Last updated on 28 February 2018

SUMMARY

SUMMARY

IDENTIFICATION

SCIENTIFIC NAME(s)

Sebastolobus alascanus

SPECIES NAME(s)

Shortspine thornyhead

COMMON NAMES

shortspine channel rockfish, rock cod, spinycheek rockfish

Shortspine thornyhead (Sebastolobus alascanus) are found in the waters off of the West Coast of the United States from northern Baja California to the Bering Sea. They are found from 20 to over 1,500 meters in depth. Shortspine thornyhead do not appear to be distributed evenly across the West Coast, with higher densities (kg/ha) of thornyheads in shallower areas (under 500 meters) off of Oregon and Washington, and higher densities in deeper areas off of California (Piner and Method 2001).

Although their densities vary, shortspine thornyheads are present in almost all trawlable areas below 500 m. They are caught in 91% of the trawl survey hauls below 500 m and 94% of the commercial bottom trawl hauls below 500 m. Trawl landings represent only bottom trawl gear and non-trawl landings include all other gears, the majority of which is longline, with some catch by pot gear. Both trawl and non-trawl landings are divided into North (the waters off Washington and Oregon) and South (the waters off California) fleets although they are assumed to be fishing on the same unit stock (Taylor and Stephens 2013).

Genetic studies of stock structure do not suggest separate stocks along the west coast. Siebenaller (1978) and Stepien (1995) found few genetic differences among shortspine thornyheads along the Pacific coast.

This resource is modeled as a single stock because genetic analyses do not indicate significant stock structure within this range. This is the same stock assumption made in the most recent assessment of shortspine thornyhead in 2005 (Hamel 2005).

This fishery was certified by the Marine Stewardship Council system in June 2014. Click here to link to the MSC fishery page and to learn more about the MSC fishery certification unit.


ANALYSIS

Weaknesses

The absence of a reliable ageing method provides a significant hindrance to estimating growth and natural mortality of shortspine thornyhead (Taylor and Stephens 2013).

The indices of abundance are all relatively flat, providing little information about the scale of the population (other than providing evidence that it has not been declining) (Taylor and Stephens 2013).

FISHSOURCE SCORES

Management Quality:

Management Strategy:

NOT YET SCORED

Managers Compliance:

NOT YET SCORED

Fishers Compliance:

NOT YET SCORED

Stock Health:

Current
Health:

NOT YET SCORED

Future Health:

NOT YET SCORED


RECOMMENDATIONS

RETAILERS & SUPPLY CHAIN
  • Monitor the progress in closing out conditions placed upon the MSC certification of the fishery and if agreed timelines are met. Offer assistance in closing conditions where possible.

FIPS

No related FIPs

CERTIFICATIONS

  • US West Coast limited entry groundfish trawl:

    MSC Certified

Fisheries

Within FishSource, the term "fishery" is used to indicate each unique combination of a flag country with a fishing gear, operating within a particular management unit, upon a resource. That resource may have a known biological stock structure and/or may be assessed at another level for practical or jurisdictional reasons. A fishery is the finest scale of resolution captured in FishSource profiles, as it is generally the scale at which sustainability can most fairly and practically be evaluated.

ASSESSMENT UNIT MANAGEMENT UNIT FLAG COUNTRY FISHING GEAR
US west coast United States United States Single boat bottom otter trawls

Analysis

OVERVIEW

Last updated on 17 October 2016

Weaknesses
US west coast

Last updated on 17 October 2016

The absence of a reliable ageing method provides a significant hindrance to estimating growth and natural mortality of shortspine thornyhead (Taylor and Stephens 2013).

The indices of abundance are all relatively flat, providing little information about the scale of the population (other than providing evidence that it has not been declining) (Taylor and Stephens 2013).

RECOMMENDATIONS

Last updated on 1 November 2018

Recommendations to Retailers & Supply Chain
  • Monitor the progress in closing out conditions placed upon the MSC certification of the fishery and if agreed timelines are met. Offer assistance in closing conditions where possible.

