Colin Bannister (2011)

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Colin Bannister (2011)

  1. 1. DRUMMOND LECTURE 2011 Securing resources -- a scientists view Dr Colin Bannister Fisheries & Shellfisheries ScientistTrustee of the Buckland Foundation Chairman of SAGB
  2. 2. Last Year’s Lecture: Peter Hunt’s Vision The C F P Inshore Management 6-12 miles Sustainable Management Regional Management Plans Environmental Impact Static Gear & Mollusc Culture What does this really mean ? Mobile Gear Naturalised Species Polluter pays Improved water treatment Monitoring pollution Classification of shellfish waters Toxin management Crustacean management , regional inshore brown crab management Restoration of regional rural fishing communities Phasing out preserved historic practices Maximising the value of shellfish.
  3. 3. Sustainability (of capture fisheries)Policy Definitions and obligationsThe objectives & actions required Scientific objectives Precautionary frameworks Fish stock examples of MSYKnowledge required Stock status and management criteria Shellfish examples from 3 types of management regimeWider issues Future needs Climate change
  4. 4. Recommendations and LawsWorld Commission on Environment & Development (Brundtland,1987) ……development that meets our needs without restricting/pre-empting future choices or needs ....1982 United Nations Law of the Sea:Includes a call to manage fisheries for maximum sustainable yield (MSY)1995 United Nations Fish Stock Agreement (for straddling andhighly migratory stocks):Specifies an OBLIGATION to secure sustainability/optimal utilisation : stocks capable of producing maximum sustainable yield (MSY) stocks that are above levels where reproduction is impaired use of best scientific advice that is necessarily precautionary2002 Johannesburg World Summit on Sustainable Development Where possible, fish stocks should reach MSY not later than 2015 !!
  5. 5. The Precautionary Approach: --this is not a whimsy but a formal structure FAO (1995) Guidelines on the Precautionary Approach The formal PA requires: a management process (data , stock monitoring, research/advice, management plan, enforcement, review) pre-defined desirable (target) & undesirable (limit) outcomes (=ref.points) a specified harvest strategy to achieve the outcomes with high probability decision rules: response to stock status changes is pre-agreed i.e not a belated ad-hoc response to crisis, but a pre-determined plan to define in advance how managers will respond to stock changeFAO 1995 is not legally binding, but it is the basis for applying the PA in most internationalscientific & management bodies including EU & NEAFC (advised by ICES), and NAFO.
  6. 6. A refresher on MSY MSYHeavy fishing means fewer old fish:You catch more, but they are smaller, SO Yield (sum of numbers * weight at age) has a maximum (or a plateau depending on growth rate) ** in this example juvenile numbers are constant but in the real world, fishing beyond MSY may/will eventually impair recruitment 6 October 14, 2010 Dr Colin Bannister
  7. 7. What is impaired recruitment ? (2 key examples) North Sea Herring Stock-Recruitment N Sea Herring 120 Blim Bpa A Recruits age 0 (Billions) Age 0 recruits 90 G 98 00 Stock collapse below 800 000 t The Stock is outside safe v. 91 biological limits. E 99 60 Spawning 95 94 92 96 biomass 93 30 0 97Collapsed in 1976 0Recovered after closure 0 500 1000 2001 1500 2002 2000 Spawning Stock (1000 tonnes) 2500 (Data SSB 2010, 1.3 mill t from North Sea Cod Stock-Recruitment 1000 The Stock is outside safe biological limits. ICES & N Sea Cod A High risk of collapse Bpa Pre-’87 CEFAS) Post-’87 79 70 SSB is in the region of Blim. 76 800 F is estimated to be about Flim Age 1 recruits G 69 Recruits age 1 (Millions) 85 v. E 600 83 81 Blim 78 66 65 77 74 Spawning 400 96 63 64 1 93 91 80 82 72 biomass 200 99 94 95 88 87 86 73 75 68 ? 90 67 71 84 92 98 89 Danger of collapse 0 00 97 unquantifiable 0 50 2001 2002 100 150 200 250 300 Spawning Stock (1000 tonnes) SSB 2011, 58 000 t Spawning stock biomass (‘ooo tonnes)
