2018 TRAC Status ReportsNEFMC meeting

Plymouth, MA September 26, 2018

2018 TRACEastern Georges Bank Cod

I. Andrushchenko, C.M. Legault, R. Martin, Y. Wang and E.N. Brooks

5Zjm Cod – Catches

• Canadian + USA 2017 total catch: 526 mt (Quota 730 mt).

• Canadian 2017 catch 488 mt (Quota 584 mt).

• Canadian discards were estimated at 7 mt from the groundfish fishery, 7 mt from the scallop fishery

• USA 2016 catch 38 mt (USA using different quota year, 146 mt).

• US discards were 4 mt from the groundfish fishery

0

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1978 1983 1988 1993 1998 2003 2008 2013

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2010 2011 2012 2013 2014 2015 2016 2017

Catc

h (

mt)

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USA Canada

5Zjm Cod – Fishery Catch at Age

• Ages 3 and 4 made major contribution to the catch in 2017

• Older ages still low/absent

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ear

Age

Proportion of Age Composition

• Scaled series of survey biomass

• All three decreased below the series mean

Figure 21, Table 10

5Zjm Cod - Survey Biomass Indices

Weights at Age (WAA)

• WAA declined throughout the 1990s and 2000s

• Fishery WAA on ages 5-9 improved in recent years, but improvement not

seen in survey WAA.

• Population WAA likely remains low.

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igh

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SurveyFishery

Condition of Fish

• Fulton’s K decreased to series low

in late 2000s.

• Recovered since then and is

currently around long-term mean

for all three surveys.

Figure 23

VPA Output

• The 2018 3+ biomass is

estimated at 9,502 mt; model

has a strong retrospective.

• Recent increases in biomass

are driven by recruitment

events: 2003, 2010 and 2013

yearclasses.

• Many recent recruitments are

the lowest on record (2002,

2004, 2007, 2007, 2008,

2012, 2015, <0.7 million).

• Recruitment estimate for the

2016 year class is low (1

million)

• Current estimate of adult

biomass remains below levels

needed for higher recruitment

Figures 32, 31 and Table 14

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00m

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recruitment

biomass

• 2018 model estimates F4-9

increasing to a peak in 2012, then

decreasing sharply. Not consistent

with relative F.

• Recent trends subject to strong

retrospective.

• 2018 model estimates 2017 F4-9 =

0.04.

Figure 34

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Catch

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F=0.11

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1978 1983 1988 1993 1998 2003 2008 2013 2018

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tive

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1978 1983 1988 1993 1998 2003 2008 2013 2018

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tive

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Relative F - NMFS spring survey

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ages6-8

VPA Output

ASAP Output

• ASAP shows similar trend in

biomass and F, but different

scale.

• Has diagnostic issues

(retrospective, residuals,

poor performance).

• Last year of survey data not

in model.

Empirical approach

• An empirical method was developed in 2016 to provide another means of quota advice independent of the two models (VPA and ASAP).

• Last point in survey series has a big impact; method can show drastic variation from year to year.

Slope last year

Slope this year

TRAC Catch advice

• For the 2019 quota advice, TRAC recommends a range of 602 mt (‘low’) to 676 mt(‘neutral’).

• The low risk catch advice (602 mt) is derived from the VPA and ASAP 25% risk (743 mtand 418 mt) of exceeding model-specific reference F and the empirical approach median (644 mt).

• The neutral risk catch advice (676 mt) is the average of the VPA and ASAP 50% risk (860 mt and 524 mt) and the empirical approach median (644 mt).

• Even in the absence of fishing, the stock is not expected to increase from 2019 to 2020 or 2020 to 2021 in the VPA due to the 2013 cohort entering the ages of high natural mortality.

Questions?

Eastern Georges Bank Haddock

M. Barrett, L. Brooks, and Y. Wang

5Zjm

Eastern Georges Bank Haddock Updatefor 2018

▪ Eastern Georges Bank haddock has been showing positive signs:

▪ 6 strong year classes in the last 15 years

▪ Expanded age structure

▪ Broad spatial distribution

▪ Adult biomass at the beginning of 2017 is estimated to be the second highest in the time series

▪ In 2016, TRAC was tasked with preparing an update report

▪ Indicators of stock status (fishery and survey)

▪ Determine if advice from the previous assessment is still appropriate.

▪ In 2017, an evaluation of the update report was completed.

2017 Commercial Catch

▪ USA + Canadian total catch was 13,679 mt in 2017 (quota 50,000 mt), 27% of total quota

▪ Canadian catch was 13,384 mt in 2017, 65% of quota

▪ USA catch was 295 mt in 2017, 1.4% of quota (fishing year)

50,000 mt

13,679 mt

EGB Haddock- Yearclass Growth

▪ Data from DFO

survey

▪ Decrease in

growth rates at

age

▪ At age 5, 2013

year class was

39.3 cm

compared to 44.5

cm for 2010 year

class

2017-2018 Survey Trends

• Biomass index from the surveys show similar trends

▪ Significant decrease for NMFS spring and fall

▪ Slight decrease for DFO

▪ Biomass indices for all 3 surveys are above historical values

DFO Weight at Age (WAA) and Condition

▪ RV survey data show declining

trends in mean WAA from 2000 to

present; especially ages 3 and older

▪ Age 5 WAA (2013 yc) in 2018 is

lowest in time series

▪ Fish condition (W/L3) has generally

been below the long term average

since 2004, lowest value in 2017.

