3.6 Human impact on the environment overfishing Flashcards
What are the 3 types of fishing?
-Purse seining
-Beam trawling
-Long line fishing
Describe purse seining
-Good for shoaling species, little bycatch
-Not useful for mixed shoals (turtle, shark,dolphin)
-Results in killing rare species, reducing biodiversity
Describe beam trawling
-Most destructive form of bottom trawling
-Large net with heavy beam dragged across sea bed
-Iron tickler chains disturb fish in front
-Used for bottom fish and shrimp
-Large bycatch
Describe long line fishing
-long lines kill non target that are attracted by bait
-Sea birds get hooked
What is overfishing?
Rate of fish harvesting exceeds rate of fish reproduction
What is agricultural exploitation?
Conflict between farming methods and conservation
What are the effects of overfishing?
-Breakdown of sea ecosystems and industries
-Extinction
What measures can counteract overfishing?
-Ban fishing of threatened species
-Quotas and landing size regulation
-Exclusion zone
-Closed season for breeding
-Restrict mesh size
-Fish farm
What are the advantages of fish farms?
-Reduced predation
-Carefully monitored
-Artificial fertilisers and pesticides to increase producer growth
-Growth hormones
What are the disadvantages of fish farms?
-disease spread to wild population
-Breed with and weaken wild population
-Eutrophication
-Fish food made from other fish (imbalance ecosystem)
-Salmon contain PCBs, linked to cancers and immune deficiencies
What is an environmental impact assessment?
A process to identify positive and negative effects of a proposed development
What must be included in an Environmental Impact Assessment?
-Description of site
-Outline of project
-Abiotic and biotic factors
-Mitigation
-i.e. air, soil, and water quality
What is conservation?
The planned preservation of biodiversity
What are examples of some conservation methods?
-SSSIs
-Sperm/seed bank
-Public awareness
-Captive breeding programmes
What is ecotourism?
-Responsible travel to protected habitats that conserves environment and improves wellbeing of locals
-Use local resources
-Educate visitors
-Co-operate with locals to conserve natural habitat
