Report on Economic and Scientific Conditions in the Massachusetts Multispecies Groundfishery

Transcription

1 Report on Economic and Scientific Conditions in the Massachusetts Multispecies Groundfishery Paul Diodati (DMF) and Brian Rothschild (SMAST) Co chairs; Steve Cadrin, Dan Georgianna, Kevin Stokesbury, Emily Keiley, Cate O Keefe (SMAST); David Pierce, Melanie Griffin, Micah Dean & Story Reed (DMF)

2 Council Motion (Jan 2011) In keeping with NMFS Director Eric Schwaab s suggestion to Chairman Pappalardo, the MFI Report on Scientific and Economic information that Supports Increases in Multispecies Groundfish Annual Catch Limits be forwarded to the SSC for a review of the report. MFI Conclusion: Information in the MFI report should be considered for future ABC recommendations, including specifications : OFLs should be based on direct estimates of F MSY when possible. OFLs should be based on risk neutral stock assessments. ABC should be based on the Council s desired risk tolerance.

3 Outline of Presentation Wednesday Afternoon Groundfish Catch Limits (Steve Cadrin) Background Basis for increased ACLs F MSY Stock Assessments Uncertainty Buffers Rebuilding Plans Recommendations for SSC consideration Thursday Morning Economic Analysis (Dan Georgianna) Wrap up (Steve Cadrin) Requested information from Wednesday Recommendations Thursday Afternoon SSC discussion and recommendations

4 Mass. Marine Fisheries Institute The UMass School for Marine Science and Technology and the Mass. Division of Marine Fisheries established a partnership to develop innovative and practical fisheries management applications contributing to scientific understanding, management, and economic growth and sustainability of our oceans and communities of Massachusetts that border on the ocean NOAA Award New England Multi Species Surveys and Development Assessment and Management System Systems approach to stock assessment and management analyses of scallop and groundfish resources; participation in stock assessments and supplemental analyses.

5 Jan 07 Timeline Magnuson Act Reauthorization Jul 07 Jan 08 Jul 08 Groundfish Stock Assessments Jan 09 NMFS Guidelines on Catch Limits Jul 09 Groundfish Catch Limits Jan 10 Jul 10 Jan Fishing Year Letter from Gov. Patrick Reply from Sec. Locke & Council Motion

6 The Reauthorized Magnuson Act Each Council shall establish a mechanism for specifying annual catch limits in the plan, at a level such that overfishing does not occur in the fishery. Overfishing means a rate or level of fishing mortality that jeopardizes the capacity of a fishery to produce the maximum sustainable yield on a continuing basis. (F MSY ). Yield Fishing Mortality

7 National Standard Guidelines Annual Catch Limits should be based on an estimate of the catch that results in overfishing and uncertainty in the estimate, and ACL cannot exceed Acceptable Biological Catch (NOAA 2009). Annual Catch Overfishing Limit (F MSY x Stock Biomass) Uncertainty in overfishing limit Acceptable Biological Catch Annual Catch Limit

8 Groundfish ABCs (July 2008) The SSC reviewed the PDT s proposed ABC approach. ABC should be derived as a function of scientific uncertainty in projected catch at F rebuild (for rebuilding stocks) or F MSY (for rebuilt stocks). Considering precision of the most recent estimates of stock size and subsequent recruitment, there is a distribution of projected catch. A percentile of the lower tail should be selected as the ABC, with the percentile being determined by productivity and uncertainty factors. Probability Projected Catch (mt) at Fmsy

9 Groundfish ABCs(July 2008) Productivity and uncertainty factors were proposed to determine the percentile of catch used to determine ABC. S t o c k P r o d u c ti v i t y ABC = 10%ile Fcontrol rule 10%ile Freb ABC = 10%ile Fcontrol rule or 10%ile Freb ABC = 1%ile Fcontrol rule or 1%ile Freb 1 ABC=25%ile of Fcontrol rule Or 25%ile of Freb ABC=25%ile of Fcontrol rule Or 25%ile of Freb ABC = 10%ile Fcontrol rule or 10%ile Freb 2 ABC= Fcontrol rule Or ABC=50%ile catch at Freb ABC=25%ile of Fcontrol rule Or 25%ile of Freb ABC = 10%ile Fcontrol rule or 10%ile Freb 3 Probability Assessment Uncertainty of 30 Projected Catch (mt) at Fmsy Steve Cadrin New England ABCs

