*Manuscript
Click here to download Manuscript: Marin Jarrin and Miller_resubmission.docx
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
Click here to view linked References
Sandy beach surf zones: an alternative nursery habitat for 0-age Chinook salmon
2
1
3
Marin Jarrin J.R.* and 2Miller J.A.
4
5
Running head: Surf zones: alternative nursery for Chinook salmon
6
7
8
1Department
9
Marine Science Center, Oregon State University. 2030 SE Marine Science Dr., Newport, OR
of Fisheries and Wildlife, Coastal Oregon Marine Experiment Station, Hatfield
10
97365. Email address: Jose.MarinJarrin@Oregonstate.edu
11
2Department
12
Marine Science Center, Oregon State Universi ty. 2030 SE Marine Science Dr., Newport, OR
13
97365. Email address: Jessica.Miller@Oregonstate.edu
of Fisheries and Wildlife, Coastal Oregon Marine Experiment Station, Hatfield
14
15
*Corresponding Author: Jose R. Marin Jarrin
16
Current address: Engineering and Technology Building 126A, Central Michigan University
17
Mount Pleasant, MI 48858.
18
Telephone number: 1-541-270-8820
19
Email address: marin1jr@cmich.edu
20
21
22
23
1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
ABSTRACT
2
The role of each habitat fish use is of great importance to the dynamics of populations. During
3
their early marine residence, Chinook salmon (Oncorhynchus tshawytscha), an anadromous fish
4
species, mostly inhabit estuaries but also use sandy beach surf zones and the coastal ocean.
5
However, the role of surf zones in the early life history of Chinook salmon is unclear. We
6
hypothesized that surf zones serve as an alternative nursery habitat, defined as a habitat that
7
consistently provides a proportion of a population with foraging and growth rates similar to those
8
experienced in the primary nursery. First, we confirmed that juvenile Chinook salmon cohorts
9
are simultaneously using both habitats by combining field collections with otolith chemical and
10
structural analysis to directly compare size and migration patterns of juveniles collected in two
11
Oregon (USA) estuaries and surf zones during three years. We then compared juvenile catch,
12
diet and growth in estuaries and surf zones. Juveniles were consistently caught in both habitats
13
throughout summer. Catches were significantly higher in estuaries (average ± SD = 34.3 ± 19.7
14
ind. 100 m-2) than surf zones (1.0 ± 1.5 ind. 100 m-2) and were positively correlated (r = 0.92).
15
Size at capture (103 ± 15 mm fork length, FL), size at marine entry (76 ± 13 mm FL), stomach
16
fullness (2 ± 2% body weight) and growth rates (0.4 ± 0.0 mm day-1) were similar between
17
habitats. Our results suggest that when large numbers of 0-age Chinook salmon inhabit estuaries,
18
juveniles concurrently use surf zones, which serve as an alternative nursery habitat. Therefore,
19
surf zones expand the available rearing habitat for Chinook salmon during early marine
20
residence, a critical period in the life history.
21
Keywords: habitat use, Chinook salmon, surf zone, alternative nursery habitat, spatially-split
22
cohort
23
2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
2
1. Introduction
Anadromous fish use a diversity of habitats throughout their life (Dadswell et al., 1987;
3
McDowall, 1988). Using multiple environments can increase access to resources, reduce the risk
4
of a catastrophic event (e.g. floods, droughts, predation pulse) eliminating a cohort (Hilborn et
5
al., 2003; Secor, 2007; Schindler et al., 2010), and has been hypothesized to confer resilience to
6
populations in the face of climate change and other anthropogenic impacts (Secor, 2007; Waples
7
et al., 2009; Katz et al., 2012).
8
Heterogeneity in habitat use can occur within a life stage, with individuals of a cohort
9
concurrently using multiple environments (Dadswell et al., 1987; McDowall, 1988; Bertness et
10
al., 2001). When individuals within a cohort simultaneously use multiple habitats, the cohort is
11
often defined as spatially-split (Skúlason and Smith, 1995). In anadromous fish, reliance on
12
multiple habitats can occur when individuals follow different migratory pathways. Variability in
13
migratory paths among individuals of a cohort has been hypothesized to be a consequence of the
14
prey availability and predation risk fish encountered during previous life stages (Secor, 2007).
15
Chinook salmon (Oncorhynchus tshawytscha) is an anadromous species naturally
16
distributed throughout the North Pacific Ocean that spawns in most coastal rivers of western
17
North America north of San Francisco, California (Quinn, 2004). For fall-run populations, the
18
majority of juveniles initiate their migration to the ocean at age-0 (sub-yearlings) or age-1
19
(yearlings). On the west coast of the continental USA, most fall Chinook salmon migrate to the
20
ocean as subyearlings (Rich, 1920; Reimers, 1973; Nicholas and Hankin, 1988). Subyearling fall
21
Chinook salmon reside in streams and rivers for several months before migrating to the estuary
22
during the spring, summer or fall of their first year of life (Reimers, 1973; Healey, 1991; Bottom
23
et al., 2005a). Estuaries are considered a nursery for Chinook salmon due to the potential for
3
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
enhanced growth, refugia from predation, and physiological acclimation to marine waters
2
(Reimers, 1973; Healey, 1980; Simenstad et al., 1982). Subyearlings may inhabit estuaries for an
3
extended period (≥6 months) before continuing their migration to the ocean (Hering et al., 2010;
4
Volk et al., 2010). This initial residence in estuaries and coastal waters is considered a critical
5
period for juvenile salmon due to high and variable levels of mortality (for review see Pearcy,
6
1992).
7
During this important early marine residence period, a small number of sub-yearling
8
Chinook salmon (<10% of a population) inhabit sandy beach surf zones mostly adjacent to
9
estuary mouths (Healey, 1980; Allen and Pondella II, 2006; Marin Jarrin, 2012). Along the west
10
coast of North America, juveniles have been collected at beaches adjacent to estuary mouths
11
during all stages of the tide and times of day in shallow and outermost parts of the surf in
12
summer where they feed on a relatively high abundance and diversity of prey (Dawley et al.,
13
1981; Marin Jarrin et al., 2009; Marin Jarrin, 2012). Reimers (1973) hypothesized that juveniles
14
moved to surf zones due to increasing abundance of conspecifics and decreasing prey availability
15
throughout the summer in a small Oregon estuary. Marin Jarrin (2012) found that juvenile
16
Chinook salmon mostly used beaches that were immediately adjacent to their estuary of origin
17
and hypothesized that juveniles were concurrently using estuarine and surf zone habitats. By
18
using both habitats, Marin Jarrin (2012) suggested that Chinook salmon populations presented a
19
spatially-split cohort, where the majority of juveniles reside in estuaries prior to moving offshore
20
and a minority reside in surf zones for an unknown period of time before moving to deeper
21
coastal waters.
22
Beck et al. (2001) refined the concept of nurseries and proposed a framework to
23
characterize these important environments. Several subsequent studies also suggested that even
4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
though a species or population uses one main nursery where the majority of individuals reside,
2
other habitats may serve as important alternatives to the main nursery (Secor, 2007; Fodrie et al.,
3
2009; Vivier and Cyrus, 2009). We define alternative nursery habitats as environments where
4
some individuals reside and encounter foraging and growth conditions similar to the main
5
nursery. These alternative nurseries expand rearing habitat and therefore potentially increase the
6
total number of individuals that survive to adulthood.
7
In the case of Chinook salmon, estuaries are considered the main nursery habitat during
8
their first months of marine life (Reimers, 1973; Healey, 1980; Simenstad et al., 1982). However,
9
surf zones could serve as an alternative nursery habitat because juveniles may experience high
10
growth rates due to an abundance and high diversity of prey (Marin Jarrin et al., 2009) and low
11
predation rates due to the turbid and high dynamic nature of surf zone waters (McLachlan and
12
Brown, 2006). We tested the hypothesis that surf zones adjacent to estuary mouths provide an
13
alternative nursery habitat for subyearling Chinook salmon. First, we determined that juveniles
14
using surf zones and estuaries were part of the same cohort by comparing size at capture and size
15
at and timing of marine entrance for juveniles collected in both habitats. We then compared
16
catch, diet composition, stomach fullness and growth rates of juveniles collected simultaneously
17
in two estuaries and two adjacent surf zones during three years. If surf zones provide alternative
18
nursery habitats, we expected juvenile stomach fullness and growth rates to be similar between
19
estuaries and surf zones. Based on previous studies, we expected catches to be higher in estuaries
20
than in surf zones (Marin Jarrin, 2012). We hypothesized that even though diet composition
21
would be different between habitats, prey diversity would be similarly high because of the
22
diverse prey fields present in estuaries and surf zones and the opportunistic feeding nature of
23
juvenile Chinook salmon (Gray et al., 2002; Schabetsberger et al., 2003; Marin Jarrin, 2007).
