Final answer:
The shutdown of thermohaline circulation would disrupt the transport of nutrients in oceans, affecting primary productivity and marine biodiversity.
Step-by-step explanation:
If thermohaline circulation is shut down, it would have a significant impact on the transport of nutrients among the oceans of the world. The thermohaline circulation is responsible for the movement of water and nutrients in the ocean. It is driven by differences in temperature and salinity, which create density gradients. As warm surface waters move towards the poles, they cool and become denser, sinking to the deep ocean and carrying nutrients with them. These nutrients are then transported to other parts of the world's oceans, supporting marine life.
Without thermohaline circulation, the transport of nutrients would be disrupted. Nutrient-rich deep waters would not reach the surface, leading to a decrease in primary productivity—the production of organic matter by photosynthetic organisms such as phytoplankton. This would have cascading effects on the entire marine food web, impacting the abundance and distribution of marine species.
Overall, the shutdown of thermohaline circulation would result in changes in nutrient availability, primary productivity, and marine biodiversity in the oceans of the world.