scholarly journals ON THE PROBLEM OF REPRODUCTIVE PRODUCTS HETEROGENEITY IN SALMONID FISH: PINK SALMON (ONCORHYNCHUS GORBUSCHA) EGGS CASE-STUDY

Author(s):  
Людмила Александровна Лысенко ◽  
Надежда Павловна Канцерова ◽  
Марина Юрьевна Крупнова ◽  
Денис Александрович Ефремов ◽  
Нина Николаевна Немова ◽  
...  
1998 ◽  
Vol 55 (2) ◽  
pp. 281-296 ◽  
Author(s):  
Carl James Schwarz ◽  
Carolyn Gail Taylor

The simple-Petersen estimator is a well-known mark-recapture method to estimate animal abundance. Two key assumptions are equal catchability in both samples and complete mixing of tagged and untagged animals. If these are violated, severe bias can occur. The stratified-Petersen estimator can be used to account for some of the heterogeneity in catchability or mixing. In this paper, we first review recent developments in the stratified-Petersen experiment for fisheries audiences and demonstrate some of the practical problems that can occur that have not been discussed in the theoretical literature. Second, we present a case study to estimate the gross escapement of Fraser River pink salmon (Oncorhynchus gorbuscha) in 1991. The motivation for this study is a discrepancy of over 5 million fish between the estimates as derived by the Pacific Salmon Commission (PSC) (7.5 million fish based on a hydroacoustic method) and the Department of Fisheries and Oceans (DFO), Canada (13.0 million fish based on a mark-recapture method). One hypothesis put forward was that the discrepancy may be due to the use of a pooled-Petersen estimator when there is differential migration over time. The stratified-Petersen model suggests that little of this discrepancy can be explained by differential migration.


1965 ◽  
Vol 22 (6) ◽  
pp. 1477-1489 ◽  
Author(s):  
H. T. Bilton ◽  
W. E. Ricker

Among 159 central British Columbia pink salmon that had been marked by removal of two fins as fry and had been recovered in commercial fisheries after one winter in the sea, the scales of about one-third showed a supplementary or "false" check near the centre of the scale, in addition to the single clear-cut annulus. This evidence from fish of known age confirms the prevailing opinion that such extra checks do not represent annuli, hence that the fish bearing them are in their second year of life rather than their third. Unmarked pink salmon from the same area, and some from southern British Columbia, had a generally similar incidence of supplementary checks. In both marked and unmarked fish the supplementary checks varied in distinctness from faint to quite clear. In a sample of scales of 14 double-fin marked chum salmon which were known to be in their 4th year, all fish had the expected 3 annuli, and 12 fish had a supplementary check inside the first annulus.


2012 ◽  
Vol 69 (5) ◽  
pp. 955-969 ◽  
Author(s):  
Sara E. Miller ◽  
Milo Adkison ◽  
Lewis Haldorson

Water column stability has been hypothesized to affect growth and ultimately survival of juvenile fish. We estimated the relationships between stability and the growth, condition, and marine survival of several stocks of pink salmon ( Oncorhynchus gorbuscha ) within Prince William Sound (PWS), Alaska, USA, and the northern coastal Gulf of Alaska (GOA) shelf. There was a stronger correlation among the biological parameters of the fish than between the biological parameters and physical conditions. While stability and fish condition during early marine residence in PWS were important to year-class survival, stability of the water column that juveniles experienced as they migrated to the open waters of the GOA did not play a key role in determining survival to adulthood. Below-average stability just prior to capture within PWS combined with positive fish condition was related to increased year-class survival. Our results are similar to previous studies that concluded that slower and weaker development of stratification with a deeper mixed layer depth may be important for juvenile pink salmon survival in PWS.


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