Populations and

sustainability :-

FisheriesDaniel Sandars

(10-12-2014)

2010=US$ 91.2 billion

http://www.statista.com/chart/2280/the-global-fish-farming-industry-is-booming/

http://www.un.org/depts/los/convention_agreements/reviewconf/FishStocks_EN_A.pdf

EU Fishing Effort 1950

http://wwf.panda.org/?203247/Wild-west-fishing-in-distant-waters

EU Fishing effort Now

http://wwf.panda.org/?203247/Wild-west-fishing-in-distant-waters

Conflicts

http://en.wikipedia.org/wiki/Cod_Wars

http://moneyweek.com/1-september-1958-the-first-cod-war-begins/

Global fish stocks

The ‘tragedy of the

commons’

http://www.fao.org/docrep/003/T0509E/T0509E01.gif

Play the fisheries game

http://es.earthednet.org/fishing-game

Fisheries Management

Biological conservation

Fish stocks & Natural habitats

Fishing

Employment, viable remote communities,

foreign exchange, economic efficiency, &

social equity

Sustainability

http://en.seafood.no/Sustainability/Norway's-commitment

Biological Conservation

Population Dynamics

Stock Assessment

EnvironmentStock

Interactions

http://www.burg.org.au/photos_fish_survey2.htmlhttp://www.fishex.com/seafood/salmon/salmon-life-cycles.html

http://deborahmph720.blogspot.co.uk/2010/06/mercury-occurence-and-movement-in.html

http://worldoceanreview.com/en/wor-2/ecosystems-and-species/fish-habitats/

Socio economics –

markets, labour, & incomes

Fishing - effort, technology, structure,

& investment

Fishing –access, rights & enforcement

Exploitation

management

http://www.constantinealexander.net/itqscatch-shares/page/2/http://www.newlynfishfestival.org.uk/

http://worldfishingtoday.com/news/default.asp?nyId=7310

Management system

Management

Economic

Direct

Days at sea, number of vessels, fishing times,

holding capacity, engine size

Indirect

Taxes on fuel or sales of fish

Fishing rights – licences, sole ownership, individual quota, community quota,

territorial rights

Biological

Net sizes, quotas, area closures, nursery area

protection

Monitoring Judicial system

Fisheries management

Scientific approach

to fisheries

management

http://www.theorsociety.com/Pages/Feature/Feature201309Johari.aspx

Operational Research

methods

•Descriptive Mathematical

Modelling

•Qualitative information on complex variable systems

•Anticipate stock behaviour in response to environment, fishing, regulation

•Computer Simulation

•What-if of management choices

•Qualitative evaluation of management strategies

•Information on the dynamic behaviour of complex systems

•Mathematical Programming

•The optimal solution/ management decisions

•Most profitable fishing effort and investment

•Least cost regulation and monitoring

•Decision Theory

•Evolving decisions given evolving information (catch data) availability

•Fisheries management decisions

•Fishing management decision

•Statistical Estimation

•The impact of uncertainty/ stochasticity

•Statistical analysis of other modelling approaches

•Design of exploitation and monitoring efforts

Operational Research

methodsDescriptive

mathematical modelling

Population dynamics

Stock exploitation

Stock interactions

Stock allocation

Socio-economic

issues

Computer simulation

Population dynamics

Stock assessment

Stock exploitation

Stock interactions

Environmental dependencies

Stock allocation

Socio-economic

issues

Optimizing mathematical programming

Population dynamics

Stock assessment

Stock exploitation

Environmental dependencies

Decision theory

Population dynamics

Stock exploitation

Statistical estimation

Stock assessment

Stock exploitation

Fish Population

Dynamics

http://www.qub.ac.uk/research-

centres/WelcometoSustainableDevelopmentatQueens/RelatedResearch/EcosystemApproachtoF

isheriesManagement/

Population dynamics

Learn about the behaviour and sensitivity

of the fishery

• Given key assumptions and

parameter estimates

• Do equilibrium conditions develop?

• What are the nature of any dynamic

fluctuations?

• Is the population stable?

• Does it exhibit statistical stationarity?

• How robust and complete is the

model? Are results repeatable?

Model typology

Population dynamics

Lumped parameters

Discrete time Ricker 1975

Continuous time

Schafer model (Schafer 1957)

Dynamic pools (age cohorts)

Beverton and Holt 1957

• Beverton RJH and Holt SJ 1957 On the dynamics of exploited fish populations. Fisheries

Investigations Series II, vol. 19. Ministry of Agriculture, Fisheries and Food, Her Majesty's

Stationary Office, London, UK, 533pp

• Ricker WE 1975 Computation and interpretation of biological statistics of fish populations.

Bulletin Fisheries Research Board Canada 191, 382pp

• Schaefer MB (1957) "Some considerations of population dynamics and economics in

relation to the management of marine fishes" Journal of the Fisheries Research Board of

Canada, 14: 669–81.

BIDE Model

• N1 = N0 + B − D + I − E

• N=Number in population in time period 1 or 0

• B=Births

• D=Deaths

• I=Immigrants

• E=Emmigrants

Caswell, H. 2001. Matrix population models: Construction, analysis and interpretation, 2nd Edition.

Sinauer Associates, Sunderland, Massachusetts. ISBN 0-87893-096-5.

Carrying capacity

• Ricker model –density dependence

• N= population size at time t

• r0 = intrinsic growth rate (births and immigration)-

(deaths + emigration)

• K = carrying capacity

http://sites.duke.edu/ecologytools/populationdynamics/scenario-1/

Harvest Control Rule

Population data –data

poor environments

• Birth rate or recruitment to catchable size

• + Growth rate – size and length

• - Death rate –harvested or natural (predation, age,

disease)

• Commercial catches give regular data on the

catchable fraction – Survey ships give less data on all

age groups

• NB Over-simplistic modelling of fisheries has resulted

in the collapse of key stocks

Concluding remarks

• Wild fisheries suffer from the tragedy of the commons

• Global competitive markets are emerging

• Strong fishing drivers for increased productivity with

lower investment and operating costs

• Increasing awareness of complex environmental

issues

• Better sustainable fisheries management practice

are needed

• The significant role of OR models seems

unquestionable

http://blogs.edf.org/edfish/2014/07/28/investing-in-the-transition-to-thriving-eu-waters-a-visionary-new-framework/

References

• Lane, D.E. Operational research and fisheries

management (1989) European Journal of Operational

Research, 42 (3), pp. 229-242. Cited 6 times.

• Bjørndal, T., Lane, D.E., Weintraub, A. Operational

research models and the management of fisheries and

aquaculture: A review (2004) European Journal of

Operational Research, 156 (3), pp. 533-540. Cited 26

times.

• Arnason, R. Fisheries management and operations

research (2009) European Journal of Operational

Research, 193 (3), pp. 741-751. Cited 11 times.