5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
Finally, we correlated catches between estuaries and surf zones to determine if surf zone use was
2
related to juvenile densities in estuaries (Reimers, 1973).
3
4
2. Material and Methods
5
2.1 Study Region
6
This study was conducted in lower Coos and Alsea bays and their adjacent sandy beach
7
surf zones (Coos and Alsea Surf) located in Oregon, USA during 2008-2010 (Fig. 1). Adjacent
8
sandy beaches were located within 500 m of the estuary mouth. Coos and Alsea Surf are
9
dissipative (shallower slope) sandy beaches (McLachlan, 1980; Short and Wright, 1983)
10
experiencing moderate wave height in the summer (average wave height: 1-2 m) when sand
11
accretion may transform them into intermediate beaches (Komar et al., 1976). Coos Surf is
12
located immediately to the south of Coos Bay and is approximately 3 km long while Alsea Surf
13
is located immediately to the south of Alsea Bay and is approximately 10 km long. Coos and
14
Alsea Bay are drowned river mouth estuaries, influenced by high stream flows in fall and winter,
15
and low to inexistent summer flows (Emmett et al., 2000). Coos and Alsea Bay are different in
16
their sizes and classification based on human development (Table 1). Juvenile origin is also
17
different between watersheds as juveniles at Coos Bay are of hatchery and natural origin while in
18
Alsea Bay all juveniles are naturally-produced. Chinook salmon populations in both watersheds
19
are currently considered stable (ODFW, 2005).
20
2.2 Fish collection
21
Prior research found that juvenile Chinook salmon were present in estuaries and adjacent
22
surf zones during all stages of the tidal cycle, at different depths and throughout the day during
23
the summer (Reimers, 1973; Healey, 1980; Dawley et al., 1981; Marin Jarrin, 2012); therefore,
6
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
juveniles were collected in both habitats during lower low spring tide for safety reasons.
2
Samplings were conducted from 1 June to 30 September of 2008-2010 at all sites (Table 2).
3
During 2008, to increase our sample sizes, juveniles were also collected on the beach
4
immediately to the north of Alsea Bay mouth, which is also 10 km long, and has similar physical
5
characteristics as Alsea Surf (Marin Jarrin, unpublished data, Fig. 1).
6
Juvenile Chinook salmon were collected in sandy beach surf zones using a small beach
7
seine (15 m x 1.5 m x 1.0 cm) as detailed in Marin Jarrin and Shanks (2011), and in estuaries by
8
Oregon Department of Fish and Wildlife personnel using a 38 m x 4 m x 1.3 cm beach seine with
9
a bag (2.5 m x 2.5 m x 1 cm). Three to six tows were conducted in each habitat, and up to 30
10
juvenile Chinook salmon were euthanized with MS-222 (tricaine methanesulfonate, Argent
11
Chemical Laboratories, 150 mg·l-1) buffered with baking soda (sodium bicarbonate, 300 mg·l-1)
12
and then transported back to the laboratory on ice. Additional Chinook salmon were counted and
13
measured (fork length, FL, mm) prior to release.
14
2.3 Juvenile size, catch and stomach content analysis
15
In the lab, juveniles were measured (FL, mm) and weighed (g), and stomachs and otoliths
16
were extracted. Juvenile catch was estimated by determining the area of the circle and triangle
17
sampled by the net in estuaries and surf zones, respectively (individuals 100 m-2). We identified
18
and counted stomach contents to the lowest taxonomic level possible. Stomach fullness (SF) was
19
calculated as the percentage of juvenile body weight as follows:
20
(1)
21
7
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
2
2.4 Otolith analysis: size at marine entry, timing of entrance and growth in marine waters
To confirm that estuarine and surf zone caught juveniles (from here on referred to as
3
estuarine and surf zone juveniles) are part of the same group of fish and compare growth
4
between habitats, we determined size at and day of marine entry and estimated marine growth
5
rates using otolith structure and chemistry. Otoliths were extracted and polished using wet-or-dry
6
paper and lapping film to expose the dorsal-ventral growth axis (Miller, 2007). Otolith structure
7
was analyzed using ImagePro Plus® software. Otoliths were photographed at 40 and 400x to
8
measure otoliths and count increments. We obtained chemical data (Sr:Ca and Ba:Ca) using laser
9
ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) at Oregon State
10
University’s WM Keck Collaboratory for Plasma Spectrometry, Corvallis, Oregon. The laser
11
was set at a pulse rate of 7 Hz with a 50-µm ablation spot size and travelled at a speed of 5 um
12
sec-1. Transects were located along the dorsal-ventral growth axis through the core at the widest
13
location of the otolith. Background levels of Ca, Sr, and Ba were measured 30 s prior to otolith
14
ablation. Calcium was used as an internal standard to account for variation in amount of material
15
ablated and instrument variation. Ratios were obtained for each element by converting
16
normalized ion ratios using a glass standard from the National Institute of Standards and
17
Technology (NIST 610) and the background levels of each element (Kent and Ungerer, 2006;
18
Miller, 2007). Ratios are reported in mmol mol-1. The mean percent relative standard deviation
19
of NIST 610, used as a measure of instrument precision during data collection, was Ca = 2.3, Sr
20
= 2.4 and Ba = 3.3%. To estimate accuracy, we used a calcium carbonate standard of known
21
composition (US Geological Survey, MACS -2). Measured values were within 3% of known
22
Sr:Ca and Ba:Ca values.
8
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
Certain elements, such as Sr and Ba, are incorporated into an otolith in proportion to their
2
water concentration, allowing determination of the size at and time of marine entry, and therefore
3
residence in marine waters (Kraus and Secor, 2004a; Zimmerman, 2005; Miller et al., 2010).
4
Strontium:calcium ratios are usually higher in ocean waters (>8 mmol mol-1) than in fresh waters
5
(< 5 mmol mol-1). However, because Sr:Ca fresh water values in the Coos Bay watershed ranged
6
from 5-8 mmol/mol (TableA1), we included Ba:Ca ratios, which were consistently >50 μmol
7
mol-1 within the Coos watershed, and thus allowed for a more precise discrimination between
8
fresh and marine waters (Miller, 2011; Table A1). We used the inflection point at which Sr:Ca
9
increased, when present, and Ba:Ca decreased to marine levels to signify a transition from fresh
10
to marine water. We use the term “marine water” to indicate brackish/ocean waters because there
11
is minimal variation in Sr:Ca and Ba:Ca above salinities of ~9 – 10 (Kraus and Secor, 2004a;
12
Zimmerman, 2005; Miller et al., 2010). There is a rapid increase in otolith Sr:Ca and decline in
13
otolith Ba:Ca after exposure to elevated salinity (1-2 d), however stabilization can take longer
14
(Miller et al., 2011). Therefore, we used a conservative 1 d marine residence time for fish whose
15
otoliths had no discernible changes in Sr:Ca or Ba:Ca at their edges.
16
To estimate day of marine entry, we counted the number of increments from the otolith
17
edge to the inflection point of Sr:Ca and/or Ba:Ca. Based on the habitat transitions identified
18
using otolith Sr:Ca and Ba:Ca data, we estimated juvenile size at marine entry using the
19
proportional back-calculation method, which accounts for individual variability in fish size
20
(Francis, 1990). Due to variability in slopes, we used separate equations, which were obtained by
21
regressing juvenile FL against otolith width (OW), for each estuary/surf zone site during each
22
year (Table 3):
23
(2)
9
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
where FLC = fork length (mm) at capture and OWC = otolith width (μm) at capture.
2
We then back-calculated fork length as described below
3
(3)
4
where FLBC = fork length (mm) at a back-calculated size, FLEC = estimated fork length at capture
5
(mm, estimated using equation 2), OWBC = otolith width (μm) at marine entry.
