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Niblack Property Prince of Wales Island, Alaska
Eelgrass Survey
March 2007
Prepared for:
Niblack Mining Corp.
615-800 West Pender Street
Vancouver, BC
Canada V6C 2V6
Prepared by:
HDR Alaska, Inc.
2525 C Street, Suite 305
Anchorage, Alaska 99503
Niblack Property Eelgrass Survey
March 2007
- 1 -
Introduction and Purpose The objective of this report is to identify the abundance and distribution of eelgrass (Zostera
marina) along nearshore habitats adjacent to the Niblack property located on Prince of Wales
Island, Alaska. The property includes a patented mining claim owned by the Niblack Mining
Corporation. The approximately 23-acre survey area is situated near the head of Niblack
Anchorage, a two-mile long inlet east of Clarence Strait.
Eelgrass is a narrow-leaved (2 to 5 mm wide and up to 1 meter long) flowering vascular plant that
grows along nearshore, shallow marine waters. Eelgrass communities support habitat for many
marine invertebrates and fish throughout the year, providing excellent sources of shelter and food
(McRoy 1970). Eelgrass is found throughout southeast Alaska.
A consideration for the siting of nearshore developments by the Niblack Project is the presence of
eelgrass beds. Federal regulations and policies (40 CFR Sec. 230.43) require projects to
minimize their impacts on special aquatic sites, such as eelgrass beds, and to locate projects in
those areas only if there is no practicable alternative with lesser environmental impact.
Field Survey HDR Alaska, Inc. was contracted by Niblack Mining Corporation in January 2007 to perform a
winter survey of eelgrass along approximately 1,000 feet of nearshore intertidal and subtidal
waters adjacent to the Niblack property. Jeff Schively, an HDR biologist, conducted the field
survey on February 20, 2007. Prior to the survey, Mark Minnilo, a habitat biologist with the
Alaska Department of Natural Resources (DNR), was contacted to discuss the survey approach
and potential limitations involved with conducting the survey during winter. Mr. Minnilo noted
several locations where he had observed eelgrass during a previous site visit and requested that
those areas be a part of the survey. As discussed with DNR, the limitations of conducting a
winter eelgrass survey are primarily related to the reduced growth rate of the plant coinciding
with short days, low light, and cold temperatures. Weather conditions, wave action, water
turbidity, and ice cover are also issues that could reduce survey accuracy; wherever possible, the
conditions of these parameters were noted in the field.
Figure 1. February 2007 NOAA Tide Predictions: Ketchikan
1
1 From NOAA tides and currents website, available at:
http://tidesandcurrents.noaa.gov/get_predictions.shtml?year=2007&stn=1421+Ketchikan
-5
0
5
10
15
20
2/1/
07
2/3/
07
2/5/
07
2/7/
07
2/9/
07
2/11
/07
2/13
/07
2/15
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2/17
/07
2/19
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2/21
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2/23
/07
2/25
/07
2/27
/07
Date
Heig
ht
High Tide
Low Tide
Feb. 20 - Field Survey Low Tide: -1.2' at 8:23am High Tide: +17' at 2:31pm
Niblack Property Eelgrass Survey
March 2007
- 2 -
The survey was completed during a low tide event (1.2 feet (ft) below sea level (bsl) at 8:23am)
on February 20, 2007 (Figure 1). February’s tidal cycle is included above to show the average
tide range for the area. The survey started at 7:53am and lasted approximately four hours.
Weather and field conditions were favorable during the survey. An overcast sky with occasional
clear periods was present during most of the survey. No wind was present and the water surface
was flat. A light rain fell for approximately 10 minutes near the end of the survey.
Figure 2. Bathymetry Model of Survey Area
A 26-foot skiff was used to facilitate on-water portions of the survey. The boat operator followed
a series of transects extending the entire length of the study area at a slow, trolling speed
(estimated at less than 2 knots). Each transect was logged into a handheld Thales
MobileMapperTM
Pro global positioning system (GPS) unit. GPS data was post-processed to fix
differential correction errors using a National Geodetic Survey base station located on Annette
Island. In deep waters (greater than 20 ft bsl), the presence of eelgrass was sought using an
AquaScope II underwater viewer. Within shallower waters, the underwater viewer was not used
unless excessive glare prevented a clear view of the underwater ground floor.
