Coho salmon (Oncorhynchus kisutch) ocean migration patterns: insight from marine coded-wire tag recoveries

2002 ◽  
Vol 59 (7) ◽  
pp. 1100-1115 ◽  
Author(s):  
Laurie Weitkamp ◽  
Kathleen Neely
Keyword(s):  
Geographic Variation ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Principal Component ◽  
Distribution Patterns ◽  
Geographic Region ◽  
Small Scale ◽  
Adult Size ◽  
Wild Populations ◽  
Specific Distribution

We investigated geographic variation in the ocean migration of coho salmon (Oncorhynchus kisutch) by examining recovery locations of 1.77 million coded-wire tagged fish from 90 hatcheries and 36 wild populations along the west coast of North America. Principal component, cluster, and similarity analyses were used to reveal both large- and small-scale variation in marine recovery patterns. We identified 12 distinct ocean distribution patterns, each associated with a particular geographic region. Despite these distinct patterns, however, fish from a given population were widely dispersed in the coastal ocean. Recovery patterns for tagged wild populations were consistent with those of hatchery populations from the same region, suggesting that marine distributions based on hatchery populations are reasonable proxies for distributions of wild populations. These region-specific distribution patterns suggest unappreciated life history diversity for coho salmon in the marine environment. When combined with region-specific adult size variation, they suggest migratory differences earlier in the ocean residence period as well. These results provide a novel framework with which to view geographic variation in salmon ocean ecology, conservation, and management.

Morphological Differences between Hatchery and Wild Populations of Coho Salmon (Oncorhynchus kisutch): Environmental versus Genetic Origin

1991 ◽  
Vol 48 (9) ◽  
pp. 1783-1791 ◽  
Author(s):  
D. P. Swain ◽  
B. E. Riddell ◽  
C. B. Murray
Keyword(s):  
Maternal Effects ◽  
Genetic Divergence ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Principal Component ◽  
Wild Populations ◽  
Genetic Origin ◽  
Environmental Component ◽  
Morphological Differences ◽  
Median Fins

Previous studies have demonstrated morphological differences between hatchery-reared coho salmon (Oncorhynchus kisutch) of hatchery origin and wild-reared coho of wild origin. We tested for a genetic component to this divergence by comparing coho from hatchery and wild populations both reared in the same hatchery environment and for an environmental component by comparing hatchery- and wild-reared coho both of wild origin. As in the previous studies, wild-reared fish from wild populations had greater head dimensions, larger median fins, and deeper bodies than did hatchery-reared fish from hatchery populations. This difference, summarized by the first principal component (PC1) of the size-adjusted data, was related to rearing environment rather than to genetic differences between hatchery and wild populations. Genetic divergence (or maternal effects) did occur between hatchery and wild populations along PC2 and PC3, but this divergence was slight compared with the environmentally induced differences between the two types of fish along PC1.

Distribution Patterns of Escherichia coli O157:H7 in Ground Beef Produced by a Laboratory-Scale Grinder†

2002 ◽  
Vol 65 (12) ◽  
pp. 1894-1902 ◽  
Author(s):  
ROLANDO A. FLORES ◽  
MARK L. TAMPLIN
Keyword(s):  
Escherichia Coli ◽  
Ground Beef ◽  
Distribution Patterns ◽  
Small Scale ◽  
Escherichia Coli O157 ◽  
Inoculum Level ◽  
E Coli ◽  
Specific Distribution ◽  
Low Levels ◽  
G Prior

This study determined the distribution patterns of Escherichia coli O157:H7 in ground beef when a contaminated beef trim was introduced into a batch of uncontaminated beef trims prior to grinding in a small-scale laboratory grinder. A beef trim (15.3 ± 2 g) was inoculated with a rifampicin-resistant strain of E. coli O157:H7 (E. coli O157:H7rif) and introduced into a stream of noncontaminated beef (322 ± 33 g) prior to grinding. Seven inoculum levels (6, 5, and 4 total log CFU [high]; and 3, 2, 1, and 0 total log CFU [low]) were studied in triplicate. E. coli O157:H7rif was not detected in 3.1 to 43% of the ground beef inoculated with the high levels or in 3.4 to 96.9% of the ground beef inoculated with the low levels. For all inoculum levels studied, the five ground beef fractions (each 7.8 ± 0.6 g) with the highest pathogen levels accounted for 59 to 100% of the total pathogens detected. For all inoculum levels, there was a linear relationship between the quantity of ground beef containing E. coli O157:H7rif and the inoculum level. The quantity of E. coli O157:H7rif in the beef remaining in the grinder was proportional to the inoculum level and was related to the location in the grinder. Different components of the grinder accumulated E. coli O157:H7rif in different quantities, with the most significant accumulation being in the nut (collar) that attaches the die to the blade. This study determined specific distribution patterns of E. coli O157:H7rif after the grinding of a contaminated beef trim along with uncontaminated trims, and the results indicate that the grinding operation should be regarded as a means of distribution of microbial contamination in risk analyses of ground beef operations.