6
We estimated recent growth rates using two approaches. First, we estimated fish size 14
7
days prior to capture with the same approach as described above but using OW 14 days prior to
8
capture instead of OW at marine entry. We then calculated growth rates by dividing the
9
difference between FL at capture and FL 14 days earlier by 14. Second, we measured the otolith
10
increment widths (μm) for the last 14 days of the fish’s life to generate otolith growth
11
trajectories. We chose the last 14 days because we collected juveniles every 14 days and prior
12
analysis of individual otolith growth trajectories indicated there was no difference in average
13
increment widths between the last 14 and 10, 7 or 3 days (Kruskal-Wallis test, p > 0.05, Fig. 2),
14
which suggests otolith growth rates were similar throughout the fish’s last 14 days of life. For
15
these analyses we only used fish whose otolith chemistry indicated they had been present in
16
marine waters for at least 14 days. Increment widths were measured twice at least a week apart
17
and the difference in measurements recorded to estimate error (<5%).
18
2.5. Statistical comparison of variables between estuarine and surf zone juveniles
19
We compared results for Coos sites (i.e. estuary vs. surf zone) separately from Alsea sites
20
due to differences between estuaries (detailed above) that can influence juvenile salmonid
21
ecology (Zhang and Beamish, 2000; Weitkamp, 2008; Chittenden et al., 2010). We compared
10
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
estuarine and surf zone catches during each year using a non-parametric rank-sum test due to
2
differences in sampling methodology and habitat type. Estuarine and surf zone catches were
3
compared using Pearson correlation coefficients. Catch data (% of total catch per site) were
4
previously square root transformed.
5
We compared size at capture, size at and day of marine water entrance, stomach fullness
6
and growth rates (back-calculated and increment width) between estuarine and surf zone fish
7
using two- and one-way ANOVAs for Coos and Alsea sites, respectively. Data from 2009 (Coos
8
and Alsea sites) and 2010 (Alsea sites) were not used in these analyses due to low sample sizes
9
in surf zones (<10 fish). Therefore, at Coos, we used habitat (estuary and surf zone) and year
10
(2008 and 2010) as fixed factors, while at Alsea, we only had one fixed factor (i.e. habitat). For
11
both analysis day was the sampling unit. We only included days when estuarine and surf zone
12
collections were within a week of each other to compare size at capture to account for the
13
increase in fish size with time (Fig. 3). Parametric assumptions for the ANOVA were met after
14
log10(x + 1) transformation. Assumptions were tested using normal probability (quantile–
15
quantile) plots, and boxplots of residuals versus fitted values (Sokal and Rohlf, 1981). Tukey
16
HSD test was used for pair-wise comparisons.
17
We used the Percent Similarity Index (PSI, see Hurlbert, 1978, for review) to compare
18
diet composition between estuaries and surf zones using daily mean diet composition as the
19
sampling unit.
20
(5)
21
where Pxi = numerical percentage of preyi in surf zone and Pyi = numerical percentage of preyi in
22
estuary. In this analysis, a value of 0 and 100 signify no and complete similarity between
23
habitats, respectively. This type of analysis does not provide a cut-off value for significant
11
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
differences. Therefore, we also compared diet composition between the two estuaries and
2
between the two surf zones in order to establish a baseline for comparison between estuaries and
3
surf zones.
4
5
3. Results
6
3.1 Juvenile size, catch and stomach content analysis
7
Juveniles were collected during all collection days in estuaries but not in surf zones
8
(Table 2). Overall, catches were consistently lower in surf zones than in estuaries in both Coos
9
and Alsea habitats each year (Rank Sum test, W ≥ 15, n ≥ 3, p < 0.05, Table 4). Estuarine and
10
surf zone catches were positively correlated (r = 0.92, p < 0.01, Fig. 4). Juvenile size at capture
11
ranged from 69 to 145 mm FL (average 103 ± 15 mm SD) and did not differ between habitats
12
(F1,11 = 2.45, p > 0.05) or years (F1,11 = 0.11, p > 0.05), nor was there an interaction observed
13
(F1,11 = 3.23, p > 0.05) at Coos sites (Fig. 3), or between habitats at Alsea sites during 2008 (F1,8
14
= 4.35, p > 0.05).
15
In estuaries, juveniles fed on 49 taxa, the most abundant of which was a gammarid
16
amphipod, Corophium spp. (60% of total prey items, Table A.2). The main prey groups were
17
amphipods (70% of taxa), crustacean zoea and megalopae (15%), cumaceans (5.3%) and
18
dipteran insects (3.3%). Surf zone juveniles fed on 57 taxa, the most abundant of which was a
19
gammarid amphipod, Jassa spp. (42% of total prey items). The main prey groups were
20
amphipods (70% of taxa), dipteran insects (14%), mysids (6%), crab megalopae (5%), isopods
21
(1%), and larval and juvenile fish (1%). Diet compositions were most similar between the two
22
estuaries (mean PSI = 60.27%) and then between the two surf zones (PSI = 31.12%) (Table 5).
23
Compositions were most dissimilar between estuarine and surf zone sites (mean PSI = 11.78%).
12
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
Similarities between estuaries were mostly due to the high abundance of Corophium spp. and
2
Porcellanid zoea in juvenile stomachs, while in surf zones similarities were due to Jassa spp.
3
(Fig. 5).
4
Overall, stomach fullness of juveniles varied from 0.02 to 11.88% of body weight.
5
Juvenile stomach fullness was significantly higher during 2008 than 2010 (3.6 ± 2.1 vs. 1.6 ± 1.3
6
% of body weight, respectively, F1,12 = 5.76, p < 0.05), but there was no significant difference
7
between habitats (F1,15 = 0.71, p > 0.05) or an interaction between habitat and year (F1,12 = 4.28,
8
p > 0.05) at Coos sites (Table 4), or between habitats at Alsea sites in 2008 (F1,8 = 0.68, p >
9
0.05).
10
11
3.2 Otolith analysis: size at marine entry, timing of entrance and growth in marine waters
Overall, juveniles were between 48 and 112 mm FL at marine entry (average: Coos sites
12
= 75 ± 14 mm, Alsea sites = 77 ± 12 mm). At Coos sites, juveniles were significantly longer at
13
marine entry during 2010 when compared to 2008 (F1,12 = 61.65, p < 0.0001, Fig. 6) but there
14
was no significant difference between habitats (F1,12 = 0.95, p > 0.05) nor was there an
15
interaction between habitats and years (F1,12 = 1.03, p > 0.05). At Alsea sites, size at marine
16
entry did not differ between habitats during 2008 (F1, 8 = 0.33, p > 0.05). Overall, juveniles had
17
been present in marine waters for an average of 23 ± 4 days (1 – 53 days, Fig. 7), and
18
continuously migrated to marine waters from May 14 to August 10. Across all years, average
19
values of marine entry were May 31 ± 9 days for estuarine and June 14 ± 15 days for surf zone
20
fish. The majority of juveniles emigrated by early June (>50% of fish). When comparing day of
21
marine entry, we observed a significant interaction between habitat and year at Coos sites (F1,11 =
22
10.05, p < 0.01, Table 4). Mean day of marine entry was earlier for Coos Bay than Coos Surf
23
juveniles during 2008 (post-hoc, p < 0.05) but not during 2010 (p > 0.05). At Alsea sites, day of
13
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
marine entry for estuarine juveniles was also earlier than surf zone fish during 2008 (F1,8 = 5.61,
2
p = 0.05).
3
Overall, juvenile growth rates ranged from 0.28 to 0.53 mm per day (average 0.4 ± 0.1
4
SD mm day-1, Table 4). At Coos sites, growth rates averaged 0.43 ± 0.01 mm day-1 and were not
5
significantly different between habitats (F1,12 = 0.20, p > 0.05) or years (F1,12 = 4.38, p > 0.05)
6
and there was no interaction (F1,12 = 2.26, p > 0.05) (Table 4). At Alsea sites, growth rates
7
averaged 0.40 ± 0.01 mm day-1 and were not significantly different between estuary and surf
8
zone during 2008 (F1,7 < 5.59, p > 0.05). Slopes of otolith growth trajectories varied from 2.09 to
9
6.34 (Fig. 2). At Coos sites, slopes were significantly higher during 2010 when compared to
10
2008 (F1,12 = 9.69, p < 0.01) but were not significantly different between habitats (F1,12 = 0.04, p
11
> 0.05), and there was no interaction of the factors (F1,12 = 1.61, p > 0.05). At Alsea habitats,
12
slopes did not differ between estuarine and surf zone juveniles in 2008 (F1,8 = 0.01, p > 0.05).