Since a bathymetry layer was not available for the surveyed area, an estimate of water depths was
collected by logging point locations into the GPS and noting the depths of each point using a
commercial-grade depth finder on the skiff. This depth information was entered into a
geographic information system (GIS) database where a surface model was interpolated to obtain
estimated bathymetry contours for the study area (Figure 2).
A total of six marine transects and one beach transect were completed for the survey (Figure 3).
GPS locations along each of these transects were collected where eelgrass was observed, where
changes in substrate occurred, and where depth readings were collected. Notes taken at each of
these GPS locations are included at the end this report. Point locations and GPS surveyed
transects are shown on the attached map.
Lower Intertidal
Note: Depth locations shown in red mark eelgrass. One-foot bathymetry contour intervals shown.
Transects
Niblack Property Eelgrass Survey
March 2007
- 3 -
Figure 3. Approximate Locations of Survey Area Transects
Results Eelgrass was observed at several locations within the study area. These locations are shown on
Figure 5. In general, most subtidal areas were too deep to permit eelgrass growth; an estimated
76 percent of the surveyed subtidal areas are deeper than 15.0 ft bsl. The deepest elevation where
eelgrass was observed was 11.9 ft bsl; the shallowest elevation was 3.0 ft bsl. During the survey,
it was difficult to view the bottom of Niblack Anchorage at depths greater than 25.0 ft bsl.
Eelgrass was absent within the entire intertidal zone that was surveyed (Figure 4 – photograph 1).
The largest bed of eelgrass is located approximately 20 ft beyond the intertidal and subtidal
boundary in the northwestern portion of the study area (see GPS points 25, 26, 38, and 39 on the
attached map). This bed was initially observed from the beach survey (GPS points 7 and 8) and
then verified while conducting transects M-05 and M-06 (Figure 3 and 5). Plant density was
greatest and most widespread within this bed. The underlying substrate within this bed is a mix
of sand and gravel (Figure 4 - photographs 2 and 3).
A total of nine smaller, isolated patches of eelgrass were observed along transects M-04, M-05,
and M-06. Only a single shoot was observed at GPS point 28, only three shoots at GPS point 27.
In general, no dense beds of eelgrass were observed at any other location, only sparse beds were
seen. At all locations where eelgrass was observed, a mix of sand and gravel made up the
underlying substrate.
No eelgrass was seen growing in any of the rocky or coarse gravel beds surveyed (Figure 4 –
photographs 4 and 5). A large area in the upper subtidal zone near GPS point 4 was covered by a
thick layer of detritus (Figure 4 – photograph 6); no eelgrass was observed in that location.
Niblack Property Eelgrass Survey
March 2007
- 4 -
Photograph 1. Intertidal beach at low tide
Photograph 2. Eelgrass as seen from the
AquaScope
Photograph 3. Sand/gravel mix substrate
Photograph 4. Coarse gravel substrate
Photograph 5. Rocky substrate
Photograph 6. Detritus covered substrate
Figure 4. Site Photographs
Discussion A winter survey of eelgrass has the opportunity to underestimate the overall coverage of the plant.
Our study included looking for additional indicators beyond just the visual presence or absence of
Niblack Property Eelgrass Survey
March 2007
- 5 -
the plant. Physical parameters such as substrate type, water depth, wave scour, detritus cover, ice
cover, and proximity to freshwater streams were evaluated. For summary purposes, we offer the
following conclusions concerning the surveyed area:
1. Most of the study area is likely too deep to permit extensive growth of eelgrass.
2. Along the southwestern portion of the study area, a significant change of underlying
substrate occurs. This substrate change includes a change from finer gravels and sand to
larger gravels and rock. Based on our observations of where eelgrass occurs within the
study area, the likelihood that eelgrass colonizes the rocky, coarse gravel substrates, even
during summer, is probably low.
3. A thick bed of detritus exported from the southern freshwater stream appears to
accumulate in the lower intertidal and upper subtidal zones. This may have a blanket
effect in some areas and limit growth of eelgrass and other marine plant-life. Very little
plant growth was observed in that area at the time of the field survey. This blanketed
area may fluctuate throughout the year.
