Population
Level
Impacts
Shannon
L.
Cass­
Calay
NOAA
Fisheries
Miami
Laboratory
Quantifying
Population
Level
Impact
°
Equivalent
Adult
Losses
 
Goodyear,
C.
P.
1978.
Entrainment
impact
estimates
using
the
equivalent
adult
approach.
U.
S.
Fish
and
Wildlife
Service,
Division
of
Biological
Services.
FWS/
OBS­
78/
65.

 
EPA
316(
b)

°
Leslie
Matrices
 
Vaughan,
D.
S.
and
S.
B.
Saila.
1976.
A
method
for
determining
mortality
rates
using
the
Leslie
matrix.
Trans.

Am.
Fish.
Soc.
105:
380­
383.
Quantifying
Population
Level
Impact
°
Dynamic
Pool
(
Yield
per
recruit)
Models
 
Jensen,
A.
L.
and
T.
A.
Hamilton.
1982.
Application
of
a
conventional
fishery
model
for
assessment
of
entrainment
and
impingement
impact.
Env.
Biol.
Fish.
7:
181­
185.

°
Surplus
Production
Model
 
MacCall,
A.
D.
et
al.
1982.
Power
plant
impact
assessment:

A
simple
fishery
production
model
approach.
Fish.
Bull.

81:
613­
619.
Data
Requirements
°
Equivalent
Adult
Losses
 
Number
of
eggs,
larvae,
juveniles
and
adults
entrained
and
impinged.

 
Daily
or
stage­
specific
mortality
rates
°
Leslie
Matrix
 
Age­
specific
fertility
 
Age­
specific
survivorship
 
Numbers
or
proportion
of
population
at
age
x
 
Can
examine
the
role
of
E&
I
by
varying
the
age­
zero
survivorship
Data
Requirements
°
Dynamic
Pool
 
Growth
parameters
 
Eggs
produced
per
female
 
Duration
of
egg
stage
 
Hatching
fraction
 
Duration
of
larval
period
 
Age
at
entry
to
fishery
 
Fishing
Mortality
Coefficient
 
Natural
Mortality
Coefficient
 
Size
of
mature
population
 
Total
population
size
 
Annual
water
intake
 
Eggs
and
larvae
entrained
Data
Requirements
°
Production
Model
 
Standing
stock
of
larvae/
eggs
 
Number
of
eggs
and
larvae
entrained
 
Number
of
adults
impinged
 
Natural
Mortality
rate
 
Adult
biomass
Equivalent
Adult
Losses
°
Previous
estimates
were
made
for
Compass
Point
LNG
station
by
a
consultant
(
ENSR
International)

°
For
this
presentation,
I
will
reexamine
the
approach
for
3
species:
Red
Snapper,
Red
Drum
and
Menhaden
Equivalent
Adult
Losses
(
Red
Drum)

°
Assumptions
 
Egg
Stage
Duration
=
1
day
 
Egg
Daily
Survival
=
50%

 
Eggs
entrained
=
2,070,640
 
Larvae
entrained
=
23,226,019
 
Juvenile
Stage
Duration
=
365
 
egg
duration
 
larval
duration
 
Daily
survival
of
juveniles
=
99%

°
Result:
perhaps
5,000
 
20,000
AE.
More
extreme
values
are
possible
°
Previous
estimate
=
5,849
ESTIMATED
ADULT
EQUIVALENTS
RED
DRUM
80000
100000
120000
160000140000
180000
200000
60000
400
00
20000
Daily
Survival
Probability
of
Larvae
0.72
0.74
0.76
0.78
0.80
0.82
0.84
0.86
0.88
0.90
Larval
Duration
(

Days)
18
20
22
24
26
28
30
Equivalent
Adult
Losses
(
Menhaden)

°
Assumptions
 
Egg
Stage
Duration
=
4
day
 
Egg
Daily
Survival
=
50%

 
Eggs
entrained
=
53,717,351
 
Larvae
entrained
=
602,538,351
 
Juvenile
Stage
Duration
=
365
 
egg
duration
 
larval
duration
 
Daily
survival
of
juveniles
=
99%

°
Result:
perhaps
100,000­
1,000,000
AE.
More
extreme
values
are
possible.

°
Previous
estimate
175,000
ESTIMATED
ADULT
EQUIVALENTS
MENHADEN
1e+

6
2e+

6
4e+

6
3e+

6
6e+

6
5e+

6
8e
+

6
7e+

6
Daily
Survival
Probability
of
Larvae
0.86
0.88
0.90
0.92
0.94
Larval
Stage
Duration
(

days)
30
40
50
60
70
80
90
Equivalent
Adult
Losses
(
Red
Snapper)

°
Assumptions
 
Egg
Stage
Duration
=
1
day
 
Egg
Daily
Survival
=
50%

 
Eggs
entrained
=
779,492
 
Larvae
entrained
=
8,743,424
 
Juvenile
Stage
Duration
=
365
 
egg
duration
 
larval
duration
 
Daily
survival
of
juveniles
=
99%

°
Result:
perhaps
1,000
 
10,000
AE.

More
extreme
values
are
possible
°
Previous
estimate
=
73
ESTIMATED
ADULT
EQUIVALENTS
RED
SNAPPER
5000
10000
15000
20000
25000
35000
30000
45000
40000
50000
60000
55000
65000
Daily
Survival
Probability
of
Larvae
0.76
0.78
0.80
0.82
0.84
0.86
0.88
0.90
Larval
Stage
Duration
(

days)

20
22
24
26
28
30
32
