What Makes migration Tough for Fish?...What Makes migration Tough for Fish? Identify the obstacles...
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What Makes migration Tough for Fish? Identify the obstacles and check your answers on the right! 1. Grazing cattle can damage river banks and degrade water quality. 2. Runoff from fertilizers can degrade water quality. 3. Irrigation can reduce water levels; remaining water can then become too warm for native fishes. 4. Historic mill dams can affect the natural flow of rivers and prevent fish from migrating. 5. Traditional round culverts tend to hinder or totally block fish movement. 6. Non-native fish prey on juvenile migratory fish and disrupt the food chain. 7. Dams may delay or totally prevent migration and altered flow may favor non-migratory and/or non-native fish. 8. Predators intercept migrating fish in coastal waters. 9. Waste water discharge may degrade water quality. 10. See 5. 11. Fish trapped below culverts can be easy prey for birds. 12. See 5. 13. See 4. Abandoned dams are also unsafe. 14. Years ago, rivers were straightened so logs could get to mills. This degraded fish habitat. 15. Migratory fish may be legally harvested in other countries; here they are sold in a fish market. 16. Many species of birds eat migratory fish. 17. Some migratory fish are intercepted at sea en route to and from spawning habitat. 18. Migratory fish are an important food source for birds like bald eagles. 19. Air pollution from factories and sewage treatment plants can degrade water quality. 20. Migratory fish may be an unintended bycatch in fisheries targeting other species. 21. Migratory fish are an important natural food source for birds like ospreys. 22. Warming of rivers and oceans can impact fish survival. 23. A west coast elephant seal may prey on migratory fish. 24. An east coast harbor seal may prey on migratory fish. 25. The brown pelican is a natural predator of migratory fish. 26. Intake pipes can suck juvenile fish into the industrial plant’s cooling process. 27. Abandoned dams used during the log drive days continue to block fish migration. 28. See 5. Undersized culverts also disrupt natural flow and sediment transfer. 29. A changing climate can alter oceanic currents vital to migratory fish.
Transcript of What Makes migration Tough for Fish?...What Makes migration Tough for Fish? Identify the obstacles...
What Makes migrationTough for Fish?
Identify the obstacles and check your answers on the right!
1.
Graz
ing
cattl
e ca
n da
mag
e riv
er b
anks
and
deg
rade
wat
er q
ualit
y.2.
Ru
noff
from
ferti
lizer
s ca
n de
grad
e w
ater
qua
lity.
3.
Irrig
atio
n ca
n re
duce
wat
er le
vels
; rem
aini
ng w
ater
can
then
bec
ome
too
war
m fo
r nat
ive
fishe
s.
4.
Hist
oric
mill
dam
s ca
n af
fect
the
natu
ral fl
ow o
f riv
ers
and
prev
ent fi
sh fr
om m
igra
ting.
5.
Trad
ition
al ro
und
culv
erts
tend
to h
inde
r or t
otal
ly b
lock
fish
mov
emen
t. 6.
N
on-n
ativ
e fis
h pr
ey o
n ju
veni
le m
igra
tory
fish
and
dis
rupt
the
food
cha
in.
7.
Dam
s m
ay d
elay
or t
otal
ly p
reve
nt m
igra
tion
and
alte
red
flow
may
favo
r non
-mig
rato
ry a
nd/o
r non
-nat
ive
fish.
8.
Pred
ator
s in
terc
ept m
igra
ting
fish
in c
oast
al w
ater
s.
9.
Was
te w
ater
dis
char
ge m
ay d
egra
de w
ater
qua
lity.
10.
See
5.11
. Fi
sh tr
appe
d be
low
cul
verts
can
be
easy
pre
y fo
r bird
s.12
. Se
e 5.
13.
See
4. A
band
oned
dam
s ar
e al
so u
nsaf
e.
14.
Year
s ag
o, ri
vers
wer
e st
raig
hten
ed s
o lo
gs c
ould
get
to m
ills.
Thi
s de
grad
ed fi
sh h
abita
t.
15.
Mig
rato
ry fi
sh m
ay b
e le
gally
har
vest
ed in
oth
er c
ount
ries;
her
e th
ey a
re s
old
in a
fish
mar
ket.
16.
Man
y sp
ecie
s of
bird
s ea
t mig
rato
ry fi
sh.
17.
Som
e m
igra
tory
fish
are
inte
rcep
ted
at s
ea e
n ro
ute
to a
nd fr
om s
paw
ning
hab
itat.
18.
Mig
rato
ry fi
sh a
re a
n im
porta
nt fo
od s
ourc
e fo
r bird
s lik
e ba
ld e
agle
s.19
. Ai
r pol
lutio
n fro
m fa
ctor
ies
and
sew
age
treat
men
t pla
nts
can
degr
ade
wat
er q
ualit
y.20
. M
igra
tory
fish
may
be
an u
nint
ende
d by
catc
h in
fish
erie
s ta
rget
ing
othe
r spe
cies
. 21
. M
igra
tory
fish
are
an
impo
rtant
nat
ural
food
sou
rce
for b
irds
like
ospr
eys.
22.
War
min
g of
rive
rs a
nd o
cean
s ca
n im
pact
fish
sur
viva
l. 23
. A
wes
t coa
st e
leph
ant s
eal m
ay p
rey
on m
igra
tory
fish
.24
. An
eas
t coa
st h
arbo
r sea
l may
pre
y on
mig
rato
ry fi
sh.
25.
The
brow
n pe
lican
is a
nat
ural
pre
dato
r of m
igra
tory
fish
. 26
. In
take
pip
es c
an s
uck
juve
nile
fish
into
the
indu
stria
l pla
nt’s
cool
ing
proc
ess.
27.
Aban
done
d da
ms
used
dur
ing
the
log
driv
e da
ys c
ontin
ue to
blo
ck fi
sh m
igra
tion.
28
. Se
e 5.
Und
ersi
zed
culv
erts
als
o di
srup
t nat
ural
flow
and
sed
imen
t tra
nsfe
r.
29.
A ch
angi
ng c
limat
e ca
n al
ter o
cean
ic c
urre
nts
vita
l to
mig
rato
ry fi
sh.
