Last updated on 28 February 2018

SUMMARY

SUMMARY

IDENTIFICATION

SCIENTIFIC NAME(s)

Sebastolobus altivelis

SPECIES NAME(s)

Longspine thornyhead

COMMON NAMES

longspine channel rockfish

Longspine thornyhead (Sebastolobus altivelis) are found from the southern tip of Baja California, Mexico, to the Aleutian Islands but are abundant from Southern California northward (Medley et al 2014).

Population genetic studies based on mitochondrial DNA sequences (mtDNA) support the prediction of wide ranging dispersal with little to no geographic population diversity off the US west coast. For modelling purposes, one stock of longspine thornyhead was assumed to exist in the assessed area. It is unlikely that there are significant interactions across the northern (US/Canada) and southern (US/Mexico) boundaries of the stock unit, thus, this species is managed as a single stock within the US EEZ from the Canadian to Mexican border (Fay 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 major sources of uncertainty in this stock assessment include: (1) the catchability coefficient (q) for the slope survey(s), and (2) the value(s) assumed for the rate of natural mortality (M). The assessment is datalimited and driven by the slope survey biomass estimates and the values for q and M. A likelihood profile for the slope survey catchability (q) revealed that although this parameter is highly uncertain, only extremely high values (>15, which are very unlikely) result in estimates of 2005 population status that are close to or below the minimum stock size threshold (Fay 2005).

Options

Landings (target and bycatch) mostly by OT (1964 – present); discards observer derived and historical studies; higher in North and 16% recently; assumed 100% PCM (Fay 2005).

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 US west coast United States Single boat bottom otter trawls

Analysis

OVERVIEW

Last updated on 12 October 2016

Weaknesses
US west coast

Last updated on 12 October 2016

The major sources of uncertainty in this stock assessment include: (1) the catchability coefficient (q) for the slope survey(s), and (2) the value(s) assumed for the rate of natural mortality (M). The assessment is datalimited and driven by the slope survey biomass estimates and the values for q and M. A likelihood profile for the slope survey catchability (q) revealed that although this parameter is highly uncertain, only extremely high values (>15, which are very unlikely) result in estimates of 2005 population status that are close to or below the minimum stock size threshold (Fay 2005).

Options
US west coast

Last updated on 12 October 2016

Landings (target and bycatch) mostly by OT (1964 – present); discards observer derived and historical studies; higher in North and 16% recently; assumed 100% PCM (Fay 2005).

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 12 October 2016

Aging data available with no evidence of aging bias. Steepness assumed = 0.75. Limited historical and survey maturity and fecundity data. M estimated in assessment model = 0.06 (Medley et al 2014).

2005 spawning biomass of longspine thornyhead is estimated to be 71% of the unexploited equilibrium level. The stock is therefore well above the management target of SB40%. The current fishing mortality rate is also well below the Fmsy proxy (F50%) (Fay 2005).

The stock, is currently only lightly exploited, with spawning 2013 biomass estimated to be over 29,400 t with a depletion of 75% (95% confidence interval of 53.5% - 96.9%) (Stephens and Taylor 2014).

SCIENTIFIC ADVICE
US west coast

Last updated on 12 October 2016

Tagging suggests limited movements while age/size/sex data indicate mixing as adults. Genetics is suggestive of one stock (Medley et al 2014).

A more thorough investigation/examination of the slope surveys is required to better determine the catchability coefficient (q) and selectivity. More extensive estimates of thornyhead density and habitat associations, perhaps from remote camera observations would improve knowledge regarding slope survey parameters and help to resolve uncertainty for these parameters (Fay 2005).

Reference Points

Last updated on 12 Oct 2016

The Pacific Fishery Management Councilís current target harvest rate for longspine thornyhead is F50%, which was estimated to be 0.055 for the base-case model. The Councilís current target biomass level for exploited groundfish stocks is SB40%, i.e., a spawning biomass that is 40% of that expected in the absence of fishing. The reference point at which groundfish stocks are defined to be overfished is currently SB25%, i.e., a spawning biomass that is 25% of that expected in the absence of fishing. Estimated values for SB40% and SB25% for longspine thornyhead are 42,063 mt and 26,289 mt respectively (Fay 2005)..

CURRENT STATUS
US west coast

Last updated on 12 October 2016

Total and spawning biomass of longspine thornyhead has shown a decline since the late 1980s, with the rate of this decline slowing since the mid 1990s due to reduced catches. The stock, however, is only lightly exploited, and the current spawning biomass is estimated to be over 75,000 mt, i.e. 71% of the unfished equilibrium level (Fay 2005)..

The stock, is currently only lightly exploited, with spawning 2013 biomass estimated to be over 29,400 t with a depletion of 75% (95% confidence interval of 53.5% - 96.9%) (Stephens and Taylor 2014).