1.STOCK STATUS

STOCK ASSESSMENT
US west coast

Last updated on 17 October 2016

Spawning biomass is estimated to have remained stable until the mid-1970s and then declined from the 1970s to about 80% in the 1990s, followed by a slower decline under the lower catch levels in the 2000s. The estimated spawning biomass in 2013 is 140,753 t, which represents a depletion of 74.2% (95% CI of 56.1% - 92.3%). The depletion estimated for 2005 is 76.4%, which is higher than the 62.9% estimated for 2005 in the previous assessment (Taylor and Stephens 2013).

The stock status remained above 40% in all years, regardless of the state of nature or management decision. The most pessimistic forecast scenario, combining the low state of nature with the high catch stream, resulted in a projected stock status of 41.6%, just above the target value. All other projections led to a higher projected status, with a maximum of 89.1% for the combination of the high state of nature and low catch (Taylor and Stephens 2013).

SCIENTIFIC ADVICE
US west coast

Last updated on 17 October 2016

Reference Points

Last updated on 17 Oct 2016

In general, the population is at a healthy status relative to the reference points. Sustainable total yield (landings plus discards) was estimated at 2,034 mt when using an SPR50% reference harvest rate and ranged from 633 – 3,435 mt based on estimates of uncertainty. The spawning biomass equivalent to 40% of the unfished spawning output (B40%) was 75,906 mt.

The most recent catches (landings plus discards) have been lower than the estimated long-term yields calculated using an SPR50% reference point, but not as low as the lower bound of the 95% uncertainty interval. However, this is due to the fishery not fully attaining the full ACL. The OFL and ACL values over the past 6 years have been approximately 2,400 mt and 2,000 mt, respectively. Both of those values are lower than the OFL and ACL values predicted in short-term forecasts, which are around 3,200 mt and 2,700 mt respectively for 2015–2016 (Taylor and Stephens 2013).

CURRENT STATUS
US west coast

Last updated on 17 October 2016

Populations have declined in all areas assessed. Overall it has declined by 53% from the estimated unfished biomass to the biomass in 1998 (Taylor and Stephens 2013).

Currently, stock status was determined to be above the target biomass and catches did not attain the full management limits so reassessment of thornyheads has not been a higher priority (Taylor and Stephens 2013).

Trends

Last updated on 17 Oct 2016

Landings of shortspine are estimated to have risen to a peak of 4,815 mt in 1989, followed by a sharp decline during a period of trip limits and other management measures imposed in the 1990s. Since the institution of separate trip limits for shortspine and longspine thornyheads, the fishery had more moderate removals of between 1,000 and 2,000 mt per year from 1995 through 1998. Landings fell below 1,000 mt per year from 1999 through 2006, then rose to 1,531 in 2009 and have declined since that time (Hamel 2005).

2.MANAGEMENT QUALITY

MANAGEMENT
US west coast

Last updated on 17 October 2016

Since early 2011, trawl harvest of each thornyhead species has been managed under the PFMC’s catch share, or individual fishing quota (IFQ), program. Whereas the trip limits previously used to limit harvest restricted only the amount of fish each vessel could land, individual vessels fishing under the catch-share program are now held accountable for all of the quota-share species they catch.

Catches for shortspine thornyheads have not fully attained the catch limits in recent years. Increases in ACLs in 2007 was associated with higher catch levels in 2006–2010, but in 2011 and 2012, catches were about half of the allowed limit. The fishery for shortspine thornyhead may be limited more by the ACLs on sablefish with which they co-occur and by the challenging economics of deep sea fishing, than by the management measures currently in place (Taylor and Stephens 2013).

3.ENVIRONMENT AND BIODIVERSITY

BYCATCH
Other Species
US west coast

Last updated on 17 October 2016

Discard rates (landings divided by total catch) for shortspine have been estimated as high as 43% per year, but are more frequently below 20%. Discard rates in the trawl fisheries declined over the period where they are available from West Coast Groundfish Observer Program (WCGOP) from 2003–2011 and dropped to less than 1% in 2011, the only estimate available under catch shares system that began that year (Taylor and Stephens 2013).

