Challenges Associated with Assessing Maturity, Skipped Spawning, and Abortive Maturation Rates: A Case Study on Sebastes Pinniger

Incorporating accurate estimates of life history parameters into population models can increase the reliability of biomass estimates used to manage groundfish stocks. In addition, understanding the reproductive biology and life history strategies of these fish provides support for sustainable management. However, seasonal data collection can create challenges for gaining a full understanding of the reproductive biology of some species. Many groundfish species on the U.S. West Coast spawn between November and March, when opportunities to collect biological data on research surveys or from fisheries landings are limited. We examined the reproductive biology and maturity schedule of canary rockfish, Sebastes pinniger, using ovary specimens collected on the West Coast groundfish bottom trawl survey (WCGBT) from 2009 – 2014 (n = 431) and from Oregon Department of Fish and Wildlife (ODFW) port biologists in 2014 and 2015 (n = 250). This allowed for comparisons of length and age at maturity estimates based on the histological examination of ovaries collected within and outside the canary rockfish spawning season. Temporal and spatial patterns in oocyte development, and rates of abortive maturation and skip-spawning, were investigated to determine their impact on canary rockfish reproductive patterns.