Adult snapper typically spawn their eggs in areas of highly productive waters, adjacent to estuaries and harbours. The Hauraki Gulf (a large embayment) is an important area for snapper spawning.

Spawning takes place between October and March, during which time adult snapper will likely spawn several times. Each adult fish is capable of spawning millions of small (0.8-2 mm) eggs during a season. These eggs hatch after around two days.

How impacts such as climate change and its associated increasing ocean acidity affect snapper eggs and larvae, which are likely most vulnerable to this form of influence, is as yet unknown. 

NIWA
Snapper - eggs. [NIWA]