Is spawner biomass a sensitive measure of the reproductive and recruitment potential of Northeast Arctic cod?

Marshall, C. Tara; Kjesbu, Olav Sigurd; Yaragina, Nathalia A.; Solemdal, Per; Ulltang, Øyvind

doi:10.1139/cjfas-55-7-1766

Cited by 129 publications

(190 citation statements)

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“…The remaining variability may be due to a number of processes not included in the present exercise such as egg fertilisation (Vallin et al 1999) and the influence of parental characteristics (age and size structure, condition) on egg and larval characteristics (buoyancy, survival probability, e.g., Marshall et al 1998;Trippel 1998) and a potential starvation of larvae due to a shortage of suitable food supply (Grønkjaer and Wieland 1997) but also uncertainties in the way that variables are assumed to represent processes of interest (e.g., reproductive volume effect on egg survival, predation relative to predator-prey overlap). Results from recent studies on these topics are becoming available for Baltic cod (e.g., Nissling et al 1998) and potentially could also be incorporated into new generations of recruitment models (Vallin et al 1999).…”

Section: Applicability Of Stock-recruitment Modelsmentioning

confidence: 99%

“…For example, it is now evident that variations in stock structure and condition of the adults can affect the level of egg production (Marshall et al 1998;Marteinsdottir and Thorarinsson 1998;Marshall and Frank 1999) and impact on egg viability and buoyancy. Variations in egg viability and buoyancy influence the survival probability of eggs and larvae (e.g., Kjesbu et al 1996;Nissling et al 1998;Trippel 1998) and, combined with variations in stock reproductive effort, are targeted as being responsible for recruitment fluctuations (Marshall et al 1998;Marteinsdottir and Thorarinsson 1998;Jarre-Teichmann et al 2000). Furthermore, the effects of predation on fish eggs and larvae (e.g., Bailey and Houde 1989) have the potential to reduce the reproductive success of a stock.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Developing Baltic cod recruitment models. II. Incorporation of environmental variability and species interaction

Köster¹,

Hinrichsen²,

John³

et al. 2001

Can. J. Fish. Aquat. Sci.

101

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Abstract:We investigate whether a process-oriented approach based on the results of field, laboratory, and modelling studies can be used to develop a stock-environment-recruitment model for Central Baltic cod (Gadus morhua). Based on exploratory statistical analysis, significant variables influencing survival of early life stages and varying systematically among spawning sites were incorporated into stock-recruitment models, first for major cod spawning sites and then combined for the entire Central Baltic. Variables identified included potential egg production by the spawning stock, abiotic conditions affecting survival of eggs, predation by clupeids on eggs, larval transport, and cannibalism. Results showed that recruitment in the most important spawning area, the Bornholm Basin, during 1976-1995 was related to egg production; however, other factors affecting survival of the eggs (oxygen conditions, predation) were also significant and when incorporated explained 69% of the variation in 0-group recruitment. In other spawning areas, variable hydrographic conditions did not allow for regular successful egg development. Hence, relatively simple models proved sufficient to predict recruitment of 0-group cod in these areas, suggesting that key biotic and abiotic processes can be successfully incorporated into recruitment models.Résumé : Nous cherchons à savoir si une approche axée sur les processus et basée sur des études de terrain, de laboratoire et de modélisation peut servir à développer un modèle stock-milieu-recrutement pour la morue franche (Gadus morhua) de la Baltique centrale. À la suite d'une analyse statistique exploratoire, des variables significatives qui influençaient la survie des premiers stades et qui variaient systématiquement d'une site de fraie à un autre ont été incorporées dans des modèles de stock-recrutement, d'abord pour les sites de fraie les plus importants et ensuite combinés pour toute la Baltique centrale. Les variables identifiées comprennent la production potentielle d'oeufs par le stock de géniteurs, les conditions abiotiques qui affectent la survie des oeufs, la prédation des oeufs par les clupéidés, le transport des larves et le cannibalisme. Les résultats indiquent que le recrutement durant la période 1976 à 1995 au site de fraie le plus important, le bassin de Bornholm, était en relation avec la production d'oeufs; cependant, d'autres facteurs significatifs affectaient la survie des oeufs (oxygénation, prédation) et, une fois incorporés, ils expliquaient 69% de la variation dans le recrutement du groupe 0. À d'autres sites de fraie, les conditions hydrographiques variables ne permettaient pas un développement normal et réussi des oeufs. Ainsi, des modèles relativement simples se sont avérés adéquats pour prédire le recrutement des morues du groupe 0 dans ces sites, ce qui laisse croire que des processus dominants abiotiques et biotiques peuvent être incorporés avec succès dans les modèles de recrutement.[Traduit par la Rédaction] Köster et al. 1556

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Section: Applicability Of Stock-recruitment Modelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Developing Baltic cod recruitment models. II. Incorporation of environmental variability and species interaction

Köster¹,

Hinrichsen²,

John³

et al. 2001

Can. J. Fish. Aquat. Sci.

