Recruitment of Baltic cod and sprat stocks: identification of critical life stages and incorporation of environmental variability into stock-recruitment relationships
Köster, F.W.; Hinrichsen, H.-H.; Schnack, D.; St. John, M.; MacKenzie, B.R.; Tomkiewicz, J.; Möllmann, C.; Kraus, G.; Plikshs, M.; Makarchouck, A.; Aro, E. (2003). Recruitment of Baltic cod and sprat stocks: identification of critical life stages and incorporation of environmental variability into stock-recruitment relationships. Sci. Mar. (Barc.) 67(S1): 129-154. https://dx.doi.org/10.3989/scimar.2003.67s1129 In: Scientia Marina (Barcelona). Consejo Superior de Investigaciones Científicas. Institut de Ciènces del Mar: Barcelona. ISSN 0214-8358; e-ISSN 1886-8134, more Also appears in:Ulltang, Ø.; Blom, G. (2003). Fish stock assessments and predictions: integrating relevant knowledge. SAP Symposium held in Bergen, Norway 4-6 December 2000. Scientia Marina (Barcelona), 67(S1). Institut de Ciències de Mar: Barcelona. 374 pp. https://dx.doi.org/10.3989/scimar.2003.67s1, more | |
Keywords | Environments Organisms > Aquatic organisms > Animals > Aquatic animals > Marine animals > Fishes > Aquatic animals > Marine fishes > Osteichthyes > Cod Population functions > Recruitment Stock assessment ANE, Baltic [Marine Regions] Marine/Coastal |
Authors | | Top | - Köster, F.W.
- Hinrichsen, H.-H.
- Schnack, D.
- St. John, M.
| - MacKenzie, B.R., more
- Tomkiewicz, J.
- Möllmann, C.
- Kraus, G.
| - Plikshs, M.
- Makarchouck, A.
- Aro, E.
|
Abstract | The recruitment processes of Baltic cod and sprat were analysed and critical periods were identified by addressing the major impact factors on individual early life history stages separately and relating observed abundance data between successive stages. For cod, recruitment appeared to be dependent on egg survival, with low oxygen concentration in dwelling depths and predation by clupeids as the major causes for egg mortality. Surviving egg production and larval abundance were weakly correlated, whereas larval abundance was significantly related to year class strength. This indicated that the period between the late egg and the early larval stage is critical for cod recruitment. A potential variable identified to affect this life stage was prey availability for larvae. For sprat, early and late egg stage production as well as late egg stage production and larval abundance were significantly related. However, year class strength was largely independent of larval abundance. Thus, the period between the late larval and early juvenile stage appeared to be critical for sprat recruitment. Potential variables identified to affect this life stage were ambient temperature and wind stress. Environmental factors showing statistically significant covariance with the survival of one of these critical life stages were incorporated into stock-recruitment models for individual spawning areas separately and for the Central Baltic combined. |
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