Sammanfattning

The recruitment process and its underlying mechanisms are among the most studied phenomena in fisheries ecology. Traditional models estimate fish recruitment assuming a direct relationship with spawning stock size. However, highly variable environmental conditions, feeding conditions, and other factors can influence and complicate the results of a simple linear regression analysis between stock and recruitment. We used generalized additive models (GAMs) to investigate the influence of environmental conditions and stock structure on the recruitment processes of Baltic cod. The interaction between abiotic factors and old spawners (>5+ years) and eggs produced by old spawners were the most significant explanatory variables. Eggs produced by young spawners have a positive impact on cod recruitment only at high levels of reproductive volume, while old spawners' eggs have the highest positive effect at low levels of reproductive volume. Here we show: (i) that the number of Baltic cod recruits is strictly dependent on the age structure of the population; (ii) that interactions between biotic and abiotic factors are crucial in explaining recruitment variability; and (iii) that GAMs are a powerful technique for defining and quantifying the intricate multidimensional relationship between biotic and abiotic variables involved in recruitment processes.

Publicerad i

Canadian Journal of Fisheries and Aquatic Sciences
2000, Volym: 57, nummer: 12, sidor: 2402-2409
Utgivare: NATL RESEARCH COUNCIL CANADA

UKÄ forskningsämne

Jordbruksvetenskap


Publikationens identifierare

DOI: https://doi.org/10.1139/f00-221

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/42747