SSC Report to NEFMC: Groundfish (Gulf of Maine Haddock, Georges ...
9/29/2014
SSC Report to NEFMC: Groundfish (Gulf of Maine Haddock, Georges Bank yellowtail flounder) & Small-Mesh Multispecies (Whiting and Red Hake) Hyannis, MA September 30, 2014 Steve Cadrin, Scientific 7 Statistical Committee
SSC Meetings & Recommendations
• August 25-26 (Boston MA)
– Acceptable Biological Catch recommendations for: • • • •
Gulf of Maine haddock Georges Bank yellowtail flounder Whiting (silver hake) red hake
– Feedback on Council’s draft risk policy – Presented by Steve Cadrin, SSC member
• August 28-29 (Portsmouth NH) – SSC Peer Review of Gulf of Maine cod update assessment
• September 15 (Boston MA) – Acceptable Biological Catch recommendations for: • Scallops • Gulf of Maine cod
– Presented by Jason McNamee, SSC member
1
9/29/2014
OFL & ABC Recommendations • Terms of Reference: – Review the SAW/SARC 59 assessment and the work of the Groundfish Plan Development Team (PDT) and – provide the overfishing limit (OFL) and Acceptable Biological Catch (ABC) for each year for fishing years 2015-2017 that will prevent overfishing and is consistent with the default control rule.
OFL & ABC Recommendations
Total Catch (mt)
• The SSC recommends the OFL and ABC values based upon the Final Model:
+ ++ ABCs
2
9/29/2014
Uncertain Recruitment Estimates • An important source of uncertainty in the assessment is the estimated size of recent strong recruitment events in 2010 and 2012.
Recruitment (age-1 thous.)
Spawning Biomass (mt)
– Overestimation of those cohorts can lead to overestimation of spawning stock biomass, resulting in catch advice that is too high. – Abundance of the 2012 year class is estimated from only two surveys, creating less confidence in its estimation than the 2010 year class.
Uncertain Recruitment Estimates • The SSC concluded that the Final Model is a sufficient basis for catch advice. – The SAW/SARC endorsed the Final Model as the best available science. – The status of the stock is strong and extra precaution is unwarranted. – An operational assessment is forthcoming in 2015, and we will not rely on longer term projections for 2016 and 2017. – If the Final Model is overly optimistic, a sensitivity analysis suggests that the probability of overfishing in 2015 would be approximately risk-neutral.
3
9/29/2014
Stock Mixing • Exchange of haddock between the larger Georges Bank stock and the Gulf of Maine stock remains a consideration. – The SSC reiterates our earlier conclusion, which corroborates that of the PDT, that data are insufficient to estimate mixing rates, and therefore to incorporate mixing into the assessment and catch advice. – The SAW identified the “sabbatical” model, which allows for non-permanent movement between the two stock areas, as the most biologically plausible. The outcomes of catch projections using the sabbatical model do not differ greatly from projections assuming no mixing.
• The SSC endorsed the SARC conclusion that additional empirical research is needed to resolve mixing rates.
Gulf of Maine Haddock Recommendations 1. OFL and ABC for 2015, 2016 and 2017 are based on the Final Model from SAW/SARC59. 2. Catch advice for 2016 and 2017 should be updated based upon the operational assessment planned for 2015, especially in light of the uncertainties associated with the size of large 2012 cohort. 3. Data remain insufficient to confidently estimate mixing rates for assessment and management purposes, and additional empirical research is needed to resolve this uncertainty.
4
9/29/2014
Georges Bank Yellowtail Flounder • Terms of Reference: – provide the overfishing limit (OFL) and Acceptable Biological Catch (ABC) for each year for fishing years 2015 and 2016 that will meet management objectives and prevent overfishing.
• The SSC recommends an ABC for 2015 of 354mt based on an exploitation rate of 16% applied to the most recent estimate of average survey-based biomass. – For the time being, the SSC recommends an ABC for 2016 of 354mt, assuming in the absence of additional information that biomass will not change. – However, the SSC expects that the 2016 ABC will be revisited and revised in 2015 based on a new TRAC assessment.
• OFL remains unknown for this stock.
Georges Bank Yellowtail Flounder
5
9/29/2014
Georges Bank Yellowtail Flounder
ABC
Georges Bank Yellowtail Flounder • These ABC (354mt) represent a modest reduction from the current ABC of 400mt, and the target exploitation rate represents a reduction from the fishing mortality limit, Fref. • Such reductions are appropriate for a stock estimated to be at low biomass and trending downward. • Despite the estimated stock condition and trend, the SSC is not recommending a greater reduction because the fishery does not seem to be the main factor influencing the stock and in light of the expected impacts of a drastic reduction on the industry.
