Final answer:
Estuaries are good habitats for the juveniles and young of many species because they are highly productive and protected from wave action.
Step-by-step explanation:
Estuaries are highly productive and relatively protected from wave action, making them good habitats for the juveniles and young of many species. Estuaries provide a unique environment where freshwater from rivers meet saltwater from the ocean, creating a brackish water mixture. This mixture of water and the protection from wave action make estuaries ideal for young organisms to grow and thrive.