APPENDIX 3. — Comparison of depth of collection and 1% optical depths in each region. The 1% optical depth is defined as the euphotic zone depth (Zeu, m), or depth where Photosynthetically Active Radiation (PAR) (Zeu) is 1% of PAR at the surface (0 m) (Lee et al. 2018).

Location of collection	Depth range (m) of collection	Diffuse Attenuation Coefficent (KPAR, m-1)	1% Optical Depth (m) (4.6/KPAR, Kirk 2011)	Source
Ho‘okuleana (Penguin Banks), Hawai‘i	90-107	0.041	112	Spalding et al. 2019
Udo, Jeju Korea	15-20	0.163	28	Kim et al. 2015 (calculated from 10.4 m average Secchi depth (ZSD), where K=1.7/ ZSD from Idso & Gilbert 1974)
Karikari Bay, North Island, New Zealand	5-30	0.132	35	Howard-Williams et al. 1995 (K for Coastal I waters)