6
9/29/2014
Georges Bank Yellowtail Flounder • Future ABCs based on this approach could vary considerably if survey indices change substantially. • Time and resources be dedicated to a more thorough analysis and discussion of other surveybased control rules, relative to the ad hoc approach adopted herein, in advance of the 2015 TRAC and application of its outcomes.
Georges Yellowtail Recommendations 1. ABC for 2015 is 354mt, based on an exploitation rate of 16% applied to the most recent estimate of average survey-based biomass. 2. ABC for 2016 should be revisited based on the outcomes of the expected 2015 TRAC. If new information is not available in 2015, ABC for 2016 remains 354mt assuming no change from the most recent estimate. 3. More thorough analysis and discussion of survey-based control rules for the stock should take place before applications of the 2015 TRAC outcomes.
7
9/29/2014
Small-Mesh Multispecies • Terms of Reference: – Review the recent assessment updates and the work of the Whiting Plan Development Team (PDT) and – provide an Overfishing Limit (OFL) and an Acceptable Biological Catch (ABC) for each year for • • • •
northern silver hake, southern silver hake, northern red hake and southern red hake
– for fishing years 2015-2017 that will meet management objectives and prevent overfishing.
Small-Mesh Multispecies Northern red hake Northern silver hake
Southern silver hake
Southern red hake
8
9/29/2014
OFL & ABC Recommendations • The SSC recommends OFLs (mt) for each of the four hake stocks as estimated during the operational assessment. • ABC recommendations (mt) use the current control rule, estimated by the NEFSC and reviewed by the Whiting PDT. • These specifications would remain the same in 2015, 2016 and 2017 in the absence of new information suggesting a change is warranted.
Small-Mesh Multispecies
ABC
ABC
ABC
ABC
9
9/29/2014
Overfishing of Red Hake • Overfishing was primarily a result of exceeding catch limits rather than scientific uncertainty that led to substantial misspecification of catch advice. – Catch exceeded the ABC (by 21% in 2012 and by 13% 2013) and the OFL (by 5% in 2012). – The 2013 fishing year catch was under the OFL by 2%. – The three-year (2012-2014) stock biomass index did not decline, influenced mostly by the higher 2014 biomass estimate and new recruitment first observed in spring 2014.
• The most appropriate response is to more effectively control catch, including improved estimation of discards, rather than revise the risk tolerance (i.e., percentile of OFL for ABC). • Concerns about the overfishing definition lead the SSC to recommend that the biological reference points should be updated at the next appropriate opportunity and more thoroughly re-evaluated at a benchmark assessment.
Shifting Distributions
• Movements of fish in response to variations in environmental conditions have the potential to alter both survey indices and landings. – Geographic distributions of red and silver hake are associated with temperature. – Reference points for hakes rely on survey indices, so temperaturedependent movements or changes in catchability can alter the perception of the stock. – Fish responses to climate change may also alter distributions and induce changes in productivity, which may influence our perception of assessment stock boundaries.
• Future assessments for these stocks should evaluate whether temperature or other environmental indicators (e.g. the Gulf Stream North Wall Index) can explain variability in the survey indices as well as changes in stock structure, and if so, should consider how to incorporate this knowledge when setting benchmarks.
10
9/29/2014
Hake Recommendations 1. OFLs and ABCs should remain unchanged for each stock in 2015, 2016 and 2017 in the absence of new information suggesting otherwise. 2. Overfishing of the northern stock of red hake was due to exceeding catch limits rather than misspecification of catch advice due to scientific uncertainty. Therefore, efforts are needed to better control catch, including improved estimation of discards. 3. Reference points should be updated at the next opportunity and more thoroughly re-evaluated at a benchmark assessment. 4. Effects of changing temperatures on the behavior of both red and silver hake should be thoroughly investigated given the implications for assessment outcomes, catch advice and catch. 5. Inclusion of a Fishery Performance Report in the integrated SAFE report was a welcome addition.