References
McRoy, C. P. 1970. On the Biology of Eelgrass in Alaska. University of Alaska. Fairbanks,
AK. 156pp.
U.S. Federal Register. December 24, 1980. Rules and Regulations, Vol. 45, No. 249. U.S.
Department of Defense. Corps of Engineers, Department of the Army. 40 CFR Sec.
240.43.
Transect M-01
Transect M-02
Transect M-03
Transect M-04
Transect M-05
Transect B-01
Transect M-06
Project Camp
Intertidal
Subtidal
Approximate15 ft bsl contour
Approximate Locationof Existing Barge
Landing/Road(constructed in 2006)
9
8
7
6
5
4
3
2
1
39
38
37
36
3534
3332
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
C1
Niblack ProjectEelgrass Survey
Legend
Eelgrass Beds
GPS Transects
Beach Transect
Marine Transects
GPS Survey Points
Eelgrass Present
Eelgrass Absent
Intertidal
Subtidal
0.0’ elev.
-46.0 elev.
Map Notes:1. Field survey completed by HDR on February 20, 2007.2. Bathymetry shown is approximate, data collected from commerical depth finder.3. Mapping by HDR for Niblack Mining Corp.
Figure 50 200 400100
Feet
Nib
lack P
rop
ert
y E
elg
rass
Su
rvey
Ma
rch
20
07
- 7
-
Fie
ld N
ote
s
A
las
ka
Sta
tep
lan
e Z
on
e 1
, N
AD
27
c
oo
rdin
ate
s
GP
S
Sit
e #
Ap
pro
xim
ate
D
ep
th (
fro
m
se
a l
eve
l)
Ee
lgra
ss
P
res
en
t (Z
.
ma
rin
a)
No
rth
ing
E
as
tin
g
No
tes
C-1
n
/a
1
,18
3,8
21
.56
3
,00
4,9
96
.14
G
PS
co
ntr
ol p
oin
t (t
ied t
o lo
ca
l g
rou
nd
co
ntr
ol su
rve
y)
B-0
1
n/a
1,1
83
,81
5.9
5
3,0
05
,16
7.7
7
Be
ach
tra
nsect
1
-1.0
1,1
83
,96
0.0
7
3,0
04
,89
6.8
2
Ro
cky inte
rtid
al.
Su
bstr
ate
mad
e u
p o
f 6"-
2' d
iam
ete
r a
ng
ula
r b
locky r
ocks.
No
m
ud
or
sa
nd
su
bstr
ate
.
2
-1.0
1,1
84
,02
7.6
8
3,0
04
,87
4.4
1
Su
bstr
ate
typ
e c
ha
ng
e in
bo
th in
tert
ida
l a
nd
sub
tid
al. R
ocky (
sim
ilar
to s
ite #
1)
to s
ou
th, coa
rse
gra
ve
l/sa
nd
mix
to
no
rth
. B
arn
acle
co
ve
red
in
tert
ida
l ro
cks.
S
ea
we
ed
pre
se
nt.
Min
k s
ee
n in
this
lo
ca
tion
.
3
-1.0
1,1
84
,11
3.3
0
3,0
04
,86
4.0
5
Su
bstr
ate
typ
e a
nd b
each
gra
die
nt cha
ng
e.
Be
ach
is fla
tte
r th
an
sites 1
an
d 2
.
Accum
ula
ted d
eb
ris lin
e o
n b
ea
ch
ab
ove
wa
ter
line
. S
malle
r co
bb
les/r
ocks
(mix
ed
ro
un
de
d a
nd
an
gu
lar)
.
4
-1.0
1,1
84
,26
5.6
1
3,0
04
,89
7.2
7
Su
btida
l ha
bita
t bu
ried
und
er
org
an
ic d
etr
itus.
Th
ick la
ye
r o
f b
ark
, b
ranch
es,
ne
ed
les, e
tc.
5
-1.0
1,1
84
,39
6.7
3
3,0
04
,87
9.2
1
Fre
sh
wa
ter
str
eam
/Ma
rin
e m
ixin
g lo
cation
. S
ea
we
ed
pre
se
nt.
8
0%
2"-
4"
an
gu
lar
rock, 1
0%
san
d, a
nd
10
% g
rave
l in
up
pe
r su
btid
al. G
rave
l/co
bb
le m
ix
thro
ugh
ou
t in
tert
ida
l.
