Age-specific natural mortality rates of adult Pacific herring (Clupea pallasi) from southern British Columbia

2000 ◽  
Vol 57 (11) ◽  
pp. 2258-2266 ◽  
Author(s):  
R W Tanasichuk
Keyword(s):  
British Columbia ◽  
Mortality Rate ◽  
Sampling Bias ◽  
Mortality Rates ◽  
Energy Requirements ◽  
Pacific Herring ◽  
Natural Mortality ◽  
Clupea Pallasi ◽  
Surplus Energy ◽  
Using Data

I used data for over 665 000 Pacific herring (Clupea pallasi) seined or gillnetted in southern British Columbia between 1951 and 1998 to estimate age- and year-specific adult natural mortality rates. Apparent sampling bias precluded using data collected before 1980. The instantaneous natural mortality rate is an increasing exponential function of age. Surplus energy requirements for gonad recrudescence appear to cause the death of adult herring.

Comparison of Some Life History Characteristics of Pacific Herring (Clupea pallasi) from the Canadian Pacific Ocean and Beaufort Sea

1993 ◽  
Vol 50 (5) ◽  
pp. 964-971 ◽  
Author(s):  
R. W. Tanasichuk ◽  
A. H. Kristofferson ◽  
D. V. Gillman
Keyword(s):  
Pacific Ocean ◽  
Beaufort Sea ◽  
Larval Period ◽  
Pacific Herring ◽  
Strait Of Georgia ◽  
Clupea Pallasi ◽  
Surplus Energy ◽  
Ripe Ovary ◽  
Using Data ◽  
Sea Fish

We compared several growth and reproductive characteristics of Pacific herring (Clupea pallasi) from the Canadian Pacific Ocean and Beaufort Sea using data for 2310 fish gillnetted in the northern Strait of Georgia or near Tuktoyaktuk, N.W.T., over the 1985 spawning season. Weight-at-age was similar but Beaufort Sea fish were longer-at-age. Total weight-at-length was significantly greater for Strait of Georgia herring because their size-specific ripe ovary weights were 2.1 times greater. We attributed differences in growth and surplus energy allocation to adult instantaneous mortality rates being 1.8 times higher for Strait of Georgia herring. Size-specific ripe egg weight was 30% smaller in Beaufort Sea herring presumably because warmer sea temperatures over the larval period resulted in a higher mortality rate. Weight-specific fecundity was 1.5 times greater in Strait of Georgia fish. Ovarian growth rates near spawning were lower in Beaufort Sea herring because they mature in colder water.

Estimation of Sea Mortality Rates for the 1960 Brood-Year Pink Salmon of Hook Nose Creek, British Columbia

1964 ◽  
Vol 21 (5) ◽  
pp. 1019-1034 ◽  
Author(s):  
Robert R. Parker
Keyword(s):  
British Columbia ◽  
Mortality Rate ◽  
Marine Environment ◽  
Pink Salmon ◽  
Mortality Rates ◽  
Natural Mortality ◽  
Two Stage ◽  
Fishing Season ◽  
Salmon Fry ◽  
Bella Coola

Seaward migrating pink salmon fry at Hook Nose Creek, British Columbia, were estimated to total 1,153,000 in 1961. Of these, 41.5% or 479,000, were marked by amputation of both ventral fins (BV). Following this marking 36,900 fingerling were captured in the marine environment and marked by removal of the adipose and right ventral fins (ARV). During the 1962 fishing season 1,160,645 adult pinks were examined and 7050 BV and 184 ARV marks recognized. For the Hook Nose Creek stock, survival at sea from natural causes is shown to approximate 22% and the rate of exploitation was 95%. This stock is shown to be more exposed to fishing than the Bella Coola stock, for which a rate of exploitation of 69–80% is estimated. Rate of exploitation for Dean Channel stocks is even lower. These differences are explained as due to times of entry and rates of travel through the fishery. The two-stage marking experiment failed to estimate the natural mortality rate of juvenile pinks during the initial 5 weeks of sea life because of this dissimilarity between rates of exploitation on the stocks in the area.

