Aquatic Ecology and Resources: Oceanography.pptx

Oceanography

1. OCEANOGRAPHY (Seawater) PCF 106 Aquatic Ecology and Resources

2. “Ecology” from two Greek roots: oikos , meaning “ house or household ” or “ place to live ” and ology , meaning “ study of .” AQUATIC ECOLOGY

3. Aquatic ecology includes the study of relationships between individuals of the same species, between different species, and between organisms in all aquatic environments, including oceans, estuaries, lakes, ponds, wetlands, rivers, and streams. AQUATIC ECOLOGY Introduction to Aquatic Ecology - Regional Aquatics Monitoring Program (RAMP)

4. covers the scientific disciplines that study the physical and biological characteristics of the world's oceans and seas as well as observable phenomena. is a scientific discipline that delves into the vast and complex world of our oceans. Oceanography

5. our planet is predominantly covered by water. the world ocean, spanning a vast 70% of Earth's surface, forms a thin film of seawater over the planet's crust. has average depth of 3,700 meters across its 13,250-kilometer diameter, it hosts an incredible diversity of plant and animal life. divided into four major ocean basins: the Atlantic, Pacific, Indian, and Arctic. the seawater's unique composition: roughly 96.5% pure water and 3.5% dissolved compounds. SEAWATER

6. The substances found within the ocean can be categorized into: 1. Inorganic substances: Salts and essential nutrients for the growth of marine organisms. 2. Dissolved gases: Primarily nitrogen, carbon dioxide, and oxygen. 3. Organic compounds: Essential for life, including fats, oils, carbohydrates, vitamins, amino acids, and proteins. Seawater

7. • Seawater salinity, the concentration of dissolved salts, is typically around 35 parts per thousand (ppt). • It varies significantly, with low salinity near river mouths (approaching 0 ppt) and higher salinity in enclosed seas like the Red Sea (exceeding 80 ppt). • Salinity fluctuations are influenced by factors like evaporation, precipitation, river runoff, and ice formation/melting. Salinity

8. • Major ions: Dominated by salts like sodium chloride. • Essential nutrients: Nitrate and Phosphate are crucial for plant growth. • Dissolved gases: Nitrogen ( ) Carbon dioxide ( ) Oxygen ( )   Dissolved Substances

9. Mg, Ca, HCO 3 (bicarbonate), and Silicate are essential for the formation of hard structures in marine organisms. Oxygen (O 2 ) is vital for the respiration of most marine life. Carbon dioxide (CO 2 ) plays a key role in photosynthesis and influences ocean acidity. Biological Significance

10. Carbon dioxide (CO 2 ) reacts with seawater to form carbonic acid (H 2 CO 3 ), which dissociates to release hydrogen ions (H+). The concentration of H+ ions determines seawater acidity (pH). Increased CO 2 levels lead to ocean acidification. Ocean Acidity

11. Nitrate and Phosphate are essential nutrients for marine plant growth. These nutrients are cycled through the ecosystem, with plant uptake, animal consumption, and excretion playing key roles. Nutrient Cycles

12. Temperature: A critical factor for marine life, with most organisms thriving within a range of 0°C to 30°C. Thermocline: The region where temperature and density change rapidly with depth. Characterized by a distinct two-layer system: A well-mixed surface layer A stable, deeper layer Seawater Temperature

13. Density: Seawater density increases with; Decreasing temperature: Cold water is denser than warm water. Increasing salinity: Saltier water is denser than less salty water. Density-driven circulation: Dense water formed at the surface (due to cooling, evaporation, or freezing) sinks. These sinking drives ocean circulation, transporting heat and nutrients. Seawater Densities