Tracing growth patterns in cod (Gadus morhua L.) using bioenergetic modelling

Area of Science:

• Fisheries Science
• Ecosystem-based Management
• Climate Change Impact

Background:

• Accurate fish growth estimation is vital for fisheries management.
• Traditional methods like otolith readings and tag-recapture have limitations.
• Bioenergetic modeling offers an alternative for understanding fish growth dynamics.

Purpose of the Study:

• To develop an individual-based bioenergetic model for Western Baltic cod (Gadus morhua).
• To investigate the effects of environmental changes, particularly warming, on cod growth.
• To provide insights into climate change impacts on commercially important fish species.

Main Methods:

• Developed an individual-based bioenergetic model for Western Baltic cod.
• Integrated in-situ data on spatial distribution and feeding behavior.
• Incorporated laboratory-derived physiological data (gastric evacuation, consumption, etc.).

Main Results:

• The model successfully reproduced observed seasonal growth patterns in the field.
• The model explained the detrimental effects of summer heat periods on cod growth.
• Simulations highlighted a mechanism for climate change-induced growth reduction.

Conclusions:

• Bioenergetic modeling is a reliable tool for assessing fish growth and environmental impacts.
• Warming waters pose a significant threat to Western Baltic cod growth.
• Findings have implications for managing similar fish populations in changing climates.