  8. 8. Reference point & control rule concepts Critical zone Cautious zone Reproduction impaired or at Reduce harvest risk: reduce rate to promote harvest rate rebuilding to lowest possible level Harvest control rule (or zero) Fmsy* Healthy (Low F /High B) Cap harvest rate at F msyHarvest = sustainable fishing rate B limit B msy (= B trigger)* or proxies at F msy* ( = new F limit) Stock status
  9. 9. Status of 30 NE Atlantic fish stocks, 2003 ( ICES data) Fishing Mortality Fishing Mortality Species/stock Biomass Fopt Flim F03 Species/stock Biomass Fopt Flim F03 Cod Plaice NE Arctic 430000 0.13 0.70 0.84 N Sea 250000 0.12 0.60 0.41 Iceland 311000 0.15 0.61 Irish Sea 5172 0.12 0.56 Baltic 84238 0.16 0.96 1.05 E Chan 2670 0.11 0.54 0.57 Faroe Plat 52537 0.17 0.68 0.71 Celtic Sea 1553 0.11 0.55 N Sea 37600 0.15 0.86 1.11 W Chan 1434 0.11 0.63 Western 7659 0.17 0.90 1.01 Sole W Scotland 5844 0.16 0.80 0.79 N Sea 32300 0.09 0.56 Irish Sea 4932 0.17 1.00 1.30 E Chan 14800 0.13 0.43 Haddock Irish Sea 4210 0.18 0.40 0.40 N Sea 347000 0.16 1.00 1.06 Celtic Sea 2904 0.12 0.54 NE Arctic 72385 0.20 0.49 0.53 W Chan 1814 0.11 0.28 0.41 Iceland 68877 0.17 1.00 Other Faroe 62537 0.19 0.40 0.38 Mackerel 3080000 0.19 0.26 0.20 W Scot 62511 0.15 0.63 N Sea herring 1699000 0.13 nd 0.24 Saithe Northern hake 115400 0.11 0.28 0.29 NE Arctic 359930 0.11 0.45 0.22 Western monk 27600 0.05 0.33 0.30 N Sea 298000 0.09 0.60 0.28 Faroe 101175 0.16 0.40 0.32Fopt (proxy for Fmsy) is 0.05-0.20: sustainability requires very moderate harvest ratesBut F ‘03 was 2-5 times higher, and several were >> Flim (red colour code)Getting to ‘genuinely sustainable fishing’ is tough: best to cap effort early !!!
  10. 10. Knowledge & ImplementationThe PA, and the MSC Accreditation Assessment Tree, raise key questions:Can the management system deliver sustainability? (MSC Prin 3)Is the stock actually being fished sustainably ? (MSC Prin 1)(I am using MSC principles as a guideline, and not as a hard-sell for certification !)Prin 3: diagnostic indicators : inter aliaGeneral attributesLaws, processes & standards able to deliver sustainable fisheriesRoles, responsibilities, consultation are transparent, defined, effectiveLong term objectives conform to PA & MSC principlesFishery specific attributesDefined fishery objectives that deliver PA & MSC principlesEffective decision processes: transparent & deliver the objectivesMonitoring & enforcement secure demonstrably effective compliance
  11. 11. Prin 1: diagnostic indicators Attributes (& knowledge) needed to demonstrate sustainability Stock status (> point of impairment with high probability) Reference points (limit > pt of impairment; target delivers MSY) Harvest strategy: specified measures that deliver the fishery objectives Harvest rules: pre-agreed, deliver F <Fmsy, B>Blim, or stock recovery Data (stock structure, productivity, the fishing fleet etc) Assessment (measures stock status w.r.t to ref points & uncertainty; methods tested by simulation or in practice ; internal & external peer review) (Stocks lacking data may use alternative risk-based criteria =RBF) Based on MSC FAM2 Prin 1 Performance Indicators(MSC Prin 2: How fishery affects habitat & ecosystem: likely to be pressurepoints for certain target species and gears……….. for another day !!