Social interactions of coho salmon (Oncorhynchus kisutch) smolts in seawater

1985 ◽  
Vol 63 (10) ◽  
pp. 2401-2407 ◽  
Author(s):  
Cynthia A. Paszkowski ◽  
Bori L. Olla
Keyword(s):  
Social Behavior ◽  
Social Interactions ◽  
Social System ◽  
Agonistic Behavior ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Distribution Patterns ◽  
Oregon Coast ◽  
Fish Hatchery ◽  
Free Ranging

The behavior of coho salmon (Oncorhynchus kisutch) smolts was examined under laboratory conditions to determine if the hierarchical–territorial social system characteristic of this species in freshwater persisted in seawater. When held in groups of two to eight fish, hatchery-reared, accelerated underyearling smolts formed hierarchies controlled by a single dominant who was responsible for most of the observed movement, chases, and feeding. Agonistic behavior also occurred within pairs of recently smolted fingerlings from two hatchery stocks with different rearing histories and in groups containing free-ranging fish captured off the Oregon coast. Possible relationships between the observed social behavior and marine distribution patterns of juvenile coho salmon are discussed.

Selection for Adult Size in Female Coho Salmon (Oncorhynchus kisutch)

1986 ◽  
Vol 43 (10) ◽  
pp. 1946-1959 ◽  
Author(s):  
L B. Holtby ◽  
M. C. Healey
Keyword(s):  
Coho Salmon ◽  
Pacific Salmon ◽  
Oncorhynchus Kisutch ◽  
Selective Advantage ◽  
Evolutionary Stable Strategy ◽  
Relative Fitness ◽  
Female Size ◽  
Adult Size ◽  
Stable Strategy ◽  
Wide Range

Several recent studies have presented evidence that large size confers a selective advantage to female Pacific salmon. Nevertheless, a wide range of female sizes is normally present in any spawning population. Two possible explanations exist for the observed range in female size. First, average female size might be determined by an optimizing process with variation around the optimum size due to individual differences in success at obtaining food. Second, various sizes of females might coexist as a mixed evolutionary stable strategy. Under the first explanation, females of sizes other than the optimum would display lower fitness whereas, under the second explanation, females of all sizes would be equally fit. We investigated factors affecting survival of eggs, fry, and smolts of coho salmon (Oncorhynchus kisutch) in Carnation Creek on Vancouver Island with a view to determining the relative fitness of different sized females. Egg-to-fry mortality was best explained by a model that included only the effects of stream bed scour and gravel quality. Including an effect of female size, expressed through depth of egg burying, worsened the model's predictive capability. We could find no evidence that the eggs of large females consistently survived better during incubation than those of small females. In fact, we observed three instances in which it appeared that the eggs of small females survived better. In Carnation Creek, large 1- and 2-yr-old smolts did not consistently survive better in the marine environment than small smolts. Thus, we were unable to demonstrate that the reproductive success of large females was consistently higher than that of small females, contrary to the hypothesis that female size is the result of an optimizing process. In Carnation Creek the observed range of female sizes probably represents an evolutionary stable strategy in which all sizes have equal fitness. We propose a model that predicts female size and variance in size based on the conflicting selective effects of gravel quality, scour, and competition for nest sites.