VPA Projections vs. Survey Trends• Biomass was projected to decrease

from 274,482 to 265,881 mt in 2018 (down 3%).

• Average survey biomass decreased from 174,822 to 68,017 mt (down 61%) in 2018 and was 74% lower than predicted by VPA (49% lower for rho adjusted).

• Survey biomass indices:– 2013 yc (age 5) was highest in time series

for DFO and second highest for NMFS spring.

• Weight at age (DFO)– Declining trend since 2000

– WAA were similar to the ones used for projections except for overestimating 2010 and 2013 yc

Special Considerations

• Different vessels for NMFS fall (2017) and DFO (2018) surveys.

• Model inputs for both the 2013 and 2010 year classes were overestimated in the 2017 assessment resulting in overestimation of population biomass.

• Total mortality calculated from the survey average was high for the 2013 yc, suggesting only 30% survival, however, relative fishing mortality was low.

Indicators and Recommendation

Maintain Existing Catch Advice Reduce Catch Advice

In 2018, DFO survey index of abundance for

Age 5 (2013 year class) fish are at the highest

value for the time series and the second

highest for NMFS spring survey.

Average biomass from the surveys was 74%

lower than the biomass predicted in the VPA for

2018, despite only 27% of the quota being

caught in 2017.

VPA estimate of adult biomass in 2017

declined slightly from 2016 value, which was

the highest in the time series.

Weights at age from the DFO survey have been

declining since 2000, and 2018 values were

overestimated for the very large 2013 and 2010

year classes.

Only 27% of the 2017 quota was caught. Recent quotas selected for neutral risk have not

been fully caught, yet F>Fref (2010-2014). Risk

is being underestimated and catch is being

overestimated.

2017 NMFS fall and 2018 DFO and NMFS

survey total biomass indices decreased, but

all three are above historical values.

A retrospective pattern has been observed in the

2017 TRAC assessment. The pattern leads to

overestimated biomass and underestimated F.

Probability of exceeding Fref 25% 50% 75%

2018 catch 71,000 mt 86,000 mt 102,000 mt

2018 catch (rho adjusted) 35,000 mt 44,000 mt 53,000 mt

2019 catch 44,500 mt 53,000 mt 63,000 mt

2019 catch (rho adjusted) 23,000 mt 27,500 mt 33,000 mt

Scientific Advice Provided at TRAC

• In 2017, the TMGC agreed on a quota of 40,000 mt for 2018 and suggested an upper level of 40,000 mt for catch advice for 2019.

• Positive signals for the stock: DFO and NMFS spring high index of abundance for 2013 year class, survey biomass above average values, only 27% of quota caught, and the 2018 projected quota unlikely to be caught.

• However, large discrepancy between model projected biomass and the average survey biomass, uncertainty for the 2013 year class, incompatibility between survey total mortality(Z) and fishing mortality(f); impact of survey decline on population abundance estimates, and overestimation of 2013 and 2010 year classes WAA.

• 2018 TRAC advice was that the upper bound of 40,000 mt suggested at TMGC for 2019 catch advice is too high.

• TRAC advised that the rho adjusted 2019 catch for low and neutral risk, which yields a range of 23,000 mt to 27,500 mt, is a more appropriate range for catch in 2019.

Questions?

2018 TRAC Status ReportsGeorges Bank yellowtail flounder

Chris Legault and Quinn McCurdy

Georges Bank Yellowtail Flounder

70° 69° 68° 67° 66°

40°

41°

42°

Georges Bank

4X5Y

InternationalBoundary

Area II

GB Yellowtail Flounder Catch

Canadian + USA 2017 total catch 95 mt (Quota 300 mt)

Canadian 2017 catch 3 mt (Quota 93 mt)

USA catch 92 mt (USA using different quota year, 207 mt)

2017 Catch was 63% discards, 37% landings

Survey Trends

Trend of all 3 surveys is very consistent

Current survey levels are very similar to early 1990s

• Fall 2017 2nd lowest in 55 years

• Spring 2018 lowest in 51 years

• DFO 2017 lowest in 32 years

• The three survey biomasses indicate the capacity of the stock is significantly diminished.

• Stock biomass is low and productivity is poor.

Survey Trends

Relative F and Z

• Relative fishing mortality has declined since 1995, although total

mortality(Z) from all sources has remained high.

