Effects of Bathymetric Grid-Cell Sizes on Habitat Suitability Analysis of Cold-water Gorgonian Corals on Seamounts

ABSTRACT

We investigated the effects of the spatial resolution of bathymetry data on the predicted local distribution of large gorgonian corals on the southern Emperor Seamounts in the high seas of North Pacific. Terrain attributes were calculated from bathymetric survey data at six different grid-cell sizes (25–800 m) to investigate how the values of bottom terrain attributes and the prediction of MaxEnt habitat suitability models would vary with grid-cell size. The values of each terrain attribute showed different patterns among different grid-cell sizes, and MaxEnt demonstrated better performance at grid-cell size of 100 m or less than at larger sizes.

KEYWORDS:

• Cold-water corals
• habitat suitability modeling
• multi-beam bathymetry
• seamounts
• spatial resolution
• terrain analysis

Acknowledgements

The authors are grateful to the captain, crew, and on-board researchers of R/V Kaiyo-maru and T/V Koyo-maru. They especially thank Shaun Walbridge (oceans engineer, ESRI) for technical support with regard to the BTM. They are also grateful to the two anonymous reviewers for their valuable comments and suggestions.

Funding

This study was conducted as part of a Fisheries Agency of Japan project on evaluation of the status of the seafloor environment of fishing grounds on the high seas.