5.1 TOC, 5.8 Impacts of Overfishing, 5.16 Aquaculture

Fisheries

Populations of fish used for commercial fishing

Fishery collapse

When overfishing causes 90% population decline in a fishery

Economic consequences

Lost income for fishermen, lost tourism for dollars for communities

Tragedy of the Commons

No incentive of penalty to prevent overfishing from ‘75 to ‘85

Bottom Trawling

Especially harmful fishing method that involves dragging a large net across ocean floor

Bycatch

Unintended species like dolphins, whales, turtles caught in nets

What is fishing down the food web and trophic cascade

As we deplete large, predatory fisheries, we move down to smaller fish species. The depletion of smaller fish population limits fishery recovery and decreases food supply of marine mammals and seabirds

What are some sustainable options?

Marine Protected Areas (safe zones without fishing), Bycatch friendly nets, Government intervention using maximum quotas

What are benefits of aquaculture?

Requires small amount of water, space and fuel, reduces the risk of fishery collapse, and doesn’t take up any land space

Aquaculture benefits

Raising fish, or other aquatic species in cages/ enclosures underwater

What are the drawbacks of aquaculture?

High density produces high concentration of waste and increases disease risk, may introduce non native species or GMOs to local ecosystem if captive fish escape, fish are fed antibiotics which can contaminate water with their waste

Tragedy of the Commons (TOC)

Individuals used shared/public resources in their own zeal interest, degrading them

Examples of TOC

Overgrazing, overfishing, water and air pollution, overuse of groundwater, deforestation

Why does it happen?

When people don’t own a resource, nobody directly suffers the consequences of depleting, degrading, or overusing it.So people assume others will overuse it if they don’t, which eventually leads to the resource depleting. There isn’t a penalty for polluting many public’s resources

What could overfishing lead to?

It could lead to fishery collapse (pop. Collapse) which causes loss of income and starvation

What could air pollution lead to

Bronchitis, asthma, and increased healthcare costs

What does pesticide runoffs do?

It leads to contamination of drinking water

How to solve TOC

Private land ownership, fees or taxes for use, taxes, fines, criminal charges for pollution of shared air/soil/water resouces

Legislators

Clean Air Act, Clean Water Act, safe Drinking Water Act, Bureau of Land Management