SSC Meetings & Recommendations
• August 25-26 (Boston MA)
– Acceptable Biological Catch recommendations for: • • • •
Gulf of Maine haddock Georges Bank yellowtail flounder Whiting (silver hake) red hake
– Feedback on Council’s draft risk policy – Presented by Steve Cadrin, SSC member
• August 28-29 (Portsmouth NH) – SSC Peer Review of Gulf of Maine cod update assessment
• September 15 (Boston MA) – Acceptable Biological Catch recommendations for: • Scallops • Gulf of Maine cod
– Presented by Jason McNamee, SSC member
11
SSC Report to NEFMC: Groundfish (Gulf of Maine Haddock, Georges Bank yellowtail flounder) & Small-Mesh Multispecies (Whiting and Red Hake) Hyannis, MA September 30, 2014 Steve Cadrin, Scientific 7 Statistical Committee
SSC Meetings & Recommendations
• August 25-26 (Boston MA)
– Acceptable Biological Catch recommendations for: • • • •
Gulf of Maine haddock Georges Bank yellowtail flounder Whiting (silver hake) red hake
– Feedback on Council’s draft risk policy – Presented by Steve Cadrin, SSC member
• August 28-29 (Portsmouth NH) – SSC Peer Review of Gulf of Maine cod update assessment
• September 15 (Boston MA) – Acceptable Biological Catch recommendations for: • Scallops • Gulf of Maine cod
– Presented by Jason McNamee, SSC member
1
9/29/2014
OFL & ABC Recommendations • Terms of Reference: – Review the SAW/SARC 59 assessment and the work of the Groundfish Plan Development Team (PDT) and – provide the overfishing limit (OFL) and Acceptable Biological Catch (ABC) for each year for fishing years 2015-2017 that will prevent overfishing and is consistent with the default control rule.
OFL & ABC Recommendations
Total Catch (mt)
• The SSC recommends the OFL and ABC values based upon the Final Model:
+ ++ ABCs
2
9/29/2014
Uncertain Recruitment Estimates • An important source of uncertainty in the assessment is the estimated size of recent strong recruitment events in 2010 and 2012.
Recruitment (age-1 thous.)
Spawning Biomass (mt)
– Overestimation of those cohorts can lead to overestimation of spawning stock biomass, resulting in catch advice that is too high. – Abundance of the 2012 year class is estimated from only two surveys, creating less confidence in its estimation than the 2010 year class.
Uncertain Recruitment Estimates • The SSC concluded that the Final Model is a sufficient basis for catch advice. – The SAW/SARC endorsed the Final Model as the best available science. – The status of the stock is strong and extra precaution is unwarranted. – An operational assessment is forthcoming in 2015, and we will not rely on longer term projections for 2016 and 2017. – If the Final Model is overly optimistic, a sensitivity analysis suggests that the probability of overfishing in 2015 would be approximately risk-neutral.
3
9/29/2014
Stock Mixing • Exchange of haddock between the larger Georges Bank stock and the Gulf of Maine stock remains a consideration. – The SSC reiterates our earlier conclusion, which corroborates that of the PDT, that data are insufficient to estimate mixing rates, and therefore to incorporate mixing into the assessment and catch advice. – The SAW identified the “sabbatical” model, which allows for non-permanent movement between the two stock areas, as the most biologically plausible. The outcomes of catch projections using the sabbatical model do not differ greatly from projections assuming no mixing.
• The SSC endorsed the SARC conclusion that additional empirical research is needed to resolve mixing rates.
Gulf of Maine Haddock Recommendations 1. OFL and ABC for 2015, 2016 and 2017 are based on the Final Model from SAW/SARC59. 2. Catch advice for 2016 and 2017 should be updated based upon the operational assessment planned for 2015, especially in light of the uncertainties associated with the size of large 2012 cohort. 3. Data remain insufficient to confidently estimate mixing rates for assessment and management purposes, and additional empirical research is needed to resolve this uncertainty.
4
9/29/2014
Georges Bank Yellowtail Flounder • Terms of Reference: – provide the overfishing limit (OFL) and Acceptable Biological Catch (ABC) for each year for fishing years 2015 and 2016 that will meet management objectives and prevent overfishing.
• The SSC recommends an ABC for 2015 of 354mt based on an exploitation rate of 16% applied to the most recent estimate of average survey-based biomass. – For the time being, the SSC recommends an ABC for 2016 of 354mt, assuming in the absence of additional information that biomass will not change. – However, the SSC expects that the 2016 ABC will be revisited and revised in 2015 based on a new TRAC assessment.
• OFL remains unknown for this stock.
Georges Bank Yellowtail Flounder
5
9/29/2014
Georges Bank Yellowtail Flounder
ABC
Georges Bank Yellowtail Flounder • These ABC (354mt) represent a modest reduction from the current ABC of 400mt, and the target exploitation rate represents a reduction from the fishing mortality limit, Fref. • Such reductions are appropriate for a stock estimated to be at low biomass and trending downward. • Despite the estimated stock condition and trend, the SSC is not recommending a greater reduction because the fishery does not seem to be the main factor influencing the stock and in light of the expected impacts of a drastic reduction on the industry.