13
14
15
4. Discussion
The present study is the first to evaluate the role of sandy beach surf zones for Chinook
16
salmon juveniles by directly comparing migratory, foraging and growth characteristics of
17
juveniles collected in estuaries, a well-defined nursery habitat, and surf zones (Reimers, 1973;
18
Simenstad et al., 1982; Bottom et al., 2005a). Our comparisons indicate that cohorts of juvenile
19
Chinook salmon are spatially-split, with individuals concurrently inhabiting estuaries and surf
20
zones during the summer potentially due to high juvenile densities in estuaries. Our study also
21
supports the concept that surf zones serve as alternative nursery habitat because subyearling
22
Chinook salmon that were collected in surf zones and estuaries consumed similarly diverse prey,
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
and displayed no differences in their stomach fullness or growth rates. Using a diversity of
2
habitats may spread the risk of mortality among individuals that live in environments that
3
experience highly variable physical conditions and where competition is high (Robinson and
4
Wilson, 1994; Skúlason and Smith, 1995). In coastal environments of western North America,
5
summer habitat conditions are influenced by oceanic processes that can vary dramatically
6
spatially and temporally (Hickey and Banas, 2003; Schwing et al., 2010). Besides the large
7
numbers of Chinook salmon of natural and hatchery-origin that use nearshore habitats, these
8
environments are also inhabited throughout the year by many larval and juvenile fish (e.g.
9
herring, other salmon species, northern anchovy, rock fish) (Myers, 1980; Healey, 1991; Auth et
10
al., 2011; Dauble et al., 2012). Chinook salmon may therefore be spreading the risk of mortality
11
by splitting the cohort and using estuaries and surf zones where they can forage and grow at
12
similar rates.
13
Our highly variable surf zone catches strongly suggest that surf zone use varies among
14
years. Reimers (1973) hypothesized that juveniles moved to surf zones due to increasing
15
abundance of conspecifics and decreasing prey availability throughout the summer in the
16
estuary. In our sites, there was a positive relationship between estuarine and surf zone catches
17
providing some support for Reimers’ (1973) hypothesis. We also observed that surf zone
18
juveniles entered marine waters at a later time than estuarine juveniles in two of three
19
comparisons. Therefore, during summers, increasing juvenile densities may decrease prey
20
resources, leading some later arriving juvenile Chinook salmon to move to surf zones, thus
21
spatially splitting the cohort. Similar patterns of multiple habitat use have been documented in
22
other fish species where competition for prey or space leads later arriving, slower growing or less
23
competitive individuals to move to an alternative habitat during an early life stage (Metcalfe and
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
Thorpe, 1992; Post et al., 1997; Kraus and Secor, 2004b). Similarly to our study, the mechanism
2
leading to cohort splitting in these previous studies also appears to be density dependence
3
(Skúlason and Smith, 1995).
4
Surf zones may expand the available rearing habitat for juvenile Chinook salmon during
5
a period of high mortality (Pearcy, 1992). Alternatively, if juveniles that use surf zones do not
6
survive the summer, surf zones may serve as a sink (Pulliam, 1988). Reimers (1973) followed a
7
cohort of Chinook salmon to adulthood and found that some juveniles that had moved to surf
8
zones during the middle of the summer had survived to adulthood. We did not estimate juvenile
9
survival to the end of summer or adulthood. However, juvenile size, foraging and growth were
10
similar in estuaries and surf zones, which suggest juveniles in both habitats can attain similar
11
sizes by the end of the summer. Because survival to adulthood is often positively related to
12
juvenile size during early marine residence (Claiborne et al., 2011; Duffy and Beauchamp, 2011;
13
Tomaro et al., 2012), surf zone fish could have survived at rates similar to estuarine juveniles.
14
Consequently, not only do surf zones expand rearing habitat for juvenile Chinook salmon during
15
a critical period but may also allow an increase in the total number of juveniles that survive to
16
adulthood.
17
Subyearling Chinook salmon migrated to estuaries and surf zones continuously
18
throughout the late spring and summer. Similar results were observed in previous studies
19
conducted in other Oregon estuaries (Reimers, 1973; Bottom et al., 2005b; Volk et al., 2010).
20
Reimers (1973) proposed four subyearling life history types in the Sixes River. Juveniles from
21
Type 1 migrated downstream and into the ocean within a few weeks after emergence from the
22
gravel in winter. Chinook salmon from Types 2 and 3 moved to the estuary during the spring and
23
summer and then continued their migration to the ocean during the middle and late summer,
16
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
respectively. Type 4 subyearlings stayed in the main river until early summer and then quickly
2
migrated through the estuary and into the ocean. In more recent studies, researchers studying
3
timing of marine entrance found that subyearling Chinook salmon continuously migrate from
4
fresh to marine waters from spring to fall (Bottom et al., 2005b; Volk et al., 2010). We observed
5
similar migration patterns, with subyearling Chinook salmon from Coos and Alsea Bay
6
populations continuously migrating to marine waters during the spring and summer. Unlike in
7
estuaries, Chinook salmon are only present in surf zones in the summer (Marin Jarrin, 2012).
8
Juvenile densities in the estuary significantly decrease during the fall (Reimers, 1973; Fisher and
9
Pearcy, 1990; Bottom et al., 2005b). Therefore, it appears that no juveniles that migrate to
10
marine waters during the fall use surf zones, potentially due decreasing competition for resources
11
in the estuary.
12
There was only one exception to the migration patterns observed in estuarine and surf zone
13
fish: during 2010 at Coos sites, estuarine and surf zone juveniles entered marine waters at similar
14
times. In 2010, we began catching juveniles in surf zones on 20 June, which is an average of 10
15
days before we usually catch juveniles in surf zones (Marin Jarrin, 2012), although sampling
16
began on 1 June. This early marine entrance may have occurred because overall Coos juveniles
17
were significantly larger at release from hatcheries and at capture during 2010 than 2008 (6.9 vs.
18
6.1 g at release, respectively, http://www.rmpc.org/). Larger juveniles have been known to
19
migrate from fresh waters earlier than smaller fish (Cramer and Lichatowich, 1978; Dawley et
20
al., 1986). Therefore, many juveniles may have moved to estuarine waters earlier in 2010, thus
21
prompting earlier migration to the surf zone.
22
23
Estuarine and surf zone juvenile Chinook salmon consumed diverse diets that were
comprised of different prey items. High prey diversity has also been reported in previous studies
17
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
conducted in other surf zones, various types of estuaries, and deeper exposed and protected
2
oceanic waters (reviewed in Healey, 1991; Quinn, 2004; Marin Jarrin, 2012) and is hypothesized
3
to be due to the opportunistic feeding nature of juvenile Chinook salmon (Healey, 1991;
4
Schabetsberger et al., 2003). High prey diversity is also hypothesized to provide resiliency to a
5
predator population since the loss of a prey item would not affect total consumption as strongly
6
as it would for more specialist foragers (Wootton, 1998). Differences in prey taxa between
7
estuarine and surf zone juveniles may be due to the dissimilarities in wave action, sediment grain
8
sizes and physical structure between estuaries and surf zones (Short and Wright, 1983; Hickey
9
and Banas, 2003; McLachlan and Brown, 2006) that support different prey field assemblages.
10
The influence of habitat characteristics on Chinook salmon diet is best exemplified by
11
Corophium spp. and Jassa spp., the main juvenile prey items in estuaries and surf zones,
12
respectively, in the present study. The genus Corophium is composed of tube building gammarid
13
amphipods in soft sediment (i.e. mostly mud and silt) that are very abundant on mud flats located
14
in the lower portion of many estuaries of western North America (Wilson, 1983; Carlton, 2007).
15
The Jassa genus are also a group of tube building gammarid amphipods known to inhabit
16
shallow, hard substrate, intertidal to subtidal marine environments with fast moving water
17
(Carlton, 2007) and to feed on phytoplankton blooms (Chess, 1979). Off the coast of Northern
18
California, individuals from this genus were observed migrating onshore in spring and summer,
19
where they became highly abundant (Chess, 1979), and therefore potentially available to juvenile
20
Chinook salmon in sandy beaches (Marin Jarrin et al., 2009). Consequently, our study suggests
21
that surf zones provide Chinook salmon with a unique prey field that is as diverse as other
22
juvenile habitats.
