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2021 Assessment Of The Thornyhead Stock Complex In The Gulf Of Alaska

In accordance with the approved schedule, no assessment was conducted for this stock this year, however, a full stock assessment will be conducted in 2022. Until then, the values generated from the previous stock assessment (below) will be rolled over...
February 07, 2022 - Assessments ,

2020 Assessment Of The Thornyhead Stock Complex In The Gulf Of Alaska

Rockfish have historically been assessed on a biennial stock assessment schedule to coincide with the availability of new trawl survey data (odd years). In 2017, the Alaska Fisheries Science Center (AFSC) participated in a stock assessment...
January 29, 2021 - Assessments ,

2019 Assessment of the Thornyhead Stock Complex in the Gulf of Alaska

NOTE: In accordance with the approved schedule, no assessment was conducted for this stock this year, however, a full stock assessment will be conducted in 2020.
February 03, 2020 - Assessments ,

2018 Assessment of the Thornyhead Stock Complex in the Gulf of Alaska

Rockfish have historically been assessed on a biennial stock assessment schedule to coincide with the availability of new trawl survey data (odd years). In 2017, the Alaska Fisheries Science Center (AFSC) participated in a stock assessment prioritization process. It was recommended that the Gulf of Alaska (GOA) thornyhead complex remain on a biennial stock assessment schedule with a full stock assessment produced in even years and no stock assessment produced in odd years. However, we performed a partial stock assessment in 2017 because the allowable biological catch (ABC) has been exceeded in the past in the western GOA, and because the biomass estimates provided by the GOA trawl surveys have at times displayed extreme variability between surveys. We followed the recommendation of the Science and Statistical Committee (SSC) and the GOA Groundfish Plan Team that “partial assessments for Tiers 4-5 should be an expanded version of the current off-year executive summaries, including catch/biomass ratios for all species in addition to re-running the random effects model” (SSC minutes – February 2017).
January 30, 2019 - Assessments ,

2016 Assessment of the Thornyhead Stock Complex in the Gulf of Alaska

Shortspine thornyhead (Sebastolobus alascanus; SST) are a long lived, deep dwelling species that inhabit the northeastern Pacific Ocean from Baja Mexico to the Gulf of Alaska (GOA), westward to the Aleutian Islands (AI),  eastern Bering Sea (BS), and into the Seas of Okhotsk and Japan (Echave et al. 2015).  Adult SST are generally found along the continental slope at depths of 150 – 450 m. Thornyheads (Sebastolobus species) are groundfish belonging to the family Scorpanenidae, which contains the rockfishes. While thornyheads are considered rockfish, they are distinguished from the “true” rockfish in the genus Sebastes primarily by reproductive biology. Thornyheads are also differentiated from Sebastesin that they lack a swim bladder, making them ideal tagging specimens.
February 19, 2016 - Assessments ,

2015 Assessment of the Thornyhead Stock Complex in the Gulf of Alaska

Thornyheads (Sebastolobus species) are groundfish belonging to the family Scorpanenidae, which contains the rockfishes. The family Scorpanenidae is characterized morphologically within the order by venomous dorsal, anal, and pelvic spines, numerous spines in general, and internal fertilization of eggs. While thornyheads are considered rockfish, they are distinguished from the “true” rockfish in the genus Sebastes primarily by reproductive biology; all Sebastes rockfish are live-bearing (ovoviviparous) fish, while thornyheads are oviparous, releasing fertilized eggs in floating gelatinous masses. Thornyheads are also differentiated from Sebastes in that they lack a swim bladder. There are three species in the genus Sebastolobus, including the shortspine thornyhead Sebastolobus alascanus, the longspine thornyhead Sebastolobus altivelis, and the broadfin thornyhead Sebastolobus macrochir (Eschmeyer et al. 1983, Love et al. 2002).
February 21, 2015 - Assessments ,