Term
| What two orders of whales and dolphins are there? |
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Definition
Baleen whales- seive-like structure on upper jaw- filter feeders
Toothed whales- Have teeth (obviously) - carnivores |
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Term
| What are whales hunted for? |
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Definition
Blubber (whale oil)- major fuel for lighting, soap, lipstick etc.
Baleen (whale bone)- corset stays, horse whips
Meat- eaten or turned into oil |
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Term
| Give me the timeline of whaling. |
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Definition
16th century: whaling began
19th and 20th century: peak of whaling
1860: steam-driven boats especially for whaling
1870: harpoon gun
1925: factory ships
1930: bowhead whale gets intl. protection
1935: hunting of right whales banned intl. |
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Term
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Definition
1945: created
1975: partial bans in certain parts of the world- no blue, gray and humpback whales
1985: ban on all commercial whaling (-japan, norway and iceland)
2003: berlin initiative to monitor survival prospects of all cetacean species. |
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Term
Why are whales vunerable to extinction?
Have they recovered? |
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Definition
Large home range.
Low population densities
Large-bodies animal: long time to reach sexual maturity
Produce few offspring, one at a time
Long period of infant dependancy on mother
Blue whale: no signs of recovery for 25 years
Right whale: no signs of recovery for 60 years |
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Term
| What is the purpose if ICCAT? |
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Definition
International commission for the conservation of atlantic tunas
1970: inter-governmental fishery organisation responsible for the conservation of tuna and tuna-like species in the Atlantic ocean.
Manage W and E population separately- now evidence of mixing.
WZ bluefin spawning pop decline over 20 years by 90%
EA bluefin pop declined by 81% over similar time. |
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Term
| Why are tuna at risk of overexploitation? |
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Definition
- Low rate of reproduction
- Long time to grow to sexual maturity
- Populations will take long time to recover
High demand: sushi and sashimi in japan
Illegal fishing
Bycatch can also include other endangered species |
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Term
| What is predicted to happen to fisheries? |
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Definition
By 2006 25% of fisheries have collapsed.
As shortages in popular fishes emerge, other fish will be caught to replace the demand.
Increase in aquaculture. |
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Term
| What are the environmental costs of aquaculture? |
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Definition
Loss of mangroves: Thailand lost 17% to shrimp ponds
Pollution from effluent: Faeces from stock, Excess food and chemical treatments
Will also cause an increase in fishing of low-value fishmeal (even herbivorous fish are fed it), causing the food chain to become disrupted. |
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Term
| What are the effects of overexploitation likely to be? |
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Definition
60% of worlds fish stocks overfished
demand growing at 1.5% a year
Scarcity causes prices to rise and encourages trade.
Nearly 1bn rely of fish as primary source of protein
As prices rise they will not be able to rely on the food source.
Caused my misguided fishing subsidies- solved by international cooperation. |
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