18
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
In surf zones, subyearling Chinook salmon can feed and grow at rates comparable to
2
estuaries. Our juvenile stomach fullness indices and growth rates were similar in estuaries and
3
surf zones and within the ranges observed in other estuarine and deeper oceanic waters (≥ 1% of
4
body weight and 0.2 to >1 mm day-1, respectively) (Fisher and Pearcy, 1995; Schabetsberger et
5
al., 2003; Koehler et al., 2006; Baldwin et al., 2008; MacFarlane, 2010). The high diversity and
6
abundance of prey available to juvenile salmon in both habitats could account for these
7
similarities (Gray et al., 2002; Bieber, 2005; Marin Jarrin, 2007). During the summers of 2008-
8
2010, Coos and Alsea Surf presented higher wave height and lower water temperature than Coos
9
and Alsea Bay (10.32 ± 0.67 vs. 12.14 ± 1.04 °C, respectively, Marin Jarrin, 2012) that could
10
affect juvenile growth rates. However, the differences between habitats in temperature and water
11
movement may have been offset by the higher energetic content of the surf zone prey when
12
compared to estuarine prey (4250 ± 429 vs. 3788 ± 468 Joules per gram, respectively, Marin
13
Jarrin, 2012). Future studies looking at growth during juvenile Chinook salmon emigration could
14
include analysis of growth hormones, which are strongly related to recent specific growth rates
15
in salmonids (reviewed in Picha et al., 2008). Growth hormone analysis could also further clarify
16
the factors influencing cohort-splitting since hormone levels can vary due to recent stressful
17
situations such as low prey availability.
18
Sandy beach ecosystems are threatened by a variety of anthropogenic stressors throughout
19
the world (Defeo et al., 2009). These pressures vary spatially and temporally, from localized short-
20
term effects (e.g. trampling due to recreational activities) to global-long term effects (e.g. sea-level
21
rise). Climate change is predicted to significantly impact aquatic habitats, including sandy beach surf
22
zones, throughout the world in the near future. There are predictions for an increase in fresh water
23
temperature (1.5 to 5°C), sea surface temperature (1.2°C), annual precipitation (1 to 2%), sea surface
24
height (0.2 to 1.3 m) and wave height (0.75 m) in western North America in the next 50 years
19
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
(Mantua et al., 2009; Mote and Salathé, 2009; Ruggiero et al., 2010). Some researchers predict local
2
upwelling winds will either not change (Mote and Mantua, 2002; Mote and Salathé, 2009) or
3
increase in strength and variability in the near future (Di Lorenzo et al., 2005; Bakun et al., 2010;
4
García-Reyes and Largier, 2010). All of these changes could impact conditions in surf zones and
5
estuaries, thus changing the role of both habitats for juvenile Chinook salmon. In western North
6
America, estuaries are considered to be particularly vulnerable to climate because of impacts they
7
have already sustained from human development and introduction of exotic species, and an inability
8
for these habitats to move inland due to the steep coastal topography (Emmett et al., 2000; Galbraith
9
et al., 2002). Habitat conditions in sandy beach surf zones may also be altered. For example,
10
increasing wave and sea-surface height may change sediment movement and therefore beach
11
topography, which is known to influence the biological communities inhabiting sandy beach
12
ecosystems (Dexter, 1992; McLachlan and Dorvlo, 2005).
13
Our results suggest that during the summer as juvenile Chinook salmon densities in the
14
estuary increase, prey resources decrease, leading some juveniles that arrive in marine waters
15
later in the season to move to adjacent surf zones, another shallow habitat with an abundant and
16
diverse prey field. This movement produces a spatially-split cohort, with juveniles concurrently
17
using estuaries and surf zones, thus expanding the total available rearing habitat. During these
18
periods, surf zones serve as alternative nursery habitats where juveniles experience similar
19
foraging and growth rates as those encountered in estuaries. Our study provides novel
20
information on surf zones, a poorly studied habitat, and estuaries, a known nursery habitat for
21
Chinook salmon, during a critical period. Given our extensive data collection and comparison
22
with a nursery habitat, our results provide a robust evaluation of the role of surf zones for the
23
early life history of Chinook salmon.
20
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
Acknowledgements
2
The authors would like to thank present and previous Miller lab members, and D. Bottom, B.
3
Emmett, T. Hurst, D. Noakes, B. Peterson and A. Shanks for comments on previous drafts.
4
Special thanks to B. Buckman, C. Deckard, G. Vonderohe and D. Wilson from Oregon
5
Department of Fish and Wildlife for providing estuarine samples and suggestions. We are
6
indebted to the many volunteers, field and lab technicians, and Lincoln County Community
7
Services Consortium Youth Work Crew who helped with sampling. Research was supported by
8
Mamie Markham Research Award, Lylian Brucefield Reynolds Scholarship, Neil Armantrount
9
Graduate Scholarship, Henry Mastin Graduate Fund, Bill Wick Marine Fisheries Award and an
10
Oregon Conservation Strategy Grant. Map made by M. Schuiteman.
11
References
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
Allen, L.G., Pondella II, D.J., 2006. Surf zone, coastal pelagic zone and harbors. In: Allen, L.G.,
Pondella II, D.J., Horn, M.H. (Eds.), The Ecology of Marine Fishes, California and
Adjacent Waters. University of California Press, Berkeley and Los Angeles, California,
pp. 149–166.
Auth, T.D., Brodeur, R.D., Soulen, H.L., Ciannelli, L., Peterson, W.T. 2011. The response of fish
larvae to decadal changes in environmental forcing factors off the Oregon coast. Fisheries
Oceanography 20, 314–328.
Bakun, A., Field, D.B., Redondo-Rodriguez, A., Weeks, S.J. 2010. Greenhouse gas, upwellingfavorable winds, and the future of coastal ocean upwelling ecosystems. Global Change
Biology 16, 1213–1228. doi: 10.1111/j.1365-2486.2009.02094.x.
Baldwin, R.E., Miller, T.W., Brodeur, R.D., Jacobson, K.C., 2008. Expanding the foraging
history of juvenile Pacific salmon: combining stomach-content and macroparasite
community analyses for studying marine diets. Journal of Fish Biology, 72:1268–1294.
Beck, M.W., Heck Jr., K.L., Able, K.W., Childers, D.L., Eggleston, D.B., Gillanders, B.M.,
Halpern, B., Hays, C.G., Hoshino, K., Minello, T.J., Orth, R.J., Sheridan, P.F., Weinstein,
M.P., 2001. The identification, conservation, and management of estuarine and marine
nurseries for fish and invertebrates. BioScience 51, 633-641.
Bertness, M.D., Gaines, S.D., Hay, M.E., 2001. Marine Community Ecology. Sinauer
Associates, Inc. Sunderland, MA, 550 pp.
Bieber ,A., 2005. Variability in juvenile Chinook foraging and growth potential in Oregon
estuaries: Implications for habitat restoration. M.Sc. Thesis, University of Washington,
WA, 111 pp.
21
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
Bottom, D.L., Simenstad, C.A., Burke, J., Baptista, A.M., Jay, D.A., Jones, K.K., Casillas, E.,
Schiewe, M.H., 2005a. Salmon at river’s end: the role of the estuary in the decline and
recovery of Columbia River salmon. National Oceanic and Atmospheric Administration,
Northwest Fisheries Science Center Technological Memorandum, NMFS-NWFSC-68,
Seattle, WA, 246 pp.
Bottom, D.L., Jones, K.K., Cornwell, T.J., Gray, A., Simenstad, C.A., 2005b. Patterns of
Chinook salmon migration and residency in the Salmon River estuary (Oregon).
Estuarine, Coastal and Shelf Science 64, 79–93.
Callihan, J.L., Takata, L.T., Woodland, R.J., Secor, D.H., 2008. Cohort splitting in bluefish,
Pomatomus saltatrix, in the US mid-Atlantic Bight. Fisheries Oceanography 17, 191–
205. doi: 10.1111/j.1365-2419.2008.00468.x.
Carlton, J.T., 2007. The Light and Smith Manual, Intertidal Invertebrates from Central California
to Oregon. 4th Edition. University of California Press, Berkeley, CA, 1019 pp.
Chess, J.R., 1979. High densities of benthic amphipods related to upwelling on the northern
California Current. Coastal Oceanography and Climatological News 1(3), 31.
Chittenden, C.M., Biagi, C.A., Davidsen, J.G., Davidsen, A.G., Kondo, H., McKnight, A.,
Pedersen, O.-P., Raven, P.A., Rikardsen, A.H., Shrimpton, J.M., Zuehlke, B., McKinley,
R.S., Devlin, R.H., 2010. Genetic versus rearing-environment effects on phenotype:
hatchery and natural rearing effects on hatchery- and wild-born coho salmon. Plos One 5,
1–11. doi: 10.1371/journal.pone.0012261.
