3 Kind of Pacific Cod

Of the fish peptidases mentioned, cod trypsin I has the highest sequence identity (95–98%) to trypsins from Gadus macrocephalus (pacific cod), Boreogadus saida (polar cod) and Theragra chalcogramma (Alaska pollock). Cod trypsin I shows 82% identity to trypsin IA (NP_001117183) from Salmo salar (Atlantic salmon), 82% identity to trypsin isoform 2 (BAG65814.1) from Oncorhynchus keta (Chum salmon) and 65% identity to trypsin 2 (AAI34795) from Bos taurus (cattle).

Steller Sea Lion

Thomas R. Loughlin, Thomas S. Gelatt, in Encyclopedia of Marine Mammals (Third Edition)

 Ecology

Steller sea lions eat a variety of fishes and invertebrates (Sinclair and Zeppelin, 2002). In Alaska, the principal prey is walleye pollock (Theragra chalcogramma); Pacific cod (Gadus macrocephalus), Atka mackerel (Pleurogrammus monopterygius), octopus, squid, herring (Clupea harengus), flatfishes, sculpins, but a wide variety of other fishes and invertebrates are also consumed. At specific times of the year, other prey may be eaten when plentiful (e.g., Pacific salmon, Oncorhynchus spp.). During the breeding season, females with pups generally feed at night; territorial males eat very little or not at all while on territory. Feeding occurs during all hours of the day once the breeding season ends

Killer whales (Orcinus orca) and sharks eat Steller sea lions. However, the possible impact of these predators on population trends is equivocal

A cacophony of noise engulfs rookeries and haul-out sites, with animals of both sexes and all ages vocalizing throughout the day and night. Territorial males use low-frequency roars to signal threats to other males and to court females. Females vocalize frequently, calling to their pups and squabbling with other sea lions of all ages. Pups have a bleating, sheep-like cry; their voice deepens with age

Production of Marine Oils

Fish Liver Oils

Fish liver oils have been used as far back as the Middle Ages, and populations in Scandinavia have used them for thousands of years (Breivik, 1992). The most important raw material for the production of liver oils comes from the fisheries for cod, coalfish, and haddock. The livers of ling; tusk; several species of shark such as dogfish, Greenland shark and basking shark; and halibut have also been used in the production of liver oils. In order to obtain high quality, light colored oils with good flavor and odor containing a minimum of free fatty acids, it is important to eviscerate the fish and recover the livers so that they can be processed as quickly as possible

The oil is contained in the liver protein and can normally be easily recovered by steam cooking the livers. This grade of oil is generally the medicinal grade liver oil. The residue can then be caustic treated to destroy the protein and release the residual oil. This grade of oil has higher vitamin content and is generally classified as a veterinary grade. In modern times, the cooked livers are processed through centrifuges that are more efficient at separating the liquid and solid fractions. The liquid fraction is then centrifuged to recover the oil. This centrifuge process recovers more primary grade oil than the old gravity separation processes. A typical process for the production of fish liver oils is shown in Figure 4.10The production of liver oils has varied over time and is dependent upon the availability of the raw materials used to supply the livers. In modern times, identified cod liver oil has been displaced by liver oils from various other fish species such as Alaska pollock, other gadoid species, and hake liver oils. Figure 4.11 shows the production of different liver oils from 1990 to 2008. The data show that defined cod liver oil has been replaced by other liver oils from species not easily identified (nei), according to FAO data (2010)