  12. 12. Capture shellfishery examplesSustainability attributes under 3 management systemsManagement system mainly international e.g. Nephrops (langoustine)Mixed management system (EU, national, local ) e.g. Brown crabLocal management system (SFC Regulating Orders) e.g..CockleDoes management of these stocks conform to PA criteria?Are the stocks being fished sustainably ?
  13. 13. Nephrops norwegicus Langoustine•Densely packed burrows in cohesive mud•Stocks (‘Functional Units’) generally delimited byhabitat & larval retention in gyres•Long history of previous biological research•Populations & production generally stable•Capture (trawl or creel ) depends on daily patterns ofemergence & seasonal patterns of reproduction•Harvest rate is usually lower on females•Fishery landings already limited by precautionary TACs•Days at sea are constrained by cod rules
  14. 14. Nephrops stock surveys TV Survey Fladen N Minch VMS S Minch MorayTV survey Forth Clyde Farn I Sea WestTV surveySource: www.ices.dk
  15. 15. TV survey trends Reported Landings (ICES W Gp data) --western 18000 TV survey trends 16000N Minch 14000 --eastern 12000 ICES VIa 10000 N Minch S Minch 8000 Fladen 6000 Clyde 4000 2000S Minch 0 1990199219941996199820002002200420062008 25000 20000 Moray 15000 ICES VII Clyde I Sea W 10000 I Sea E 5000 0 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 Forth 35000 I Sea W 30000 25000 ICES IV 20000 15000 Farn Dp Farn Fladen 10000 Forth 5000 Moray 0Source: www.ices.dk 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008
  16. 16. Stock status:compare F to Fmsy, stock number to Bmsy Status of selected Nephrops stocks from ICES Advice for 2011 & 2012 (my extract ) % Harvest rate Stock number Stock status* ADVICE (control rule) Stock FU Fnow MSY Now Btr F B Fnow Objective next F Farn 6 14.3 12.9 778m 958m F>Fmsy B<Btr 14.3 trans msy 13.5 Fladen 7 7.3 10.2 5457m 2767m F<Fmsy B>Btr 7.3 msy 10.2 Forth 8 23.3 15.0 732m 292m F>Fmsy B>Btr 23.3 trans msy 21.7 Moray F 9 14.0 12.7 415m 262m F>Fmsy B>Btr 14.0 trans msy 13.7 Noup 10 na na na na na na I Sea E 14 15.0 13.0 214.6m na F>Fmsy 15.0 trans msy 14.6 I Sea W 15 19.0 17.1 4.62 b 3.0 b F>Fmsy B>Btr 19.0 trans msy 18.6 Clyde ) 13 26.0 16.4 1499m 579m F>Fmsy B>Btr 26.0 trans msy 24.1 Jura ) 13 2.0 14.5 251m na F<Fmsy na 2.0 msy 14.5 S Minch 12 13.0 12.3 1542m 1016m F>Fmsy B>Btr 13.0 trans msy 12.9 N Minch 11 22.0 12.5 729m 330m F>Fmsy B>Btr 22.0 trans msy 20.1Fmsy is derived from proxies (F0.1, F35%spr,Fmax) * unofficial indicative colour codeBtr=Btrigger =lowest obsd in TV survey series trans msy = first of 5 steps to MSY B is mostly above proxy Bmsy-trigger . In 2 fisheries F is below F msy, In 5 fisheries F is only slightly above Fmsy, In 3 fisheries F is significantly above Fmsy. Advice (next F) moves towards MSY
  17. 17. Summary attributes for NephropsPositivesInternational management framework (EU-ICES :- PA & MSY framework)Routine stock monitoring (LPUE, size comp, TV survey burrow counts (improved )Annual harvest rate estimates (catch /stock number , or by length-based analysis)True Fmsy or Bmsy-trigger not measurable, but good proxies are in placeFormal biennial ICES advice with clear objective, harvest strategy & decision rules (ICES-EU ‘transition to MSY’ & avoidance of impaired recruitment)Harvest rates mostly close to proxy Fmsy, so required reductions are mostly modestNegativesNo hard information on stock & recruitment, or on BlimNo internationally agreed reference pointsICES assesses stocks individually, but the TAC is aggregated to ICES Division: this cannot ASSURE sustainability of individual stocks a potential MSC ‘Fail’ under Prin 3The only shellfish example on a par with the fish worldHarvest rates are moderate & the system meets numerous sustainability criteriaSome limitations, and one major long standing weakness (the aggregated EU TAC)
