Sebastes Pinniger Research Articles

Sebastes pinniger

This datasheet on Sebastes pinniger covers Identity.

Assessing the performance of a cost-effective video lander for estimating relative abundance and diversity of nearshore fish assemblages

Rocky reefs in the temperate Northeast Pacific constitute a small portion of the nearshore seabed, yet are highly valued as productive habitat for local fisheries. Surveying these structurally complex, untrawlable habitats requires robust gear that can be deployed in rough sea states. Here, a cost-effective, compact video lander was evaluated for its ability to survey the diversity and abundance of nearshore (<40m), rocky-reef-associated fish populations (e.g. Sebastes, Cottidae, Hexagrammidae). To determine the application and limitations of surveying complex rocky reefs with this new tool, this study sought to (1) determine the frequency of observation of known nearshore fish species, (2) evaluate the influence of baiting the lander on the observed fish assemblage, (3) identify the optimal deployment time to maximize observed species richness and abundance, and (4) evaluate species-specific behavioral responses to the lander characterized a priori as attractive, avoidance, or neutral. Seventy percent of lander deployments met established requirements of visibility, view, and habitat. Seventy-seven percent of observed fishes were identifiable to species. The method observed 15 species belonging to 5 families; 5 species were classified as common (observed in >20% of deployments), the remaining rare. Contrary to lander studies in other regions, bait was not found to improve species-specific identification, increase observed species richness or abundance (at the species or feeding guild level), or shorten deployment duration. A deployment time of 8min on the benthos was determined as optimal for observing maximum species richness and abundance in the nearshore, doubling the previously described lander drop durations evaluated in deeper Oregon, U.S.A., waters. Species-specific behavioral responses to this compact lander were evaluated by viewing trends in species abundance (assessed within 30s bins) over the deployment duration; no attractive or avoidance behaviors were observed. Results confirm that this simple, cost-effective video lander configuration is suitable for sampling the suite of fish species found in the nearshore, including rockfish species federally designated as “overfished” (Sebastes pinniger and Sebastes ruberrimus). Furthermore, this study illustrates the importance of evaluating the performance of survey tools in the specific environment in which the tool will be used to determine best-practices from long-term monitoring.

Techniques for improving estimates of maturity ogives in groundfish using double-reads and measurement error models

The reproductive output of a population depends upon physiological factors, including maturation rates and fecundity -at-size and -at-age, as well as the rate at which post-maturation females fail to spawn (i.e. skipped spawning). These rates are increasingly included in stock assessment models, and are thought to change over time due to harvest and environmental factors. Thus, it is important to accurately estimate maturation and skipped spawning rates while also including information on imprecision. For this task, we developed a new double-read and measurement-error modeling protocol for estimating maturity that is based on the use of multiple histological reads of ovaries to account for reader error caused by poorly prepared slides, nuclear smear, and early yolk development. Application to three U.S. West Coast groundfishes (Pacific hake Merluccius productus, darkblotched rockfish Sebastes crameri, and canary rockfish Sebastes pinniger) indicates that reader uncertainty is strongly predictive of reader error rates. Results also show differences in rates of skipped spawning among species, which should be further investigated. We recommend that future maturity studies record reader certainty, use models that incorporate covariates into the analysis, and conduct an initial double reader analysis. If readers exhibit little variation, then double reads may not be necessary. In addition, slide quality should also be recorded, so that future studies do not confuse this with reader imprecision. This improved protocol will assist in estimating life history, as well as environmental, and anthropogenic effects on maturity.

Quantification of Habitat and Community Relationships among Nearshore Temperate Fishes Through Analysis of Drop Camera Video

