Why are estuaries important nursery habitats for fish and shellfish, and what factors optimize juvenile survival?

• A. They provide shelter, abundant prey, and flushing; juvenile survival improves with stable salinity, adequate substrate, and good water quality.
• B. They are poor in prey but high in shelter; juvenile survival relies on high salinity only.
• C. They host adult breeding populations exclusively; juvenile survival is unaffected by water quality.
• D. They limit flushing; juvenile survival improves with rapid salinity fluctuations.

Answer: (A)