Fisheries Management Flashcards
what are anadromous fish?
fish that can ADAPT from both SALT WATER to FRESH
salmon are a what species?
a KEYSTONE species
what do salmon feed on?
they feed on ZOOPLANKTON
what are redds?
gravel nests that salmon make for their eggs
salmon bring what to the ecosystem?
they bring massive amounts of NITROGEN from the OCEAN when they die (after swimming upstream to reproduce)
what are hogs?
HUGE chinook salmon up to 60lbs
what is the current status of SALMON?
LESS than 10% of regions historic POPULATION (only 1 million adult salmon & steelhead on average vs the 10-16million population BEFORE)
what happened in 1992 in regards to SALMON?
there was only ONE MALE snake river sockeye swam 900 miles to redfish lake in central idaho (LONESOME LARRY)
who is LONESOME LARRY?
when only ONE MALE snake river sockeye swam 900 miles to redfish lake in central idaho and was ALONE
what are pit tags?
passive integrative transponder
what are pit tags used for?
TRACKING fish
define anadromous fish
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.
define resident fish
fish that live their ENTIRE LIVES in FRESHWATER, sometimes confined to a lake, particular stream section or single tributary
describe the 1980 Northwest power act.
- prepare electric power plan
- inform public re: POWER
- protect, mitigate, and enhance fish and wildlife
what is this describing?
- prepare electric power plan
- inform public re: power
- protect, mitigate, and enhance fish and wildlife
the 1980 northwest power act
what was causing the decline in fish pop of salmon?
- sediment pollution (BUILDUP)
- thermal pollution (too hot/cold)
- urban pollution (oil grease, salt, heavy metals)
- overfishing
- DAMS
how do dams affect salmon?
juveniles are DRAWN INTO the dam TURBINES. only 10% make it to the ocean; upstream migration difficult as well
what do dams have?
dams have a LIFECYCLE due to weathering factors
how did scientists help the migration and population of salmon regarding dams?
- built fish hatcheries
- built fish LADDERS
- 93-96% of the fish MUST survive
what are the habitat requirements for FISH?
- temperature
- WATER depth & velocity
- turbidity
- DISSOLVED oxygen
- salinity
- substrate
- cover
- FOOD supply
temperature can impact..?
- upstream migration
- EMBRYO DEVELOPMENT
- juvenile BEHAVIOR and growth
describe the effects of water depth and velocity
- successful migration requires MINIMUM DEPTHS and VELOCITIES (lower = better)
- high stream level INCREASES spawning habitat
what do dams do to the water temps?
they decrease water temps
define turbidity
amount of suspended sediment
FISH AVOID STREAMS W HIGH TURBIDITY
describe the effects of dissolved oxygen (DO) for FISH
- highest lvls in SHALLOW FAST moving streams
- fish need at least 5ppm DO
define salinity and its EFFECTS ON FISH
salinity - concentration of salts (ESPECIALLY IMPORTANT FOR FISH IN ESTUARIES AND COASTAL MARSHES)