Fisheries Management Flashcards
1
Q
what are anadromous fish?
A
fish that can ADAPT from both SALT WATER to FRESH
2
Q
salmon are a what species?
A
a KEYSTONE species
3
Q
what do salmon feed on?
A
they feed on ZOOPLANKTON
4
Q
what are redds?
A
gravel nests that salmon make for their eggs
5
Q
salmon bring what to the ecosystem?
A
they bring massive amounts of NITROGEN from the OCEAN when they die (after swimming upstream to reproduce)
6
Q
what are hogs?
A
HUGE chinook salmon up to 60lbs
7
Q
what is the current status of SALMON?
A
LESS than 10% of regions historic POPULATION (only 1 million adult salmon & steelhead on average vs the 10-16million population BEFORE)
8
Q
what happened in 1992 in regards to SALMON?
A
there was only ONE MALE snake river sockeye swam 900 miles to redfish lake in central idaho (LONESOME LARRY)
9
Q
who is LONESOME LARRY?
A
when only ONE MALE snake river sockeye swam 900 miles to redfish lake in central idaho and was ALONE
10
Q
what are pit tags?
A
passive integrative transponder
11
Q
what are pit tags used for?
A
TRACKING fish
12
Q
define anadromous fish
A
species that BEGIN their lives in FRESHWATER, but then travel to and mature in the SEA. After maturation they RETURN to their NATIVE stream to reproduce and die.
13
Q
define resident fish
A
fish that live their ENTIRE LIVES in FRESHWATER, sometimes confined to a lake, particular stream section or single tributary
14
Q
describe the 1980 Northwest power act.
A
- prepare electric power plan
- inform public re: POWER
- protect, mitigate, and enhance fish and wildlife
15
Q
what is this describing?
- prepare electric power plan
- inform public re: power
- protect, mitigate, and enhance fish and wildlife
A
the 1980 northwest power act
16
Q
what was causing the decline in fish pop of salmon?
A
- sediment pollution (BUILDUP)
- thermal pollution (too hot/cold)
- urban pollution (oil grease, salt, heavy metals)
- overfishing
- DAMS
17
Q
how do dams affect salmon?
A
juveniles are DRAWN INTO the dam TURBINES. only 10% make it to the ocean; upstream migration difficult as well
18
Q
what do dams have?
A
dams have a LIFECYCLE due to weathering factors
19
Q
how did scientists help the migration and population of salmon regarding dams?
A
- built fish hatcheries
- built fish LADDERS
- 93-96% of the fish MUST survive
20
Q
what are the habitat requirements for FISH?
A
- temperature
- WATER depth & velocity
- turbidity
- DISSOLVED oxygen
- salinity
- substrate
- cover
- FOOD supply
21
Q
temperature can impact..?
A
- upstream migration
- EMBRYO DEVELOPMENT
- juvenile BEHAVIOR and growth
22
Q
describe the effects of water depth and velocity
A
- successful migration requires MINIMUM DEPTHS and VELOCITIES (lower = better)
- high stream level INCREASES spawning habitat
23
Q
what do dams do to the water temps?
A
they decrease water temps
24
Q
define turbidity
A
amount of suspended sediment
FISH AVOID STREAMS W HIGH TURBIDITY
25
describe the effects of dissolved oxygen (DO) for FISH
- highest lvls in SHALLOW FAST moving streams
- fish need at least 5ppm DO
26
define salinity and its EFFECTS ON FISH
salinity - concentration of salts (ESPECIALLY IMPORTANT FOR FISH IN ESTUARIES AND COASTAL MARSHES)
27
define SUBSTRATE and describe the effects of it on FISH HABITAT
substrate- bed materials of stream or river
- spawning requires LARGE GRAVEL (.5-1.5in on average)
- spawning fish use gravel to make a REDD NEST
28
define cover and describe the effects on FISH HABITAT
cover - provides SHADE, rest areas, protection
- overhanging riparian vegetation
- undercut banks
- aquatic vegetation
- large woody debris
- boulders
- deep water pools
29
describe the effects of food supply on FISH
- stream PRODUCTIVITY varies
- more ORGANIC MATTER supports LATGER INVERTEBRATE pops.
- sources of organic matter
30
what’s organic matter?
- leaves, needles & twigs
- aquatic vegetation
- sewage runoff
- livestock operations
31
what are fish great at?
great at REPRODUCTION, not so much survival
32
what are the 6 natural limitations of fish?
1. storms & SOIL MASS movements
2. ANIMAL activities
3. natural barriers
4. vegetation disturbances
5. predation by NATIVE ANIMALS
6. WINTERKILL
33
what is the first natural limitation of fish?
storms and soil mass movements
- after location of pools and riffles
- DEPOSIT sediment
- erode stream banks
- BURY FOOD sources
34
what is the second natural limitation of fish?
ANIMAL ACTIVITIES
- beaver dams pond streams
- ponds INCREASE water temp
- blocks fish passage but FLOODING PROVIDES habitat
- ungulates trample and REMOVES RIPARIAN PLANTS
35
what is the third natural limitation of fish?
natural barriers!!
- WATERFALLS can block upstream fish MIGRATION
- ideal leaping conditions (depth of pool below waterfall 1.25x height of falls)
- HIGH VELOCITY WATER can also BLOCK migration
36
what is the FOURTH natural limitation of fish?
VEGETATION DISTURBANCES
- RIPARIAN vegetation damage from WILDFIRE, INSECTS, & DISEASE
- reduced cover
- ALTERED stream TEMPS
- decreased LITTERFALL
37
what is the 5th natural limitation of fish?
predation by NATIVE ANIMALS
- other fish
- reptiles
- birds
- mammals
- fish cannibalism
38
what is the 6th natural limitation of fish?