10 Groundfish ABCs (April 2009) The PDT evaluated performance of the proposed ABC for 3 stocks: Gulf of Maine cod, Georges Bank cod and Cape Cod yellowtail. The ABCs produced overfishing because of retrospective patterns. GOM cod SSB SSB in 000's mt GARM 2 ssb fw 42 proj GARM 3 GARM3 cat 10th per GARM year

11 Groundfish ABCs (May 2009) In the absence of better information on what an appropriate buffer should be between OFL and the ABC, a relatively simple ABC was applied to all groundfish stocks. Given the guidance for specifying ABC as the lesser of 75%F MSY or F rebuild, and the definition of optimum yield in the current Multispecies Fishery Management Plan as that associated with 75%F MSY, the SSC recommended that the Council consider this ABC specification be applied to all groundfish stocks.

12 Groundfish ABCs (May 2009) Probability Density % F MSY F MSY Lower Uncertainty Probability Density Shaded area is the probability that the target (75% F MSY ) is overfishing 75% F MSY F MSY Higher Uncertainty P* = 10.5% Fishing Mortality Rate P* = 26.6% Fishing Mortality Rate

13 Letter from Sec. Locke to Rep. Frank "I am prepared to issue an emergency regulation to revise catch limits whenever there is both sufficient economic and sound scientific data available to meet these requirements. You have graciously offered to provide scientific and economic information that could support the exercise of the emergency rule authority in response to the current situation in New England. MFI scientists compiled scientific information available for consideration in increasing catch limits for New England groundfish. The intention of the MFI report was to document economic impacts and provide scientific information to justify increases in ACLs. The intention was NOT to challenge NEFSC science, Peer Review decisions or SSC recommendations.

14 Summary of MFI Report Scientifically valid alternatives are available for several components of ACLs that meet conservation mandates: 1) direct estimates of F MSY, 2) alternative stock assessment models, 3) smaller uncertainty buffers, and 4) revised rebuilding objectives. Alternative scientific decisions would support increases in ACLs for all New England groundfish stocks, with substantial increases for common choke stocks (Gulf of Maine cod, Georges cod, Georges yellowtail, Gulf of Maine winter flounder, and southern New England winter flounder). Increased ACLs for common choke stocks are expected to allow the fleet to achieve more of their allocation of other stocks, thereby substantially increasing mixed stock economic yield.

15 Response from Sec. Locke and Mr. Schwaab I am forwarding a copy of your report to John Pappalardo, Chair of the Council, as I believe that the lasting solutions to the problems raised by the Commonwealth are best addressed by the Council's process.

16 Council Motion (Jan 2011) In keeping with NMFS Director Eric Schwaab s suggestion to Chairman Pappalardo, the MFI Report on Scientific and Economic information that Supports Increases in Multispecies Groundfish Annual Catch Limits be forwarded to the SSC for a review of the report. MFI Conclusion: Information in the MFI report should be considered for future ABC recommendations, including specifications : OFLs should be based on direct estimates of F MSY when possible. OFLs should be based on risk neutral stock assessments. ABC should be based on the Council s desired risk tolerance.

17 Outline of Presentation Wednesday Afternoon Groundfish Catch Limits (Steve Cadrin) Background Basis for increased ACLs F MSY Stock Assessments Uncertainty Buffers Rebuilding Plans Recommendations for SSC consideration Thursday Morning Economic Analysis (Dan Georgianna) Wrap up (Steve Cadrin) Requested information from Wednesday Recommendations Thursday Afternoon SSC discussion and recommendations

18 1. Direct Estimates of F MSY The age structured approach to estimating MSY reference points is essentially a 2 stage population model (e.g., Beverton et al. 1984, Sissenwine and Shepherd 1987): Recruits e (F+M) reproduction Adults

19 If: 1. Direct Estimates of F MSY spawners and recruits are measured in the same units (abundance) spawners only spawn once (semelparous), and recruitment is measured at time of maturity replacement is the 1:1 line. If not (iteroparous), we need to find the R that replaces SSB A: = 2.718, = B: = 7.389, = C: = , = R replacement S A B C

20 1. Direct Estimates of F MSY At a given F, there is a constant SSB per recruit (SPR) Linear relationship between R and resulting SSB (S=xR) SPR=2kg SSB=2*R SPR=2kg SSB=2*R Resulting Spawners (kg) Recruits Recruits Resulting Spawners

