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44 Cards in this Set

  • Front
  • Back
What could fisheries be causing?
The extinction of fish
What was the World Marine Fish Harevest in 1950 and in 1989
21 million metric tons,
86 million metric tons.
Quadrupled
What is a Maximum sustainable yield?
Amount that can be caught without affecting future yields
How did the amounts of fish fed to humans and to livestock change since 1950?
More fish fed to livestock now
Why is feeding fish to our future food sources bad?
Adds another level to the foodchain, decreases ecological efficiency
What is true for 70% of marine stocks today?
Overfished, depleted, or rebuilding
What do cod eat?
Bottom feeders: crabs, squid, clams, small fish
How long until cod are adult, and how long do they live?
3-7 years, 20-25 years
What 3 different methods have been used through history to catch cod?
Handlines,
long lines with hooks
trawls
In the 1950s, what countries started using factory trawlers and where?
What happened to the yields?
USSR, UK
on Newfoundland Banks

Yields decreased from 800,000 tons to 200,000 tons/year
What did US and Canada do to their Exclusive Economic Zones?
Extended them from 3 to 200 miles. Home fishermen replaced foreigners
What eventually happened to cod fishing?
Canada banned commercial fishing in Newfoundland, National Marine Fishery Service closed cod fishery in 1994
Where are cod and haddock fisheries banned in Europe?
North Sea, Skagerrak, Irish Sea, West Coast of Scotland
Why are trawlers bad for corals?
Scrape away habitat for future generations to live
What animal did people start catching once traditonal fisheries were depleted?
Sharks
Why are shark populations decimated?
Caught for sharkfin soup.
Low reproductive rates and long maturation periods
Where are salmon fisheries?
Pacific NW and Alaska
Salmon: where do they spawn, how long do they stay there, then where do they go and how long do they stay there?
Spawn in FW
1 year in rivers
Go to sea
1-4 years at sea
What is it called when salmon return home to spawn?
chemotaxis
what are problems for salmon fisheries?
hydroelectric and flood control dams.
timber wastes
What are hatcheries? and why are they good?
eggs hatches and juveniles released after a year.
supplement wild populations
Where are peruvian anchovy fisheries?
coastal upwelling
What are peruvian anchovies used for?
fishmeal
What event devastated the peruvian anchovy fishery?
El nino- nutrient upwelling stopped
What is by-catch wastage?
What is a by-catch of Shrimp nets?
What is a by-catch of pollock and cod trawling?
When trawling, legally have to discard species that you arent liscenced to catch.
Turtles
halibut, salmon, king crab
What are 3 problems of fisheries?
by-catch wastage, gill nets, highly effective detection methods
Why are gill nets bad?
nondegradable
What is a highly effective detection method?
satellites for tuna
An increase in the amount of _____ is part of the cause of overfishing
ships
what are 5 remedies to the overfishing problem?
fish sanctuaries, habitat protection, fishing methods, recuperatie bans, licensed catches
What is the difference between aquaculture and mariculture?
Aquaculture in Freshwater
Mariculture in Seawater
On What continent is aquaculture successful?
Asia
How are bivalves grown in aquaculture
on submerged rafts
What are some problems for salmon raised in floating pens?
spread diseases to wild fish,
antibiotics enter marine regions,
pink meat instead of red,
lower levels of polyunsaturated fatty acids
What are three endangered marine mammals?
Manatees, seals, sea otters
In 1900, where did whalers move to and from where?
To Antarctic from N. Atlantic
What happened to Blue whale population in 1930 and 1962
1930- less than 4% of original levels
1962- down to 1000
In whaling, factory ships negated the need for ______
shore-based processing stations
What happened to commercial whaling in 1985
moratorium by International Whaling Commission
Which great whales are severely depleted?
blue, right, humpback, finback, bowhead, sei
what great whales have been recovered or sustained?
sperm whale, gray whale, minke whale
What can cause marine mammal strandings?
-High intensity sonar
-Microbial or viral infections
-pollutant accumulation in fatty tissues
What are problems for dolphins?
Japanese eat them
Used as bait in South America
Caught in tuna nets
Psychologically stressed by marine parks
How do dolphins get caught in tuna nets?
They feed on tuna, so fishermen follow them. they get caught in nets, suffocate.