colin bannister (2011)
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DRUMMOND LECTURE 2011
Securing resources
-- a scientists view
Dr Colin Bannister
Fisheries & Shellfisheries Scientist
Trustee of the Buckland Foundation
Chairman of SAGB
Last Year’s Lecture: Peter Hunt’s Vision
The C F PInshore Management 6-12 miles
Sustainable ManagementRegional Management PlansEnvironmental ImpactStatic Gear & Mollusc CultureMobile GearNaturalised SpeciesPolluter paysImproved water treatmentMonitoring pollutionClassification of shellfish watersToxin managementCrustacean management , regional inshore brown crab managementRestoration of regional rural fishing communitiesPhasing out preserved historic practicesMaximising the value of shellfish.
What does this really mean ?
Sustainability (of capture fisheries)
Policy
Definitions and obligations
The objectives & actions required
Scientific objectives
Precautionary frameworks
Fish stock examples of MSY
Knowledge required
Stock status and management criteria
Shellfish examples from 3 types of management regime
Wider issues
Future needs
Climate change
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 precautionary
2002 Johannesburg World Summit on Sustainable Development
Where possible, fish stocks should reach MSY not later than 2015 !!
1995 United Nations Fish Stock Agreement (for straddling and highly migratory stocks):
1982 United Nations Law of the Sea: Includes a call to manage fisheries for maximum sustainable yield (MSY)
Recommendations and Laws
World Commission on Environment & Development (Brundtland,1987)
……development that meets our needs without restricting/pre-empting future choices or needs ....
FAO 1995 is not legally binding, but it is the basis for applying the PA in most international scientific & management bodies including EU & NEAFC (advised by ICES), and NAFO.
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 change
The Precautionary Approach:--this is not a whimsy but a formal structure
October 14, 2010 Dr Colin Bannister 6
Yield (sum of numbers * weight at age) has a maximum
(or a plateau depending on growth rate)
Heavy fishing means fewer old fish:You catch more, but they are smaller,
SO
MSY
A refresher on MSY
** in this example juvenile numbers are constant but in the real world, fishing beyond MSY may/will eventually impair recruitment
North Sea Cod Stock-Recruitment
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Spawning Stock (1000 tonnes)
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2001 2002
The Stock is outside safe biological limits.
High risk of collapse
SSB is in the region of Blim.
F is estimated to be about Flim
Bpa
What is impaired recruitment ? (2 key examples)
(Data from
ICES & CEFAS)
North Sea Herring Stock-Recruitment
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Spawning Stock (1000 tonnes)
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Bpa
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N Sea CodAge 1 recruits
v. Spawning biomass
N Sea HerringAge 0 recruits
v. Spawning
biomass
Spawning stock biomass (‘ooo tonnes)
SSB 2010, 1.3 mill t
SSB 2011, 58 000 t
Danger of collapseunquantifiable
Collapsed in 1976Recovered after closure
Blim
Blim
Stock collapse below 800 000 t
?
Pre-’87
AGE
0
Post-’87
Reference point & control rule concepts
Harvestrate
Stock status
B limit B msy (= B trigger)at F msy* ( = new F limit)
Harvest control rule
Critical zoneReproduction impaired or at risk: reduceharvest rateto lowest possible level(or zero)
Cautious zone
Reduce harvestrate to promote rebuilding
Healthy (Low F /High B)
Cap harvest rate at F msy= sustainable fishing
Fmsy*
* or proxies
Status of 30 NE Atlantic fish stocks, 2003 ( ICES data)Fishing Mortality Fishing Mortality
Species/stock Biomass Fopt Flim F'03 Species/stock Biomass Fopt Flim F'03
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 0.32
Fopt (proxy for Fmsy) is 0.05-0.20: sustainability requires very moderate harvest rates
But 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 !!!
The 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 !)
Knowledge & Implementation
Prin 3: diagnostic indicators : inter aliaGeneral attributesLaws, processes & standards able to deliver sustainable fisheries Roles, responsibilities, consultation are transparent, defined, effectiveLong term objectives conform to PA & MSC principles
Fishery specific attributesDefined fishery objectives that deliver PA & MSC principlesEffective decision processes: transparent & deliver the objectivesMonitoring & enforcement secure demonstrably effective compliance
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
Prin 1: diagnostic indicatorsAttributes (& knowledge) needed to demonstrate sustainability
(MSC Prin 2: How fishery affects habitat & ecosystem: likely to be pressure points for certain target species and gears……….. for another day !!
Capture shellfishery examples
Sustainability attributes under 3 management systems
Management system mainly internationale.g. Nephrops (langoustine)
Mixed management system (EU, national, local )e.g. Brown crab
Local management system (SFC Regulating Orders)e.g..Cockle
Does management of these stocks conform to PA criteria?Are the stocks being fished sustainably ?
