Complex sentence: Japanese bereaved family members also consider the sites of sunken Japanese shipwrecks in Kwajalein lagoon to be sacred gravesites, and they are often discouraged by the activities of American divers who attempt to disturb these wrecks.
Split into simpler sentences: Japanese bereaved family members also consider the sites of sunken Japanese shipwrecks in Kwajalein lagoon to be sacred gravesites. They object to the activities of American divers who attempt to explore these wrecks.