21 1. Direct Estimates of F MSY As F increases survival to SSB decreases Low F high F Resulting Spawners (kg) Low F - SPR=2kg - SSB=2*R High F - SPR=1kg - SSB=1*R Recruits Recruits Resulting Spawners

22 1. Direct Estimates of F MSY Stock recruit models predict R/S SPR analysis predicts S/R When the SPR at a given F is equal or greater than the observed R/S [(SPR) F =1/(R/S) obs ], the population can replace itself Recruitment 1.4 Increasing Fishing Mortality 1.2 No Fishing Spawning Stock Recruits e (F+M) reproduction Adults

23 Estimating F MSY Equilibrium recruitment and SSB decrease with increasing F. Equilibrium Yield has a maximum (MSY) Yield (kt) Recruits (mil) recruits SSB F Fmsy F SSB (kt)

24 1. Direct Estimates of F MSY NEFSC (2002) found the best model using model selection methods (example: SNE winter flounder). NEFSC (2002)

25 1. Direct Estimates of F MSY Council chose to replace F MSY with F 40% as the overfishing definition. 2.5 Large-Mesh Small-Mesh Large-Mesh Fishing Fishing (Fmsy=0.6, (Fmsy=0.15, (Fmsy=0.6, MSY=2300t,Bmsy=3300t MSY=2300t) MSY=1700t) F40%=0.3, Y=2200t, B=7900t) 25 Yield (kt) F40% Fmsy F40% as a proxy for Fmsy: long term yield is nearly MSY (96%) short term yield is much less (50%) rebuilding target is much greater (x2) replaces the legal definition of overfishing with a safer approximation Stock Biomass (kt) Fishing Fishing Mortality Mortality

26 1. Direct Estimates of F MSY Southern New England Winter Flounder: F 40% is less than F MSY, and the B MSY proxy (39kt) is greater than B MSY (30kt). Fmsy=0.32 Bmsy=30.1kt MSY=10.6kt

27 1. Overfishing Reference Points Clark (1993) estimated MSY for a wide range of life histories and found that maintaining stocks at ~36% of maximum produced at least 75% of MSY. Common implementation of %SPR proxies is precautionary (40% for gadids, flatfish, etc.; 50% for redfish, rockfish, etc.) A B

28 1. Direct Estimates of F MSY GARMIII Report: most of the groundfish assessments did not display compelling support for any particular functional form of stock recruitment (SR) relationship, and the SR parameters were generally poorly determined GARMIII Report (Reference Point Appendix): When no parametric model of the stock recruitment relationship is considered suitable for BRP estimation (as was the case for all or nearly all of the GARM III stocks reviewed), mean SSB is straightforward to compute, being simply the product of average recruitment and SSB/R.

29 1. Direct Estimates of F MSY GARMIII Report (white hake): Although the Ricker relationship is marginally preferred over the Beverton Holt, estimates of biological reference points differ markedly between the two. (Ricker F MSY =0.24; B MSY =25.6kt) However estimates of mean recruitment are similar across the four assessments, so that for a robust basis for BRP estimation, the approach finally chosen is to use the F 40% proxy basis (F 40% =0.125; B MSY =56.3kt)

30 1. Direct Estimates of F MSY The stock recruit relationship is critical for modeling MSY. Recruitment (mil) Shepherd Stock Recruit Functions R S Spawning Stock Biomass (kt) S K β=1 β=1.2 β=1.4

31 1. Direct Estimates of F MSY F MSY F40%SPR %MSP MSY of Gulf of Maine cod is much greater than yield at F 40% (and F 40% is much less than F MSY ) as the stockrecruit function becomes more domed (expressed as the Shepherd stock recruit shape parameter, β) BETA β Rothschild & Jiao, in review 100.0

32 1. Direct Estimates of F MSY New England sea scallop Monte Carlo randomization of yield curve (NEFSC 2010). Probability NEFSC 2010

33 1. Direct Estimates of F MSY Advocacy for F %SPR as a proxy for F MSY assumes a deterministic application (Clark 1991, 1993; Thompson 1993; Mace and Sissenwine 1993; Mace 1994; Dorn 2002). None of these evaluations included an additional uncertainty buffer. F 40% as a replacement for F MSY Overfishing Limit (FXXXX MSY x Stock Biomass) Annual Catch Uncertainty in overfishing limit Acceptable Biological Catch Annual Catch Limit F 40% as a limit?