6
-1.0
1,1
84
,47
0.7
1
3,0
04
,87
5.0
6
Sh
allo
w/lo
w-g
rad
ien
t su
btid
al. 9
5%
sm
all
gra
ve
l, 5
% 2
-4"
dia
me
ter
rock.
7
-1.0
X
1
,18
4,5
24
.81
3
,00
4,9
07
.57
Sh
allo
w/lo
w-g
rad
ien
t su
btid
al. 3
0%
sa
nd
, 5
0%
gra
ve
l, 2
0%
2-4
" dia
me
ter
rock.
S
eve
ral sm
all
sin
gle
pla
nts
of e
elg
rass (
cou
nt 3
sh
oo
ts f
rom
be
ach
) a
pp
roxim
ate
ly 1
2"
long
, 4
to
5 b
lad
es p
er
sh
oo
t.
8
-1.0
X
1
,18
4,5
75
.88
3
,00
4,9
64
.84
Ee
lgra
ss b
ed
ap
pro
xim
ate
ly 1
00
deg
rees e
ast
fro
m G
PS
po
int,
abo
ut 2
0 f
ee
t fr
om
ed
ge
of
wa
ter
(-1
fe
et)
. D
ep
th o
f e
elg
rass is a
pp
roxim
ate
ly 3
fe
et b
sl.
Sp
ars
e g
row
th b
ut con
sis
ten
t co
ve
r.
30
% s
an
d,
50%
gra
vel, a
nd
20
% 2
-4"
dia
me
ter
rock.
9
-1.0
1,1
84
,74
7.1
8
3,0
05
,02
2.9
7
No
ee
lgra
ss f
rom
th
is G
PS
po
int
back to
po
int #
8. R
ocky s
ub
tid
al.
2-8
" d
iam
ete
r ro
ck (
60%
), 3
0%
gra
ve
l, 1
0%
san
d.
10
-1
.0
1
,18
4,6
39
.14
3
,00
5,5
69
.25
B
arg
e la
ndin
g a
rea
. N
o e
elg
rass.
20
% s
an
d,
40
% g
rave
l, 4
0%
4-6
" d
iam
ete
r ro
ck.
M-0
1
-42
.0
O
ute
r stu
dy a
rea
tra
nsect.
T
hic
k w
ith
je
llyfish
. S
tart
ing
tra
nse
ct
at
no
rth
end
.
11
-4
4.7
1,1
84
,63
9.1
4
3,0
05
,56
9.2
5
De
pth
po
int.
Un
ab
le to
se
e b
ott
om
.
Nib
lack P
rop
ert
y E
elg
rass
Su
rvey
Ma
rch
20
07
- 8
-
Ala
sk
a S
tate
pla
ne
Zo
ne
1,
NA
D2
7
co
ord
ina
tes
G
PS
S
ite
#
Ap
pro
xim
ate
D
ep
th (
fro
m
se
a l
eve
l)
Ee
lgra
ss
P
res
en
t (Z
.
ma
rin
a)
No
rth
ing
E
as
tin
g
No
tes
12
-4
6.0
1,1
84
,37
7.2
1
3,0
05
,61
6.9
3
De
pth
po
int.
Un
ab
le to
se
e b
ott
om
.
13
-2
5.0
1,1
83
,91
7.0
9
3,0
05
,74
9.0
0
Aq
ua
Sco
pe
su
rve
y.
Sa
nd
/gra
ve
l/la
rge r
ock b
ott
om
. U
nve
geta
ted
.
M-0
2
-17
.0
S
tart
of m
arin
e t
ranse
ct #
2. S
tart
ing t
ransect
at sou
th e
nd
of stu
dy a
rea
.
Bo
tto
m c
ha
racte
ristics s
am
e a
s G
PS
#1
3.
14
-3
5.8
1,1
84
,10
7.9
2
3,0
05
,56
6.6
7
De
pth
po
int.
Un
ab
le to
se
e b
ott
om
.
15
-4
2.4
1,1
84
,41
6.9
3
3,0
05
,42
2.6
6
De
pth
po
int.
Un
ab
le to
se
e b
ott
om
.