6
9/29/2014
Georges Bank Yellowtail Flounder • Future ABCs based on this approach could vary considerably if survey indices change substantially. • Time and resources be dedicated to a more thorough analysis and discussion of other surveybased control rules, relative to the ad hoc approach adopted herein, in advance of the 2015 TRAC and application of its outcomes.
Georges Yellowtail Recommendations 1. ABC for 2015 is 354mt, based on an exploitation rate of 16% applied to the most recent estimate of average survey-based biomass. 2. ABC for 2016 should be revisited based on the outcomes of the expected 2015 TRAC. If new information is not available in 2015, ABC for 2016 remains 354mt assuming no change from the most recent estimate. 3. More thorough analysis and discussion of survey-based control rules for the stock should take place before applications of the 2015 TRAC outcomes.
7
9/29/2014
Small-Mesh Multispecies • Terms of Reference: – Review the recent assessment updates and the work of the Whiting Plan Development Team (PDT) and – provide an Overfishing Limit (OFL) and an Acceptable Biological Catch (ABC) for each year for • • • •
northern silver hake, southern silver hake, northern red hake and southern red hake
– for fishing years 2015-2017 that will meet management objectives and prevent overfishing.
Small-Mesh Multispecies Northern red hake Northern silver hake
Southern silver hake
Southern red hake
8
9/29/2014
OFL & ABC Recommendations • The SSC recommends OFLs (mt) for each of the four hake stocks as estimated during the operational assessment. • ABC recommendations (mt) use the current control rule, estimated by the NEFSC and reviewed by the Whiting PDT. • These specifications would remain the same in 2015, 2016 and 2017 in the absence of new information suggesting a change is warranted.
Small-Mesh Multispecies
ABC
ABC
ABC
ABC
9
9/29/2014
Overfishing of Red Hake • Overfishing was primarily a result of exceeding catch limits rather than scientific uncertainty that led to substantial misspecification of catch advice. – Catch exceeded the ABC (by 21% in 2012 and by 13% 2013) and the OFL (by 5% in 2012). – The 2013 fishing year catch was under the OFL by 2%. – The three-year (2012-2014) stock biomass index did not decline, influenced mostly by the higher 2014 biomass estimate and new recruitment first observed in spring 2014.
• The most appropriate response is to more effectively control catch, including improved estimation of discards, rather than revise the risk tolerance (i.e., percentile of OFL for ABC). • Concerns about the overfishing definition lead the SSC to recommend that the biological reference points should be updated at the next appropriate opportunity and more thoroughly re-evaluated at a benchmark assessment.
Shifting Distributions
• Movements of fish in response to variations in environmental conditions have the potential to alter both survey indices and landings. – Geographic distributions of red and silver hake are associated with temperature. – Reference points for hakes rely on survey indices, so temperaturedependent movements or changes in catchability can alter the perception of the stock. – Fish responses to climate change may also alter distributions and induce changes in productivity, which may influence our perception of assessment stock boundaries.
• Future assessments for these stocks should evaluate whether temperature or other environmental indicators (e.g. the Gulf Stream North Wall Index) can explain variability in the survey indices as well as changes in stock structure, and if so, should consider how to incorporate this knowledge when setting benchmarks.
10
9/29/2014
Hake Recommendations 1. OFLs and ABCs should remain unchanged for each stock in 2015, 2016 and 2017 in the absence of new information suggesting otherwise. 2. Overfishing of the northern stock of red hake was due to exceeding catch limits rather than misspecification of catch advice due to scientific uncertainty. Therefore, efforts are needed to better control catch, including improved estimation of discards. 3. Reference points should be updated at the next opportunity and more thoroughly re-evaluated at a benchmark assessment. 4. Effects of changing temperatures on the behavior of both red and silver hake should be thoroughly investigated given the implications for assessment outcomes, catch advice and catch. 5. Inclusion of a Fishery Performance Report in the integrated SAFE report was a welcome addition.
SSC Meetings & Recommendations
• August 25-26 (Boston MA)
– Acceptable Biological Catch recommendations for: • • • •
Gulf of Maine haddock Georges Bank yellowtail flounder Whiting (silver hake) red hake
– Feedback on Council’s draft risk policy – Presented by Steve Cadrin, SSC member
• August 28-29 (Portsmouth NH) – SSC Peer Review of Gulf of Maine cod update assessment
• September 15 (Boston MA) – Acceptable Biological Catch recommendations for: • Scallops • Gulf of Maine cod
– Presented by Jason McNamee, SSC member
11