34 1. Direct Estimates of F MSY Direct estimates of F MSY would allow several increases in groundfish ACLs. Overfishing Reference Point Fmsy proxy Fmsy ACL increase GOM cod % Georges cod % Georges yellowtail % SNE yellowtail % GOM winter flounder % SNE winter flounder % White hake % Contemporary estimates from NEFSC (2002, 2003, 2008) Estimates of Fmsy were not provided by NEFSC (2008), except for white hake

35 1. Direct Estimates of F MSY NEFSC (2002)

36 1. Direct Estimates of F MSY NEFSC (2002)

37 1. Direct Estimates of F MSY Georges Bank Yellowtail NEFSC (2002)

38 1. Direct Estimates of F MSY NEFSC (2002)

39 1. Direct Estimates of F MSY NEFSC (2002)

40 1. Direct Estimates of F MSY F40% F=0 NEFSC (2003)

41 1. Direct Estimates of F MSY Magnuson Act: Overfishing means a rate or level of fishing mortality that jeopardizes the capacity of a fishery to produce the maximum sustainable yield on a continuing basis. (F MSY ). If ABC is to represent the Council s desired risk tolerance of overfishing, OFL should be based on F MSY whenever possible rather than a proxy for F MSY. Probability of catch>ofl is confounded by proxies. If F MSY is poorly defined, uncertainty can be evaluated rather than replacing it with a precautionary proxy.

42 Outline of Presentation Wednesday Afternoon Groundfish Catch Limits (Steve Cadrin) Background Basis for increased ACLs F MSY Stock Assessments Uncertainty Buffers Rebuilding Plans Recommendations for SSC consideration Thursday Morning Economic Analysis (Dan Georgianna) Wrap up (Steve Cadrin) Requested information from Wednesday Recommendations Thursday Afternoon SSC discussion and recommendations

43 2. Stock Assessments Several alternative stock assessment approaches were developed for the 3 rd Groundfish Assessment Review Meeting (NEFSC 2008). Many models had substantial uncertainty manifest by retrospective inconsistency. Georges Yellowtail

44 2. Stock Assessments Some previous retrospective patterns persisted and caused overfishing (Georges yellowtail in 2004), which may justify an adjustment for inconsistency.

45 2. Stock Assessments The 2008 Georges yellowtail assessment accepted both the base case and a split models that assumed survey efficiency increased in the mid 1990s.. The GARMIII Panel chose the split model.

46 2. Stock Assessments Survey Data (no model): Catch and survey data for Georges yellowtail suggest that stock size is relatively high and fishing mortality is relatively low.

47 2. Stock Assessments Some retrospective patterns went away meaning a retrospective adjustment would have imposed Cape Cod yellowtail greater bias. Southern New England yellowtail NEFSC 2008

48 2. Stock Assessments Estimation error assumes that the model is correct, but historical or retrospective inconsistencies can indicate model specification error. ABC Witherell, 2010 OFL ˆ OFLz P * ABC OFL 1 Bexp

49 2. Stock Assessments Retrospective adjustments were only made in one direction; when terminal F appeared to be underestimated. Gulf of Maine haddock: There is a moderate retrospective pattern observable in the terminal year F estimates

50 2. Stock Assessments Alternative assessments would allow further increases in groundfish ACLs. Stock Size Estimate GARMIII base case %increase Georges cod % Georges yellowtail % Plaice % Witch flounder % GOM winter flounder % SNE winter flounder % Redfish %

51 2. Stock Assessments

52 2. Stock Assessments

53 2. Stock Assessments

54 2. Stock Assessments

55 2. Stock Assessments

56 2. Stock Assessments

57 2. Stock Assessments Variability among models can be included in the evaluation of scientific uncertainty. If a retrospective pattern results from persistent, systematic bias: Annual Catch identify source of bias and correct the model, or include retrospective inconsistency in the magnitude of scientific uncertainty. Underestimated biomass Overfishing Limit (F MSY x Stock Biomass) Uncertainty in overfishing limit Acceptable Biological Catch Annual Catch Limit XXXXXXXXXXX (include model error?)

