scholarly journals Use of parasites to clarify residency and migration patterns of Pacific sardine (Sardinops sagax) in the California Current

2019 ◽  
Vol 117 (3) ◽  
pp. 72-86
Author(s):  
Kym Jacobson ◽  
Rebecca Baldwin ◽  
Michael Banks ◽  
Robert Emmett
Keyword(s):  
California Current ◽  
Migration Patterns ◽  
Pacific Sardine ◽  
Sardinops Sagax ◽  
And Migration

scholarly journals Corroboration and refinement of a method for differentiating landings from two stocks of Pacific sardine (Sardinops sagax) in the California Current

2013 ◽  
Vol 71 (2) ◽  
pp. 328-335 ◽  
Author(s):  
David A. Demer ◽  
Juan P. Zwolinski
Keyword(s):  
California Current ◽  
Practical Method ◽  
Potential Habitat ◽  
Point Conception ◽  
Stock Biomass ◽  
Habitat Transition ◽  
Good Potential ◽  
Pacific Sardine ◽  
Sardinops Sagax ◽  
Spatio Temporal

Abstract Demer, D. A., and Zwolinski, J. P. 2014. Corroboration and refinement of a method for differentiating landings from two stocks of Pacific sardine (Sardinops sagax) in the California Current. – ICES Journal of Marine Science, 71: 328–335. Efforts to survey, assess and manage Pacific sardine (Sardinops sagax) in the California Current may depend on accurate differentiation of the purported two migrating stocks. The southern stock spans seasonally from southern Baja California, México to Point Conception, California; the northern stock spans seasonally from Punta Eugenia, México northwards to southern Alaska. Their seasonal north–south migrations are approximately synchronous within their respective domains, resulting in segregated spawning and different identities. A decade ago, a practical method was proposed for differentiating landings from the two stocks using concomitant measurements of sea-surface temperature (SST). Here, we corroborate and refine the method using regional indices of optimal and good potential habitat for the northern stock, and SST-based indices associated with the 99.9 and 100% confidence intervals of the potential habitat. For months when the index is <0.5, (i.e. when the minority of a fishing region probably includes potential northern stock habitat), the landings are attributed to the southern stock, and vice versa. We applied this method to regional monthly landings data from 2006–2011 and the results indicated that an average of 63–72 and 32–36% of the summertime landings at Ensenada, México and San Pedro, southern California were probably from the southern stock, respectively, depending on the index used. Allocation error could be reduced if the landings were evaluated on finer spatio-temporal scales, particularly during habitat-transition periods. Our method may be used to improve estimates of northern stock biomass, spatial and length distributions, recruitment, and mortality.

Ecological and economic considerations in the conservation and management of the Pacific sardine (Sardinops sagax)

2009 ◽  
Vol 66 (5) ◽  
pp. 859-868 ◽  
Author(s):  
Rögnvaldur Hannesson ◽  
Samuel Herrick, ◽  
John Field
Keyword(s):  
Fishery Management ◽  
California Current ◽  
Forage Fish ◽  
Ecological Significance ◽  
Trade Offs ◽  
The Pacific ◽  
Pacific Sardine ◽  
Commercially Important ◽  
Sardinops Sagax ◽  
Economic Considerations

In this paper, we consider economic and ecological issues associated with the Pacific sardine ( Sardinops sagax ) as a commercially harvested species relative to its importance as prey for species of commercial, recreational, and ecological significance. Using economic theory and ecosystem modeling results for the California Current, we investigate whether sardines might be more valuable as forage than as commercial landings. Our analysis considers various conditions under which this would be justified. For example, ex-vessel prices of commercially important sardine predators near the high end of their respective ranges in recent years and the ex-vessel price of sardine at the low end of its respective range would favor leaving more sardine as forage fish. However, even if it were advisable to reduce the volume of the sardine fishery to leave more forage for other, more valuable species, it does not necessarily imply that the sardine fishery should be shut down altogether. Rather, our results indicate that consideration of the trade-offs is a key element of ecosystem-based fishery management.

scholarly journals Abundance patterns of early stages of the Pacific sardine (Sardinops sagax) during a cooling period in a coastal lagoon south of the California Current

2012 ◽  
Vol 76 (2) ◽  
pp. 247-257 ◽  
Author(s):  
René Funes-Rodríguez ◽  
Rafael Cervantes-Duarte ◽  
Silverio López-López ◽  
Alejandro Hinojosa-Medina ◽  
Alejandro Zárate-Villafranco ◽  
...  
Keyword(s):  
Coastal Lagoon ◽  
California Current ◽  
Cooling Period ◽  
Early Stages ◽  
Abundance Patterns ◽  
The Pacific ◽  
Pacific Sardine ◽  
Sardinops Sagax

scholarly journals Measurements of natural mortality for Pacific sardine (Sardinops sagax)

2013 ◽  
Vol 70 (7) ◽  
pp. 1408-1415 ◽  
Author(s):  
Juan P. Zwolinski ◽  
David A. Demer
Keyword(s):  
United States ◽  
California Current ◽  
The United States ◽  
Assessment Model ◽  
Entire Period ◽  
Natural Mortality ◽  
Pacific Sardine ◽  
The Mean ◽  
Sardinops Sagax ◽  
The One

Abstract Zwolinski, J. P., and Demer, D. A. 2013. Measurements of natural mortality for Pacific sardine (Sardinops sagax). – ICES Journal of Marine Science, 70: . The northern stock of Pacific sardine (Sardinops sagax) in the California Current Ecosystem is periodically assessed to provide harvest guidelines for the United States and Canadian fisheries. The assessment model incorporates the estimates of abundance from acoustic-trawl method (ATM) and other surveys and many parameters including a constant value for the instantaneous natural mortality coefficient (M). Here, the ATM-estimated length-structured sardine abundances for 2006–2011 are combined to directly estimate M. The stock was dominated by the 2003, 2004, and 2005 year classes (2003–2005 cohort) from 2006 to 2010 and by the 2009 and 2010 year classes in 2011. Insignificant recruitments during 2006–2010 allowed the 2003–2005 cohort to be tracked and M to be estimated. The bootstrap distributions of estimated M encompass the assessment-assumed value of 0.4−year. The measurements suggest that M is high for a new cohort, declines during mid-life, then increases as the fish approach their longevity. The mean M for the entire period, 0.52, is 30% higher than the one currently assumed for the assessment, reflecting the steeper decline in the ATM-estimated biomass versus that in the assessment model.

Population trends and migration patterns in the critically endangered Yellow-breasted Bunting (Emberiza aureola) in the Republic of Korea

2020 ◽  
Vol 27 (1) ◽  
pp. 56-63
Author(s):  
Jong-Gil Park ◽  
Chang-uk Park ◽  
Kyoung-Soon Jin ◽  
Yang-Mo Kim ◽  
Hee-Young Kim ◽  
...  
Keyword(s):  
Population Trends ◽  
Critically Endangered ◽  
Republic Of Korea ◽  
Migration Patterns ◽  
The Republic ◽  
And Migration
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