The cause of the event is thought to be unusually warm inshore waters, preventing the normal upwelling of cold, nutrient-rich waters that sustain the local ocean food chain.
(The cause of the event; is thought; ) (The cause of the event; to be; unusually warm inshore waters) (cold, nutrient-rich waters; sustain; the local ocean food chain)
The cause of the event The cause of the event cold, nutrient-rich waters
is thought to be sustain
unusually warm inshore waters
the local ocean food chain