AbstractTemperate nearshore reefs along the Pacific coast of North America are highly valuable to commercial and recreational fisheries yet comprise a small fraction of the seabed. Monitoring fisheries resources in this region is difficult; high‐relief structural complexity and adverse sea conditions have led to a paucity of information on temperate reef species assemblage patterns. Reliable, inexpensive tools and methods for monitoring are needed, as many traditional tools are both logistically complicated and expensive, limiting the frequency of their implementation over a large scale. Video drop cameras of varying designs have previously been employed to estimate fish abundance and distribution. We surveyed a nearshore rocky reef off the northern Oregon coast with a video lander (a video camera mounted on a landing platform so it can be dropped to the seafloor) over the spring and winter of 2011. We designed a 272‐point systematic grid to document the species assemblage and the distribution and habitat associations of the reef species, including two overfished rockfishes: Canary Rockfish Sebastes pinniger and Yelloweye Rockfish Sebastes ruberrimus. Species assemblages differed significantly across the reef by depth and by season for the outer part of the reef. Well‐defined habitat associations existed for many species; Canary Rockfish were associated with complex moderate‐relief habitat types such as large boulders and small boulders, while Yelloweye Rockfish were associated with high‐relief habitats like vertical walls. Species associations were evaluated pairwise to identify nearshore complexes. We compared our site with five exploratory reef sites off the central Oregon coast and found that nearshore reefs differed from our site, while offshore reefs were more similar. Video landers provide a solution to the need for increased sampling of temperate reef systems that are subject to difficult conditions and can contribute to habitat mapping, fish abundance indices, and fish assemblage information for monitoring and management of fisheries resources.Received October 18, 2014; accepted January 3, 2015

Testing the robustness of data-poor assessment methods to uncertainty in catch and biology: a retrospective approach

Abstract The quality and quantity of data affect the reliability of all stock assessments. Over time, we expect data to improve and assessment predictions to become more reliable. There is a potential for strong bias in estimates of sustainable yield if the available data are not a good representation of stock dynamics, particularly for catch-based data-poor methods that rely on limited information and assumptions about stock status. We retrospectively investigated the interaction of data quantity and quality through time using the “real-world” data for a stock as it progressed from data-poor to data-rich. For this analysis, we chose a currently data-rich and overfished stock with historical assessments representing both a data-poor and data-moderate state, the canary rockfish (Sebastes pinniger). We asked how changes in the catch history and biological parameters over time affected the estimates of sustainable yield and the overfishing limit (OFL) predicted by two data-poor assessment tools, depletion-corrected average catch (DCAC) and depletion-based stock reduction analysis (DB-SRA). We found that both of these methods underestimated the “true” OFL in simulations with catch error alone. While there was slightly less bias for DB-SRA than DCAC, increasing error in the catch led to a more rapid increase in the variance of the DB-SRA harvest limit (HL). Our retrospective analysis showed that the expectation for a more accurate HL estimate between the data-poor and data-moderate canary rockfish assessments does not come from an increase in the quantity or quality of the catch data alone; a decrease in the quality of the biological data between assessments had the greatest impact. By evaluating these methods with historical data, our retrospective approach highlighted the impact of change in data quality and quantity on HL estimates for a long-lived rockfish, and could be used to define the amount and type of error included in simulation studies that further evaluate data-poor methods.

The divergent effect of capture depth and associated barotrauma on post-recompression survival of canary (Sebastes pinniger) and yelloweye rockfish (S. ruberrimus)

We evaluated the external signs of barotrauma and 48-h post-recompression survival for 54 canary and 81 yelloweye rockfish captured at depths of 46–174m, much deeper than a similar prior experiment, but within the depth range of recreational fishery catch and discard. Survival was measured using specialized sea cages for holding individual fish. The external physical signs associated with extreme expansion and retention of swimbladder gas (pronounced barotrauma), including esophageal eversion, exophthalmia and ocular emphysema, were common for both species at these capture depths and were more frequent than in prior studies conducted at shallower depths. Despite similar frequencies of most external barotrauma signs, 48-h post-recompression survival of the two species diverged markedly as capture depth increased. Survival of yelloweye rockfish was above 80% across all capture depths, while survival of canary rockfish was lower, declining sharply to just 25% at capture depths greater than 135m. Fish of both species that were alive after 48h of caging displayed very few of the external signs of pronounced barotrauma and had a high submergence success rate when released at the surface. Logistic regression analysis, using a combined data set from this and an earlier experiment conducted at shallower capture depths, was used to more broadly evaluate factors influencing post-recompression survival. For canary rockfish, depth of capture was negatively related to survival (P<0.0001), but the surface-bottom temperature differential was not (P>0.05). Exophthalmia and ocular emphysema were each negatively associated with survival for canary rockfish (P<0.05). For yelloweye rockfish, no significant associations were found between post-recompression survival and capture depth, the surface-bottom temperature differential or any of the signs of pronounced barotrauma (P>0.05).

