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Understanding the basic biology of exploited fish populations, and how it changes across the waterscape, is essential to sustainable management. Biological features (age, growth, reproductive investment, and fish condition) for the newly described Deacon Rockfish Sebastes diaconus were evaluated between two different population segments, an exploited nearshore population and an unexploited offshore population, and were used to parameterize population dynamics models to evaluate how area‐specific biological features influence measures of stock status. Monthly hook‐and‐line sampling was conducted for 1 year, with ˜50 fish collected per area per sampling period. Despite the relatively small (<50 km) distance between the two sampling areas, there were discernible differences in the biology of Deacon Rockfish. When fish of the same size‐class were compared between offshore and nearshore segments, the unexploited offshore fish were older, suggesting that fishing may have decreased the overall age structure of the exploited nearshore population segment. Parameters of the von Bertalanffy growth model differed the most between the sexes and secondarily between the nearshore and offshore population segments. Length at 50% maturity was 28 cm and age at 50% maturity was 4.1 years for females, which is smaller and younger than previously reported in the literature. Deacon Rockfish were captured in both the nearshore and offshore areas throughout the year, which suggests that at least some component(s) of the population is present in both areas throughout the year. These differences had a nontrivial influence on measures of stock status and will be important to consider during future stock assessments and as management considers the effect of the recent reopening of the offshore population segment to fishing. [ABSTRACT FROM AUTHOR]

Little is known about intraspecific variation within the deacon rockfish (Sebastes diaconus), a recently described species found in the northeast Pacific Ocean. We investigated population structure among fish sampled from two nearshore reefs (Siletz Reef and Seal Rock) and one offshore site (Stonewall Bank) within a <50‐km2 area off the Oregon coast. Fish from the three sample sites exhibited small but statistically significant differences based on genetic variation at >15,000 neutral loci, whether analyzed independently or classified into nearshore and offshore groups. Male and females were readily distinguished using genetic data and 92 outlier loci were associated with sex, potentially indicating differential selection between males and females. Morphometric results indicated that there was significant secondary sexual dimorphism in otolith shape, but further sampling is required to disentangle potential confounding influence of age. This study is the first step toward understanding intraspecific variation within the deacon rockfish and the potential management implications. Since differentiation among the three sample sites was small, we consider the results to be suggestive of a single stock. However, future studies should evaluate how the stock is affected by differences in sex, age, and gene flow between the nearshore and offshore environments. [ABSTRACT FROM AUTHOR]

Fish age validation with bomb-produced radiocarbon ( 14 C) requires a known-age Δ 14 C reference chronology spanning the era of a marine increase in bomb-produced 14 C (1950s to 1960s). Concordance between otolith Δ 14 C in a validation sample and the reference chronology indicates accurate test ages. Here, we present an information-theoretic approach to hypothesis testing and use Bayesian data analysis with Markov chain Monte Carlo simulation as a probabilistic framework to quantitatively estimate age determination bias and its uncertainty. Using this approach, we compare a new Δ 14 C reference chronology from the eastern Bering Sea and a previously established reference from the Gulf of Alaska with otolith Δ 14 C in two validation species, eastern Bering Sea yellowfin sole ( Limanda aspera ) and Gulf of Alaska northern rockfish ( Sebastes polyspinis ). Our goals were twofold: (i) to validate the age determination methods for northern rockfish and yellowfin sole using comparisons within oceanic basins, and (ii) to explore the outcome of making naïve comparisons of these validation data sets to reference chronologies across oceanic basins. Based on within-basin comparisons we concluded that estimated ages for eastern Bering Sea yellowfin sole and Gulf of Alaska northern rockfish were accurate. We further concluded that there were important differences in otolith 14 C uptake between fish from the two ocean basins. [ABSTRACT FROM AUTHOR]