Complex sentence: Both scientists conclude the octopus is from the Mindanao Deep, having been forced from its natural habitat by hydrogen bomb testing in the area, which has made the octopus radioactive, driving off its natural food supply.
Split into simpler sentences: Both scientists conclude the octopus is from the Mindanao Deep and has been forced out of its natural habitat by hydrogen bomb testing in the area. This testing has made the octopus radioactive, which has driven off its natural food supply.