• Fishing does not appear to be a major driver of stock status currently

Relative F = catch / surveySurvey Z

Empirical Results

Recent Biomass Trend 29% decline from 2015 to 201638% decline from 2016 to 201764% decline from 2017 to 2018

• Using the new q=0.31 estimate and wing spread results in biomass estimates being approximately 3 times larger than biomass estimates based on q=0.37 and door spread

• Biomass trends are identical because all years are scaled by the same constant value

Exploitation rate

Biomass (mt) Wings 0.02 0.06

Year DFO Spring Fall (year-1) Average Catch Advice (mt)

2010 29452 68752 83490 60565 1211 3634

2011 12344 29621 27821 23262 465 1396

2012 18113 46209 30354 31559 631 1894

2013 2249 12766 31199 15404 308 924

2014 1654 8564 10828 7015 140 421

2015 2650 5861 12682 7064 141 424

2016 5569 3610 5811 4997 100 300

2017 1104 2819 5432 3118 62 187

2018 812 143 2424 1126 23 68

TRAC Advice

• Recommend 6% as upper bound for exploitation rate which results in catch advice of 68mt for 2019.

• Survey biomass has decreased 98% from 2010 to 2018.

• Historical exploitation rates can be computed from either the quota or the catch. The TRAC used the exploitation rate associated with the quota to set the catch advice because it has limited the catch directly and indirectly.

Special Considerations

• U.S. catch in 2017 increased from 2016 primarily due to rotational management of the US scallop fishery allowing fishing in Closed Area II. Rotational management of the US scallop fishery is expected to cause changes in the amount of US discards depending on years when the fishery is allowed in Closed Area II.

• When quotas and abundance are low, discards can exceed landings, as they did in 2014 and 2017.

Other Terms of Reference• Describe any adjustments to the benchmark assessment

model applied during the TRAC, including impacts on the advice given to TMGC.

– The 2017 NMFS fall survey was completed by NOAA ship Pisces, due to issues with the regular vessel (NOAA ship Henry B. Bigelow). In 2018, the DFO survey was conducted by the Mersey Venture also due to issues with the usual survey vessels (CCGS Alfred Needler and Teleost).

– The Pisces and Bigelow are sister ships, and the Mersey Venture is a sister ship to the Teleost.

– In May 2018, a TRAC intersessional call agreed:

• to accept both surveys as valid indicators of population trends because the timing was within previous survey times

• to assume the replacement ships had the same catchability as the standard ships so that no conversion factors would be applied.

Other Terms of Reference

• Describe the rationale for the range of exploitation rates provided by the TRAC as catch advice compared to previous guidance.

– The TRAC external reviewers and science members recommended an exploitation rate of 2% to 6% for catch advice

– The average exploitation rate associated with the quota for years 2010 to 2017 is 6% (the upper bound) whilst the average exploitation rate associated with the catch for years 2010 to 2017 is 2%. Applying this range of exploitation rate to this year’s updated surveys results in catch advice of 23 mt to 68 mt for 2019.

– The TRAC noted that increasing the exploitation rate above the average from 2010 to 2017 when the stock declined substantially is risky and reduces the chances of rebuilding.

– Catch advice of 300 mt (the quota in 2018) would have an associated exploitation rate of 27% in 2019.

Questions?

Allocation shares for Canada and the USA on Georges Bank through fishing

year 2019

Melanie Barrett1 and Liz Brooks2

CERTComité d'évaluation desressources transfrontalières

TRACTransboundary ResourceAssessment Committee

2NOAA/NMFS Northeast Fisheries Science Center

166 Water Street

Woods Hole, Massachusetts 02543

USA

1Fisheries and Oceans Canada

531 Brandy Cove Road

St. Andrews, New Brunswick E5B 3L9

Canada

Canada/USA Joint Management Unit Area

70° 69° 68° 67° 66° 65°

40°

41°

42°

Georges Bank

Northern Edge

NortheastPeak

InternationalBoundary

GreatSouthChannel

200m

70° 69° 68° 67° 66° 65°

40°

41°

42°

Georges Bank

Northern Edge

NortheastPeak

InternationalBoundary

GreatSouthChannel

200m

cod &

haddock

yellowtail

flounder

5Zjm

5Zhjmn

CANUSA

USA CAN

Canada/USA Allocation Shares

• The purpose of the allocation shares is to achieve similar exploitation rates on the Canadian and USA sides.

• That is, to achieve similar ratios of catch to biomass

Canada/USA Allocation Shares

• Agreement is to use a combination of updated resource distribution and catch history(1967 to 1994 )

• From 2010 on, Resource Distribution (β) = 90% and Country Utilisation (α) = 10%

%shareyear,country = (year x %utilizationyear,country) + (year x %resource distributionyear,country)

where year = percentage weighting for utilization in year

year = percentage weighting for resource distribution in year

year + year =100%

Survey Distribution

• Smoothed 3 species spatial distribution in 33 years window.

• White line is proportion of resource in CDN waters before smoothing.

Resource distribution in 2017:

Cod: 28% USA, 72% CDN

Had: 51%USA, 49% CDN

Ytl: 74% USA, 26% CDN

Allocation Shares in 2019

Cod Haddock YTL

USA 27%->29% 39%->50% 71%->76%

Canada 73%->71% 61%->50% 29%->24%

Allocation shares trend

Questions?