In the mid-seventies, a $70-million international joint venture succeeded in collecting multi-ton quantities of manganese nodules from the abyssal plains (18,000+ depth)of the eastern equatorial Pacific Ocean. Significant quantities of Nickel (the primary target) as well as Copper and Cobalt were subsequently extracted from this "ore" using both pyro and hydro methods. In the course of this 8-year project, a number of ancillary developments evolved, including the use of near-bottom towed side-scan sonar array to assay the nodule population density on the abyssal silt whilst simultaneously performing a sub-bottom profile with a derived, vertically-oriented, low-frequency acoustic beam.
The technology and art developed during the course of this project were never commercialized because the last two decades of the 20th century saw a glut of Nickel production. The estimated $3.5-billion (1978 US dollars) investment to implement comercialization was an additional factor. Sumitomo Metal Mining continues to maintain a small (place-keeping) organization in this field.