Claiborne, A.M., Fisher, J.P., Hayes, S.A., Emmett, R.L., 2011. Size at release, size-selective
mortality, and age of maturity of Willamette River hatchery yearling Chinook salmon.
Transactions of the American Fisheries Society 140, 1135–1144. doi:
10.1080/00028487.2011.607050.
Cortright, E, Weber, J, Bailey, R., 1987. The Oregon estuary plan book. Oregon Department of
Land Conservation and Development. Available at http://www.inforain.org/
oregonestuary/.
Cramer, S.P., Lichatowich, J.A., 1978. Factors influencing the rate of downstream migration of
juvenile Chinook salmon in the Rogue River. Proceedings of the 1977 Northeast Pacific
chinook and coho salmon workshop. Fisheries Marine Services (Canada) Technical
Report, pp. 43–48.
Dadswell, M.J., Klauda, R.J., Moffitt, C.M., Saunders, R.L., Rulifson, R.A., Cooper, J.E., 1987.
Common Strategies of Anadromous and Catadromous Fishes. American Fisheries Society
Symposium 1, 561 pp.
Dauble, A.D., Heppell, S.A., Johansson, M.L. 2012. Settlement patterns of young-of-the-year
rockfish among six Oregon estuaries experiencing different levels of human
development. Marine Ecology Progress Series 448, 143-154.
Dawley, E.M., Sims, C.W., Ledgerwood, R.D., Miller, D.R., Williams, J.G., 1981. A study to
define the migrational characteristics of Chinook and coho salmon in the Columbia River
estuary and associated marine waters. Coastal Zone and Estuarine Studies Division,
Northwest Fisheries Scientific Center, NMFS, Seattle WA, 341 pp.
Dawley, E.M., Ledgerwood, R.D., Blahm, T.H., Sims, C.W., Durkin, J.T., Kirn, R.A., Rankis,
A.E., Monan, G.E., Ossiander, F.J., 1986. Migrational characteristics, biological
observations and relative survival of juvenile salmondis entering the Columbia River
estuary, 1966-1983. Final Report, National Marine Fisheries Service, Northwest and
Alaska Fisheries Center, NOAA, Seattle, WA, 224 pp.
22
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Defeo, O., McLachlan, A., Schoeman, D.S., Schlacher, T.A., Dugan, J., Jones, A., Lastra, M.,
Scapini, F. 2009. Threats to sandy beach ecosystems: a review. Estuarine, Coastal and
Shelf Science 81, 1–12.
Dexter, D.M. 1992. Sandy beach community structure: The role of exposure and latitude. Journal
of Biogeography 19(1), 59–66.
Di Lorenzo, E., Miller, A.J., Schneider, N., McWilliams, J.C. 2005. The warming of the
California Current system: Dynamics and ecosystem implications. Journal of Physical
Oceanography 35, 336-362.
Duffy, E., Beauchamp, D.A., 2011. Rapid growth in the early marine period improves the marine
survival of Chinook salmon (Oncorhynchus tshawytscha) in Puget Sound, Washington.
Canadian Journal of the Fisheries and Aquatic Sciences 68, 232–240.
Emmett, R., Llanso, R., Newton, J., Thom, R., Hornberger, M., Morgan, C., Levings, C.,
Copping, A., Fishman, P., 2000. Geographic signatures of North American west coast
estuaries. Estuaries 23, 765–792.
Fisher, J.P., Pearcy, W.G., 1990. Distribution and residence times of juvenile Fall and Spring
Chinook salmon in Coos Bay, Oregon. Fisheries Bulletin 88, 51–58.
Fisher, J.P., Pearcy, W.G., 1995. Distribution, migration, and growth of juvenile Chinook
salmon, Oncorhynchus tshawytscha, off Oregon and Washington. Fisheries Bulletin 93,
274–289.
Fodrie, F.J., Levin, L.A., Lucas, A.J., 2009. Use of population fitness to evaluate the nursery
function of juvenile habitats. Marine Ecology Progress Series 385, 39–49. doi:
10.3354/meps08069.
Francis, R.C., 1990. Back-calculation of fish length: a critical review. Journal of Fish Biology
36, 883–902.
García-Reyes, M., Largier, J. 2010. Observations of incrased wind-driven coastal upwelling off
central California. Journal of Geophysical Research 115, C04011.
doi:10.1029/2009JC005576.
Gray, A., Simenstad, C.A., Bottom, D.L., Cornwell, T.J., 2002. Contrasting functional
performance of juvenile salmon habitat in recovering wetlands of the Salmon River
estuary, Oregon, U.S.A. Restoration Ecology 10, 514–526.
Healey, M.C., 1980. Utilization of the Nanaimo River estuary by juvenile Chinook salmon,
Oncorhynchus tshawytscha. Fisheries Bulletin 77, 653-668.
Healey, M.C., 1991. Life history of Chinook salmon (Oncorhynchus tshawytscha). In: Groot, C.,
Margolis, L. (Eds.), Pacific Salmon Life Histories, UBC Press, Vancouver, Canada, pp
311-395.
Hering, D.K., Bottom, D.L., Prentice, E.F., Jones, K.K., Fleming, I.A., 2010. Tidal movements
and residency of subyearling Chinook salmon (Oncorhynchus tshawytscha) in an Oregon
salt marsh channel. Canadian Journal of the Fisheries and Aquatic Sciences 67, 524–533.
Hickey, B.M., Banas, N.S., 2003. Oceanography of the U.S. Pacific Northwest coastal ocean and
estuaries with application to coastal ecology. Estuaries 26, 1010–1031.
Hilborn, R., Quinn, T.P., Schindler, D.E., Rogers, D.E., 2003. Biocomplexity and fisheries
sustainability. Proceedings of the National Academy of Science 100, 6564–6568.
Hurlbert, S.H., 1978. The measurement of niche overlap and some relatives. Ecology 59(1), 67–
77.
23
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
Katz, J., Moyle, P.B., Quiñones, R.M., Israel, J., Purdy, S., 2012. Impending extinction of
salmon, steelhead, and trout (Salmonidae) in California. Environmental Biology of
Fishes. doi: 10.1007/s10641-012-9974-8.
Kent, A., Ungerer, C., 2006. Analysis of light lithophile elements (Li, Be, B) by laser
ablation ICP-MS: comparison between magnetic sector and quadrupole ICP-MS.
American Mineralogist 91, 1401–1411.
Koehler, M.E., Fresh, K.L., Beauchamp, D.A., Cordell, J.R., Simenstad, C.A., Seiler, D.E., 2006.
Diet and bioenergetics of lake-rearing juvenile Chinook salmon in Lake Washington.
Transactions of the American Fisheries Society 135, 1580–1591. doi: 10.1577/T05-178.1.
Komar, P.D., Quinn, W., Creech, C., Rea, C.C., Lizarraga-Arciniega, J.R., 1976. Wave conditions
and beach erosion on the Oregon coast. The ORE BIN 38, 103–112.
Kraus, R.T., Secor, D.H., 2004a. Incorporation of strontium into otoliths of an estuarine fish.
Journal of the Experimental Marine Biology and Ecology 302, 85–106.
Kraus, R.T., Secor, D.H., 2004b. Dynamics of white perch Morone americana population
contingents in the Patuxent River estuary, Maryland, USA. Marine Ecology Progress
Series 247, 247–259.
MacFarlane, B., 2010. Energy dynamics and growth of Chinook salmon (Oncorhynchus
tshawytscha) from the Central Valley of California during the estuarine phase and first
ocean year. Canadian Journal of Fisheries and Aquatic Sciences 67, 1549–1565.
Mantua, N., Tohver, I., Hamlet, A. 2009. Impacts of climate change on key aspects of freshwater
salmon habitat in Washington State. Climatic Change 102(1-2), 187-223.
Marin Jarrin, J.R., 2007. The ecology of surf zone fauna of dissipative sandy beaches in southern
Oregon U.S.A. M.Sc. Thesis. Department of Biology, University of Oregon, Eugene, OR.
Available at https://scholarsbank.uoregon.edu/xmlui/handle/1794/5232, 144 pp.
Marin Jarrin, J.R., Shanks, A.L., Banks, M.A., 2009. Confirmation of the presence and use of
sandy beach surf-zones by juvenile Chinook salmon. Environmental Biology of Fishes
85, 119–125. doi: 10.1007/s10641-009-9470-y.
Marin Jarrin, J.R., Shanks, A.L., 2011. Spatio-temporal dynamics of the surf-zone faunal
assemblages at a Southern Oregon sandy beach. Marine Ecology 32, 232–242. doi:
10.1111/j.1439-0485.2010.00414.x.