  18. 18. Brown Crab (Cancer pagurus) 61 60 59 D3 D4 D5 D6 D7D8 D9 E0 E1 E2 E3 E4 E5 E6 E7 E8 E9 F0 F1 F2 F3 F4 F5 F6 F7 F8 Faeroe Bank 50 49 48 47 46 45 58•Fished from inshore to well offshore on extensive regional stocks Rockall 44 Bank 43 57 42 41 56 40 39 55•Periodic MAFF/Cefas research on migration, larvae, biology, ageing 38 37 54 36 Porcupine 35 53 Bank(Edwards, Bennett, Addison,Thompson, Eaton, Sheehy) 34 33 52 32 31 51 30•Migrating hens & nomadic cocks support seasonal fisheries, but 29 50 28 27 49 26 La Chapelle 25 48 stock structure is not fully worked out Bank 24 23 47 -17 -15 -13 -11 -9 -7 -5 -3 -1 1 3 5 7 9•Stocks are relatively stable over time, but complex spatial patterns arenot well understood biologically•Small inshore potters (<10m) fish seasonally in mixed fisheries•Fast work boats (10-15+m) pot both ‘in & off’ as weather allows•Viviers (>15m) fish nomadically all round UK for most of the yearPressure points•Many of the productive fisheries are on ripe hens !!•Few recruitment data, but may be resilient due to longish life span &high fecundity---up to 2--4 million eggs per female•UK management is mainly by technical measures & local byelaws,but potters say that number & density of pots is rising unchecked•Prices are poor in the principal markets (export to Europe)
  19. 19. 7000 Edible crab 6000 Northumberland 5000 Yorkshire 4000 E.Anglia Landings (tonnes) 3000 2000 1000 0 Source: Defra 2010 12000 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Edible crab 10000 South coast South Devon 8000 Landings (tonnes) South Cornwall 6000 4000 Hebrides 2000 0 Orkney 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1800 1500 Edible crab Papa 1200 North Cornwall Landings (tonnes) Wales 900 North west Sule 600S Minch 300 from Mill et al, 2009, draft 0 Source: 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Cefas 2011
  20. 20. Assessments :Periodic size-based assessments with informal reference point indicators Number at age, for different mortalitiesSplit size frequency data into ‘age’ groups (using growth from tagging)Estimate current harvest rate (F) from decline of numbers with ‘age’ 120 10% survivors 100Model effect of lower or higher harvest rates (at constant recruitment) 80 60 40 18% 26% 20 40% 0 50% 0 1 2 3 4 5 6 7 8 9 10Yield (per recruit) (YPR) Age in Years Identify F at maximum on the curve = FmaxEgg production per recruit (EPR) Convert to % age of unfished (virgin) egg productionInformal reference point indicators (various standards world wide) Target /precautionary indicator : 35% or 25 % virgin egg production Limit e.g. 20% or 10% of virgin egg production Proxy for MSY = FmaxIn progress: EFF (SAGB-Cefas) project on management proxies (M Smith, Cefas)
  21. 21. Typical crab assessment result(e.g. North Sea, from CEFAS 2009 draft ) Max yield per recruit (at Fmax) growth overfishing Present fishing rate YPR female 1.4 600 YPR male 100 F female %VirgSPR female 1.2 F male 90 %VirgSPR male 500 %VirgEPR female 80 Fishing rate per size class % virgin SPR or EPR 1 70 400 60 0.8 YPR 300 50 F 0.6 40 200 30 0.4 20 100 10 0.2 0 0 0 0.5 1 1.5 2 0 F multiplier 110 130 150 170 190 210 Proportion of present fishing rate size class (mm) % virgin eggs per recruit Need 70% cut in harvest rate to reach Fmax & increase EPRSimilar analyses by England, Scotland and Ireland for all major regional crab areasSee Bannister, 2009, On the Management of Brown Crab Fisheries (SAGB London)
