waters are shown with an illustrative 6% annual continuation scenario.
NOAA Arctic Report Card ↗ and West Greenland 2019 observations ↗.
The health line includes all three stressor trajectories. Sampling methods and particle-size thresholds differ between studies; points are not a harmonized monitoring record.
Figure 03
Ocean acidification
A Greenland Sea upper-ocean pH trend is reconstructed from the published 1981–2019 measured decline rate.
Trend source: Acidification of the Nordic Seas ↗ (Greenland Sea, 0–200 m).
The health line includes all three stressor trajectories. 2020 onward extends the observed −0.00219 pH/year trend; it is a scenario, not a climate-model forecast.
Figure 04 / Station environmental relationship
Environmental conditions and estimated station health
Each dot is one station. Its health index is calculated with GACHE Model v2: surface temperature is converted to a deep-reef proxy, then combined with ocean pH and microplastic density in a nonlinear multi-stressor response. The line is an OLS fit through those station scores.
Figure 05 / Reference context
Arctic estimate and tropical reef context
This is not a like-for-like health ranking: GACHE's Arctic value is a modelled 0–100 index, while the tropical value is measured global live hard-coral cover. It is shown to give the estimate ecological context.
Global tropical live hard-coral cover was 29.5% in 2019, after an estimated 14% loss since 2009. Source: GCRMN Status of Coral Reefs of the World ↗.