Which accurately describes the relationship between nutrients and life-forms in an estuary?

Estuaries are incredibly productive ecosystems that provide many nutrients for a variety of life forms. Here's a step-by-step explanation of the relationship:

1. Nutrient Cycling: Estuaries are often described as 'nurseries of the sea' because they provide a nutrient-rich environment for young fish and other marine life. Nutrients such as nitrogen and phosphorus are cycled through the ecosystem, supporting a high level of primary productivity.

2. Food Web: These nutrients support the growth of plants and algae, which form the base of the food web in an estuary. These primary producers are consumed by small invertebrates, which are then eaten by larger animals, and so on up the food chain.

3. Biodiversity: The abundance of nutrients in estuaries supports a high level of biodiversity. Many different species of birds, fish, mammals, and invertebrates can be found in these habitats.

4. Human Impact: Humans also rely on the nutrients found in estuaries. Many important commercial and recreational fish species spend part of their life cycle in estuaries. Additionally, the plants in estuaries help to filter pollutants out of the water, improving water quality.

In conclusion, nutrients play a crucial role in supporting life in estuaries. They fuel the food web, support biodiversity, and provide important services for humans.