  22. 22. English assessment results for all regions (Source: Cefas, draft 2009, cited in Bannister Crab Report 2009) Fishing Reference Point: F max Reference Points: Rate % Virgin Egg per Recruit Region Highest F Sex Status To reach Ref Pt. Observed Status To reach Fmax ref pt Central North Sea 0.6-1.0 F F>Fmax -68% 25% 6% < -80% M F>Fmax -71% 10% 6% < -43% Southern North Sea 1.0-1.5 F F>Fmax -74% 25% 5% < -82% M F>Fmax -76% 10% 5% < -53% Eastern Channel 0.3-1.0 F F>Fmax -57% 25% 7% < -74% M F>Fmax -46% 10% 7% < -32% Western Channel 0.6-0.8 F F>Fmax -47% 25% 9% < -69% 0.2-0.3 M F<Fmax 8% 10% 9% < -12% Celtic Sea 0.6-1.4 F F>Fmax -59% 25% 8% < -76% M F>Fmax -65% 10% 8% < -29% Irish Sea 0.5-1.5 ? F F> Fmax -72% 25% 6% < -84% 1.0-2.5 ? M F> Fmax -63% 10% 6% < -56% Suggests sustainable fishing requires significant reductions
  23. 23. Summary attributes for brown crab•Mixed management framework (EU, national administrations, English IFCAs)•Regional stock monitoring (landings, log books, port- & sea-based sampling,some VMS, tagging)•Periodic assessments & harvest rate estimates (length-based, Eng, Scot, Eire)•Informal reference points (Fmax, 35%, 25% & 10% of virgin EPR)•Technical measures (e.g. EU mls & crab claws + various SFC byelaws)•English SFC permit schemes and pot limitation schemes•10 yrs of SAGB & industry pressure for better/ more coherent management,culminating in Bannister & Nautilus reports, NFFO strategy, and TransnationalStakeholder Group
  24. 24. Conclusions for brown crabNegativesNo unified assessment /reference points/advisory frameworkAsessments have uncertainties, but F appears >> Fmsy in most regions,especially on hensEffort is rising, and a big concern is the latent effort inherent in existingshellfish entitlementsGrowing industry agreement in favour of action, but not on what action to takeSo far, management lacks the formal coherent fishery objectives, harveststrategy, and decision rules that meet PA guidelines Many brown crab stocks are not fished sustainably Present thrust to cap effort is a minimal position relative to the PA Can the mixed management frameworks deliver sustainability ? There is WORK TO DO !
  25. 25. Cockle (Cerastoderma edule) Wash 2009 ESFJC•Siphonate bivalve common on mid-tide muddy sands•Main stocks occur in large estuaries with larval retention e.g.Wash, Thames, Burry Inlet, Three Rivers, Dee, Morecambe Bay, Solway•Many previous MAFF /Cefas surveys & studies (Hancock & Thames EstuaryUrquhart, 1960s, Pickett & Franklin, 1970s, Dare, Bannister, 2010, K&E SFCWalker, Bell, 1990s)•Ongoing surveys & studies by SFC’s & Cefas Short life cycle with high natural mortality & early maturation (age 2) Episodic large spatfalls separated by leaner periods, Burry Inlet 2010 SW SFC causing time-space variability Variation originates in larval phase (temp, circulation, productivity) + likely density-dependent settlement Figures are from SFC Reports, and Cefas
  26. 26. 1990s cockle working party ‘SFC/Bannister strategy’ •1970s Wash collapse illustrated the danger of overharvesting •Essential to manage the carry over of good spatfalls into the lean years • ‘one third rule’: keep harvest < 33% of fishable biomass (proxy for MSY, and secures stock for wading birds) • Rotate access to beds according to abundance, density & size of cockles •Suction dredging is too efficient for smaller estuaries •In large estuaries, partition the beds: hand rake on high density beds & suction dredging on lower density beds • Control suction dredge damage rates (SFC studies in Wash & Thames) Evolved by SFC’s into BEST PRACTICE Active hands-on approach using Fishery Orders & Byelaws (licensing, quotas, seasonal & bed closures, vessel restrictions, based on routine annual stock surveys) Burry Inlet Cockle Fishery Order 1965 ( now MSC certified) Wash Fishery Order 1992 Thames Estuary Cockle Regulating Order 1994
  27. 27. Historical landings Recent decadesWash landings ‘70-99 Tight regulation Variable landings remain in historical range. One recent ‘die off ’episode Stock NumberThames landings ‘70-99 Tight regulation. Stock variable but rising Sustainable fishery.Burry Inlet landings ‘70-99 Long term moderate harvest rate were sustainable until early 2000’s, when mystery ‘die- off’s’ set in.