Marin Jarrin, J.R., 2012. Sandy beach surf zones: What is their role in the early life history of
juvenile Chinook salmon (Oncorhynchus tshawytscha)? Ph.D Dissertation. Department
of Fisheries and Wildlife, Oregon State University, Corvallis, OR. Available at
http://hdl.handle.net/1957/35597, 182 pp.
McDowall, R.M., 1988. Diadromy in fishes: Migrations between Freshwater and Marine
Environments. Timber Press, Portland, OR, 250 pp.
McLachlan, A., 1980. The definition of sandy beaches in relation to exposure: A simple rating
system. South African Journal of Science 76, 137–138.
McLachlan, A., Brown, A.C., 2006. The Ecology of Sandy Shores. 2nd edition. Academic Press.
Burlington, MA, 273 pp.
McLachlan, A., Dorvlo, A. 2005. Global patterns in sandy beach macrobenthic communities.
Journal of Coastal Research 21(4), 674–687.
Metcalfe, N.B., Thorpe, J.E., 1992. Early predictors of life-history events: the link between first
feeding date, dominance and seaward migration in Atlantic salmon, Salmo salar L.
Journal of Fish Biology 41, 93–99.
24
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
Miller, J.A., 2007. Scales of variation in otolith elemental chemistry of juvenile Staghorn Sculpin
(Leptocottus armatus) in three Pacific Northwest estuaries. Marine Biology 151, 483–
494.
Miller, J.A., 2011. Effects of water temperature and barium concentration on otolith composition
along a salinity gradient: Implications for migratory reconstructions. Journal of
Experimental Marine Biology and Ecology 405, 42–52.
Miller, J.A., Butler, V.L., Simenstad, C.A., Backus, D.H., Kent, A.J.R., 2011. Life history
variation in upper Columbia River Chinook salmon (Oncorhynchus tshawytscha): a
comparison using modern and ~500-year-old archaeological otoliths. Canadian Journal of
Fisheries and Aquatic Sciences 68, 603–617.
Miller, J.A., Gray, A., Merz, J., 2010. Quantifying the contribution of juvenile migratory
phenotypes in a population of Chinook salmon, Oncorhynchus tshawytscha. Marine
Ecology Progress Series 408, 227–240.
Mote, P., Salathe, E. 2009. Future climate in the Pacific Northwest. Climatic Change 102(1-2),
29-50.
Mote, P.W., Mantua, N.J. 2002. Coastal upwelling in a warmer future. Geophysical Research
Letters 29, 2138. doi: 10.1029/2002GL016086.
Myers, K.W. 1980. An investigation of the utilization of four study areas in Yaquina Bay, Oregon
by hatchery and wild juvenile salmonids. M.Sc. Thesis Oregon State University,
Corvallis, Oregon, 250pp.
Nicholas, J.W., Hankin, D.G., 1988. Chinook salmon populations in Oregon coastal river basins:
description of life histories and assessment of recent trends in run strength. Oregon
Department of Fish and Wildlife, Research and Development Section, Information
Reports Number 88-1, OR, 382 pp.
Oregon Department of Fish and Wildlife. 2005. 2005 Oregon native fish status report: volume ii
assessment methods & population results. Oregon Department of Fish & Wildlife - Fish
Division. 571 pp. Available at: http://www.dfw.state.or.us/fish/onfsr/report.asp.
Pearcy, W.G., 1992. Ocean Ecology of North Pacific Salmonids. Washington Sea Grant
Program. University of Washington, Seattle, WA, 190 pp.
Post, J.R., Johannes, M.R.S., McQueen, D.J., 1997. Evidence of density-dependent cohort
splitting in age-0 yellow perch (Perca flavescens): potential behavioural mechanisms and
population-level consequences. Canadian Journal of Fisheries and Aquatic Sciences 54,
867-875.
Pulliam, H.R., 1988. Sources, sinks, and population regulation. The American Naturalist 132,
652–661.
Quinn, T.P., 2004. The Behavior and Ecology of Pacific Salmon and Trout. University Press,
Seattle, WA, 378 pp.
Reimers, P., 1973. The length of residence of juvenile fall Chinook salmon in Sixes River,
Oregon. Oregon Fish Commission Research Report 4, 1-40.
Rich, W.H., 1920. Early history and seaward migration of Chinook salmon in the Columbia and
Sacramento rivers. Bulletin of the Bureau of Fisheries 37, 1-73.
Robinson, B.W., Wilson, D.S., 1994. Release and displacement in fishes: A neglected literature.
The American Naturalist 144, 596–627.
Ruggiero, P., Komar, P.D., Allan, J.C. 2010. Increasing wave heights and extreme value
projections: The wave climate of the U.S. Pacific Northwest. Coastal Engineering 57,
539–552.
25
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
Schabetsberger, R., Morgan, C.A., Brodeur, R.D., Potts, C.L., Peterson, W.T., Emmett, R.L.,
2003. Prey selectivity and diel feeding chronology of juvenile Chinook (Oncorhynchus
tshawytscha) and coho (O. kisutch) salmon in the Columbia River plume. Fisheries
Oceanogr 12, 523–540.
Schindler, D.E., Hilborn, R., Chasco, B., Boatright, C.P., Quinn, T.P., Rogers, L.A., Webster,
M.S., 2010. Population diversity and the portfolio effect in an exploited species. Nature
465, 609–614.
Schwing, F.B., Mendelssohn, R., Bograd, S.J., Overland, J.E., Wang, M., Ito, S., 2010. Climate
change, teleconnection patterns, and regional processes forcing marine populations in the
Pacific. Journal of Marine Systems 79, 245–257.
Secor, D.H., 2007. The year-class phenomenon and the storage effect in marine fishes. Journal of
Sea Research 57, 91–103.
Short, A.D., Wright, L.D., 1983. Physical variability of sandy beaches. In: McLachlan, A.,
Erasmus, T. (Eds.), Sandy Beaches as Ecosystems. W. Junk, The Hague, pp. 133-144.
Simenstad, C.A., Fresh, K.L., Salo, E.O., 1982. The role of Puget Sound and Washington coastal
estuaries in the life history of Pacific salmon: an unappreciated function. In: Kennedy,
V.S. (Eds.), Estuarine Comparisons. Academic Press, New York, NY, pp 343–362.
Skúlason, S., Smith, T.B., 1995. Resource polymorphisms in vertebrates. TREE 10, 366–370.
Sokal, R.R., Rohlf, F.J., 1981. Biometry: The Principles and Practice of Statistics in Biological
Research. W. H. Freeman. San Francisco, CA, 880 pp.
Tomaro, L.M., Teel, D.J., Peterson, W.T., Miller, J.A., 2012. When is bigger better? Early marine
residence of middle and upper Columbia River spring Chinook salmon. Marine Ecology
Progress Series 452, 237–252. doi: 10.3354/meps09620.
Vivier, L., Cyrus, D.P., 2009. Alternative nursery habitat for estuarine associated marine fish
during prolonged closure of the St Lucia estuary, South Africa Estuarine, Coastal and
Shelf Science 85, 118–125.
Volk, E.C., Bottom, D.L., Jones, K.K., Simenstad, C.A., 2010. Reconstructing juvenile Chinook
salmon life history in the Salmon River estuary, Oregon, using otolith microchemistry
and microstructure. Transactions of the American Fisheries Society 139, 535–549.
Waples, R.S., Beechie, T., Pess, G.R., 2009. Evolutionary history, habitat disturbance regimes,
and anthropogenic changes: What do these mean for resilience of Pacific salmon
populations. Ecology and Society 14, 3.
Weitkamp, L.A., 2008. Buoyancy regulation by hatchery and wild coho salmon during the
transition from freshwater to marine environments. Transactions of the American
Fisheries Society 137, 860–868.
Wilson, S.L., 1983. The life history of Corophium salmonis in the Columbia River estuary. M.Sc.
Thesis, Oregon State University, Corvallis, OR., 73 pp.
Wootton, R., 1998., Ecology of Teleost Fishes. Kluwer Academic Publishers, Boston, MA, 392
pp.
Zhang, Z., Beamish, R.J., 2000. Use of otolith microstructure to study life history of juvenile
Chinook salmon in the Strait of Georgia in 1995 and 1996. Fisheries Research 46, 239–
250.
