Gulf of Maine, Explained: Salmon Scales

In this edition of Gulf of Maine, Explained, Gulf of Maine Research Institute (GMRI) Quantitative Research Associate Miguel Barajas discusses how he studies changes in salmon scales to understand the endangered species' life cycle. Atlantic salmon play a vital role in connecting river and ocean ecosystems, and studying them informs broader conservation efforts aimed at maintaining a healthier global ecosystem.

Salmon scales have mineralized ridges on them known as circuli, and like the rings of a tree, these rings tell a story about individual salmon growth. Wider gaps indicate periods of faster growth and narrower gaps represent slower growth. This growth data can then be connected to marine survival rates, changing environmental conditions, and migratory pathways, and Miguel's job is to try and piece that story together. He researches how long salmon spend at sea and how much they grow compared to their counterparts, and links those differences to other important variables like temperature changes and changes in food availability to identify barriers and obstacles facing the population.

Miguel emphasizes the current challenges facing Atlantic salmon populations, which are continually decreasing despite conservation efforts. That's why identifying and addressing obstacles and barriers to their survival in the ocean is crucial. His research contributes to informed management and conservation efforts aimed at protecting this keystone species.