Advances in Fish Tagging and Marking Technology

2012 ◽  
Keyword(s):  
Climate Change ◽  
Chinook Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Distribution Patterns ◽  
Distinct Region ◽  
Online Database ◽  
Specific Distribution ◽  
The Pacific ◽  
The Pacific Ocean

<i>Abstract</i>.—The coded wire tag (CWT) database contains detailed information on millions of Pacific salmon <i>Oncorhynchus </i>spp. released from hatcheries or smolt traps and recovered in the Pacific Ocean and its tributaries. I used this information to compare marine distribution patterns of hatchery coho <i>O. kisutch </i>and Chinook <i>O. tshawytscha </i>salmon, based on recoveries of an estimated 1.99 million tagged salmon in coastal areas from southern California to the Bering Sea. Both species show distinct region-specific distribution patterns. Within these release regions, coho and Chinook salmon marine distributions were often similar, with fish distributed largely in local waters. In other regions, Chinook salmon were distributed father north than coho salmon originating from the same region. Only in two regions did the two species have fundamentally different marine distributions, with coho south of, and Chinook salmon north of, the natal stream. The analysis also revealed several “hot spots” of salmon diversity, identified by numerically few recoveries that represented many of the hatcheries used in the analysis. These hotspots may serve as important reservoirs for the continued existence of populations that are particularly vulnerable to climate change due to their restricted marine distributions. Although CWT technology is primitive by modern standards, the enormous amount of data collected in a consistent fashion over decades and contained in an online database provides a unique and underutilized opportunity to address many elusive questions about Pacific salmon.

The influence of hatchery coho salmon (Oncorhynchus kisutch) on the productivity of wild coho salmon populations in Oregon coastal basins

2003 ◽  
Vol 60 (9) ◽  
pp. 1050-1056 ◽  
Author(s):  
Thomas Nickelson
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Wild Fish ◽  
Wild Populations ◽  
Large Numbers ◽  
Average Proportion ◽  
Coastal Basins ◽  
High Concentrations ◽  
Coastal River ◽  
Release Strategy

To aid in the recovery of depressed wild salmon populations, the operation of hatcheries must be changed to reduce interactions of juvenile hatchery fish with wild fish. Evidence suggests that productivity of wild populations can be reduced by the presence of large numbers of hatchery smolts in lower rivers and estuaries that attract predators. An index of productivity based on the density-independent rate of reproduction of wild coho salmon (Oncorhynchus kisutch) in 12 Oregon coastal river basins and two lake basins was negatively correlated with the average number of hatchery coho salmon smolts released in each basin. The index of productivity was not significantly correlated with the average proportion of hatchery coho salmon in each naturally spawning population or with habitat quality. Alterations to hatchery programs that could encourage recovery of wild populations include (i) avoiding release of large numbers of smolts in areas with high concentrations of wild fish, (ii) decreasing the number of smolts released, and (iii) using a volitional release strategy or a strategy that employs smaller release groups spread temporally.

Use of Hatchery Coho Salmon (Oncorhynchus kisutch) Presmolts to Rebuild Wild Populations in Oregon Coastal Streams

1986 ◽  
Vol 43 (12) ◽  
pp. 2443-2449 ◽  
Author(s):  
Thomas E. Nickelson ◽  
Mario F. Solazzi ◽  
Steven L. Johnson
Keyword(s):  
Surface Area ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Early Time ◽  
Wild Populations ◽  
Pool Surface ◽  
Coastal Streams

We evaluated the effectiveness of using hatchery coho salmon (Oncorhynchus kisutch) presmolts to rebuild wild populations in Oregon coastal streams. Juvenile and adult populations were monitored in 15 stocked and 15 unstocked streams from summer 1980 until summer 1985. During the summers following the planting of presmolts, the number of juveniles per square metre of pool surface area was higher in the stocked streams than in the unstocked streams. However, wild juveniles were significantly less abundant in the stocked streams during the 2 yr when density of wild juveniles was estimated separately from hatchery juveniles. Adult returns to the stocked streams were not significantly different from adult returns to the unstocked streams, but returns tended to be earlier in the stocked streams than in the unstocked streams. Despite similar numbers of adults per kilometre in the stocked streams and unstocked streams in the years the presmolts returned to spawn, the resulting densities of juveniles in the stocked streams were significantly lower than the densities of juveniles in the unstocked streams. We concluded that the early time of spawning of the hatchery coho salmon was largely responsible for their failure to rebuild the populations in the streams stocked with presmolts.

scholarly journals The role of coastal ocean variation in spatial and temporal patterns in survival and size of coho salmon (Oncorhynchus kisutch)

