Effects of Human Activities & Sustainability
- Created by: beth-marie2511
- Created on: 19-06-16 22:57
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- Over Fishing
- Problems
- Drifting nets are so large that they catch large numbers of unwanted species of fish
- Trawling nets have small gaps in the mesh compared to other nets
- This is now banned because it prevented fish from escaping
- Effects on other wildlife
- Knock on effect along the food chain
- E.G. Herring is eaten by cod.
- If the herring are over-fished then cod populations will decrease
- E.G. Herring is eaten by cod.
- Fish stocks decrease
- Knock on effect along the food chain
- Solutions
- Fish Quotas - restricts the number of fish that can be caught
- Restricted Net Sizes - catches fish of the correct size and age
- Also allows smaller, less mature fish to escape
- International Agreements
- Limits the number of catches and restricts where they can fish
- Exclusion Zones
- Cannot fish in these areas
- Allows the populations time to recover
- Closed Seasons
- Fish Farming
- When fish are bred an grown in lakes and ponds in managed enclosures.
- Reduces predation and food supply is maintained
- Fish grow rapidly
- Impacts
- Fertilisers are added for phytoplankton to grow rapidly
- This leads to eutrophication
- Pesticides
- Used to control fish parasites
- Not specific so they affects other marine organisms
- Overcrowding leads to disease in fish
- Disease could spread to wild fish
- The fish live in close proximity so disease can spread faster
- Fertilisers are added for phytoplankton to grow rapidly
- When fish are bred an grown in lakes and ponds in managed enclosures.
- Problems
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