Earth's Oceans and Marine Ecosystems

Earth's Ocean: A Comprehensive Overview

• Earth's ocean covers approximately 70% of its surface.
• The ocean is vital for life, driving the water cycle and moderating global temperatures.
• One global ocean is comprised of interconnected basins (e.g., North Pacific, South Atlantic).
• Ocean basins have diverse features like trenches, ridges, and plateaus, influenced by plate tectonics.
• The ocean floor holds a wealth of life forms, just as diverse as terrestrial landscapes.
• Ocean water's properties include salinity, density, freezing point and pH balance, crucial for marine ecosystems.

Ocean Life and Ecosystems

• The ocean supports a vast array of life, from microscopic microbes to large marine mammals like blue whales.
• Most ocean life is microscopic, forming the base of the food web.
• Phytoplankton, microscopic plants and bacteria, are essential primary producers, generating oxygen and consuming CO2.
• Phytoplankton thrive in shallow, warm areas like continental shelves.
• The ocean absorbs significant amounts of atmospheric CO2 and methane, playing a role in the carbon cycle.

Ocean and Weather/Climate

• The ocean absorbs solar radiation, regulating global temperatures.
• Heat exchange between the ocean and atmosphere drives weather patterns (winds, currents, storms).
• El Niño Southern Oscillation (ENSO) and La Niña are examples of ocean-atmosphere interactions that affect global weather.
• Ocean currents, heat absorption & release, and water vapor transportation significantly influence Earth's climate.

Ocean Chemistry and Human Impact

• Ocean water is a complex system of organic and inorganic substances.
• Salinity (salt content) varies across different locations, influencing ocean currents.
• Ocean acidification results from increased CO2 absorption, threatening marine life.
• Human activities, including pollution and resource extraction, impact ocean chemistry and life.
• Changes in temperature and pH affect species survival and biological diversity (e.g., coral bleaching, shell formation inhibition).

Human-Ocean Interconnections

• Ocean health impacts human lives in many ways: supplying freshwater, promoting climate regulation, providing resources (food, medicines, minerals).
• Coastal communities and economies rely heavily on the ocean.
• The ocean connects cultures, is a source of inspiration, recreation and discovery.
• Human activity significantly impacts the ocean's ecosystems, necessitating responsible resource management and conservation.

Ocean Exploration and Oceanography

• Less than 15% of the ocean has been explored.
• Ocean exploration is interdisciplinary, involving scientists from various fields.
• Oceanographic research includes studying the ocean's systems and processes using various technologies (ships, robots, satellites).
• Understanding the ocean is crucial for human survival.