2001 ◽  
Vol 58 (10) ◽  
pp. 2021-2036 ◽  
Author(s):  
Alistair J Hobday ◽  
George W Boehlert
Keyword(s):  
Mixed Layer ◽  
Environmental Conditions ◽  
Coho Salmon ◽  
Mixed Layer Depth ◽  
Puget Sound ◽  
Oncorhynchus Kisutch ◽  
Vancouver Island ◽  
Coastal Ocean ◽  
Release Time ◽  
Adult Size

Interannual and decadal variability in ocean survival of salmon are well known, but the mechanisms through which environmental variability exerts its effects are poorly understood. Data on hatchery-reared coho salmon (Oncorhynchus kisutch) from individual releases (1973–1998) along the species' entire North American range were analyzed to provide information on survival and size. Three geographic regions (north of Vancouver Island, Puget Sound and Strait of Georgia, and the outer coast south of the tip of Vancouver Island) showed coherent trends in survival and size of returning fish. Within each region, multivariate nonlinear models were used to relate coho survival and final size to spatially and temporally tailored environmental variables at time periods of release, jack return, and adult return. The most important environmental variable, as indicated by the highest amount of variance explained, was a calculated proxy for mixed-layer depth, followed by sea level. In all regions, survival and adult size were most influenced by environmental conditions at the release time. A shallow mixed layer was associated with increased survival and decreased size in all regions. Improved understanding of the relationship between environmental conditions and size and survival of coho salmon provides insight into production patterns in the coastal ocean.

Variation in Agonistic Behavior between Newly Emerged Juveniles from Hatchery and Wild Populations of Coho Salmon, Oncorhynchus kisutch

1990 ◽  
Vol 47 (3) ◽  
pp. 566-571 ◽  
Author(s):  
D. P. Swain ◽  
B. E. Riddell
Keyword(s):  
Agonistic Behavior ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Its Region ◽  
Population Level ◽  
Mirror Image ◽  
Aggressive Display ◽  
Wild Populations ◽  
Breeding Programs ◽  
Stimulation Tests

We compared agonistic behavior of newly emerged coho salmon (Oncorhynchus kisutch) between hatchery and wild populations using mirror image stimulation tests. We used hatchery populations from two different regions of Vancouver Island B.C., each matched with a wild population from its region. In both comparisons, hatchery juveniles were more aggressive than wild juveniles. Rates of aggressive display increased with time since emergence for both hatchery and wild fish, as did the differences in behavior between the two types. By the sixth day of observation (13 d postemergence), the overall effect of fish type was highly significant for all aggressive behaviours. Since the individuals compared were reared from eggs under identical conditions, these differences are presumably genetic. Comparisons involved relatively few families from each population. However, because heritability was moderate to low within populations, and variance between population types exceeded variance among families within populations, these results indicate real differences at the population level. These results may have important implications for programs to rebuild wild populations using hatchery transplants and for selective breeding programs to develop domestic stocks of coho.

Spatial and interannual variability of juvenile coho salmon growth in the Strait of Georgia (2012-2015)

2020 ◽  
Vol 646 ◽  
pp. 145-160
Author(s):  
ML Journey ◽  
C Neville ◽  
G Young ◽  
M Trudel ◽  
BR Beckman
Keyword(s):  
Growth Factor ◽  
Regional Variation ◽  
Positive Relationship ◽  
Coho Salmon ◽  
Regional Growth ◽  
Oncorhynchus Kisutch ◽  
Fork Length ◽  
Small Scale ◽  
Short Term ◽  
Strait Of Georgia

We conducted a 4 yr (2012-2015) study of regional growth of juvenile coho salmon Oncorhynchus kisutch in the Strait of Georgia (British Columbia, Canada). Size (fork length) and growth (insulin-like growth factor-1 [IGF-1] concentration) varied both regionally and inter-annually. Additionally, we found a positive relationship between IGF-1 concentration and fork length that varied between years, with slopes and y-intercepts higher in 2012 and 2014, respectively, as compared to 2013 and 2015. An ordinal increase of IGF-1 concentration from the south to north in 2012 and 2014 was coupled with an increase in the prevalence of both juvenile herring and juveniles of other fish species in the diet. Across all years, there was a positive relationship between regional mean IGF-1 concentration and regional mean percent of juvenile herring in the diet. Our study demonstrates relatively small-scale spatial heterogeneity in juvenile coho salmon growth that in part, was attributed to regional variation in diet. These findings also demonstrate the utility of short-term growth measures (such as IGF-1) for assessing relatively small-scale spatial and temporal differences in growth.

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