A transformative approach to rapidly assess critical life history and energetic responses of fish to environmental change
School of Fisheries and Ocean Sciences, University of Alaska Fairbanks
The goal of this project is to develop physiological and life history indices for fisheries management. To contribute to this long-term goal, we will develop innovative, cost-effective, and efficient approaches for measuring life history attributes of important fisheries species based on the chemical structure of fish tissues and hard parts inferred from spectroscopy.
Spectroscopy methods, indices, and habitat information from this study will contribute to long-term monitoring in support of fisheries management. Spectroscopy approaches are transferable to ongoing monitoring efforts and will facilitate the collection of important data to assess the impacts of changing conditions on fisheries species. Assessing habitat heterogeneity that impacts body condition and growth will help to identify important nurseries and develop strategies to incorporate spatial variability into monitoring. This work impacts Alaskan communities by advancing management to support sustainable fisheries, enhancing knowledge of important nearshore nursery habitats, and by developing cost-effective and efficient monitoring tools that can be adopted and implemented by federal, state, and local agencies.
Climate variability and change affect energetics and life history characteristics of marine finfish with potential impacts on their distribution, abundance, and physiological processes. In the Gulf of Alaska, recent drastic declines in the abundance of walleye pollock and Pacific cod were attributed to anomalously warm temperatures that increased energetic demands, coupled with low food quality and availability for all life stages. Monitoring changing dynamics using physiological indices such as growth, body condition, and maturity can provide early warning signs of change and support fisheries management strategies that may buffer economic impacts of population declines. However, current methods for measuring these indices are expensive and time-consuming, resulting in a lag between data acquisition and incorporation into management. Therefore, there is a pressing need to develop technologies that promote timely data availability.
Why is this an Alaska Sea Grant project?
The proposed research directly addresses several Sea Grant goals. Developing more cost effective methods for assessment of age, condition, and maturity supports a more rapid incorporation of information from biological samples into annual stock assessments. The resulting reduction in assessment uncertainty aligns with Sea Grant Goal 2: Sustainable Fisheries and Aquaculture, in particular Objective 5: Promote and support sustainability of fisheries and other marine resource harvests. This objective will be addressed through training and outreach and by developing tools to inform stock assessment and ecosystem-based fisheries management of harvested fish species. This work also addresses Goal 1: Healthy marine, coastal, and watershed ecosystems in Alaska, Objective 1: Increase the shared body of knowledge about marine, coastal, and watershed ecosystems in Alaska, emphasizing the concerns and interests of stakeholders and Objective 2: Support and enhance planning, management, and mitigation needed to ensure healthy ecosystems and coastal communities, through community engagement, information gathering, and providing indices that will help managers respond to environmental change. Finally, this work addresses Goal 3: Vibrant coastal communities with strong and diverse economies, Objective 7: Increase the resilience of Alaska coastal communities through diversification, growth, and strengthening of coastal/marine economic sectors and social wellbeing, identity, and values by providing training and opportunities to students and personnel and through community outreach, engagement, and participation in data collection and research.
How will researchers conduct their study?
Fourier transform near-infrared (FT-NIR) and Raman spectroscopy have the potential to efficiently measure life history and energetic properties based on the molecular composition of a material. Spectroscopy has only recently been applied to fisheries to determine age and lipid content, despite comparable applications in other disciplines. We propose a comprehensive study to develop and apply spectroscopy tools to assess age, energetics, and maturation for walleye pollock and Pacific cod. We will focus on the vulnerable first years of life when changing environmental conditions impact growth, development, and energy storage that are essential to survival. Through a coupled rearing study and field-based approach, we will develop efficient tools for fisheries monitoring, informative near-instantaneous indices for juvenile stages of pollock and Pacific cod, and recommendations for monitoring strategies.