# Presentation: 493262

## Update on groundfish stock trends for the Gulf of Alaska

- Gulf of Alaska Groundfish
- Plan Team
- November 2004

**Update on groundfish stock trends ****for the Gulf of Alaska**

- _GOA Plan Team Members_
- James Ianelli (co-chair)	AFSC
- Diana Stram (co-chair)	NPFMC
- Bill Bechtol 	ADFG
- Tory O’Connell	ADFG
- Nick Sagalkin*	ADFG
- Bob Foy	UAF
- Bill Clark	IPHC
- Eric Eisenhardt*	WDF
- Jeff Fujioka	AFSC
- Sarah Gaichas	AFSC
- Jon Heifetz	AFSC
- Tom Pearson	AKR
- Beth Sinclair	NMML
- Kathy Kuletz	USFWS

## Main events in the GOA

**18 assessments (from 14 groups)**
**Amendment 48/48**
- Biennial assessment cycle
- New treatment and assessment requirements
- Issues with projection model
**Two brand new assessments presented**
- Rex sole
- Rougheye rockfish
**Presented last year (and used this year for ABC)**
- Dover sole
- Dusky rockfish

## Amendment 48/48

**“****The proposed specifications will specify for up to 2 fishing years the annual TAC for each target species and the ‘‘other species’’ category and apportionments thereof, halibut prohibited species catch amounts, and seasonal allowances of pollock and Pacific cod.”**

- 50 CFR Part 679.

- Two-Year Ahead ABC and OFL Projections: p. 9 BSAI SAFE report

## 48/48 Considerations

**Biennial cycle of assessments**
- Author’s discretion unless special recommendation is made
- Pollock, cod and sablefish to remain annual
- Atka mackerel kept biennial since there is no age-structured model in the GOA
**2-year recommendations **
- 2005 and 2006
- Caveat on the use of the projection model:
- Uses best information available
- Likely to be conservative since full catch is often less than ABC levels

## GOA Catch and ABC levels

## ABC Summary

|  |  |  ABC  |  |  |  |
| --- | --- | --- | --- | --- | --- |
| Species | 2004 catch | 2004 | 2005 | Change |  |
| Pollock | 61,142 |      71,260  |      91,710  |  up 20,450  | (29%) |
| Pacific Cod | 42,124 |      62,810  |      58,100  |  down 4,710  | (7%) |
| Sablefish | 14,847 |      16,550  |      15,940  |  down 610  | (4%) |
| Flatfish | 7,474 |    122,510  |    116,640  |  down 5,870  | (5%) |
| Arrowtooth flounder | 15,174 |    194,930  |    216,900 |  up 21,970  | (11%) |
| Rockfish | 21,777 |     30,730  |      31,229  |  up 499  | (2%) |
| Total |                    162,538  |   498,790  |   530,519  |  up 31,729  | (6%) |

- Page 35

## GOA Pollock assessment features

**Winter EIT (acoustic) survey (Appendix A) **
**Environmental indices**
**Predator prey evaluation**

## Winter acoustics

- 2003

- 2004

## Shelikof Strait EIT survey 1981-2004

**Shelikof ****Strait ****EIT ****survey **1981-2004

## Pollockmodelresults

- Pollockmodelresults

**Spawning biomass**

**Recruitment**

## EIT fit

## Trawl survey fits

- Trawl survey fits

- NMFS

- ADFG

## Pollock biomass compared to previous analyses

- Pollock biomass compared to previous analyses

## Fishing mortality relative to FOFL

- Fishing mortality relative to FOFL

## Uncertainty in spawning stock biomass

## Gulf of Alaska predationArrowtooth flounder

**Gulf of Alaska predation****Arrowtooth flounder**

## GOA pollock arrowtooth flounder

- GOA pollock arrowtooth flounder

## What pollock eat

- What pollock eat

## Where pollock end up

- Where pollock end up

## Diet diversity of pollock predators

**Diet diversity of pollock predators**

## Trends in pollock predators

**Trends in pollock predators**

## ABC considerations

**2003 BTS survey increase (86%)**
**2004 EIT survey increase (8%)**
**2004 ADF&G survey increase (48%)**
**Concerns over recruitment since 1999**
**Ecosystem interactions clear**
- Role of arrowtooth flounder and other predators

## Added pollock conservation measures

**Model selected**
- Survey catchability assumption fixed at 1.0
**A constant-buffer scheme is used**
**Fishing mortality kept at current (low) level**
- Plan Team used an ABC that only increases by one half the FABC level (20,450 tons instead of 40,900)

