Mixed-maturation fisheries shrink Chinook salmon size, study shows

A new study published in *Scientific Reports* models the long‑term effects of harvesting immature Chinook salmon in coastal waters. The analysis shows that mixed‑maturation fisheries, which catch both immature and mature fish, drive populations toward younger ages and smaller body sizes, reducing overall productivity and future harvest yields.

Separate research on Lake Ontario Chinook salmon examined stable‑isotope ratios to compare dietary niches among females, larger "hooknose" males and precociously maturing "jack" males. While nitrogen levels were similar across groups, jack males exhibited distinct carbon signatures and a narrow isotopic niche, indicating a different diet and habitat use that could inform management strategies.