Isso provavelmente é The Legacy of Heorot , um romance colaborativo escrito entre Larry Niven, Steven Barnes e Jerry Pournelle. Foi publicado em 1987 e, portanto, se encaixa no seu calendário, e tem o enredo distintivo da doença de hibernação (um resultado do uso de sua tecnologia de animação suspensa por muito tempo), bem como os Grendels como os alienígenas. O navio da colônia é o Geographic e foi financiado pela sociedade National Geographic.
Do artigo da Wikipédia vinculado, discussão da visão geral do enredo e questões de animação suspensas:
Two hundred colonists arrive on Avalon to found a new community, having made the 100-year journey from Earth in suspended animation on the starship Geographic (the expedition is funded by the National Geographic Society). The colonists, all selected for their outstanding physical and mental attributes, make a terrible discovery: though the suspended animation technology which permitted them to survive the journey worked well enough, it had unforeseeable side effects due to the unprecedented duration of its use. Their intelligence and reasoning skill are damaged. Some are only mildly afflicted, while others have intellectual disability; eight cannot be reanimated at all. The book opens with the colonists learning how to live without the sharp and nimble minds they all once had.
E discussão dos Grendels:
The autopsy reveals that grendels (as the creatures are now known) are crocodilian in appearance and behavior, with jaws that can crush steel. Their bones are significantly stronger than those of humans, as they are not based on calcium. They have a sense of smell better than a dog's. Studying its brain shows it is not fully sapient, but that it is not far off, and is at least as smart as a gorilla. Its claws are not just weapons, but exert enough traction for the creature to sprint up rocky cliffs. Though it is not a true amphibian – it cannot breathe water – it does possess an integral snorkel enabling it to move undetected beneath several feet of water. Its cardiovascular system and musculature give it strength and stamina far beyond that of humans, and that is without its primary evolutionary advantage: A super-oxygenated blood supplement.