As cold, briny water from the antarctic circulates to the equator, it warms and rises. as it does, this upwelling carries nutrients that produce billion tons of phytoplankton that are eaten by fish and birds. those that are not eaten die, and fall back to the ocean floor, carrying nutrients with them.

The answer is one (1) billion tons of phytoplankton at any one time. Annually, its recorded that there is approximately 45 billion tons of phytoplankton in the ocean. Other than being a source of food for fish, they are critical in the carb9n cycle. This phytoplankton incorporates 45–50 billion tons of inorganic carbon into their cells and are the largest source of atmospheric oxygen.

idk but if i had to take an educated guess i’d say a c d

Humans can affect weathering and erosion in several ways.  humans cause  increases in acid rain and pollution, which increase the amount of  weathering  agents in the air and water, and then on land.for an easy answer: 1) acid rain2) pollution