Zimmerman, C.E., 2005. Relationship of otolith strontium to calcium ratios and salinity:
experimental validation for juvenile salmonids. Canadian Journal of Fisheries and
Aquatic Sciences 62, 88−97.
26
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
Tables Legends:
Table 1: Estuary size, type and classification based on human development, and number of
hatchery juveniles released in watershed (±SD). - = no juveniles of hatchery-origin released.
Table 2: Location, year, number of sampling days (Sample), number of days juveniles were
collected (Collect), and total number of juveniles euthanized for analysis (n) in two estuaries
(Coos and Alsea Bay) and two surf zones (Coos and Alsea Surf) during three years. *Includes
collections from beach North of Alsea Bay mouth.
Table 3: Parameters used in proportional back-calculation equations of juvenile size in two surf
zones (Coos and Alsea Surf) and two estuaries (Coos and Alsea Bay) during three years.
Parameters were estimated using simple linear regressions of fork length on otolith width.
Table 4: Annual mean ± SD (a) catch (ind. 100 m-2), (b) stomach fullness (% of body weight)
and (c) growth rate (mm day-1) of juveniles collected in two estuaries (Coos and Alsea Bay) and
two surf zones (Coos and Alsea Surf) during three years. Number of days included in analyses is
included in parentheses. Number of fish per day ranged from 2 to 15. * = analysis not possible
due to low number of juveniles collected.
Table 5. Percent Similarity Index (PSI) of juvenile Chinook salmon diet in two surf zones (Coos
Surf and Alsea Surf) and two estuaries (Coos Bay and Alsea Bay) during 2008-2010. “*”
indicates that no comparisons were made due to low sample sizes.
Table A1. Ratios of water Sr:Ca and Ba:Ca measured at different locations throughout Coos
watershed. Number of samples (n) collected at each site are also mentioned. Samples were
analyzed as detailed in Miller et al. (2010).
Table A.2. Prey taxa observed in stomachs of juvenile Chinook salmon collected in two estuaries
and two surf zones on the Oregon coast. Life history stage (Stage), group, number of sites at each
habitat in which the taxa was observed (Sites) and percent frequency (Frequency) are also
presented.
27
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
Figure Legends:
Fig. 1: Map with location of two estuaries (Coos Bay and Alsea Bay) and two surf zones (Coos
and Alsea Surf) where juvenile Chinook salmon were collected during 2008 – 2010.
Fig. 2. Individual otolith growth trajectories for subyearling Chinook salmon collected in Coos
and Alsea estuaries and surf zones during 2008 and 2010. Dashed line = surf zone data,
continuous line = estuarine data.
Fig. 3: Relationship between fork length at capture (mm) and day of collection in Coos and
Alsea estuaries (closed circles) and surf zones (open circles) during 2008 - 2010. Grey areas
represent period used to statistically compare estuarine and surf zone juvenile size at capture.
When necessary, surf zone data were offset to allow better visual inspection.
Fig. 4. Relationship between median estuarine and surf zone catches (percent of total catch site-1,
r = 0.92, p < 0.01). Data were square root transformed. Open circles = Coos data, closed circles =
Alsea data.
Fig. 5. Numerical percentage of juvenile Chinook salmon main prey items (group) collected in
two estuaries (Coos Bay and Alsea Bay) and two surf zones (Coos Surf and Alsea Surf) during
2008 (a), 2009 (b) and 2010 (c). Number of days and number of juveniles (in parenthesis)
included in analyses are presented above each bar. Low sample sizes did not allow analysis of
diet composition at Alsea Surf during 2010.
Fig. 6: Proportional frequency distributions for size at marine entry (cm) of juveniles collected in
estuaries (black bars) and surf zone (gray bars). Samples were collected at Coos and Alsea Bay
and Surf during 2008-2010. Number of days and fish included in analysis: 2 – 8 days per year at
each habitat and 2 – 28 fish per each day.
Fig. 7. Day of entrance into marine waters and capture for juvenile Chinook salmon collected at
Coos and Alsea estuaries and surf zones during 2008-2010. Each horizontal line represents one
juvenile. Line starts when fish entered marine water and length signifies residence in marine
water until juvenile was collected. Juveniles with no evidence of marine residence on their
otoliths are reported as entering marine waters on the same day they were collected. Continuous
line = individual collected in estuary, dashed line = individual collected in surf zone.
28
Table(s)
Click here to download Table(s): Table 1.xlsx
Characteristics
1
Size (km2)
Coos Bay
Alsea Bay
54
10
2
Type
3
Classification
4
Hatchery production
1
Oregon Coastal Atlas web-page: www.coastalatlas.net/
2
Emmett et al. 2000,
3
Cortright et al. 1987
4
Regional Mark Processing Center web-page: www.rmpc.org
Drowned river mouth
Draft Developmental
Conservation
(jetty and channels) (minor development)
2,006,043 ± 460,675
-
Table 2
Click here to download Table(s): Table 2.xlsx
Location
Coos Bay
Coos Surf
Alsea Bay
Alsea Surf
Year
2008
2009
2010
2008
2009
2010
2008
2009
2010
2008*
2009
2010
Sample
5
6
6
6
6
10
6
7
6
12
6
10
Collect
5
6
6
2
3
8
6
7
6
7
2
2
n
31
34
45
50
10
160
97
82
48
33
5
2
Table 3
Click here to download Table(s): Table 3.xlsx
Parameters
Location/Year
Coos 2008
Alsea 2008
Coos 2009
Alsea 2009
Coos 2010
Alsea 2010
a
1.008 (± 0.137 SE)
0.875 (± 0.093 SE)
0.832 (± 0.155SE)
0.988 (± 0.100 SE)
0.992 (± 0.088 SE)
0.692 (± 0.109 SE)
-2.277
-1.787
-1.701
-2.159
-2.191
-1.193
b
(± 0.439 SE)
(± 0.297 SE)
(± 0.496 SE)
(± 0.321 SE)
(± 0.285 SE)
(± 0.350 SE)
r2
0.64
0.63
0.51
0.75
0.65
0.63
n
35
54
33
35
28
72
Table 4
Click here to download Table(s): Table 4.xlsx
Coos Bay
a)
2008
2009
2010
b)
2008
2009
2010
c)
2008
2009
2010
Coos Surf
Alsea Bay
Alsea Surf
-2
Mean ± SD catch (ind. 100 m )
14.9 ± 19.2
3.2 ± 5.8
49.2 ± 24.9
0.09 ± 0.14
10.6 ± 10.0
0.3 ± 0.4
61.9 ± 24.9
0.14 ± 0.56
31.5 ± 24.9
2.8 ± 2.5
37.6 ± 23.7
0.06 ± 0.38
Mean ± SD stomach fullness (% of body weight)
2.0 ± 1.0 (3)
5.1 ± 3.1 (2)
2.0 ± 1.9 (6)
1.5 ± 0.7 (4)
2.3 ± 0.8 (4)
1.8 ± 0.8 (3)
1.9 ± 1.2 (6)
1.8 ± 0.6 (2)
1.8 ± 1.6 (5)
1.3 ± 1.0 (6)
1.3 ± 1.2 (3)
*
-1
Mean ± SD growth rates (mm day )
0.42 ± 0.09 (3)
0.48 ± 0.09 (2)
0.40 ± 0.09 (5)
0.39 ± 0.09 (4)
0.38 ± 0.12 (4)
0.29 ± 0.04 (3)
0.51 ± 0.09 (6)
0.36 ± 0.00 (2)
0.53 ± 0.13 (5)
0.49 ± 0.13 (6)
0.34 ± 0.06 (3)
*
Table 5
Click here to download Table(s): Table 5.xlsx
Comparison
Coos Bay vs. Coos Surf
Alsea Bay vs. Alsea Surf
Coos Surf vs. Alsea Surf
Coos Surf vs. Alsea Bay
Alsea Surf vs. Coos Bay
Coos Bay vs. Alsea Bay
2008
5.16
14.89
31.12
12.66
9.08
74.90
2009
*
*
*
*
*
51.83
2010
11.39
*
*
17.52
*
54.07
Figure(s)
Click here to download high resolution image
Figure 2
Click here to download high resolution image
Figure 3
Click here to download high resolution image
Figure 4
Click here to download high resolution image
Figure 5
Click here to download high resolution image
Figure 6
Click here to download high resolution image
Figure 7
Click here to download high resolution image
Appendix Table 1
Click here to download Supplementary material for online publication only: Table A.1.xlsx
Appendix Table 2
Click here to download Supplementary material for online publication only: Table A.2.xlsx