midterm Flashcards
list three factors that cause newly buttoned up fry to be smaller than expected
- frequent disturbance
- light exposure
- excess flow
- low oxygen
- sudden temperature change
- high ammonia
- supersaturation
- no substrate
what does the acronym MAWW stand for?
maximum alevin wet weight
What is the name of the following equation and what does it predict?
ATU = T a/(T-c)b
Belehradiek model
ATUs until MAWW
What is the relationship between salmonid egg size and the time to button up?
The larger the egg, the longer it will take to button up
List three suitable methods of conducting an inventory assessment on a stock of month old salmonid fry
a) weight
b) electric counter
c) volume
In the following weight/length equation, what is the value of ‘b’ for salmonids?
W = aLb
(isometric growth)
b= 3
List 2 factors which may cause a tank of salmon to have a highly variable condition factor.
a) unequal water quality
b) poor feedings
- poor circulation
- parasites/desease
- time to grade
Draw a graph with properly labeled axes to illustrate the relationship between food consumption (as a percent of body weight per day) in salmonids and fish size
Draw This Seperately. DO IT
What might you observe that would indicate the flow rate in a circular tank was too great?
the fish are trying to swim but don’t move forward
List four factors which may cause a variation in the ration level consumed by a stock of salmonids compared to that predicted by a feed table
- feeding frequency
- season
- time of day
- oxygen concentration
- stress and disease
Describe how a down hole or U-tube oxygenation device operates
oxygen and water at top, pressure at the bottom increases the dissolution
Use a figure to illustrate a crowding device that would be suitable for use in a large circular salmonid tank
DRAW IT
What effect does inflow water pressure have on water quality in a circular fish tank equipped with a spray bar?
- it oxygenates the water and increases the flow
- controls re-aeration and adds oxygen
Where are the outlet screens located in a Burrow’s pond?
DRAW IT
Use an illustration to show the components and their arrangement of a fish proof outflow for a large raceway using a screen, dam boards and a fixed baffle to resuspend fines
DRAW THIS TOO
Explain what is meant by the expression ‘plug flow’ and name the salmonid rearing container type it occurs in.
Def: enters one end, exits the other with minimal mixing
Container Type: raceways and troughs
What is a ‘Polar Cirkl’ net pen frame constructed of?
plastic pipe (foam filled polyethyline)
In what situation would a single point anchoring system be best for a salmonid net pen?
lakes
What is the weight of 9000 meters of 210 denier webbing yarn?
1 denier = 1 g. 210 grams
In a marine salmonid net pen system there are usually two concentric rings or squares of floats surrounding the sea cages. What is the purpose of the outer and inner sets of floats?
- Outer: navigation markers
- Inner: Shock absorption
List the Davis B oxygen protection levels (mg/L) for the following life history stages of salmonids
A: salmonids in seawater
B: salmonids in freshwater
A: 7ppm
B: 6ppm
Use a graph with properly labeled axes to illustrate the relationship between oxygen consumption rate of salmonids and ambient oxygen concentration. Indicate the incipient limiting oxygen tension, the incipient lethal oxygen tension, and the standard metabolic rate.
Graph it, yo.
What would be a suitable maximum stocking density for 6 inch rainbow trout, in units of pounds of fish per cubic foot of water?
3lb/ft cubed
Given a flow index of 0.2, what would be a suitable flow rate of oxygen saturated water to support 100kg of 12 cm coho salmon at 12 C in a 3 meter diameter circular tank?
W= FLI I= W/FL 100kg = (0.2)(12)(x) 100kg/(0.2)(12) = x x= 41.66 LPM
Use a graph with properly labled axes to illustrate the relationship between flow index and water temperature for a given rearing container
GRAPH
Approximately how much oxygen is consumed by salmonids for each kilogram of food they consume?
300 g/kg