FishSource Scores

MANAGEMENT QUALITY

STOCK HEALTH:

No data available
No data available
No data available
No data available
No data available
No data available
No data available
No data available
No data available
No data available
No data available
No data available

Fishery Improvement Projects (FIPs)

No related FIPs

Certifications

Marine Stewardship Council (MSC)

SELECT MSC

NAME

US West Coast limited entry groundfish trawl

STATUS

MSC Certified on 3 June 2014

SCORES

Principle Level Scores:

Principle Score
Principle 1 – Target Species – Arrowtooth flounder 85.6
Principle 1 – Target Species – Dover sole 84.4
Principle 1 – Target Species – English sole 85.6
Principle 1 – Target Species – Petrale sole 81.0
Principle 1 – Target Species – Lingcod (North) 93.8
Principle 1 – Target Species – Lingcod (South) 88.8
Principle 1 – Target Species – Sablefish 83.3
Principle 1 – Target Species – Chilipepper rockfish 88.8
Principle 1 – Target Species – Longspine thornyhead 92.5
Principle 1 – Target Species – Shortspine thornyhead 92.5
Principle 1 – Target Species – Splitnose rockfish 92.5
Principle 1 – Target Species – Widow rockfish 88.8
Principle 1 – Target Species – Yellowtail Rockfish (N – Vancouver) 92.5
Principle 1 – Target Species – Yellowtail Rockfish (N – Columbia) 87.5
Principle 1 – Target Species – Yellowtail Rockfish (N – Eureka) 87.5
Principle 1 – Target Species – Yellowtail Rockfish (South) < 60
Principle 1 – Target Species – Longnose Skate 92.5
Principle 2 - Ecosystem 85.0
Principle 3 – Management System 94.4

Certification Type: Silver

Sources

Credits
  1. Piner K. and Method M. 2001. Stock status of Shortspine thornyhead off the Pacific west coast of the United states 2001. Northwest Fisheries Science Center, 26th July 2001. 161pphttp://www.pcouncil.org/wp-content/uploads/Shortspine_Thornyhead_2001_Assessment.pdf

  2. Medley, P.A.H., O’Boyle, R., Pedersen, M.G., Tingley, G.A., Hanna, S. S., Devitt, S., 2014. MSC Assessment Report for United States West Coast Limited Entry Groundfish Trawl Fishery. Version 6: Public Certification Report. Intertek Fisheries Certification, June 2014. 403pphttp://www.msc.org/track-a-fishery/fisheries-in-the-program/certified/pacific/us_west_coast_limited_entry_groundfish_trawl/assessment-downloads-1/20140602_PCR_V2_GRO223.pdf

  3. Taylor, I. and Stephens, A., 2013. Stock Assessment of Shortspine Thornyhead in 2013. Portland: Pacific Fishery Management Council. http://www.pcouncil.org/wp-content/uploads/Shortspine_2013_Assessment.pdf

  4. Siebenaller, J. F. 1978. Genetic variability in deep-sea fishes of the genus Sebastolobus (Scorpaenidae). In: Battaglia, B. and Beardmore, J.A, [Eds.] Marine organisms: genetics, ecology and evolution.  

  5. Stepien. C. A. 1995. Population Genetic Divergence and Geographic Patterns from DNA Sequences: Examples from Marine and Freshwater Fishers. American Fisheries Society Symposium. 17:263-287. Stewart, I. J. and O. S. Hamel. In review. Bootstrapping to inform effective sample sizes for length- or age-composition data used in stock assessments.

  6. Hamel, O.S. 2005. Status and Future Prospects for the Shortspine Thornyhead Resource in Waters off Washington, Oregon, and California as Assessed in 2005. Pacific Fishery Management Council, Portland, OR, 74 pp.

References

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