Natural mortality estimates of juvenile Pacific herring (Clupea pallasi) in Prince William Sound, Alaska

2002 ◽  
Vol 59 (3) ◽  
pp. 416-423 ◽  
Author(s):  
Kevin DE Stokesbury ◽  
Jay Kirsch ◽  
E Vincent Patrick ◽  
Brenda L Norcross
Keyword(s):  
Size Structure ◽  
Mortality Rates ◽  
Pacific Herring ◽  
Natural Mortality ◽  
Prince William Sound ◽  
Clupea Pallasi ◽  
Northern Latitudes ◽  
Primary Literature ◽  
Acoustic Surveys ◽  
Young Of The Year

The densities of young-of-the-year and 1-year-old Pacific herring, Clupea pallasi, in Prince William Sound, Alaska, were estimated using acoustic surveys from June 1996 to March 1998. Four bays were surveyed with acoustic transects that were repeated three times in 24 h. Species composition and size structure were determined from net collections. Averaging over the 24-h period allowed the best use of all data, as observations between the three replicates were similar but sporadic, possibly resulting from the different seasonal day–night cycle in these northern latitudes. The average instantaneous natural mortality rates for young-of-the-year Pacific herring were 0.009 (standard deviation (SD) = 0.002) and 0.016 (SD = 0.012) for the 1996 and 1997 cohorts, respectively. The average instantaneous natural mortality rates for 1-year-old Pacific herring were 0.003 (SD = 0.007) and 0.008 (SD = 0.005) for the 1995 and 1996 cohorts, respectively. Combining our estimates with those in the primary literature for other life history phases of Pacific herring indicated a progressive decrease in instantaneous natural mortality with age. This study presents the first direct estimates of natural mortality for juvenile herring.

scholarly journals A review of factors limiting recovery of Pacific herring stocks in Canada

2010 ◽  
Vol 67 (9) ◽  
pp. 1903-1913 ◽  
Author(s):  
Jacob F. Schweigert ◽  
Jennifer L. Boldt ◽  
Linnea Flostrand ◽  
Jaclyn S. Cleary
Keyword(s):  
West Coast ◽  
Positive Relationship ◽  
Pacific Herring ◽  
Zooplankton Abundance ◽  
Natural Mortality ◽  
Population Recovery ◽  
The West ◽  
Clupea Pallasi ◽  
Adequate Food ◽  
Forage Species

AbstractSchweigert, J. F., Boldt, J. L., Flostrand, L., and Cleary, J. S. 2010. A review of factors limiting recovery of Pacific herring stocks in Canada. – ICES Journal of Marine Science, 67: 1903–1913. On the west coast of Canada, Pacific herring (Clupea pallasi) supported an intensive reduction fishery from the early 1930s until the collapse of all five major stocks in the late 1960s, which then recovered rapidly following a fishery closure. Despite conservative harvests, abundance has declined again recently, with little evidence of recovery. We investigated the effect of bottom-up forcing by zooplankton abundance, top-down forcing by fish and mammal predators, and the effects of sardine abundance as potential competitors on the natural mortality of the herring stock on the west coast of Vancouver Island. Herring mortality was positively related to Thysanoessa spinifera and southern chaetognaths and negatively to pteropod abundance. Estimated predation on herring decreased significantly during the years 1973–2008, with the main consumers changing from fish to mammals. However, the correlation with herring mortality was negative, whereas there was a significant positive relationship with sardine abundance. Population recovery is expected to be facilitated by a combination of factors, including adequate food supply, limited or reduced predation (including fishing), and limited competition particularly for wasp–waist systems, where different forage species may occupy similar niches.

Tagging along: association among individual Pacific herring (Clupea pallasi) revealed by tagging

2002 ◽  
Vol 59 (12) ◽  
pp. 1960-1968 ◽  
Author(s):  
D E Hay ◽  
S M McKinnell
Keyword(s):  
British Columbia ◽  
Oncorhynchus Mykiss ◽  
Statistical Method ◽  
Positive Association ◽  
Commercial Fisheries ◽  
Pacific Herring ◽  
Steelhead Trout ◽  
Similar Question ◽  
Clupea Pallasi ◽  
External Anchor

More than 570 000 Pacific herring (Clupea pallasi) were tagged with external anchor tags during 429 tag release sessions between 1979 and 1992. Individually numbered tags were released in quantities of 1000–2000 at a time and recovered from commercial fisheries. Often several tags were recovered at the same time and place, and some recoveries occurred as "matches", where two or more tags from a single release session were recovered together. We tested the hypothesis that the frequency of matching tag recoveries occurred by chance through random mixing of tagged herring before their recapture during fishing operations. The alternative is nonrandom, positive association among tagged individuals that persisted through time and during migrations. We used a statistical method developed to address a similar question in steelhead trout (Oncorhynchus mykiss). In separate tests, we examined tag recovery data from migratory stocks in five major regions of the British Columbia. The results indicate nonrandom association of herring for periods of 6 months to several years and through migrations over considerable distances.