Wintertime ocean conditions synchronize rockfish growth and seabird reproduction in the central California Current ecosystem

Chronologies developed from annual growth-increment widths of splitnose rockfish ( Sebastes pinniger ) and yelloweye rockfish ( Sebastes ruberrimus ) otoliths were compared with time series of lay date and fledgling success for the common murre ( Uria aalge ) and Cassin’s auklet ( Ptychoramphus aleuticus ) in the north-central California Current. All time series were exactly dated and spanned 1972 through 1994. In a principal components analysis, the leading principal component (PC1bio) accounted for 64% of the variance in the data set. By entering the upwelling index, the Northern Oscillation index, sea surface temperatures, and the multivariate ENSO (El Niño Southern Oscillation) index into principal components analysis, a time series of environmental variability PC1env was developed for each month of the year. Over the interval 1972 through 1994, PC1bio most strongly correlated with PC1env for February and, to a lesser extent, January and March. Moreover, when each of the six biological time series was related to the 12 PC1env through stepwise multiple regression, February was always the most significant (p &lt; 0.01). The same was true if upwelling index was substituted for PC1env. As upper-trophic predators, rockfish and seabirds independently corroborate that wintertime ocean conditions are critical for productivity in the California Current ecosystem.

Bomb radiocarbon age validation of Pacific ocean perch (Sebastes alutus) using new statistical methods

We used bomb-produced radiocarbon (14C) to validate ages of Pacific ocean perch ( Sebastes alutus ), which are routinely estimated with the cut-and-burn method at the Alaska Fisheries Science Center (Seattle, Washington, USA). New statistical methods to compare Δ14C in validation samples with a reference chronology are introduced: (i) calculating confidence intervals around the LOESS-smoothed Δ14C reference chronology using simultaneous inference; (ii) purposely adding biases to the validation sample ages and then analyzing the sum of squared residuals of the validation samples’ Δ14C about the LOESS-smoothed reference chronology; and (iii) standardizing the Δ14C measurements from the validation sample to better fit the reference chronology. Standardized Δ14C measurements are particularly useful when researchers suspect that environmental and biological differences between the validation samples and the reference chronology may exist that affect the level, but not the timing, of Δ14C in the samples. These new methods can be applied simultaneously. Two previous bomb radiocarbon studies on canary rockfish ( Sebastes pinniger ) and black drum ( Pogonias cromis ) were reanalyzed, further illustrating the usefulness of these new methods.

Age validation of canary rockfish (Sebastes pinniger) using two independent otolith techniques: lead-radium and bomb radiocarbon dating

Canary rockfish (Sebastes pinniger) have long been an important part of recreational and commercial rockfish fishing from south-east Alaska to southern California, but localised stock abundances have declined considerably. Based on age estimates from otoliths and other structures, lifespan estimates vary from ~20 years to over 80 years. For the purpose of monitoring stocks, age composition is routinely estimated by counting growth zones in otoliths; however, age estimation procedures and lifespan estimates remain largely unvalidated. Typical age validation techniques have limited application for canary rockfish because they are deep-dwelling and may be long-lived. In this study, the unaged otolith of the pair from fish aged at the Department of Fisheries and Oceans Canada was used in one of two age validation techniques: (1) lead-radium dating and (2) bomb radiocarbon (14C) dating. Age estimate accuracy and the validity of age estimation procedures were validated based on the results from each technique. Lead-radium dating proved successful in determining that a minimum estimate of lifespan was 53 years and provided support for age estimation procedures up to ~50–60 years. These findings were further supported by Δ14C data, which indicated that a minimum estimate of lifespan was 44 ± 3 years. Both techniques validate, to differing degrees, age estimation procedures and provide support for inferring that canary rockfish can live more than 80 years.

When do marine reserves increase fishery yield?

An age-structured model is developed for analyzing the effects of marine reserves and other long-term closures on fishery yield, assuming larvae are well-mixed and that exchange of adults between the open and closed areas is negligible. A number of analytic results are derived, including a formula for the gradient of yield with respect to fishing mortality and closure fraction. Increasing the closure fraction at equilibrium spawning stock biomass (SSB), B, will increase yield if and only if s′(B) &gt; 1/b0(0), where s′(B) is the slope of the stock–recruitment curve at B and b0(0) is SSB per recruit at zero fishing mortality. Conditions for the level of closure required to prevent stock collapse are also derived. Applications of the theory to canary rockfish (Sebastes pinniger) and Georges Bank sea scallop (Placopecten magellanicus) illustrate that long-term closures increase yield only at low SSB associated with fishing mortalities greater than FMSY and with low closure fractions. The theory presented here gives simple analytic and graphical techniques for predicting the effects of long-term closures on yield and stock persistence.