58 Outline of Presentation Wednesday Afternoon Groundfish Catch Limits (Steve Cadrin) Background Basis for increased ACLs F MSY Stock Assessments Uncertainty Buffers Rebuilding Plans Recommendations for SSC consideration Thursday Morning Economic Analysis (Dan Georgianna) Wrap up (Steve Cadrin) Requested information from Wednesday Recommendations Thursday Afternoon SSC discussion and recommendations

59 3. Uncertainty Buffers If ABC is to be based on probability of overfishing: OFL should be based on F MSY (not a precautionary proxy) OFL should not be adjusted for scientific uncertainty (e.g., retrospective inconsistency, precautionary assessment decisions). Probability Prager & Shertzer 2009

60 3. Uncertainty Buffers Optimum yield can be based on probability of overfishing (P*<50%) and other risks that account for any relevant economic, social, or ecological factor to provide the greatest overall benefit to the Nation. R P* c NEFSC 2010

61 3. Uncertainty Buffers Stochastic projections of groundfish stocks can be used to evaluate probability of overfishing and foregone yield (in mt or $) Probability of 2012F>F40% Pollock Projections P* Foregone yield Catch 75%F40 F40 Projected catch and P* from Groundfish PDT (2010) Foregone Yield ($M)

62 3. Uncertainty Buffers OFL should be risk neutral, so ABC can be risk averse. Annual Catch F 40% Underestimated as a replacement biomass for F MSY Overfishing Limit (FXXXX MSY x XXXXXXXXXXX Stock Biomass) Uncertainty XXXXXXXXXXXXXXXXXXXXXXX in overfishing limit default 25% buffer Acceptable Biological Catch Annual Catch Limit

63 4. Rebuilding Plans ABC of some stocks is based on rebuilding objectives. As illustrated for Georges yellowtail, ABC can increase if rebuilding objectives are revised (Groundfish PDT 2010). Rebuilding plans can be revised by increasing the rebuilding period, using a direct estimate of B MSY rather than a proxy, or reducing the expected probability of achieving objectives to 50%.

64 Latitude for Increased Catch Limits There is scientific support for increased catch limits for all groundfish stocks, with substantial increases for Georges yellowtail, Georges cod, Gulf of Maine winter flounder, and southern New England winter flounder. Overfishing Reference Point Stock Size Estimate Uncertainty Buffer Combined Acceptable Catch Fmsy proxy Fmsy %difference GARMIII base case %increaseabc method %increase Increases 2010 Revised GOMcod % % 75%Fmsy 31% 69% GBcod % % 75%Fmsy 31% 93% GBhaddock 0.35 unknown? % 75%Fmsy 28% 28% GOMhaddock 0.43 unknown? % 75%Fmsy 27% 27% GByellowtail % % Frebuild? >92% 1200 >2298 SNEyellowtail % % Frebuild?? 493? CCyellowtail 0.24 unknown? % 75%Fmsy 30% 30% Plaice 0.19 unknown? % 75%Fmsy 30% 84% Witch 0.20 unknown? % 75%Fmsy 30% 179% GBWflounder 0.26 unknown? % 75%Fmsy 29% 29% GOMWflounder % % 75%catch? 236% SNEWflounder % % bycatch? >36% 644 >873 Redfish 0.04 unknown? % 75%Fmsy 33% 81% White Hake % % Frebuild?? 2832? Pollock 0.25 unknown? % 75%Fmsy 30% 30% Nwindowpane 0.50 unknown? % 75%Fmsy 33% 33% Swindowpane 1.47 unknown? % 75%Fmsy 33% 33% Oceanpout 0.76 unknown? % 75%Fmsy 33% 33% Halibut 0.07 unknown? % 75%Fmsy 32% 32% 71 94

65 Latitude for Increased Catch Limits Technical interactions preclude catch of entire multispecies allocations, even with transferability. The common choke stocks are the same as those with the greatest latitude for increased ACLs. Scenario Scenario Description Total Catch (MT) 1A 1B No trading between sectors, current catch limits Optimal trading (no cost to transfer), current catch limits Percent of Total TAC (%) Choke Species* 6,826 MT 8% GOM Cod, GB Yellowtail, GB Winter Flounder 36,579 MT 44% GOM Cod, GB Cod, GB Yellowtail, GOM and GB Winter *Choke species are defined as those species for which the entire TAC was Flounder caught preventing the fishery from achieving OY for the majority of fished species.

66 Recommendations for SSC Consideration Information in the MFI report should be considered for future ABC recommendations, including specifications: OFLs should be based on direct estimates of F MSY whenever possible. OFLs should be based on risk neutral stock assessments. ABC should be based on the Council s desired risk tolerance. OFLs are currently based on F %SPR, which is less than F MSY For all stocks. OFLs are currently based on assessments that are adjusted for retrospective patterns. ABCs are currently based on 75%F MSY or F rebuild, rather than on probability of F>F MSY.