Environmental Condition 17-18 years after the Benthic Impact Experiment

摘要

Japan Deep-sea Impact Experiment (JET) is an in situ experimentaimed at evaluating environmental impacts and monitoring the recoveryprocess arising from manganese nodule mining. The experiment hasbeen done in 1994, and monitoring surveys have continued to 1996.However, due to short monitoring period, understandings of recoveryprocess was insufficient. While 17-18 years after, the Deep OceanResources Development Co., Ltd revisited the site and surveyed theenvironmental condition. As a result, the environmental impacts, whichwas recognized immediately after and one year after the benthicdisturbance were not recognized after 17-18 years. The present authorsshow the result and discuss the significance of long term monitoringsurvey.