## Pollock 2005 ABC

- Author's Recommendation

- 78,980

- 86,100

- Maximum permissible

- 124,800

- Plan Team

## Pollock Spawning biomass

**Spawning biomass (1,000’s tons)**
- 2005 = 	213
- B40%	=	229
- B20%	=	115

## ABC Summary

|  |  |  ABC  |  |  |  |
| --- | --- | --- | --- | --- | --- |
| Species | 2004 catch | 2004 | 2005 | Change |  |
| Pollock | 61,142 |      71,260  |      91,710  |  up 20,450  | (29%) |
| Pacific Cod | 42,124 |      62,810  |      58,100  |  down 4,710  | (7%) |
| Sablefish | 14,847 |      16,550  |      15,940  |  down 610  | (4%) |
| Flatfish | 7,474 |    122,510  |    116,640  |  down 5,870  | (5%) |
| Arrowtooth flounder | 15,174 |   194,930  |   216,900  |  up 21,970  | (11%) |
| Rockfish | 21,777 |     30,730  |      31,229  |  up 499  | (2%) |
| Total |                    162,538  |   498,790  |   530,519  |  up 31,729  | (6%) |

- Page 131

## GOA Catch and ABC levels

## Pacific codWhat’s New?

**Data**
- 2003 catch and length comp updated
- Preliminary 2004 catch and length comp added
- Errors in 2000/2001 length comps corrected
**No changes to the model**
**Results**
- Spawning bio. down 11%, about as expected
- ABC down 7%, about as expected
- New ABC methodology proposed

## Comparative Biomass Trends

## Recruitment by year class

## F vs Spawning biomass levels

- 2004

- 1978

## ABC RecommendationApplying the Alternative Approach to 2005

**New adjustment to ABC applied**
- Trade-off
- Maximizing yield &
- Minimizing catch variability
- 2005 ABC of 58,100 mt (compared to 2004 catch of 58,600)
- 2005 maximum permissible ABC = 73,800 mt
- 2005 OFL = 86,200 mt

## Pacific cod

## Pacific cod

**Female spawning biomass (tons)**
- 2005 = 	91,700
- B40%	=	84,400
- B35%	=	73,850

## GOA Catch and ABC levels

- Page 233

## Sablefish

**Notes**
- Survey abundance decreased ~5% from 2003 estimate
- Status “moderate”
- 2004 biomass about 4% higher than 2000 level
- Below the *B**40%* level (~91%)
- Plan Team agreed with author’s recommended ABC
- Supported the careful examination of uncertainty

## Sablefish survey indices

- Sablefish-Alaska wide

## Sablefish biomass compared to past analyses

## Sablefish summary

## Sablefish spawning biomass

**Spawning biomass (1,000’s tons)**
- 2005 = 	204
- B40%	=	223
- B35%	=	195

## GOA Catch and ABC levels

- Page 299

## New things in GOA flatfish

**Dover sole assessment**
- 1st presented last year, used this year (and for 2006)
**Rex sole assessment**
- Reviewed in September, will be used next year
**Flathead and arrowtooth flounder projected from last year’s estimates**

## Flatfish ABC’s

| Species | 2004 ABC | 2005 ABC | Change |  |
| --- | --- | --- | --- | --- |
| Deep water flatfish |       6,070  |       6,820  |  up 750  | (12%) |
| Rex sole |      12,650  |      12,650  |  same   | (0%) |
| Shallow water flatfish |     52,070  |     52,070  |  same   | (0%) |
| Flathead sole |      51,720  |      45,100  |  down 6,620  | (13%) |
| Arrowtooth flounder |    194,930  |    216,900  |  up 21,970  | (11%) |

- Deep-water ABC derived from Dover assessment (Tier 3) + others (Tier 5)

## Dover sole2nd year presented

## Dover sole

**Female spawning biomass (tons)**
- 2005 = 	36,400
- B40%	=	16,500
- B35%	=	14,400

## Rex soleNew assessment 

## Rex sole

**Female spawning biomass (tons)**
- 2005 = 	35,400
- B40%	=	18,700
- B35%	=	16,400

## Flathead sole(2003 assessment)

## Flathead sole

**Female spawning biomass (tons)**
- 2005 = 	110,000 			(assuming avg. F in projection)
- B40%	=	48,000
- B35%	=	42,000

## Arrowtooth flounder

## Arrowtooth flounder

**Female spawning biomass (tons)**
- 2005 = 	1,375,000			(assuming avg. F in projection)
- B40%	=	 620,000

## Flatfish 2005 ABC’s333,540 tons total

## GOA Catch and ABC levels

- Page 385

## Rockfish assessments

**Pacific ocean perch and Northerns updated**
- But not a “full” assessment (biennial cycle)
**New rougheye rockfish model **
- (Attachment 9B, p. 429)
**Dusky updated and used ****for ABC considerations**
**Research activities presented**

## Rockfish research

- Evaluation of management parameters (Attach 7A p. 387)
- Suggested *F**40%* sufficiently conservative (*F**msy* ~ *F**30%*)
- Reproductive potential at age; Attach 7B, p. 399
- Alternative projections (Attach 7C, p. 403)
- Result in greater uncertainty
- Part of MSE activities (Goodman et al. report)
- Estimation alternatives of SR/RE ABC’s

## Pacific ocean perch

|  |  |  | This year’s projection  |  |
| --- | --- | --- | --- | --- |
|  |  |  | 2005 | 2006 |
| B40% (mt) |  |  | 86,162 | 86,162 |
|  |  |  |  |  |
| Spawning Biomass (mt) |  |  | 92,421 | 90,572 |
|  |  |  |  |  |
| ABC F40% (mt yield at F40%) |  |  | 13,575 | 13,292 |
|  |  |  |  |  |

