Effects of freezing on length and mass measurements of Atlantic cod Gadus morhua in the Baltic Sea. Issue 6 (12th November 2019)

• Record Type: Journal Article
• Authors: McQueen, Kate; Mion, Monica; Hilvarsson, Annelie; Casini, Michele; Olesen, Hans J.; Hüssy, Karin; Radtke, Krzysztof; Krumme, Uwe
• Is Part Of: Journal of fish biology. Volume 95:Issue 6(2019)
• Page Start: 1486
• Page End: 1495
• Publication Date: 2019-11-12
• Subjects: Baltic Sea -- cod -- freezing -- Gadus morhua -- measurement bias -- shrinkage; Fishes -- Periodicals; Fishes -- Great Britain -- Periodicals; 597
• DOI: 10.1111/jfb.14171
• Languages: English
• ISSNs: 0022-1112

Abstract

Abstract: An aggregated sample of 925 Atlantic cod Gadus morhua collected by four countries in different regions of the Baltic Sea during different seasons were measured (total length, L T = 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 L T and M following death and frozen storage. There was an average (±SD) change in L T of −2.91% (±0.05%) following freezing, independent of starting L T . Total M changed by −2.65% (±0.14%), independent of starting mass. Shrinkage of L T and M did not differ significantly between 1 and 4 months frozen storage, though L T shrinkage was significantly greater after 1 or 4 months in the freezer compared with after 5 days. There was significant variation in L T and M shrinkage between regions of capture. A significant negative relationship between condition of cod and L T or M change was also observed. Equations to back‐calculate fresh L T and M from thawed L T, M and standard length ( L S ), gutted L T, gutted L S and gutted M are provided.