16
-3
7.5
1,1
84
,69
6.5
3
3,0
05
,29
4.9
3
De
pth
po
int.
Un
ab
le to
se
e b
ott
om
.
M-0
2
-20
.0
A
qu
aS
co
pe
su
rve
y.
Sa
nd
/gra
ve
l/la
rge r
ock (
bo
uld
ers
) b
ottom
. U
nve
geta
ted
.
M-0
3
-12
.9
S
tart
of m
arin
e t
ranse
ct #
3. S
tart
ing a
t no
rth
en
d o
f stu
dy a
rea
. S
ea
sta
rs.
S
an
d/g
rave
l m
ix.
Aq
ua
Scop
e s
urv
ey t
hro
ug
ho
ut.
17
-3
3.5
1,1
84
,53
6.1
4
3,0
05
,21
9.3
5
De
pth
po
int.
Un
ab
le to
se
e b
ott
om
.
18
-3
5.4
1,1
84
,24
1.4
1
3,0
05
,26
8.0
0
De
pth
po
int.
Un
ab
le to
se
e b
ott
om
.
19
-1
9.5
1,1
83
,88
6.2
7
3,0
05
,29
9.5
3
De
pth
po
int.
M-0
3
-12
.0
A
qu
aS
co
pe
su
rve
y t
o -
12
ft. b
sl.
Silt
an
d g
rave
l o
ve
r 6
"-2
' dia
me
ter
rocks.
M-0
4
-16
.0
S
tart
of m
arin
e t
ranse
ct #
4. S
tart
ing t
ransect
at sou
th e
nd
of stu
dy a
rea
.
Aq
ua
Sco
pe
su
rve
y t
hro
ug
hou
t.
20
-3
0.0
1,1
84
,14
0.4
4
3,0
05
,14
0.4
5
De
pth
po
int.
Un
ab
le to
se
e b
ott
om
.
21
-2
7.1
1,1
84
,41
9.0
1
3,0
05
,08
9.0
9
De
pth
po
int.
Un
ab
le to
se
e b
ott
om
.
22
-8
.0
X
1,1
84
,64
6.1
8
3,0
05
,05
4.3
2
Ee
lgra
ss p
rese
nt.
1
0%
san
d, 8
0%
gra
ve
l, 1
0%
4"-
6"
dia
me
ter
rock.
Sp
ars
e
gro
wth
, a
pp
roxim
ate
ly 1
'-2
' apa
rt,
2'-3
' lo
ng
bla
de
s.
M-0
5
n/a
Sta
rt o
f m
arin
e t
ranse
ct #
5. S
tart
ing t
ransect
at n
ort
h e
nd
of stu
dy a
rea
.
23
-6
.5
1
,18
4,5
55
.55
3
,00
5,0
24
.00
D
ep
th p
oin
t.
Aq
ua
Scop
e s
urv
ey.
24
-1
3.0
1,1
84
,51
8.6
3
3,0
05
,03
5.3
8
De
pth
po
int.
Aq
ua
Scop
e s
urv
ey.
La
rge m
oo
ring
anch
or.
25
-1
1.0
X
1
,18
4,4
73
.32
3
,00
4,9
51
.97
E
elg
rass th
roug
hou
t.
Th
ick p
atc
h.
Gra
vel/san
d s
ubstr
ate
.
26
-5
.0
X
1,1
84
,40
6.8
2
3,0
04
,93
9.1
9
En
d o
f e
elg
rass.
Ee
lgra
ss b
ed b
etw
ee
n t
his
GP
S p
oin
t a
nd
#2
5.
27
-4
.2
X
1,1
84
,31
9.7
4
3,0
04
,98
6.0
9
Sm
all
iso
late
d p
atc
h o
f e
elg
rass.
Th
ree
sh
oo
ts o
bse
rve
d.
80%
gra
ve
l, 1
5%
sa
nd,
5%
4"-
6"
dia
me
ter
rock.
28
-6
.5
X
1,1
84
,24
2.1
1
3,0
04
,99
6.1
3
75
% d
etr
itu
s a
nd
silt
, 1
0%
gra
ve
l, 1
0%
san
d,
5%
4"-
6"
dia
me
ter
rock. A
sin
gle
sh
oot
of e
elg
rass o
bse
rve
d.
