Which best explains the importance of estuaries? * Estuaries are freshwater areas that support a large amount of living things. Estuaries are areas where freshwater and salt water collide, resulting in a large amount of biodiversity. Estuaries are tropical areas that support an abundance of life found usually in cold regions of the ocean. Estuaries are nutrient-rich areas because they have large amounts of carbon dioxide seeping into the water from the ground below.

The best explanation for the importance of estuaries is: **Estuaries are areas where freshwater and salt water collide, resulting in a large amount of biodiversity.** **Explanation:** Estuaries are dynamic environments where rivers meet the ocean, creating a mix of freshwater and saltwater known as brackish water. This unique combination of conditions supports a wide variety of plant and animal species, making estuaries some of the most biodiverse ecosystems on the planet. The mixing of waters also brings in nutrients that enhance productivity, providing vital habitats for many marine and terrestrial organisms. **Incorrect Options:** 1. **Estuaries are freshwater areas that support a large amount of living things.** - *Incorrect:* Estuaries are brackish, not purely freshwater. 3. **Estuaries are tropical areas that support an abundance of life found usually in cold regions of the ocean.** - *Incorrect:* Estuaries exist in various climates, not just tropical, and do not specifically support cold-region marine life. 4. **Estuaries are nutrient-rich areas because they have large amounts of carbon dioxide seeping into the water from the ground below.** - *Incorrect:* While estuaries are nutrient-rich, it's primarily due to the mixing of nutrient-rich river water and ocean water, not primarily from carbon dioxide seeping in. **Final Answer:** **Estuaries are areas where freshwater and salt water collide, resulting in a large amount of biodiversity.**