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Name _______________________________________
1. The following questions deal with a tilapia pond over a three day period as shown by
the graph below. The pond is 1 meter deep and dawn is at 6 a.m. (3 pts.)
Day 1
clear and
sunny
Day 2
completely
overcast
Day 3
completely
overcast
a) Provide a short answer as to why you think the O2 content of the pond water is
declining on Day 2 and Day 3 (1 pt.)?
Light reaching much of the algae in the pond is diminished because of the overcast sky
on Day 2 and Day 3 (think of a weak light versus strong light shining through fog)
resulting in decreased photosynthesis and consequent decreased O2 production during
the day.
b) What would the Secchii disk reading be at 8:00 a.m. on Day 3 (mark the most likely
reading (1 pt.)?
Less than 25 cm _______ Less than 30 cm _______ 100 cm __X__
c) What is the condition of the tilapia at 8:00 a.m. on Day 3 (1pt.)? ___dead!__.
Second Interim Exam (A) - Page 1
Name _______________________________________
TRUE or FALSE (1 pt. each) Indicate on the line to the left of each question whether the
statement is True (T) or False (F).
2. __F __ Tilapia is a good pond fish for northern California.
Comment: Calif. Fish & Game only allows tilapia to be cultured in southern Calif. Northern
Calif. would also be too cold during the winter.
3. __T__ Atlantic salmon make up the majority of farmed salmon on a global basis.
Comment: Atlantic salmon make up 90% of all salmon
4. __T__ The red color of farmed salmon flesh is from pigments added to the feed.
Comment: true
5. __T__ California is the leading red abalone producing state in the U.S.
Comment: true
6. __F__ The U.S. trout industry is considered a growth industry because of dramatically
increasing annual sales.
Comment: just the opposite is true; sales are flat or declining
7. __F__ Florida leads the nation in the production of tilapia because of its’ warm climate.
Comment: false, California is the leading producer in the Nation
8. _T__ More Laminaria (also known as Japanese kelp) cultured than any other seaweed.
Comment: true
9. __T__ Low Secchi disk readings indicate high concentrations of algae in the water
column.
Comment: true, more algae in the water column decreases the depth at which a Secchi disk
can be seen.
10. __F__ Colorado is the leading trout producing state in the U.S.
Comment: false, Idaho produces ~ 75% of all the trout produced in the U.S.
11. __T__ Aquaculture relies more on freshwater than seawater for fish production.
Comment: true, see the right side of the production sheet
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Name _______________________________________
12. __T__ Nile tilapia can be used in place of silver carp in polyculture.
Comment: true, nile tilapia is an excellent algal filter-feeder.
13. __F__ More Nori (also known as Porphyra or laver) grown than any other seaweed.
Comment: false, see question 7
14. __T__ Cost of feed is typically the largest percentage of production costs in the U.S.
trout industry.
Comment: true, this is true of most all aquaculture systems using prepared feeds.
15. __F___ Most cultured seaweeds grow the most rapidly in the summer.
Comment: false, seaweeds used in aquaculture tend to be cold-water species and die off in the
summer
16. __F__ Global production of tilapia, catfish, and salmonids (trout and all species of
salmon) combined is now equal to that of the carp species.
17. __T__ Trout require higher dissolved oxygen content in the water than tilapia.
Comment: true, trout evolved in fast moving streams with high oxygen levels.
18. __F__ As opposed to seaweeds, single-celled algae are not used for human consumption.
Comment: Spirulina, Chlorella are often used as health foods
19. __F__ Production of so-called “pond fish” such as carp and tilapia cannot be done in
raceways with high water flow rates because the algae washes out.
Comment: carp and tilapia do very well in raceways if they are provided pelletized feed.
Second Interim Exam (A) - Page 3
Name _______________________________________
19. With respect to relative GLOBAL production tonnage, correctly order the following on
the pyramid below (2 pts each = 10 pts. total):
a) eels b) rainbow trout c) tilapias d) sturgeon e) Atlantic salmon
d)
a)
b) 576,000 mt
26,000 mt
265,000 mt
e) 1,457,000 mt
c) 2,798,000 + mt
Comment: Only the correct letter is required. Production levels added as a reminder.
20. The Stroudwater River in Maine flows west to east where it enters the Atlantic at
Portland. Six miles upstream from the mouth of the river an adult Atlantic salmon and
an adult American eel are discussing water conditions. Then they swim off; each bent
on reproduction. Question: in which direction are the two fish swimming as they go
off? How do you know what the direction is? (Your answer should be couched in the
appropriate sophisticated terminology of a fish biologist in describing life histories). (6
points).
The salmon being an anadromous (1 point) species reproduces in the cold
headwaters of freshwater streams (1 point) and thus is headed west or upstream (1
point)
The eel being an catadromous (1 point) species reproduces in the ocean (1 point)
and thus is headed east or downstream (1 point)
21. List the following from least to longest production time (10 pts):
a) Production of a 4 inch diameter (abalone) abalone = 4 years (1”/year)
b) Production of white sturgeon females for caviar = 7 – 9 years
c) Production of a 350 gram trout = ~ 12 months
d) Production of a 1 pound channel catfish = 2 years
e) Production of a 2.5 kg Atlantic salmon = ~ 3 years
Least
__c__
__d__
__e__
__a__
__b___
Second Interim Exam (A) - Page 4
Greatest
Name _______________________________________
FILL IN THE BLANKS:
22. What do the initials FAO stand for? (1 pt.) ___Food and Agricultural Organization__.
23. What to the initials FDA stand for? (1 pts.) ___Food and Drug Administration_______.
24. Original name of the World Aquaculture Society? (1 pt.) _World Mariculture Society_.
25. The percent of this diet ingredient is highest in young fish. (1 pt.) _protein___________.
26. A long, relatively shallow and narrow rectangular tank with rapidly flowing water;
typically used in the culture of trout. (1 pt.) __raceway___________________________.
