# Presentation: 193314

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

- Gulf of Alaska Groundfish
- Plan Team

**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
- Mike Ruccio	ADFG
- Bob Foy	UAF
- Kathy Kuletz	USFWS
- Bill Clark	IPHC
- Farron Wallace	WDF
- Jeff Fujioka	AFSC
- Sarah Gaichas	AFSC
- Jon Heifetz	AFSC
- Tom Pearson	AKR
- Beth Sinclair	NMML

## Main events in the GOA

**16 assessments of species groups**
**NMFS 2003 Summer bottom trawl survey**
- Gulf-wide this year (2001 excluded the EGOA
- Depths to 700m
- Results show most estimates higher than 2001
**Skate fishery development **
- Assessment included

## ABC Summary

## Slide 4

## GOA Pollock studies

**CIE Review**
**Model averaging analysis**
- Conclusion that the CHS (*F**35%*~*F**msy*) reasonable
- Environmental conditions important
**Juvenile mortality analysis**
- Attempts to account for predation on younger pollock
**Acoustic surveys in 2003:**
- Winter (Appendix D)
**New!** Summer acoustic
- Not used in assessment (feasibility)

## Winter acoustics

## Fit to recent winter acoustic surveys

- Fit to recent winter acoustic surveys

## NMFS bottom trawl survey

## Trawl survey fits

- Trawl survey fits

- NMFS

- ADFG

## Pollockmodelresults

- Pollockmodelresults

**Recruitment**

**Spawning biomass**

## Added pollock conservation measures

**Model selected**
- Survey catchability assumption fixed at 1.0
**Updated maturity-at-age used**
**Assuming average 1999 yearclass**
**Constant-buffer scheme used**

## Pollock 2004 ABC

- Average 1999 year class

- 1999 year class
- as estimated

- Author's adjustment

- 65,700

- 118,000

- Maximum
- permissible

- 78,000

- 99,400

## Pollock Spawning biomass

**Spawning biomass (1,000’s tons)**
- 2004 = 	195 (166 assuming avg 1999YC)
- B40%	=	248
- B20%	=	124

## Environmental effects on GOA Pollock

**arrowtooth flounder **

## Gulf of Alaska predationArrowtooth flounder

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

## GOA pollock&  arrowtooth flounder

- GOA pollock&  arrowtooth flounder

## ABC Summary

## Pacific cod

**Notes:**
- Selectivity estimated over three stanzas:1978-86, 1987-99, & 2000 to the present
- Risk-averse ratio applied to *F**40%*
- Steller sea lion prey species
- Survey and catch series updated (some significant changes)
- Spatial analysis of catch trends included

## Pacific cod

## Pacific cod

**Female spawning biomass (tons)**
- 2004 = 	103,000
- B35%	=	77,800
- B40%	=	88,900

## ABC Summary

## Sablefish

**Notes**
- Survey abundance decreased ~7% from 2002 estimate
- Status “moderate” and increased from recent low levels
- About at *B**40%* level
- Authors proposed ABC recommendation based on estimates of probability of future stock sizes
- Used the SSC requested approach of harvest rates in projections
- Plan Team agreed with ABC (in general)
- Two recommendations were 0.8 and 0.9 of Max ABC

## Sablefish

## Sablefish retrospective pattern

## Sablefish spawning biomass

**Spawning biomass (1,000’s tons)**
- 2004 = 	210
- B40%	=	211
- B35%	=	185

## ABC Summary

## Flatfish ABC’s

| Species | 2003 ABC | 2004 ABC | Change |  |
| --- | --- | --- | --- | --- |
| Deep water flatfish |       4,880  |       6,070  |  up 1,190  | (24%) |
| Rex sole |       9,470  |      12,650  |  up 3,180  | (34%) |
| Shallow water flatfish |     49,340  |     52,070  |  up 2,730  | (6%) |
| Flathead sole |      41,390  |      51,720  |  up 10,330  | (25%) |
| Arrowtooth flounder |    155,140  |    194,930  |  up 39,790  | (26%) |

## Flathead sole 

## Flathead sole

**Female spawning biomass (tons)**
- 2004 = 	110,000
- B35%	=	42,000

## Arrowtooth flounder

## Flatfish 2004 ABC’s265,720 tons total

## ABC Summary

## Rockfish ABC’s

| Species | 2003 ABC | 2004 ABC | Change |  |
| --- | --- | --- | --- | --- |
| Other Slope rockfish |       5,050  |       3,900  |  down 1,150  | (23%) |
| Northern rockfish |       5,530  |       4,870  |  down 660  | (12%) |
| Pacific ocean perch |      13,660  |      13,340  |  down 320  | (2%) |
| Shortraker/ rougheye |        1,620  |        1,760  |  up 140  | (9%) |
| Pelagic shelf rockfish |       5,490  |       4,470  |  down 1,020  | (19%) |
| Demersal Shelf Rockfish |          390  |          450  |  up 60  | (15%) |
| Thornyhead rockfish |       2,000  |        1,940  |  down 60  | (3%) |

## Pacific ocean perch

## Northern rockfish

## Slope Rockfish 2004 ABC’s23,870 tons total

## Rockfish spawning biomass

**Spawning biomass (1,000’s tons)**
- POP:
- 2004 = 	95.8
- B40%	=	89.7
- Northern:
- 2004 = 	36.5
- B40%	=	23.9

## Shortraker rougheye survey trends

## 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

## Pelagic shelf rockfish

**Age-structured assessment of light-dusky rockfish provided**
**Accepted as preferred by the Plan Team**
- (more conservative option)

## Pelagic shelf rockfish: catch

- 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

## Demersal shelf rockfish

## Thornyhead survey estimates

## Thornyheads

## Thornyhead spawning biomass

**Spawning biomass (1,000’s tons)**
- 2004 	= 	26.2
- B40%	=	16.9

## 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

## 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**
**Halibut fishery appears to be a large contributor**
**AFSC has developed ID keys**
- Observers trained for ID starting 2003
- Some additional shoreside sampling provided by ADFG

## Other skates

## Big and longnose

## What are the conservation concerns?

**Localized areas of directed fishery**
**Uncertain ability to monitor catches**
**Landings predominantly large females**
**Large skates vulnerable in other parts of the world **
- E.g., Atlantic Barndoor skate is a related species
**Uncertain harvest rate **
- Little known on the biology

## Plan Team recommendations for GOA skates

**Ease into more strict area and species specific ABCs**
- Minimize inadvertent harvests due to poor sampling
- Set ABC’s for main target groups to area and a conservative TAC for Central GOA
- Develop needed data collection systems

- Skate concentrations

## Summary by biomass

## Projected biomass by species~5.5 million tons total

## Summary by ABC’s

## Projected ABC’s by species 508,010 tons total (Plan Team)