WINTERKILL!!
- if sun hits ice, photosynthesis produces O2
- if snow COVERS ice, photosynthesis DECLINES, O2 drops and FISH DIE.
39
what are the 8 human induced limitations of fish?
1. WATER POLLUTION - eutrophication, sedimentation, acid deposition
2. Alterations of stream temps
3. Predation, competition and habitat modifications by EXOTICS
4. Predation by humans
5. DAMS!!
6. Resource extraction
7. Channelization
8. Recreation
40
describe eutrophication in water pollution
- increased NUTRIENTS promote excessive ALGAL growth
- dense algal bloom @ SURFACE
- blooms block sunlight from reaching deeper algae
- O2 levels DECLINE in deeper water
- O2 levels decline FURTHER when aerobic bacteria decompose dead algae
41
describe sedimentation in water pollution
- IMPROPER land management on farms or mines
—> dams also get extra sediment build up etc
42
describe ACID DEPOSITION in water pollution
- SO2 from burning coal combines w oxygen (forms sulfuric acid and blows northeast). acidic rain produces (4.0 or lower) reg rain = 5.6pH.
- acidic rain = below pH 5 water fish begin to FIR
- acid runoff dissolved toxic metals in soil
- aluminum from soil causes mucus buildup on FISH GILLS
43
describe the second human induced limitation
ALTERATIONS OF STREAM TEMP
- forestry, mining, cattle ranching (reduce stream bank vegetation)
- removing water for use then returning it to stream (irrigation etc)
44
describe the third human induced limitation
PREDATION, COMPETITION, AND HABITAT MODIFICATION BY EXOTICS (exotic fish)!!
- “biological pollution” INTENTIONAL OR ACCIDENTAL
- european carp = most destructive exotic fish
european carp
- introduced to US in 1872
- rapid pop. growth
- uproots aquatic vegetation by BOTTOM FEEDING (destroys spawning grounds, reduces food supplies and reduces DO lvls)
45
describe the fourth human induced limitation
PREDATION BY HUUUMANSS
- 1 in 10 americans fish each year
- lake sturgeon gone from lake erie due to OVERFISHING
46
describe the FIFTH human induced limitation
DAMS
- nitrogen intoxication (from DAM TURBULENCE)
- fish killed by dam turbines
- abnormal fluctuations in water levels and FLOW RATES
- ineffective or outdated fish ladders
47
describe the sixth human induced limitation
RESOURCE EXTRACTION
- logging- late 1800’s splash dams (present day = altered nutrients, water temp, and DO levels
- grazing = RIPARIAN VEGETATION SUCCULENT AND VARIED
- mining = early days dredging, straightening and polluting (today = MUST meet strict water quality standards)
48
describe the seventh human induced limitation
CHANNELIZATION
- causes significant loss or alteration of fish habitat
- intended to control FLOODS, drain wetlands, DIVERT water for cities and farms
49
describe the eighth human induced limitation
RECREATION
- swimming, boating, hiking, camping, biking, etc.
- OVERUSE can damage riparian and aquatic habitat
50
describe the problems with ARTIFICIAL PROPAGATION AND STOCKING
- more often a failure than a success
- hatchery fish weaker, more DISEASE PRONE
- risk for disease spread to NATIVE FISH
- risk for inbreeding and LOSS of genetic diversity
51
describe whirling disease
- spread by wet human shoes
- problem in inter mountain west
- caused by FISH PARASITE
- introduced to east coast fish hatcheries
- transfer of infected hatchery fish spread disease
- symptoms = whirling behavior, black tail, SKELETAL DEFORMITY
52
describe the official trout policy for federal fish hatcheries
1. stick trout in waters where they do not occur
2. stock where conditions for growth are good but spawning sites are inadequate
3. stock where fishing pressure is heavy but there is no natural production
53
describe vibert boxes
- permits egg development under stream conditions
- protects egg from predation
- cheap
54
reservoirs have _____ layers?
thermal layers
warm-water species for upper epilimnion
cold-water species for cold hypolimnion
55
describe translocations
- move large numbers of fertilized eggs
- identification of root cause of decline is key
56
describe removing undesirable fish
- incredibly difficult (chemicals, netting, commercial fishing, changing water levels, control fish spawning)
- removed is often just short term work on symptoms
57
describe controlling oxygen depletion in winter
- small lakes = remove snow w plow
- larger lakes = dynamite to blast holes, introduce O2 through ice with motorized aerators
58
describe selectively breeding superior fish
- hybrids can be LARGER
- highly controversial since long term effects are unknown
59
describe protective legislation regulations for fish
- limit size and number of fish
- catch and release
- closed seasons
- administration and enforcement is difficult :(
60
describe harmful drawdowns
- fluctuating water levels (leave eggs exposed, or force spawning in areas w other predatory fish)
61
describe beneficial drawdowns
- aerate MUCK and increase decomposition
- restrict forage fish to smaller area
- remove nongame fish
62
describe habitat protection
limit or prevent pollution
63
describe habitat RESTORATION
- repair damage to streams, lakes, and rivers
- success depends on routine, longterm monitoring
64
how can river restoration help the LCT?
- dam mediation
- removal of small dams
- legislation protections
65
describe local & regional fisheries management
- NEVADA DEPARTMENT KF WILDLIFE FISHERIES DIVISION (fish species)
- US FISH AND WILDLIFE SERVICE (pacific southwest region)
