OceanMOOC | 4.5 | Marine Ecosystem Change and Services

Summary

This lecture explores the economic and intrinsic value of marine ecosystem services and goods. It highlights the ocean's role in providing food, materials, and regulating environmental fluxes. The lecture quantifies the economic value of these services, such as the $250 billion from fisheries and the significant role of coastal vegetation in nutrient absorption. It also discusses the challenges in quantifying services like coastal protection and carbon sequestration, emphasizing the importance of preserving marine life beyond economic reasons.

Takeaways

• 🐟 The ocean provides a multi-billion dollar food industry, with annual revenues around $250 billion from seafood and fish.
• 🌾 Mariculture, the cultivation of fish and shellfish, is growing rapidly, contributing to the nourishment of the human population.
• 🏠 Materials such as coral rubble, seaweed, and sea grass have been used for construction and insulation, contributing to an estimated $6 trillion in goods annually.
• 🌿 Coastal vegetation like sea grasses and macro algae play a crucial role in nutrient absorption, reducing pollution in coastal areas.
• 💧 The role of coastal ecosystems in water regulation is quantifiable, with macrophyte beds providing nutrient retention services equivalent to $20,000 per year per hectare.
• 🏞️ Coastal vegetation also provides protection against waves and helps in sediment accretion, which is vital in the context of rising sea levels.
• 🌱 Carbon sequestration is a significant service provided by marine ecosystems, with oceans taking up 30% of excess anthropogenic carbon.
• 🌿 Coastal ecosystems, despite covering less than 1% of the ocean surface, bury up to 10% of carbon removed from the oceans.
• 💵 Tourism and ecotourism generate substantial revenues, highlighting the economic value of healthy marine ecosystems.
• 🌐 There is an intrinsic value to marine life that goes beyond economic quantification, emphasizing the ethical and philosophical importance of preserving ocean life.

Q & A

What is the main focus of the lecture?

The lecture focuses on marine ecosystem services and goods, highlighting how the ocean provides various benefits, including quantifiable economic values and non-economic values related to marine life.

How much revenue does the world fisheries industry generate annually?

The world fisheries industry generates approximately $250 billion in revenue each year from seafood and fish.

What is mariculture, and how does it contribute to the economy?

Mariculture refers to the cultivation of fish, crustaceans, and bivalves in captivity. It is a fast-growing sector that contributes significantly to global food production and economic revenues.

What are some examples of materials sourced from the sea?

Materials from the sea include coral rubble used for building on coral islands, dried seaweeds and seagrasses for mattress fillings, and mangrove wood and sand for construction purposes.

What role does coastal vegetation play in regulating nutrients?

Coastal vegetation, such as seagrasses and macroalgae, absorb nutrients like nitrogen and phosphorus that come from human activities, reducing nutrient pollution in coastal areas.

How can the economic value of nutrient retention by coastal vegetation be quantified?

The economic value of nutrient retention by coastal vegetation can be quantified by comparing it to the cost of building a wastewater treatment plant that would remove the same amount of nitrogen and phosphorus. This is estimated to be around $20,000 per hectare of macrophyte beds annually.

What is the role of marine ecosystems in carbon sequestration?

Marine ecosystems, especially phytoplankton and coastal vegetation, sequester carbon by absorbing excess CO2 and storing it in biomass or marine sediments, helping to mitigate the greenhouse effect.

Why is carbon sequestration by coastal vegetation particularly important?

Although coastal vegetation covers less than 1% of the surface of shelf seas, it buries up to 10% of all carbon removed by oceans, making it a crucial component in combating climate change.

What is the significance of tourism as a marine ecosystem service?

Tourism, particularly ecotourism, generates significant economic revenues in coastal areas. It relies on healthy marine ecosystems with clear water, abundant marine life, and the presence of marine mammals for activities like diving and whale watching.

What ethical argument does the lecture make regarding marine life conservation?

The lecture emphasizes the intrinsic value of life beyond economic considerations, arguing that humans have a responsibility to protect all forms of marine life as part of an unbroken chain of existence that connects all living organisms.