Complex sentence: By 1980 the number of Arabian Oryx in captivity had increased to the point that reintroduction to Oman was attempted from the San Diego Wild Animal Park.
Split into simpler sentences: By 1980 the number of Arabian Oryx in captivity had increased to the point that reintroduction to the wild was started. The first release to Oman was attempted with Oryx from the San Diego Wild Animal Park.