Secchi disc readings were used to determine turbidity at the reef site on a regular basis. The rope was marked at five foot intervals to determine at what distance the disc could no longer be seen on a horizontal axis.
Photographer: Dr. James P. McVey
Affiliation: NOAA Sea Grant Program
Location: Pokai Bay, Oahu
Subject: Coral Reefs
Subject: Marine Biologist
Subject: Artificial Reef