Good catch welfare can improve sustainability, profitability, and product quality, while fulfilling ethical obligations in a major global food source. However, implementing welfare into fisheries is inherently challenging. Norwegian fishers recently started using rod and line gear to capture Atlantic bluefin tuna (ABT), allowing for welfare assessment of individual fish. ABT is an economically important fishery highly dependent on quality. These characteristics, combined with the relatively young fishery, make it well positioned to adopt welfare conscious methods. This requires understanding ABT’s behavioral response to capture. Fishing gear was fitted with video cameras and accelerometers to quantify behavior through visual observations and acceleration. Video analysis included observations of behavioral categories and tail beat frequency (TBF). Acceleration data was processed into overall dynamic body acceleration (ODBA) to infer activity levels. Six capture events revealed TBF and ODBA peaked immediately post-hooking, followed by a general decline and stabilization, with occasional later peaks. Initial high activity may reflect natural predatory behavior rather than capture stress, as four out of six tuna rejoined schools shortly after hooking, suggesting limited awareness of capture. Behavioral metrics were predictive of ODBA, establishing that behavior reliably indicates activity levels during capture, providing a basis for developing empirical welfare considerations.
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