Environmental Management (0680) | Oceans as a resource

Hello, Environmental Managers! Welcome to Oceans as a Resource

Hey there! Did you know that the ocean covers over 70% of our planet? It's not just a big blue space; it's a massive bank of resources that humans rely on every single day. This chapter is all about understanding what the ocean offers us and why managing these resources sustainably is crucial for our future.

Don't worry if this topic feels vast—we'll break down the ocean's potential into easy-to-understand categories: Energy, Food, Materials, and Services.

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5.1 The Resource Potential of the Oceans

The oceans provide us with a huge range of resources. We can group them into four main categories:

1. Biological Resources (Food and medicine)
2. Non-Biological Resources (Minerals and materials)
3. Energy Resources (Power generation)
4. Services (Tourism, transport, water)

1. Food (Biological Resources)

The most obvious resource we get from the sea is food. These resources are often referred to as fisheries, which we will explore in more detail later.

• Fish and Shellfish: The ocean is the primary source of protein for billions of people globally, especially in coastal communities. Species like cod, tuna, sardines, and shrimp are vital food sources.
• Algae and Seaweed: These are increasingly being used as food sources, fertilisers, and even biofuel ingredients.

2. Chemicals and Minerals (Non-Biological Resources)

The vast quantities of seawater contain many dissolved substances that we can extract.

• Salt (Sodium Chloride): Used in food preservation and industry.
• Magnesium and Bromine: Minerals extracted from seawater, used in industrial processes, medicines, and fire retardants.
• Oil and Natural Gas: Although strictly geological, significant reserves of fossil fuels are extracted from the continental shelves beneath the ocean (off-shore extraction).

Did you know? Many medical breakthroughs and chemical compounds used in research and pharmaceuticals were first discovered in unique marine organisms (like deep-sea sponges or corals)!

3. Building Materials

Coastal areas and the continental shelves provide essential raw materials for construction.

• Sand and Gravel: These are dredged (sucked up) from the seabed, primarily close to shore, and used to make concrete and to replenish beaches that have suffered erosion.
• Environmental Concern: Dredging for sand and gravel can cause significant environmental impacts, including destroying coastal habitats and stirring up sediment, which harms marine life.

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Energy Potential: Harnessing the Power of the Sea

The movement of the oceans—the waves, tides, and temperature differences—represents huge potential for generating renewable energy. This is clean energy, meaning it doesn't rely on burning fossil fuels.

1. Wave Energy

This method uses the energy captured from the rise and fall of surface waves.

• How it Works: Devices float on the surface or are semi-submerged. As waves move, they push pistons or air chambers, which drive a turbine to generate electricity.
• Analogy: Imagine a huge buoy bobbing up and down, but that bobbing motion is connected to a machine that makes electricity!

2. Tidal Energy

Tidal power captures the energy from the massive movement of water between high tide and low tide.

• Tidal Barrages: These are like dams built across estuaries or bays. When the tide rises, water flows into the barrage, and when the tide drops, the water is released through turbines to generate electricity.
• Tidal Stream Generators: These are like underwater wind turbines placed in fast-flowing tidal currents, converting kinetic energy directly into power.

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Oceans as a Service Provider

The ocean provides essential services that support human economies and daily life, including transport, tourism, and even water supply.

1. Transport

• The ocean acts as a huge, global highway. Over 90% of global trade (goods like cars, electronics, clothes, and oil) is moved by sea on massive container ships and tankers.
• Impact: While highly efficient, this transport results in noise pollution, oil spills (if accidents occur), and significant carbon dioxide and sulfur emissions from ship engines.

2. Tourism

Coastal and marine environments are major tourist attractions globally, driving local economies.

• Examples: Cruise ships, resorts, beach holidays, diving, and sailing.
• Economic Benefit: Creates jobs and brings income to coastal nations.
• Environmental Impact: Can lead to habitat destruction (e.g., damage to coral reefs by anchors or too many tourists), increased sewage pollution, and plastic waste.

3. Potential for Safe Drinking Water (Desalination)

Although the ocean is saltwater (saline), it represents an infinite source of water if we can remove the salt.

• Process: Desalination is the process of removing salt and other minerals from seawater to produce fresh, potable (drinkable) water.
• Techniques:
1. Distillation: Boiling the water and collecting the resulting steam (pure water), leaving the salt behind.
2. Reverse Osmosis: Pushing the seawater through very fine membranes under high pressure, which allows the water molecules to pass but blocks the salt.
• Importance: This is vital for countries with poor natural freshwater supplies, such as those in the Middle East and arid coastal regions.
• Environmental Challenge: Desalination requires a lot of energy and produces highly concentrated salty waste called brine, which must be carefully returned to the ocean so it doesn't harm local marine life.