Director

Secretariat

Wencke Griemsmann
Institute of Sea Fisheries

Herwigstraße 31
27572 Bremerhaven
Phone: +49 471 94460 101
Fax: +49 471 94460 199
wencke.griemsmann@thuenen.de


The demography of fishes

Project

Otolith mit Markierungen für die Alterlesung (c) Thünen-Institut/SF
(© Thünen-Institut/SF)

Further development of age determination methods for commercial fish species

Age composition data for fish stocks are essential input parameters for stock assessment. It is therefore necessary to permanently develop age determination methodology further.

Background and Objective

Age composition data for fish stocks are essential input parameters for stock assessment. The methodology of age determination is being permanently developed further in order to work efficiently and to reach consistent results. In this respect, state-of-the-art processing methods (e.g. fully automated otolith sectioning machines) and investigation methods (e.g. digital image analysis) are being employed.

Target Group

Fisheries science

Approach

The age of fish is being determined by counting growth zones in their ear stones (otoliths). Using state-of-the-art processing techniques and image analysis, annual rings (increments) become visible and are used for age determination.

Preliminary Results

  • Various publications, e.g. Stransky, C., Gudmundsdottir, S., Sigurdsson, T., Lemvig, S., Nedreaas, K., Saborido-Rey, F. (2005): Age determination and growth of Atlantic redfish (Sebastes marinus and S. mentella): bias and precision of age readers and otolith preparation methods. ICES J. Mar. Sci. 62: 655-670.

Thünen-Contact


Involved Thünen-Partners


Duration

1.2008 - 12.2020

More Information

Projekt type:
Project status: ongoing

Publikationen

hits: 3

  1. Van der Sleen P, Stransky C, Morrongiello JR, Haslob H, Perharda M, Black BA (2018) Otolith increments in European plaice (Pleuronectes platessa) reveal temperature and density-dependent effects on growth. ICES J Mar Sci:in Press, DOI:10.1093/icesjms/fsy011
  2. Stransky C, Gutmundsdóttir S, Sigurdsson T, Lemvig S, Nedreaas K, Saborido-Rey F (2005) Age determination and growth of Atlantic redfish (Sebastes marinus and S. mentella): bias and precision of age readers and otolith preparation methods. ICES J Mar Sci 62(4):655-670, doi:10.1016/j.icesjms.2005.01.018
  3. Stransky C, Kanisch G, Krüger A, Purkl S (2005) Radiometric age validation of golden redfish (Sebastes marinus) and deep-sea redfish (S. mentella) in the Northeast Atlantic. Fisheries Res 74(1-3):186-197, DOI:10.1016/j.fishres.2005.03.003