PADI Divemaster Certification Practice Exam

What percentage of all known marine species use coral reefs as nursery grounds?

1. 10%

2. 25%

3. 50%

4. 75%

The correct answer is: 25%

Coral reefs are known to be among the most biodiverse ecosystems in the world, providing critical habitats for a vast array of marine species. A significant percentage of marine life depends on coral reefs during their early developmental stages. The figure of 25%, indicating that a quarter of all known marine species use coral reefs as nursery grounds, underscores the ecological importance of these habitats. This reliance on coral reefs for nurseries is crucial because juvenile fish and various marine organisms find shelter and abundant food resources in the complex structures of the reefs, which help them grow and develop into adulthood. The health and stability of coral reefs therefore play a vital role in maintaining overall marine biodiversity. Additionally, given the threats coral reefs face from climate change, pollution, and overfishing, understanding their importance as nurseries is key for conservation efforts. The percentages associated with the other choices do not align with scientific consensus about coral reef utilization as nursery grounds and tend to overestimate the proportion of marine species that rely exclusively on coral reefs for their early life stages. Thus, the answer indicating that approximately 25% of all known marine species use coral reefs as nursery grounds accurately represents known data.