27. Tilapias are native to what continent? (1 pt.) __Africa____________________________.
28. The DNA of genetically engineered Atlantic salmon contain genes from two additional
species, they are: (2 pts.) __Chinook (or Pacific) salmon_and_Artic pout____________.
29. The average depth of an aquaculture pond is around (mark the correct answer, 1 pt)
a) _____ 3 - 4 inches b) __X___ 3 - 4 feet c) _____ 3 - 4 meters
30. One hectare is equal to (mark the correct answer, 1 pt)
a) ___ ~ 10 meters3 b) __X__ ~ two football fields c) ____ ~ 5,000 yards2 d) ____ ~ ½ acre.
31. Culture operation - fill in the blanks (10 pts.)
Species and stage
Type of Feed
Salinity of Culture Water
Abalone veliger larvae
No feed
marine
Atlantic salmon alvins
Crumbled formulated or
pelletized feed
freshwater
Untrained elvers
Chopped worms
freshwater
Catfish growout
Floating pellets
freshwater or 3 ppt
Large-sized pellets of
formulated feed
freshwater
Atlantic salmon broodstock
Second Interim Exam (A) - Page 5
Name _______________________________________
32. Discuss 3 ways the Norwegian government shaped the development of the Norwegian
salmon industry. (3 pts.)
a)
b)
c)
any three:
government sponsored research
government regulation of siting
government regulation of size of each farm
government regulation of ownership criteria
government bailout (50 cents on the dollar) of farm owners after the crash
33. List at least three steps in the training of eels with regard to feeding (3 pts).
a)
b)
c)
any three
train them to feed at a feeding station (one spot) rather than throughout the pond
train them to feed on a dough mixture rather than worms
train them to feed during the day rather than in the dark
train them to feed at the surface rather than at the bottom of the pond
Second Interim Exam (A) - Page 6
Name _______________________________________
34. Match the correct answer to each of the following: note, some may be used more than
once and some may not be used at all (17 pts)
a) Channel catfish
d) Atlantic salmon
g) Rainbow trout
b) Tilapia
e) Basa
h) Nori
c) Sturgeon
f) Carp
i) Eel
This species grows best in freshwater at or below 15oC __g___.
California is the nations leading producer of this mainly cartilaginous fish _c___
The U.S. produces more of this species of fish than any other country. __a___ .
More of this type of fish is produced than any other _f___.
The seed of this species of fish must all be obtained from the wild __i___.
This freshwater species native to the southern U.S. can also be grown in cages __a__.
California producers try to produce only males of the fish species _b___.
Mississippi leads the nation in the production of this fish _a___.
Norway produces more of this fish than any other country __e__.
In the U.S., Idaho produces more of this fish species than any other state _a__.
This species of fish is catadromous _i___.
This species is the most popularly cultured red algal seaweed in Japan _h___.
Fillets from this species are strong competition for catfish fillets in U.S. markets _e__.
Grow-out of juvenile to adults of this species typically occurs in net pens _d or e__.
Comment: I meant to ask about “marine” net pens
The name of the larval stage of this species is from the Latin meaning “small head” _i___.
This species is fed floating pellets in the U.S. to inhibit bottom feeding __a__.
Products from this species include both eggs and meat __c__.
Second Interim Exam (A) - Page 7
Name _______________________________________
35. Production of Atlantic salmon (the following questions relate to Atlantic salmon) (6 pts)
The freshwater production phase (starting with broodstock):
How are the gametes collected (1 pt)? __ broodstock are manually stripped of gametes _.
What is the first feeding stage of Atlantic salmon called (1 pt)? __alevin____.
What is smoltification (1 pts)? _ physiological pre-adaptation for life in seawater___.
Comment: Any answer showing an general understanding such as “biological
processes involving physiological, morphological, biochemical, and behavioral,
changes”. “salmon smolts develop a silvery color and tolerance for seawater when in
preparation for a seawater existence”. Note: since one of the PowerPoint slides refers
to smoltification only as the “physiological pre-adaptation for life in seawater” that
simple answer is acceptable.
The total time for this freshwater phase is typically (1 pt)? __1 – 1.5 years___.
Comment: accept any time period between 1 and 1.5 years
The saltwater phase:
What size are the smolts when moved to the marine net pens (1 pt.)? __40 – 120 g__.
How long is the smolt to a market size salmon (mark the correct answer below) (1 pt)?
~ 6 months ____
~1 year ______
~2 years ___X____.
36. List 4 key factors that are important in rearing of unicellular algae and succinctly
discuss the importance of each (4 pts.) Any four
a) Light -
essential for photosynthesis, typically constant lighting
b) Mixing - mixing prevents self-shading of cultures and thus promotes maximal
production
c) Nutrients - nutrients in the culture media, such as nitrogen, phosphorus, trace
minerals and vitamins, are needed for algal production
d) Carbon dioxide - provision of addition carbon sources, typically by bubbling CO2
through the cultures increases algal production
e) Appropriate temperature or salinity; optimum environmental conditions
f) Cleanliness – avoidance of bacterial contamination
Second Interim Exam (A) - Page 8