Age validation of canary rockfish (Sebastes pinniger) from off the Oregon coast (USA) using the bomb radiocarbon method

The alternating translucent and opaque banding pattern in canary rockfish (Sebastes pinniger) otoliths, aged using a break-and-burn methodology, are annual markings. To validate age assignment, we compared measured radiocarbon levels in canary rockfish otolith cores with a reference chronology developed from known age Pacific halibut (Hippoglossus stenolepis). An average 2- to 3-year phase shift was detected between the canary rockfish and a Pacific halibut reference chronology that was likely the result of differences in the regional oceanography or underageing bias. The assumption of ageing bias consistency was tested with two sampling designs. The first design controled for age-related ageing error, and the second design related birth year to estimated age. No change in the magnitude of ageing bias as a function of age was detected.

Protecting rockfish through gear design: development of a selective flatfish trawl for the U.S. west coast bottom trawl fishery

This study evaluated the potential to reduce the bycatch of rockfish (Sebastes spp.) in a flatfish trawl fishery by developing a selective trawl that separates flatfish from rockfish using differences in their behavior as the trawl net approaches. Using an alternate haul, randomized block design, we compared catches between a commonly used combination trawl and a newly designed, low-rise trawl incorporating a "cutback" headrope. For most of the target flatfish species, the experimental trawl had a 25–59% higher catch rate (kilograms) than the control net (P &lt; 0.05), consistent with greater footrope length in the experimental trawl. Increased catches of some small rockfish, skates, and sablefish (Anoplopoma fimbria) were also observed (P &lt; 0.05). The catches of many larger roundfish and rockfish species, including canary rockfish (Sebastes pinniger), redstripe rockfish (Sebastes proriger), Pacific hake (Merluccius productus), and shortspine thornyhead (Sebastolobus alascanus) more than 25 cm long, were reduced from 34 to 97% in the experimental trawl (P &lt; 0.05). Under weak-stock management conditions, in which the bycatch of overfished rockfish species limits directed flatfish fisheries, trawl designs that permit nontarget species to escape before entrainment can significantly reduce bycatch mortality and prevent premature closures of directed flatfish fisheries.

Microsatellite markers for the heavily exploited canary (Sebastes pinniger) and other rockfish species

AbstractThe isolation and characterization of nine polymorphic microsatellite loci (eight tetranucleotide and one dinucleotide) from the canary rockfish Sebastes pinniger are described. Polymorphism at these loci revealed from six to 28 alleles, with expected heterozygosities ranging between 0.42 and 0.88, enabling high‐resolution genetic population structure investigation for this overfished species in the northeastern Pacific. They also amplify in 13 other congeneric species, providing highly variable loci for research on other rockfishes.

Ichthyophonus and Mycobacterium‐like bacterial infections in commercially‐important rockfish, Sebastes spp., in the eastern North Pacific Ocean

Recently there has been an increased concern about the status of demersal ®sh stocks, particularly rock®sh, Sebastes spp. (family Sebastidae), in the Paci®c Northwest (Musick, Harbin, Berkeley, Brugess, Eklund, Findley, Gilmore, Golden, Ha, Huntsman, McGovern, Parker, Poss, Sala, Schmidt, Sedberry, Weeks & Wright 2000). Offshore (slope and shelf) rock®sh ®sheries of particular concern (i.e. those that have declined signi®cantly in recent years) include canary rock®sh, Sebastes pinniger (Gill), widow rock®sh, S. entomelas (Jordan & Gilbert), Paci®c Ocean perch, S. alutus (Gilbert), yellowtail rock®sh, S. avidus (Ayres), and boccacio, S. paucispinus (Ayres) (Paci®c Fisheries Management Council 2000). Examples of rock®sh species that are considered at risk include S. pinniger and S. alutus, which are listed as `vulnerable' with a 77±93% and 81±91% decline, respectively. Sebastes avidus stocks are at 63% of pristine levels, but this stock is expected to decline because of poor recruitment (Paci®c Fisheries Management Council 2000). In a recent survey of marine ®sh for salmon pathogens conducted off the coast of British Columbia, we found that about 30% of the rock®sh examined were infected with the chlamydialike agent responsible for epitheliocystis, but most were light infections with insigni®cant associated pathological changes (Kent, Traxler, Kieser, Richard, Dawe, Shaw, Prosperi-Porta, Ketcheson & Evelyn 1998). In addition, Kent & Myers (2000) described severe liver lesions in redstripe rock®sh, S. proriger (Jordan & Gilbert), associated with a putative herpes virus. In 2000, Fisheries and Oceans Canada and Oregon Department of Fish and Wildlife research scientists conducted stock surveys of demersal ®sh, and we used this opportunity to conduct disease examinations of these ®sh to elucidate possible roles that diseases play in the demise of some of these stocks. Four species of rock®sh (S. alutus, S. avidus, S. reedi and S. pinniger) were examined from collections conducted off the coasts of Oregon on 5 May 2000 (latitude 44.35.00 N) and 20 September 2000 (latitude 44.40.00 N), and Washington (latitude 46.30.00 N) on 10 May 2000, except that S. reedi was not examined in the latter. An additional collection of S. alutus and S. avidus from Oregon was examined in September 2000. Also included here are data from 89 S. avidus, 56 S. alutus and 56 S. pinniger collected from three localities off British Columbia in the summer of 1999 (Table 1). The southernmost area in British Columbia was off the West coast of Vancouver Journal of Fish Diseases 2001, 24, 427±431

