Why are the open oceans nutrient poor? Why are coastal areas and intertidal habitats relatively nutrient rich?

Verified step by step guidance

1. Step 1: Understand the concept of nutrient distribution in the ocean. The open oceans are nutrient poor because they are far from land, which is the primary source of nutrients. Nutrients are washed into the ocean from the land by rivers and rain. In the open ocean, far from land, these sources of nutrients are absent or very limited.
2. Step 2: Understand the role of ocean currents. Ocean currents also play a role in nutrient distribution. Deep ocean currents often carry nutrient-rich water from the ocean floor to the surface, a process known as upwelling. However, in the open ocean, these currents are often weak or absent, limiting the availability of nutrients.
3. Step 3: Understand the concept of nutrient cycling. In the open ocean, nutrients that are present are quickly used up by phytoplankton and other marine organisms. Once these organisms die, their remains sink to the ocean floor, taking the nutrients with them. This makes it difficult for nutrients to be recycled back into the ecosystem.
4. Step 4: Understand why coastal areas and intertidal habitats are nutrient rich. Coastal areas and intertidal habitats are nutrient rich because they are close to land, where nutrients are plentiful. Rivers and rain wash nutrients from the land into these areas. Additionally, the action of tides and waves can stir up the bottom sediments, releasing nutrients back into the water.
5. Step 5: Understand the role of human activities. Human activities, such as agriculture and urban development, can also contribute to the nutrient richness of coastal areas and intertidal habitats. Runoff from these activities can carry large amounts of nutrients into these areas.

Key Concepts

Nutrient Cycling

Nutrient cycling refers to the movement and exchange of organic and inorganic matter back into the production of living matter. In open oceans, the vast distances and limited upwelling of nutrients from the deep sea result in lower concentrations of essential nutrients like nitrogen and phosphorus, making these areas nutrient-poor.

Upwelling

Upwelling is the process where deep, nutrient-rich waters rise to the surface, often due to wind patterns and ocean currents. This phenomenon is more prevalent in coastal areas, where the interaction of land and ocean promotes nutrient replenishment, leading to higher productivity and nutrient richness in these habitats.

Eutrophication

Eutrophication is the enrichment of water bodies with nutrients, often leading to excessive growth of algae and depletion of oxygen. Coastal areas and intertidal habitats can experience eutrophication due to runoff from land, which introduces nutrients, contrasting with the nutrient-poor conditions of the open ocean.