scholarly journals Growth, maturation, and longevity of maturation cohorts of Norwegian spring-spawning herring

2004 ◽  
Vol 61 (2) ◽  
pp. 165-175 ◽  
Author(s):  
Raymond J.H. Beverton ◽  
Arvid Hylen ◽  
Ole-Johan Østvedt ◽  
John Alvsvaag ◽  
Terence C. Iles
Keyword(s):  
Mortality Rate ◽  
Small Proportion ◽  
Stock Assessment ◽  
Adult Life ◽  
Total Mortality ◽  
Mortality Rates ◽  
Natural Mortality ◽  
Marine Research ◽  
First Time ◽  
Age At Maturation

Abstract In 1907, the Bergen Institute of Marine Research started regular sampling of scales and lengths from landings of mature Norwegian spring-spawning herring. The actual age of each fish when caught was recorded, and from the early 1920s also the age at which it spawned for the first time. The present analyses concern biological samples secured during the fishing seasons 1940–1964. Herring in this stock do not all reach maturity at the same age. A small proportion of any one year class matures at 3 years. The majority matures from the age of 4–7 years, and a small proportion of some year classes at 8 and even 9 years of age. Subsequent age composition and growth of each maturation cohort were followed throughout mature life after spawning for the first time. The maximum age was found to increase with age at maturation, rising to an asymptote of about 22 years. The von Bertalanffy parameter L∞ shows an increasing trend with age at maturation, while K decreases. There is no strict length threshold at maturation and the curve joining the length at which each maturation cohort reaches maturity is less steep than the growth curve itself over the range of maturation ages. The data suggest that fish in this stock spawn, on average, eight times during a period of their life history in which the mortality rate is independent of age. After these eight spawnings, at an age referred to in this paper as the hinge age, the mortality rate increases sharply. Thus, the adult life is divided into two phases, called here pre-senescent and senescent. The total mortality rates in the pre-senescent phase are relatively stable for all maturation cohorts 3–9, but there is some evidence of a trend towards higher mortality rates during the senescent phase for the youngest maturing fish. This trend is caused mainly by a reduced natural mortality in the fish that mature when older. These findings have interesting demographic implications. Additional mortality due to fishing will change the relative contribution of young and old maturation cohorts in the senescent phase, thus making it appear that natural mortality is dependent on the intensity of fishing. Consequently, for stock assessment, analysis on a cohort basis seems advisable.

Modelling Pelagic Fish and Plankton Trophodynamics off Southwestern Vancouver Island, British Columbia

1994 ◽  
Vol 51 (8) ◽  
pp. 1737-1751 ◽  
Author(s):  
Clifford L. K. Robinson ◽  
Daniel M. Ware
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coastal Upwelling ◽  
Squalus Acanthias ◽  
Pacific Herring ◽  
Fish Production ◽  
Clupea Pallasi ◽  
Merluccius Productus ◽  
Arrival Timing

A trophodynamics model is used to estimate annual plankton and fish production for the southern British Columbia continental shelf during 1985–89. The model describes the feeding interactions among diatoms, copepods, euphausiids, juvenile and adult Pacific herring (Clupea pallasi), Pacific hake (Merluccius productus), chinook salmon (Oncorhynchus tshawytscha), and spiny dogfish (Squalus acanthias) and is forced by empirical seasonal patterns in upwelling, sea surface temperature, and solar radiation. The most important simulation results are that (1) there is an imbalance between fish consumption and euphausiid production during the summer upwelling season, (2) the biomass and arrival timing of migratory hake significantly influence plankton and fish production, and (3) about 11% of the 332 g C∙m−2∙yr−1 annual diatom production is transferred to copepods and euphausiids and 1.0% of the diatom production to fish, while 27.5% of the 11.9 g C∙m−2∙yr−1 euphausiid production is consumed by herring and hake. The high plankton and fish production on the southern British Columbia shelf is comparable with other productive coastal upwelling regions.

Factors linking Pacific herring (Clupea pallasi) productivity and the spring plankton bloom in the Strait of Georgia, British Columbia, Canada

2013 ◽  
Vol 115 ◽  
pp. 103-110 ◽  
Author(s):  
J.F. Schweigert ◽  
M. Thompson ◽  
C. Fort ◽  
D.E. Hay ◽  
T.W. Therriault ◽  
...  
Keyword(s):  
British Columbia ◽  
Pacific Herring ◽  
Strait Of Georgia ◽  
Clupea Pallasi ◽  
Plankton Bloom
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