Young of the Year (YOY) Rockfish

By Wyatt Fournier, NOAA Fisheries, on the Northwest Explorer

Unlike our young-of-the-year focal cod species (walleye pollock and Pacific cod), larval rockfish are found in patchy aggregations. This may be due to their different reproductive strategies. Cod use a “spray and pray” technique, where males and females release their gametes into the water and fertilization takes place as the ocean currents bring them together. Rockfish are ovoviviparous, which means eggs are fertilized and develop within the mother and young are released as free-swimming individuals.

We’re focusing on Pacific ocean perch (Sebastes alutus) in this project, one of many commercially important rockfishes in Alaska. This species is often called a POP and is just one of 32 species in the genus Sebastes found in the North Pacific. Young-of-the-year Sebastes are notoriously difficult to tell apart in the field and require laboratory techniques to indentify to species. We’re working with Tony Gharrett’s lab at the University of Alaska Fairbanks to identify the POP within the rockfish we collect. His lab uses single nucleotide polymorphisms (SNPs) genetic analysis to distinguish Pacific ocean perch from other rockfish.

Larval Rockfish