TITLE:
On a Catch-Forecasting Model for the Pink Salmon Oncorhynchus gorbuscha in the Maritime Province of Siberia
AUTHORS:
Seizo Hasegawa, Naoki Suzuki, Kazumi Sakuramoto
KEYWORDS:
Density-Dependent Effect, Maritime Province of Siberia, Oncorhynchus gorbuscha, Pink Salmon, Stock-Recruitment Relationship
JOURNAL NAME:
Open Access Library Journal,
Vol.4 No.3,
March
14,
2017
ABSTRACT: The
aim of this paper is to elucidate the fluctuation mechanism in the catch of
pink salmon Oncorhynchus gorbuscha harvested in the Maritime Province of Siberia. We used catch data on pink
salmon born in odd- and even-numbered years. Monthly indices of
the Arctic Oscillation and the Pacific Decadal Oscillation were used as the
environmental factors. We assumed that the catch in year t, Ct, and
that in year t 2, Ct 2, could be used to represent the spawning stock biomass and recruitment, respectively, and Ct 2/Ct could
then be used to represent the recruitment per spawning stock biomass. Under these assumptions, we adopted the equation Ct 2/Ct = g (environmental factors) as
the model that forecasted the trajectories of the catch. The results were as
follows: 1) the trajectories of the catches of pink salmon born in odd- and
even-numbered years can be well reproduced by the model mentioned above. No
density-dependent effect was detected in the relationship between Ct 2 and Ct, which corresponds to the
stock-recruitment relationship (SRR), for catches in both odd- and
even-numbered years. The relationship between Ct 2 and Ct for odd-numbered years showed a clockwise loop; however, that for even-numbered
years showed an anticlockwise loop. It is believed that this difference occurs
in response to the negative relationship between the catches born in odd- and
even-numbered years. Pink salmon is one of the typical fish species to which a
density-dependent SRR can be applied; however, this study indicates that the assumption
of a density-dependent SRR is not valid.