L03 - Threats to Biodiversity and Solutions

Question 1

What are the dangers to fishing and marine ecosystem?

Answer 1

There are practices that lead to reduction or depletion of fishing resources:

• Industrial fishing techniques used.
• Overfishing; facilitated by industrial fishing.
• By-catch and biodiversity loss due to unwanted catch ending up dead.
• Marine pollution.
• Loss of marine habitat.
• Aquaculture industry and use of industrial feed, food, drugs, etc.

Question 2

What are the industrial fishing methods used?

Answer 2

• Trawler fishing
• Purse-seine fishing
• Drift-net fishing
• Longlining (long line fishing)
• Aquaculture or fish farming

Question 3

Human activities are the main source of damage to the environment: explain them by referencing to marine and freshwater environments.

Answer 3

• Marine
  1. Acidifying Oceans impacting coral reefs
  2. Harvesting mangrove forests
  3. Harvesting sea-grass beds
  4. Sea-level rise
  5. Ocean floor: trawling and dredging
• Freshwater
  1. Dams
  2. Excessive water withdrawal for irrigation and human use

Question 4

Why is it hard to protect marine biodiversity?

Answer 4

• Much of the damage in the ocean is not visible.
• The oceans are incorrectly viewed as an inexhaustible resource!!.
• Most of the ocean lies outside the legal jurisdiction of any country
  (the high seas)…”tragedy of the commons”.