Trends

Last updated on 12 Oct 2016

Only very small amounts of longspine thornyhead are caught using other gears. Catches increased gradually during the 1960s and 1970s, but the fishery did not expand significantly until the late 1980s with the development of a market for smaller thornyheads. At their peak in the early 1990s, annual catches were around 6,000 mt. The catches have declined in recent years in response to increased management restrictions. Catches in this assessment were estimated for the period 1964-2004. Allowing for additional discarding in early years, inclusion of estimated foreign catches for 1965-1976, and estimation of additional historical catches for 1900-1963 had little impact on model results as these catches were small relative to those during the early 1990s (Fay 2005).

The Allowable Biological Catch (ABC) and Optimum Yield (OY) for longspine thornyhead has declined since the adoption of separate ABCs for the two thornyhead species by the PFMC in 1992. Estimated catches (landings plus discard) of longspines have been below the harvest guidelines, due to the challenge involved in fully exploiting this resource without exceeding the OYs for shortspine (Medley et al 2014).

Twelve-year projections (2013 – 2024) were conducted with a total catch assumed equal to the ACL. Stock status remained above 25% 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 31.58% in 2024. All other projections led to a higher projected status, with a maximum of 86.27% for the combination of the high state of nature and low catch. Forecasts under the base case led to estimated status ranging from 2024 spawning depletion values of 50.06% in the high catch stream to 70.16% in the low catch stream. (Stephens and Taylor 2014).

2.MANAGEMENT QUALITY

MANAGEMENT
US west coast

Last updated on 12 October 2016

Longspine thornyhead is considered a QS species, and for these species traditional management tools such as trip limits and set-asides are used to control fishing mortality (Medley et al 2014).

Establishment of a maximum share that each limited access privilege holder is permitted to hold, acquire, or use, in case of Lingcod, about 2.5% (Medley et al 2014).

• Two-month or monthly cumulative landing limits (trip limits)

• Gear requirements, principally relating to trawl gear

• Time and area closures. For example, groundfish conservation areas (GCAs) prohibit vessels from fishing in depths where overfished groundfish species are more abundant. GCAs include coastwide rockfish conservation areas (RCAs) and more geographically discrete Cowcod Conservation Areas (CCAs) in the Southern California bight and Yelloweye Rockfish Conservation Areas (YRCAs) off of Oregon and Washington.

• Bycatch limits for the Pacific whiting sectors for select overfished species (PFMC, 2011q)

3.ENVIRONMENT AND BIODIVERSITY

HABITAT
US west coast

Last updated on 12 October 2016

With respect to the SI to demersal trawling, most habitats were assigned values between 0.0 (no impact) and 2.0 (substantial changes). However, with respect to habitats classified as slope - biogenic corals and slope - biogenic, sponges, values of 3.0 (major changes) were allocated. Similarly, with respect to the RI, most habitats were considered to be able to recover within 0 and 2 years (Medley et al 2014).

Thus, based on: (i) the scale of the fishery (~100 vessels), (ii) the understanding about sensitivity and recovery times, (iii) area closures in place to protect sensitive habitats, and (iv) area closures for other reasons (e.g. RCAs), it is highly unlikely that the fishery is reducing habitat structure and function to a point where there would be serious or irreversible harm (Medley et al 2014).

Marine Reserves

Last updated on 12 Oct 2016

West coast MPAs fall into four different designations, each with rather different principal goals but all generating some significant level of benthic protection from fishing in general and demersal trawling in particular.

The four designation types are:

1) Sanctuaries: there is a network of marine sanctuaries operated under the National Marine Sanctuary Program (NMSP). Sanctuaries have very restricted permitted activities. The west coast has five sanctuaries. http://sanctuaries.noaa.gov

2) Marine protected areas (MPAs): there is a large network of MPAs, with many on the west coast. www.mpa.gov/

3) EFH protection areas: areas closed to bottom fishing to protect specific EFH. http://www.pcouncil.org/groundfish/background/document-library/groundfish-essential-fish-habitatmodification-process/

4) Rockfish Conservation Areas (RCAs): closed to bottom fishing to protect overfished rockfish from trawling. These include areas closed to protect (i) rockfish assemblages, (ii) cowcod, and (iii) yelloweye rockfish. RCAs are substantial areas and have typically been closed since the early 2000’s. PFMC (2010a).

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. 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

  2. Fay, G (2005) Stock Assessment and Status of Longspine Thornyhead (Sebastolobus altivelis) off California, Oregon and Washington in 2005. School of Aquatic and Fishery Sciences, University of Washington, Seattle WA 98195-5020. 30th August 2005 http://dev.pcouncil.org/wp-content/uploads/LST_08_30_05.pdf.

  3. Stephens, I.G. and I.G. Taylor. 2014a. Stock Assessment and Status of Longspine Thornyhead (Sebastolobus altivelis) off California, Oregon and Washington in 2013. Northwest Fisheries Science Center, U. S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, 2032 S.E. OSU Drive, Newport, Oregon 97365.

References

    Comments

    This tab will disappear in 5 seconds.

    Comments on:

    Longspine thornyhead - US west coast, US west coast, United States, Single boat bottom otter trawls

    comments powered by Disqus