Commercial Blast-Freezing of Third-Stage Anisakis simplex Larvae Encapsulated in Salmon and Rockfish

Sixty-four fish were blast-frozen to -35 C for 15 hr to determine the effects of commercial blast-freezing on the viability of third-stage larvae of Anisakis simplex encapsulated in the muscle and viscera of sockeye salmon (Oncorhynchus nerka) and canary rockfish (Sebastes pinniger). Parallel tests were conducted on larval nematodes in 16 whole (round) salmon, 16 dressed salmon (heads and viscera removed), and 32 whole (round) rockfish. After blast-freezing, 4 in-the-round salmon, 4 dressed salmon, and 8 in-the-round rockfish were examined at 1, 24, 48, and 72 hr. A total of 3,539 dead and 6 live larvae were collected from the fish tissues after standard enzymatic digestion. Salmon were infected with 1,245 of these larvae, and rockfish with 2,300. The 6 live worms, 2 from salmon and 4 from rockfish rounds, were recovered from muscle 1 hr after freezing; they were slightly motile and showed severe internal damage. No viable worms were found at or after 24 hr. The commercial blast-freezing process effectively killed larval nematodes in whole or dressed fish. Market-ready samples of previously blast-frozen silver salmon (O. kisutch) and chum salmon (O. keta) fillets and chum salmon steaks yielded no live worms, thereby confirming the efficacy of this process.

Variation of Growth with Latitude in two Species of Rockfish (Sebastes pinniger and S. diploproa) from the Northeast Pacific Ocean

Variation of Growth with Latitude in two Species of Rockfish (Sebastes pinniger and S. diploproa) from the Northeast Pacific Ocean

LEAD AND CADMIUM CONTENT OF SELECTED OREGON GROUNDFISH

ABSTRACTSThe lead and cadmium content of selected Oregon groundfish was determined. Rex sole (Glyptocephalus zachirus), English sole (Parophrys vetulus), Dover sole (Microstomus pacificus), petrale sole (Eopsetta jordani), orange rockfish (Sebastes pinniger), lingcod (Ophiodon elongatus), Pacific hake (Merluccius productus), starry flounder (Platichthys stellatus) and sand sole (Psettichthys melanostictus) samples had mean lead and cadmium contents of &lt; 0.25 ppm. Therefore Oregon groundfish would not be a source of toxic levels of Pb and Cd in the diet.

Volatile Compounds Produced in Ground Muscle Tissue of Canary Rockfish (Sebastes pinniger) Stored on Ice

Volatile compounds associated with the progressive degradation of ground muscle tissue of canary rockfish (Sebastes pinniger) stored on ice were determined by combined gas–liquid chromatography and mass spectrometry. Compounds positively identified included dimethyl sulfide, n-propyl alcohol, acetaldehyde, propionaldehyde, acetone, ethyl alcohol, 2- and 3-pentanone, diacetyl, hexanal, 1-pentene-3-ol, 3-methyl-1-butanol, acetoin, trimethylamine, and dimethylamine. The following compounds were tentatively identified: propenal, octenal or octadienal, butyraldehyde, 3-methyl butanal, 2-butanone, and methyl vinyl ketone.