Ch 7 Flashcards
(28 cards)
What vertebrate fish are fished?
Largest predators first
How are reefs important to small island nations?
Fish provide protein
Maldives 50% reef and pelagic
Kiribati 30%
How do spawning aggregations affect populations?
When groupers spawn many times they are exploited since thy are grouped together. Causing drastic declines in numbers.
What are used in the Caribbean and indo pacific to fish?
Traps
Purse seines
Spearfishing
What are types of destructive fishing methods?
Dynamite
Cyanide
Longlinea
What invertebrates are caught ?
Octopus Sea cucumber Paolo worm Giant clams Urchins Spiny lobster
What fish are exported?
Trochus shells
Giant clams
Cucumber
Do small scale artisanal and recreational fishing have a large impact?
Yes, such as lobster season. It can wipe out a pop in a short amount of time.
What is the live fish trade for?
Live Food in Asia and aquarium trade
What characteristic makes groupers more vulnerable to fishing?
K selected species
ie long lived, late maturity an spawning aggregations
What does the live food trade focus on?
Rare species
What is the blue revolution?
Aquaculture
ie seaweed farming
Giant clam farms
Milkfish
What are some environmental issues with aquaculture?
Overfishing of other species for food
Unsustainable harvest of juvenile
Eutrophication of surrounding waters
Increased transmission of disease
What fish are aquaculture facilities switching to?
Lfft- live fish food trade species
More profitable
What species dominates the aquarium trade?
Pomacentridae
Small fish dominate
How many of the worlds coral reef fisheries are unsustainable?
More than half
What is grown overfishing?
Loss in biomass that is greater than biomass gained due to growth
ie. big fish produce more eggs
What is big old fat fecundity females?
Fecundity increases linearly with age and size
What is recruitment overfishing?
Spawning biomass of population is reduced
What is ecosystem overfishing?
Fish removed at such a rate that the composition of the ecosystem is changed significantly.
ie. Fishing down the food web and shifting baseline
Why are coral reef fisheries often less sustainable than other fisheries around the world?
Tight nutrient recycling
What is the Allee effect?
There are two equilibriums. There is positive relationship between size and growth. Second unstable equilibrium when pop drops to low it spirals toward extinction.
What are the traditional methods to managing fisheries?
Quotas - pops are monitored and number of fish are determined based on pop size.
Min/max landing size - insures too small or too large of fish are put back.
Gear restrictions - only certain size are caught
What happened with western rock lobster?
Lobster were caught before they could reproduce reducing pop size.
Strong restrictions on # of traps and days when traps can be used allowed rebound and stabilize
Can monitor late larval stage and predict what the stock will be in 4 years.
Managed by reducing traps and increasing min size
