EXAM 3 FISHERIES Flashcards
What are the different uses of marked animals
movement and migration
habitat use
behavior patterns
stocking success
abundance and mortality
What are the assumptions of using the mark-recapture method on closed populations
population is closed- no immigration/emigration, no recruitment/mortality
tagging does not affect matchability
animals do not lose their tags in-between sampling periods
all tags are identified and reported
What are the ecological roles of wetlands
water storage to mitigate flooding and erosion
reduce dement and nutrients to improve water quality
sequester atmospheric carbon
groundwater recharge
what is an ephemeral wet land
a wet land that is only wet in the spring
what are the effects of different forestry practices on the riparian zone
forests provide erosion control and thermal benefits
woody debris. is important to stream habitat
What are some common stream degradation issues
sedimentation
habitat loss
altered channel morphology
flooding
toxins
poor fishing practices
What is point source vs non-point source pollution
point source:
a problem that can be directly attributed to a specific location
non-point source:
problem may be obvious, but not only one single source can be identified
What are the most common sources of stream degradation in WI
agricultural
vegetation removal
construction
preservation vs restoration
preservation:
involved keeping an object from destruction and seeing to it that the object is irredeemably altered or changed
restoration:
recreated, initiate or accelerate the recovery of an ecosystem that has been destroyed
which is better preservation or restoration
preservation
what are some of the types of in-stream habitat modifications that we can do?
easement
creation of public fishery areas
prioritize watersheds
Which species, brook or brown trout, is more tolerant of lower dissolved oxygen levels and warmer temperatures
brown trout
how are trout typically distributed within a stream
first order: small, cold water, low species diversity
second order: moderate size, cool water, higher species diversity
third order: larger size, warmer water, high species diversity
What gears do we use to sample stream trout
electrofishing
Which preforms better in WI streams, wild or domestic trout
survival is 2-4 times greater for wild trout
what are some common harvest regulations for stream trout in WI
creel and length limits
gear restrictions
trophy regulations
what are some of the reasons we remove fish or wildlife from a population or area
over population
nuisance
exotic species
disease control
increase growth/size structure
undesirable effects on habitat
reduce competition/predation with desirable species
rescue operations
experiments
What are come common techniques for conduction fish and wildlife removals
piscicides (fish toxins)
mechanical- nets, electrofishing
anglers
projectiles and traps
What the different types of stockings
maintenance- recovery effort
supplemental- stock in response to poor recruitment
what is the put and take method
stock animals at a harvestable size, often with the hope they get harvested
what is the put, grow and take method
stock animals at sub-harvestable size, let them grow, and then harvest them
how is stocking funded
license dollars
special permits or stamps
private groups
what do we regulate
endangered or threatened species
migratory species
who do we regulate
anglers and hunters
using license or permits, open or limited entry
when do we regulate
seasons:
spawning/ birthing/ rearing
where do we regulate
refugees and sanctuaries
spawning areas
migratory hotspots
safety concerns
management zones
how do we regulate
gear/ technique restrictions
fair chase laws
safety concerns
what is a creel/bag and possession limit
creel/bag limit:
the number that can be harvested in one day or one trip
possession limit:
the total number you can possess at any one time, including what is in your freezer
why are creel/bag limits often ineffective tool for managing fish
often not sufficient enough to reduce harvest
most anglers do not keep fish
few people keep a legal limit
how are the quotes divided up in relation to walleye management in the Ceded Territories
tribe declares a percentage of safe harvest
anglers can harvest remaining quota
what is the total annual exploitation rate set at?
35%
how are length and slot limits used to help reduce the risk of over exploitation
anglers are able to harvest larger fish to keep resources plentiful for younger, smaller fish
open entry system vs limited entry system
open entry:
the condition where access to the fishery, for the purpose of harvesting fish is unrestricted
limited entry:
licensing is limited
Why did the walleye regulations on Lake Oahe not protect larger walleye
The walleye regulations protected smaller fish so they could grow and reproduce easier. By creating length limits, the larger fish, who are more likely to die sooner due to natural causes, will be harvested leaving resources available to growing fish.
what are some of the caused of the lake whitefish collapse in Lake Michigan
logging:
increased sediment and water temps
sea lamprey:
killed fish at a high rate
zebra mussels:
changed the food web, so walleye had to look towards other sources of energy. There was not enough food for all the walleye
What are some of the causes of the recovery of lake whitefish in Lake Michigan
clean water act:
limited pollution in waters
Great Lake fisheries commission:
conducted research to remove sea lamprey
are there different genetic stocks of lake whitefish in lake Michigan
yes, there are 6 different stocks
what are some of the challenges of managing lake whitefish in lake michigan?
lake whitefish are a migratory species, so it is hard to regulate