  28. 28. Summary attributes for cockle Comprehensive management framework (Regulating Order & Byelaws)Annual stock assessment (Transect surveys, age structure, numbers & biomass)Annual harvest rate estimates (catch /stock number)Fmsy or Bmsy-trigger not measurable, but stock density proxies in placeHarvest strategy & decision rule (one third rule or similar, quota by bed, damagerate criteria, temporary bed closure,). These also meet the bird criteria (MSC Prin 2)Strong reporting, monitoring and enforcement systemsNegativesNo agreed reference points , but harvest rate & stock density proxies in placeInherent uncertainty about the natural causes of recruitment variation,Complete uncertainty about the cause of mystery die offsConstant pressure for additional licences: need a ‘last in-first out’ ruleSuction dredge damage rates require regular monitoring Regulating Orders keep harvest rates moderate & the system meets numerous sustainability criteria (subject to natural uncertainty of estuarine recruitment).. Burry Inlet (hand raking only) has MSC certification
  29. 29. Conclusions for the 3 examplesInternational Framework: NephropsFishing is restricted by the ICES-EU framework & most harvest rates are moderateThe advice is shaping towards formal sustainability in 3-4 yearsThe only stock with increasing catch opportunity is the FladenThe aggregate TAC issue is a problem for MSC certificationMixed management framework : Brown crabMany stocks are not fished sustainably: harvest rates are at or beyond FmaxThere is no sign of recruitment failure, but need to cap effort now, as a minimumCredible PA status requires an agreed management plan with defined objectives,harvest strategy, reference points, decision rules, and REDUCED fishingLocal management framework (Regulating Orders) : CockleManagement in the three Fishery Order areas meets the intent of manysustainability criteria, and illustrates best practice.Outcomes are subject to unpredictable natural variability & mystery ‘die off’MSC has certified the Burry Inlet hand rake fishery
  30. 30. The FutureSustainable Management for Capture Shellfisheries needs:---A long term strategy to apply Precautionary Approach concepts to shellfish stocks,just as ICES does for fish stocks--Scientists and stakeholder groups to develop agreed formal long term managementplans that apply the concepts illustrated today--Plans that contain pre-agreed objectives, harvest strategy, reference points anddecision rules, or meaningful proxies, that are strong and specific--Long term stock monitoring; ongoing research on biology & population processes;an advisory process (e.g. a National Shellfish Resource Group, or equivalent, asproposed previously by SIDS)--Effective enforcement: Regulating Orders show the joint benefits of ‘controlthrough ownership’, and consensual participatory management (e.g. Wash). There isscope to develop this route further with the IFCAs.
  31. 31. Wider Issue: beware the unexpectedWE cannot control CLIMATE CHANGE— BUT we CAN start to think NOW about how the following priority impacts will affect habitats & stocks: Basic changes to temperature, salinity, ph (already occurring) Plankton changes (already occurring) Changes to the timing, intensity & duration of the seasons Changes to the biology of target species, predators, & diseases Changes to environmental triggers that cue reproduction Rainfall, flash floods, storm surges, and sea level riseAn important source:Marine Climate Change Impacts Partnership, Annual Report Cardwww.mccip.org.uk
  32. 32. AIR since 1860 UPPER SEA TEMP anomaly since 1950 2 1 N Sea Surface oC 0 temp -1 -2 1965 1975 1985 1995 2005 1000Recruit (millions ) 800 Cod 600 Recruit 400 ment 200 0 1965 1975 1985 1995 2005

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