Deep-water corals are protected in the seas around New Zealand by legislation that prohibits intentional damage and removal, and by marine protected areas where bottom trawling is prohibited. However, these measures do not protect them from the impacts of a changing climate and ocean acidification. To enable adequate future protection from these threats we require knowledge of the present distribution of corals and the environmental conditions that determine their preferred habitat, as well as the likely future changes in these conditions, so that we can identify areas for potential refugia.

In this study, we built habitat suitability models for 12 taxa of deep-water corals using a comprehensive set of sample data and predicted present and future seafloor environmental conditions from an earth system model specifically tailored for the South Pacific. These models predicted that for most taxa there will be substantial shifts in the location of the most suitable habitat and decreases in the area of such habitat by the end of the 21st century, driven primarily by decreases in seafloor oxygen concentrations, shoaling of aragonite and calcite saturation horizons, and increases in nitrogen concentrations. The current network of protected areas in the region appear to provide little protection for most coral taxa, as there is little overlap with areas of highest habitat suitability, either in the present or the future. We recommend an urgent re-examination of the spatial distribution of protected areas for deep-water corals in the region, utilising spatial planning software that can balance protection requirements against value from fishing and mineral resources, take into account the current status of the coral habitats after decades of bottom trawling, and consider connectivity pathways for colonisation of corals into potential refugia.

Data include twelve .csv files with locations of presence and absence samples for twelve deep-water coral taxa, collected from research surveys, commercial fishing operations, and museum records. Along with locality information, values for a range of parameters representing seafloor environmental conditions at the sampling sites are included.

in addition to the sampling data there are three other .csv files representing values of the environmental parameters in each cell of a 1x1 km grid covering the study area (the New Zealand Marine Region), with cell locations represented as projected coordinates in Mercator 41 Projection (EPSG: 3994). The environmental parameters are a mixture of temporally fixed and temporally variable parameters, the latter obtained from New Zealand Earth System Model outputs. One file has parameters that represent present conditions (reference period 1995-2014), the second file has parameters that represent future conditions (reference period 2080-2099) under a 'moderate' greenhouse gas increase trajectory (SSP2-4.5), and the third file has parameters that represent future conditions under a 'strong' greenhouse gas increase trajectory (SSP3-7.0).

The .csv files can be readily accessed with a wide range of open-source and proprietry software