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.

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.

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.

Habitat factors controlling Pacific herring (Clupea pallasi) egg loss in Prince William Sound, Alaska

1999 ◽  
Vol 56 (6) ◽  
pp. 1133-1142 ◽  
Author(s):  
Christopher N Rooper ◽  
Lewis J Haldorson ◽  
Terrance J Quinn II
Keyword(s):  
Fish Predation ◽  
Early Life History ◽  
Life History Stage ◽  
Pacific Herring ◽  
Prince William Sound ◽  
Bird Abundance ◽  
Air Exposure ◽  
Clupea Pallasi ◽  
Biological Variables ◽  
Loss Rates

Recruitment for many marine fishes is believed to be determined at an early life history stage. Pacific herring (Clupea pallasi) spawn in the intertidal and shallow subtidal zones and have a demersal egg stage that is susceptible to egg removals during incubation. Data were collected by the Alaska Department of Fish and Game in four years in Prince William Sound, Alaska, to identify important factors contributing to egg removals. We constructed analysis of variance models based on physical and biological variables to determine which environmental factors control egg loss rates. The habitat variables examined at each study transect were depth, wave exposure, north-south location, substrate, vegetation, mean bird abundance, abundance of loose eggs, and fish predation. Depth of spawn was the primary factor determining egg loss. Cumulative time of air exposure over incubation was substituted into the model for depth. Using the model, the total estimated egg loss from spawning to hatching ranged from 67 to 100% with an average of 75% (SE = 3.3%) in 1995. Eggs were originally deposited from 4 to -6 m depth relative to mean low water. The majority of eggs that remained in the spawning beds to hatching were deposited from 1 to -4 m depth. Egg removals due to avian predation were probably responsible for extreme egg loss rates at shallow depths.

scholarly journals Data conflicts in fishery models: incorporating hydroacoustic data into the Prince William Sound Pacific herring assessment model

2007 ◽  
Vol 65 (1) ◽  
pp. 25-43 ◽  
Author(s):  
Peter-John F. Hulson ◽  
Sara E. Miller ◽  
Terrance J. Quinn ◽  
Gary D. Marty ◽  
Steven D. Moffitt ◽  
...  
Keyword(s):  
Large Population ◽  
Population Decline ◽  
Assessment Model ◽  
Pacific Herring ◽  
Prince William Sound ◽  
Clupea Pallasi ◽  
The Pacific ◽  
Age Structured ◽  
Population Indices ◽  
Asa Model

Abstract Hulson, P-J. F., Miller, S. E., Quinn, T. J. II, Marty, G. D., Moffitt, S. D., and Funk, F. 2008. Data conflicts in fishery models: incorporating hydroacoustic data into the Prince William Sound Pacific herring assessment model. – ICES Journal of Marine Science, 65: 25–43. Data conflicts present difficulties in running integrated assessment models as shown by the age-structured assessment (ASA) model for the Pacific herring population in Prince William Sound (PWS), Alaska. After the 1989 “Exxon Valdez” oil spill in PWS, the Pacific herring (Clupea pallasi) ASA model indicated a significant decline in the population, starting in winter 1992. Back-calculated estimates from hydroacoustic abundance surveys that started in 1993 suggested that the ASA model overestimated herring biomass from 1990 to 1992 and that the population decline actually began in 1989. To expose data conflicts, we incorporated the hydroacoustic survey information with all available spawning population indices directly into the age-structured model. In this way, the substantial uncertainty about population parameters from 1989 to 1992 attributable to data conflicts was quantified. Consequently, the magnitude of declines for that period estimated from both linear and ASA models depend on the type of integrated datasets and weighting, particularly with indices of male spawners. Our view is that a major decline started in 1992 when disease affected a large population that was in weakened condition. Other views are consistent with the existing data too.

Spatial and temporal variability in the diet of juvenile Pacific herring (Clupea pallasi) in Prince William Sound, Alaska

1999 ◽  
Vol 77 (5) ◽  
pp. 697-706 ◽  
Author(s):  
Robert J Foy ◽  
Brenda L Norcross
Keyword(s):  
Energy Density ◽  
Phytoplankton Bloom ◽  
Stomach Contents ◽  
Spatial And Temporal Variability ◽  
Pacific Herring ◽  
Prince William Sound ◽  
Spring Phytoplankton Bloom ◽  
Clupea Pallasi ◽  
Nutritional Conditions ◽  
Relative Differences

The diet of juvenile Pacific herring, Clupea pallasi, from four bays in Prince William Sound, Alaska, varied spatially and seasonally. In Zaikof Bay, which was sampled in each season, stomach fullness of this herring was highest in May and declined significantly through the winter. Diversity of prey taxa in the diet was highest in June, after the spring phytoplankton bloom. In October, Oikopleura species were dominant in the fish diets of all bays. In March, fish eggs, Cirripedia nauplii, small Calanoida, and large Calanoida were the dominant prey in Eaglek, Simpson, Whale, and Zaikof bays, respectively. Energy density of stomach contents was highest in May, highlighting the importance of high lipid copepod taxa in Zaikof Bay. Estimated assimilation rates suggest that the diets of smaller age-0 herring provide close to maintenance levels of energy prior to winter. Therefore, variability in diet composition and diet energy density could account for relative differences in nutritional conditions of age-0 herring in Prince William Sound.

Why did the Prince William Sound, Alaska, Pacific herring (Clupea pallasi) fisheries collapse in 1993 and 1994? Review of hypotheses

1999 ◽  
Vol 56 (4) ◽  
pp. 711-737 ◽  
Author(s):  
W H Pearson ◽  
R A Elston ◽  
R W Bienert ◽  
A S Drum ◽  
L D Antrim
Keyword(s):  
Nutritional Status ◽  
Oil Spill ◽  
Cold Water ◽  
Pacific Herring ◽  
Prince William Sound ◽  
Natural Phenomena ◽  
Clupea Pallasi ◽  
Natural Factors ◽  
Poor Nutritional Status ◽  
Oil Exposure

Following record harvests of Pacific herring (Clupea pallasi) in Prince William Sound, Alaska, in the 3 years after the Exxon Valdez oil spill, the fishery failed in 1993. The hypotheses advanced to explain this dramatic 1993 decline occur in three categories: (i) effects associated with the 1989 oil spill, (ii) harvesting effects, and (iii) natural phenomena. Based on our review, we are convinced that a combination of increasing Prince William Sound herring biomass and decreasing food supply led to poor condition of Prince William Sound herring, which resulted in the 1993 decline. Other natural causes could have contributed to the decline, including disease, cold water temperatures, increased predation, and other natural stochastic processes. No evidence supports hypotheses that the decline resulted solely from overharvesting or underharvesting. The record high population levels and harvests of Prince William Sound herring in the years after the 1989 oil spill, the lack of change from the expected age-class distribution, and the low level of oil exposure documented for herring in 1989 and the following years all indicate that the 1989 oil spill did not contribute to the 1993 decline. Poor nutritional status, either alone or in combination with disease or other natural factors, was most likely responsible for the 1993 collapse.

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