Nephrops norwegicus Langoustine
•Densely packed burrows in cohesive mud
•Stocks (‘Functional Units’) generally delimited by habitat & larval retention in gyres
•Long history of previous biological research
•Populations & production generally stable
•Capture (trawl or creel ) depends on daily patterns of emergence & 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
Fladen
Moray
Forth
Farn
N Minch
S Minch
VMS
TV Survey
Clyde
I Sea West
TV survey
TV survey
Nephrops stock surveys
Source: www.ices.dk
N Minch
S Minch
Clyde
Fladen
I Sea W
Moray
Forth
Farn
TV survey trends--western TV survey trends
--eastern
Reported Landings (ICES W Gp data)
Source: www.ices.dk
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ICES VIa
N Minch
S Minch
Clyde
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ICES VII
I Sea W
I Sea E
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ICES IV
Farn Dp
Fladen
Forth
Moray
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
Status of selected Nephrops stocks from ICES Advice for 2011 & 2012 (my extract )
% Harvest rate Stock number Stock status* ADVICE (control rule)
Stock F U 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 20.1
Fmsy is derived from proxies (F0.1, F35%spr,Fmax) * unofficial indicative colour code
Btr=Btrigger =lowest obs'd in TV survey series trans msy = first of 5 steps to MSY
Stock status:compare F to Fmsy, stock number to Bmsy
Positives
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 modest
Negatives
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 3
The only shellfish example on a par with the fish world
Harvest rates are moderate & the system meets numerous sustainability criteria
Some limitations, and one major long standing weakness (the aggregated EU TAC)
Summary attributes for Nephrops
Brown Crab (Cancer pagurus)
•Fished from inshore to well offshore on extensive regional stocks
•Periodic MAFF/Cefas research on migration, larvae, biology, ageing (Edwards, Bennett, Addison,Thompson, Eaton, Sheehy)
•Migrating hens & nomadic cocks support seasonal fisheries, butstock structure is not fully worked out
•Stocks are relatively stable over time, but complex spatial patterns are not 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 year
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Faeroe Bank
Rockall
Bank
Porcupine
Bank
La Chapelle
Bank
D3 D4 D5 D6 D7 E2 E3 E4 E5 E6 E7 E8 E9 F0 F1 F2 F3 F4 F5 F6 F7 F8D8 D9 E0 E1
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3635
3029
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4241
3837
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3433
2625
2827
2423
Pressure 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)
Source: Defra 2010
Source:Cefas 2011
from Mill et al, 2009, draft
Papa
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Hebrides
Orkney
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Northumberland
Yorkshire
E.Anglia
Edible crab
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La
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South Devon
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Edible crab
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Assessments :
Periodic size-based assessments with informal reference point indicators
Split size frequency data into ‘age’ groups (using growth from tagging) Estimate current harvest rate (F) from decline of numbers with ‘age’Model effect of lower or higher harvest rates (at constant recruitment)
Yield (per recruit) (YPR)
Identify F at maximum on the curve = Fmax
Egg production per recruit (EPR)
Convert to % age of unfished (virgin) egg production
Informal reference point indicators (various standards world wide)
Target /precautionary indicator : 35% or 25 % virgin egg productionLimit e.g. 20% or 10% of virgin egg production
Proxy for MSY = Fmax
In progress: EFF (SAGB-Cefas) project on management proxies (M Smith, Cefas)
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Number at age, for different mortalities
10%'
18%'
26%'
40%'
50%'
Typical crab assessment result (e.g. North Sea, from CEFAS 2009 draft )
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size class (mm)
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F female
F male
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Similar analyses by England, Scotland and Ireland for all major regional crab areasSee Bannister, 2009, On the Management of Brown Crab Fisheries (SAGB London)
Max yield per recruit (at Fmax)
Present fishing rate
Need 70% cut in harvest rate to reach Fmax & increase EPR
growth overfishing
Fishing rate per size class
% virgin eggs per recruit
Proportion of present fishing rate
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%
English assessment results for all regions(Source: Cefas, draft 2009, cited in Bannister Crab Report 2009)
Suggests sustainable fishing requires significant reductions
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 Transnational Stakeholder Group
Negatives
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 existing shellfish entitlements
Growing industry agreement in favour of action, but not on what action to take
So far, management lacks the formal coherent fishery objectives, harvest strategy, and decision rules that meet PA guidelines
Conclusions for brown crab
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 !
Wash 2009ESFJC
Thames Estuary 2010, K&E SFC
Burry Inlet 2010 SW SFC
Cockle (Cerastoderma edule)
•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 & Urquhart, 1960s, Pickett & Franklin, 1970s, Dare, Bannister, Walker, 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, causing time-space variability
Variation originates in larval phase (temp, circulation, productivity) + likely density-dependent settlement
Figures are from SFC Reports, and Cefas
•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)
1990s cockle working party ‘SFC/Bannister strategy’
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
Wash landings ‘70-99
Thames landings ‘70-99
Burry Inlet landings ‘70-99
Stock Number
Tight regulationVariable landings remain in historical range.One recent ‘die off ’episode
Historical landings Recent decades
Tight regulation.Stock variable but risingSustainable fishery.
Long term moderateharvest rate were sustainable until early 2000’s, when mystery ‘die-off’s’ set in.
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, damage
rate criteria, temporary bed closure,). These also meet the bird criteria (MSC Prin 2)
Strong reporting, monitoring and enforcement systems
NegativesNo 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
.
Summary attributes for cockle
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
International Framework: NephropsFishing is restricted by the ICES-EU framework & most harvest rates are moderate The 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 certification
Mixed 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 fishing
Local management framework (Regulating Orders) : CockleManagement in the three Fishery Order areas meets the intent of many sustainability criteria, and illustrates best practice.Outcomes are subject to unpredictable natural variability & mystery ‘die off’MSC has certified the Burry Inlet hand rake fishery
Conclusions for the 3 examples
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 management plans that apply the concepts illustrated today
--Plans that contain pre-agreed objectives, harvest strategy, reference points and decision 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, as proposed previously by SIDS)
--Effective enforcement: Regulating Orders show the joint benefits of ‘control through ownership’, and consensual participatory management (e.g. Wash). There is scope to develop this route further with the IFCAs.
WE 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 rise
An important source:
Marine Climate Change Impacts Partnership, Annual Report Card
www.mccip.org.uk
Wider Issue: beware the unexpected
AIR since 1860
UPPER SEA TEMPanomaly since 1950
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