An assessment of bioenergetics to inform harvest decisions in pacific salmon terminal fisheries

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With many Pacific salmon populations declining, needed are more sustainable means to harvest target stocks.**Terminal fisheries, conducted near the end of a stock's spawning migration, are one such sustainable harvest**option for Pacific salmon. Terminal fisheries ensure that that non-target fish, and potentially less abundant**stocks or those of conservation concern, are avoided. In addition to the conservation benefits, terminal fisheries**also present new economic opportunities for First Nations communities to maintain food security and culture.**A major concern of terminal fisheries is that as Pacific salmon mature for spawning, energy is diverted from**the muscle to gonads. Meat quality can deteriorate very quickly in terminal areas, reducing its commercial**value, and after a certain point, the gonads (i.e. roe) become more valuable. Harvest strategies therefore**encompass both meat and roe, but what is lacking is knowledge of temporal dynamics of energy utilization in**maturing Pacific salmon. Such information is critical to maximize both product quality and value in terminal**fisheries. Research will focus on sockeye salmon, a valuable species commonly harvested in terminal areas and**will use colour and lipid content as markers of flesh quality. Working directly with the Lake Babine and**Sts'ailes First Nations and with various sockeye stocks, we will assess temporal dynamics of energy usage as**fish approach terminal areas, how this affects flesh quality and colour, and how these processes differ among**locations and target stocks. A non-invasive energy assessment will be conducted using a microwave energy**meter that estimates lipid content. Color of tissue samples from standard locations will be visually categorized**upon collection using a SalmoFanTM. To validate the microwave energy meter readings, bomb calorimetry**will be used to quantify fat in collected tissue samples. The final product will be a model of temporal variation**in flesh quality that will provide our industry partner an estimate of colour and fat content relative to capture**date for each stock. These results and continued use of the microwave energy meter in-season will help**processors make more informed harvest decisions.