Effects of freezing on length and mass measurements of Atlantic cod Gadus morhua in the Baltic Sea

K. McQueen*, M. Mion, A. Hilvarsson, M. Casini, Hans Jakob Olesen, Karin Hüssy, K. Radtke, U. Krumme

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review


An aggregated sample of 925 Atlantic cod Gadus morhua collected by four countries in different regions of the Baltic Sea during different seasons were measure (total length, LT = 161–890 mm and weighed (mass, M = 45–6900 g) both before freezing and after defrosting. The cod were found to decrease significantly in both LT and M following death and frozen storage. There was an average (± SD) change in LT of –2.91% (± 0.05%) following freezing, independent of starting LT. Total M changed by –2.65% (± 0.14%), independent of starting mass. Shrinkage of LT and M did not differ significantly between 1 and 4 months frozen storage, though LT shrinkage was significantly greater after 1 or 4 months in the freezer compared with after 5 days. There was significant variation in LT and M shrinkage between regions of capture. A significant negative relationship between condition of cod and LT or M change was also observed. Equations to back‐calculate fresh LT and M from thawed LT, M and standard length (LS), gutted LT, gutted LTg and gutted mass (Mg) are provided.
Original languageEnglish
JournalJournal of Fish Biology
Issue number6
Pages (from-to)1486-1495
Publication statusPublished - 2019


  • Baltic Sea
  • Cod
  • Freezing
  • Gadus morhua
  • Measurement bias
  • Shrinkage

Cite this