101

View full text Add to dashboard Cite

show abstract

“…Previously, acoustic-survey estimates of abundance were used to quantify total egg production and TLE for NA cod (Marshall et al 1998. Here, only VPA estimates of the number at age (ages 3-15+; ICES 2000) were used so that abundance of spawners would be consistently scaled throughout the entire time series.…”

Section: Total Numbers Of Females By Lengthmentioning

confidence: 99%

“…However, recent research suggests that spawner biomass is a poor proxy for total egg production for NA cod (Marshall et al 1998 and possibly for other stocks (Lowerre-Barbieri et al 1998;Scott et al 1999;Kraus et al 2000). Furthermore, variables that could influence total egg production (e.g., age diversity of the stock, condition of spawners) have shown positive associations with recruitment (Boyd et al 1998;Marteinsdottir and Thorarinsson 1998;Marshall and Frank 1999).…”

Section: Introductionmentioning

confidence: 99%

Reconstructing the stock-recruit relationship for Northeast Arctic cod using a bioenergetic index of reproductive potential

Marshall¹,

Yaragina²,

Ådlandsvik³

et al. 2000

Can. J. Fish. Aquat. Sci.

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Correlation and simulation analyses suggest that, for the Northeast Arctic (NA) cod stock, the total lipid energy (TLE (kJ)) contained in the livers of mature females is proportional to total egg production, making TLE a potential predictor of recruitment. Accordingly, the TLE of NA cod was estimated for a 51-year time period , using estimates of numbers at length derived from virtual population analysis, modelled values of proportion mature and weight at length, and observed values of the liver-condition index. A significant linear relationship between TLE and recruitment to age 3 was observed. The temporal trend in TLE suggests that the reproductive potential of the NA cod stock has been in decline since the mid-1970s. A multiple-regression model that included TLE, mean temperature, and mean alongshore wind stress as independent variables explained approximately 43% of the variation in recruitment. Reconstructing stock-recruit relationships using more sensitive measures of reproductive potential is the first step in resolving environmental effects on recruitment and in developing biological reference points that are more effective in stock conservation.Résumé : Des analyses de corrélation et de simulation suggèrent que l'énergie lipidique totale (TLE (kJ)) contenue dans le foie des femelles à maturité de la population de morues du nord-est de l'Arctique (NA) est proportionnelle à la production totale d'oeufs; la TLE est donc un critère potentiel de prédiction du recrutement. C'est pourquoi nous avons calculé les TLE de la population NA de morues pour une période de 51 ans en nous servant d'estimations tirées de populations virtuelles des nombres de poissons dans les différentes classes de longueurs, d'estimations par modélisation des proportions d'individus matures et des masses à chacune des longueurs et d'observations des coefficients de condition du foie. Il existe une relation linéaire statistiquement significative entre les TLE et le recrutement jusqu'à l'âge 3. L'évolution au cours des ans de la TLE laisse croire que le potentiel reproducteur de la population NA décline depuis le milieu des années 1970. Une analyse de régression multiple, qui utilise la TLE, la température moyenne et le stress éolien moyen le long des côtes comme variables indépendantes, explique environ 43% de la variation du recrutement. L'établissement de meilleures corrélations entre les stocks et le recrutement à l'aide d'indicateurs plus sensibles du potentiel reproducteur est un premier pas vers l'évaluation des effets de l'environnement sur le recrutement et vers l'établissement de repères biologiques plus efficaces pour la conservation des stocks.[Traduit par la Rédaction] 2442Marshall et al.

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“…Recent research indicates that maternal effects on egg survival are important (Kjesbu et al, 1991, Marshall et al, 1998. On the other hand, the results of Trippel and Neilsen (1992) and Trippel and Morgan (1994a, b) indicate that paternal effects play only a modest role in the spawning process.…”

Section: Introductionmentioning

confidence: 99%

Management Implications of Sexual Differences in Maturation and Spawning Mortality of Northeast Arctic Cod

Jakobsen¹,

Ajiad²

1999

J. Northw. Atl. Fish. Sci.

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There is evidence of earlier maturation in males than in females and indications of higher mortality among mature males than mature females in the Northeast Arctic cod (Gadus morhua L.) stock. Both factors affect the composition of the spawning stock by sex and age. One possibility is that spawning mortality is involved. Spawning mortality may occur in both sexes, but observations indicate that it might be higher in males. The possibility of a spawning mortality is investigated by adding spawning mortality in calculations of the history of a year-class to see if this improves the fit with observed sex ratios in commercial landings from the Lofoten spawning fishery. The best fit was obtained for a spawning mortality of about 0.05 on the males. However, the results are not conclusive. Splitting the spawning stock into males and females shows that the earlier maturation in males has a larger impact on the sex ratio in the spawning stock than the spawning mortality rates. Increasing the fishing mortality rates will increase the surplus of male spawners. The results have implications for estimation of biological reference points and the way spawning stock biomass is used in management considerations. Estimation of the female SSB is necessary if maternal effects are to be taken into account.

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Is spawner biomass a sensitive measure of the reproductive and recruitment potential of Northeast Arctic cod?

Cited by 129 publications

References 0 publications

Developing Baltic cod recruitment models. II. Incorporation of environmental variability and species interaction

Developing Baltic cod recruitment models. II. Incorporation of environmental variability and species interaction

Reconstructing the stock-recruit relationship for Northeast Arctic cod using a bioenergetic index of reproductive potential

Management Implications of Sexual Differences in Maturation and Spawning Mortality of Northeast Arctic Cod

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