Activity: Talks and presentations › Conference presentations
Eastern Baltic cod (Gadus morhua) is in distress, revealed by historical poor nutritional status and few large fish. Known drivers of this are poor oxygen conditions and reduced food, but an additional driver may be the seal-associated cods liver worm (Contracaecum osculatum). We here describe effects of varying infections intensities of liver worm on cod health status, bioenergetics and mortality The Eastern Baltic cod (Gadus morhua) is in distress. Today these fish are in a historical poor nutritional status (i.e. condition), growth has decreased, and large individuals are few. Known drivers of the stock into this distress are deteriorating oxygen conditions and reduced prey abundance. However, yet another potential driver of the health status of cod has emerged; the seal-associated cods liver worm (Contracaecum osculatum) to which grey seal is final host and cod one of several transport hosts. During recent years, infection load with this parasite in cod livers has increased markedly. The liver is a central organ for many vital processes related to e.g. growth and immune response, and it is an energy-rich ‘lunch box’ for the fish, and high parasite load may negatively affect the fish. We here present data describing effects of varying infections intensities of liver worm on the health status, bioenergetics and mortality of cod. Results are evaluated in relation to their applicability in bioenergetic modelling, contributing with new biological information to assessment models of Eastern Baltic cod.