29
-1
1.9
X
1
,18
4,1
63
.37
3
,00
4,9
87
.20
S
ma
ll is
ola
ted
pa
tch
of e
elg
rass.
App
roxim
ate
ly 1
0'x
15
' in
siz
e.
Nib
lack P
rop
ert
y E
elg
rass
Su
rvey
Ma
rch
20
07
- 9
-
Ala
sk
a S
tate
pla
ne
Zo
ne
1,
NA
D2
7
co
ord
ina
tes
G
PS
S
ite
#
Ap
pro
xim
ate
D
ep
th (
fro
m
se
a l
eve
l)
Ee
lgra
ss
P
res
en
t (Z
.
ma
rin
a)
No
rth
ing
E
as
tin
g
No
tes
30
-7
.0
1
,18
4,0
67
.88
3
,00
4,9
24
.43
N
o e
elg
rass.
Sa
nd
/silt
mix
.
31
-1
3.0
X
1
,18
3,9
80
.72
3
,00
4,9
54
.41
V
ery
sp
ars
e p
atc
h o
f e
elg
rass. O
nly
se
ve
ral, s
ma
ll is
ola
ted s
ho
ots
. S
ilt/g
rave
l su
bstr
ate
.
32
-1
0.0
X
1
,18
3,9
26
.77
3
,00
5,0
18
.92
Ch
an
ge
in
un
de
rlyin
g s
ubstr
ate
. V
ery
spa
rse
eelg
rass a
t th
is p
oin
t (t
o n
ort
h).
M
ud
/silt
su
bstr
ate
. A
ngu
lar
6"-
2' d
iam
ete
r ro
ck e
mb
ed
de
d in
silt
/san
d t
o n
ort
h.
N
o e
elg
rass o
bse
rve
d t
hro
ug
ho
ut
rocks.
Zig
-za
g A
qu
aS
co
pe
su
rve
y
thro
ugh
ou
t.
33
-1
2.5
1,1
83
,92
4.4
7
3,0
05
,04
5.4
0
Aq
ua
Sco
pe
su
rve
y d
one
. N
o e
elg
rass o
bse
rve
d. S
ilt o
ve
r 4"-
1.5
' dia
me
ter
an
gu
lar
rock. S
and
/silt
su
bstr
ate
. S
om
e d
etr
itu
s.
34
-9
.0
X
1,1
83
,87
2.5
2
3,0
05
,51
3.0
4
Sm
all,
iso
late
d p
atc
h o
f e
elg
rass o
bse
rve
d.
Se
ve
ral la
rge
bou
lde
rs in a
rea
s.
Sa
nd
, m
ud
, a
nd g
rave
l sub
str
ate
.
35
-1
4.0
X
1
,18
3,8
89
.08
3
,00
5,6
29
.19
S
pa
rse,
iso
late
d p
atc
hes o
f e
elg
rass b
etw
ee
n t
his
GP
S p
oin
t a
nd
#3
4, a
ll o
ccu
rrin
g a
t th
e -
10
' ba
thym
etr
y c
on
tou
r.
Gra
ve
l an
d s
and
with
la
rge
bo
uld
ers
.
M-0
6
n/a
1,1
84
,00
0.3
5
3,0
04
,89
8.1
3
Sta
rt o
f m
arin
e t
ranse
ct #
6.
36
-6
.2
X
1,1
84
,04
1.8
6
3,0
04
,87
4.5
1
Sta
rt o
f e
elg
rass b
ed
.
37
-6
.1
X
1,1
84
,35
2.0
8
3,0
04
,91
6.8
1
En
d o
f e
elg
rass.
Ee
lgra
ss b
ed b
etw
ee
n t
his
GP
S p
oin
t a
nd
#3
6.
38
-5
.3
X
1,1
84
,55
7.1
9
3,0
04
,94
1.7
5
Sta
rt o
f sp
ars
e e
elg
rass.
39
-6
.5
X
1,1
84
,00
0.3
5
3,0
04
,89
8.1
3
En
d o
f e
elg
rass.
Ee
lgra
ss b
ed b
etw
ee
n t
his
GP
S p
oin
t a
nd
#3
8 (
pla
nt d
ensity
hig
he
r o
n la
ter
1/3
clo
sest
to #
39
).