Week 4

Question 1

Major Threats in Oceans and Freshwater Systems

Answer 1

Include pollution (e.g., plastic, chemicals), overfishing, habitat destruction, invasive species, climate change, and water overuse.

Question 2

Freshwater Threats

Answer 2

Include pollution, over-extraction, damming, climate change, invasive species, and loss of wetlands and natural flow regimes.

Question 3

Water Withdrawals

Answer 3

Removal of freshwater for agriculture, industry, or domestic use; can deplete rivers and aquifers, threatening ecosystems and communities.

Question 4

Water Pollution: Point vs Non-Point Sources

Answer 4

Point source: Direct, identifiable origin (e.g., factory pipe).

Non-point source: Diffuse, from many sources (e.g., farm runoff, urban stormwater).

Question 5

Eutrophication and Dead Zones

Answer 5

Excess nutrients (esp. nitrogen, phosphorus) cause algae blooms → decay depletes oxygen → creates dead zones where aquatic life can’t survive.

Question 6

Plastic Pollution: Where It Ends Up & Solutions

Answer 6

Most plastic ends up in landfills, oceans (e.g., gyres), and food chains. Solutions: reduce use, improve waste systems, bans, recycling, cleanups, and alternatives to plastic.

Question 7

Overfishing & Solutions

Answer 7

Depletes fish stocks and harms ecosystems. Solutions: catch limits, marine protected areas, end harmful subsidies, promote sustainable aquaculture and eco-labels (e.g., MSC).

Question 8

Tragedy of the Commons

Answer 8

When individuals overuse shared resources (like oceans or fisheries) for personal gain, leading to resource depletion for all.

Question 9

Who Governs the Seas?

Answer 9

Primarily the United Nations Convention on the Law of the Sea (UNCLOS); zones include national waters (EEZs) and international waters (high seas), with fragmented global governance.