Fisheries Flashcards
Fishery definition
union of aquatic organisms and humans for sunsumptive purposes
Do fisheries treat equatic organisms as an extractive resrouce
sometimes, could be non-extractive like catch and release
Commercial fishery
extraction and sale of fish for consumptive purposes
Commercial fishery techniques
bottom trawling
longline fishing
drift nets
bottom trawling
long net on bottom of ocean like a plow
what kind of habitat disturbance does bottom trawling create
suspension of sediments
increased water turbidity
reduces habitat heterogenetiy
resuspension of contaminats
impacts on food web
lots of bycatch
What does increased water turbidity lead to
less photosynthesis
What is habitat heterogeneity
nooks and crannies
longline fishing
one line with many hooks on it
what types of fish consist of the bycatch on longline fishing
migratory species
drift nets
long nets on end of boat
bycatch
part of the capture that is discarded at sea
reasons for discarding
wrong species, size, sex
fish damaged
quota reached
lack of space
capture =
catch + bycatch + released alive
are recreational fisheries direct harvest
yes, the ppl thatt catch eat them
does noise polluition affect fish
yes, lateral line and eardrums
are lead sinkers poisionous to wildlife
yes
elements of an angling event
capture
handling
release
What trauma may you cause the fish when you capture it
increased lactic acid
increased blood glucose
disrupted osmotic balance
more chance of predation
what does increased lactic acid do
Cramps
why does the lactic acid plateau
fish gets tired
stops fighting = no cramping
what does increased blood glucose mean
flight or flight
Why does tissue damage play an important role in the survival of the fish
Infection
swimming impairment
feeding impairment
+ energy to maintenece = - energy to growth and reproduction
Why does handling impact fish
slime removal
loss of scales
samage to fish
air exposure
what does air exposure lead to
collapse and adhesion of gill filaments
compromises respiration
+ psychological disturbance
delays recovery
tissue damage
loss of equilibrium
eventually… death
factors influencing loss of equilibrium
duration of air exposure
handling time
Non lethal disturbances to fish
physiological
energetic
behavioral
fitness
fishing induces selection
when a species is selected for based on their growth rate and body size
which individuals are favored when doing fishing induces selection
slow growth rates
small body size
What is the bycatch from bottomtrawling
any non target species on the ocean floro
