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.

Role of disease in abundance of a Pacific herring (Clupea pallasi) population

2003 ◽  
Vol 60 (10) ◽  
pp. 1258-1265 ◽  
Author(s):  
Gary D Marty ◽  
Terrance J. Quinn II ◽  
Greg Carpenter ◽  
Theodore R Meyers ◽  
Neil H Willits
Keyword(s):  
Stock Assessment ◽  
Assessment Model ◽  
Fish Mortality ◽  
Viral Hemorrhagic Septicemia Virus ◽  
Pacific Herring ◽  
Population Abundance ◽  
Total N ◽  
Clupea Pallasi ◽  
The Pacific ◽  
Age Structured

Disease significantly affects population abundance of Pacific herring (Clupea pallasi). Comprehensive epidemiological study of the Pacific herring population of Prince William Sound, Alaska, U.S.A., from 1994 to 2000 included complete necropsy examination of 230–500 fish each spring and 40–160 fish each fall (total n = 2983 fish). Mortality is best estimated, through modifications of an age-structured assessment model, using a disease index that combines the prevalence of viral hemorrhagic septicemia virus (VHSV) with the prevalence of ulcers. Risk factors for an epidemic include poor body condition and abundant recruitment before spawning in the spring. Prevalence of the pathogen Ichthyophonus hoferi increased as fish aged, but changes in I. hoferi prevalence were not related to changes in population abundance. Disease that caused an epidemic in 1998 (VHSV and ulcers) nearly disappeared from the population when changes in abundance were detected by traditional stock assessment methods in 1999. Disease significantly affects recruitment — the two lowest recruitment estimates on record, in 1994 and 1999, followed increased natural mortality of adults in 1993 and 1998.

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.

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.

Ecosystem controls of juvenile pink salmon (Onchorynchus gorbuscha ) and Pacific herring (Clupea pallasi ) populations in Prince William Sound, Alaska

2001 ◽  
Vol 10 ◽  
pp. 1-13 ◽  
Author(s):  
Robert T. Cooney ◽  
J. R. Allen ◽  
M. A. Bishop ◽  
D. L. Eslinger ◽  
T. Kline ◽  
...  
Keyword(s):  
Pink Salmon ◽  
Pacific Herring ◽  
Prince William Sound ◽  
Clupea Pallasi

scholarly journals Two egg-derived molecules in sperm motility initiation and fertilization in the Pacific herring (Clupea pallasi)

2008 ◽  
Vol 52 (5-6) ◽  
pp. 743-752 ◽  
Author(s):  
Gary N. Cherr ◽  
Masaaki Morisawa ◽  
Carol A. Vines ◽  
Kaoru Yoshida ◽  
Edmund H. Smith ◽  
...  
Keyword(s):  
Sperm Motility ◽  
Pacific Herring ◽  
Clupea Pallasi ◽  
The Pacific
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