**Updated assessment, p. 385**

## Pacific ocean perch

## Northern rockfish

|  | This year’s projection 
(updated) |  |
| --- | --- | --- |
|  | 2005 | 2006 |
| B40% (mt)
 | 24,693
 | 24,693
 |
| Spawning Biomass (mt) | 38,272 | 36,108 |
|  |  |  |
| ABC F40% (mt yield at F40%) | 5,093 | 4,749 |
|  |  |  |
|  |  |  |

**Updated assessment, p. 411**

## Northern rockfish

## Shortraker & rougheyerockfish

**Plan Team recommended separate ABC’s **
- Consistent with BSAI approach
- Observer coverage not as good for GOA
**Attachment 9A (p. 416) addresses alternative ABC calculations **
- Species composition estimation methods
- Plan Team recommended splitting these species

## Rougheye model

**ABC 1,162 mt ****(similar to adopted Tier 5 of 1,007)**

- Biomass

- Catch

- Bottom trawl survey

- Longline survey

## Rockfish ABC’s

| Species | 2004 ABC | 2005 ABC | Change |  |
| --- | --- | --- | --- | --- |
| Other Slope rockfish |       3,900  |       3,900  |  same   | (0%) |
| Northern rockfish |       4,870  |        5,091  |  up 221  | (5%) |
| Pacific ocean perch |      13,340  |      13,575  |  up 235  | (2%) |
| Shortraker/ rougheye |        1,760  |        1,760  |  same   | (0%) |
| Shortraker |            -    |          753  |     |   |
| Rougheye |            -    |        1,007  |     |   |
| Pelagic shelf rockfish |       4,470  |       4,553  |  up 83  | (2%) |
| Demersal Shelf Rockfish |          450  |          410  |  down 40  | (9%) |
| Thornyhead rockfish |        1,940  |        1,940  |  same   | (0%) |
| Total |    30,730  |    31,229  |  up 499  | (2%) |

- Pelagic shelf ABC derived from dusky assessment (Tier 3) + others (Tier 5)

## Slope Rockfish 2005 ABC’s24,326 tons total

## Rockfish spawning biomass

**Spawning biomass (1,000’s tons)**
- POP:
- 2005 = 	92.4
- B40%	=	86.2
- Northern:
- 2005 = 	38.3
- B40%	=	24.7

## Pelagic shelf rockfish

**Age-structured assessment of light-dusky rockfish provided**
**Accepted as preferred by the Plan Team**

## Dusky model results

- Recruitment

- Catch

- Biomass

## Pelagic shelf rockfish: biomass

- Dusky, widow, & yellowtail

**Notes:**
2)  Pelagic shelf rockfish - formally the dusky rockfish M was applied
to a 3 survey average biomass to come up with the complex ABC.  Now the
assessment appropriately partitions out dusky rockfish and considers
them in Tier 4, versus the other components - widow and yellowtail
rockfish, which are in Tier 5.  ABCs are computed separately for dusky
(F=M x ave. biomass) and for widow and yellowtail combined (0.75M x ave.
biomass).  The slide now shows the dusky ave. biomass and the widow and
yellowtail ave. biomass

## Dusky rockfish spawning biomass

**Spawning biomass (1,000’s tons)**
- 2005 	= 	17.1
- B40%	=	14.3
- B35%	=	12.5

## Demersal shelf rockfish

## Thornyheads

## Thornyhead spawning biomass

**Spawning biomass (1,000’s tons)**
- 2005 	= 	24.5
- B40%	=	15.8

## Rockfish Stock Status

## Atka mackerel

**Easterly appearance**
- Summer bottom trawl survey and fishery data suggest influx of 1998 or 1999 year class from the Aleutians
- ABC recommended at 600 tons, sufficient to allow for bycatch levels
- Catch (817 mt) exceeded ABC in 2004
- (OFL=6,200 mt)

## Skates

**In GOA, 2 main target species**
- Big skate	(*Raja binoculata*)
- Longnose skate 	(*Raja rhina*)
**3****rd**** group composed of many species **
*Bathyraja spp.*
- not targeted to date
**Rough relative biomass estimates (in GOA)**
- Big skate ~50%,
- longnose about 32%,
- ~18% to *Bathyraja spp.*

## Skate catch estimation

**Difficult, requires expansion to linked target**
- But species ID anticipated to be sufficiently improved for 2005 mgt purposes
**Halibut fishery appears to be a large contributor**

## Skate ABC recommendations

**Last year**

## Skate ABC recommendations

**This year**

## 2005 ABC’s

## 2004 Catch

## Slide 80

## Other recommendations

**Other species TAC specifications**
- Interim measure: change other species TAC to _<_ 5% of combined GOA groundfish TACs
- Eventually specify ABCs individually as part of the non-target initiative
**Dark rockfish **
- Remove dark rockfish from the FMP