fundamentals of fisheries resource management ramon carcamo fisheries expert

Fundamentals of Fisheries Resource Management

Ramon Carcamo

Fisheries Expert

Fisheries Resources

Organic resources are the same limited resources as mineral ones. If we exhausted mineral resources, mineral resources will run out. But, as organic resources have reproductive mechanism and differ from mineral resources, we can make the best use of organic resources for permanent utilization by applying their reproductive mechanism.

Fisheries resources is also organic resources, therefore, we have to consider permanent utilization of them by applying the mechanism.

Pillage fisheries will extinguish not only fisheries resources but also fisheries themselves.

Features of the fisheries resources

Non-renewable

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Organic [Living] Resources(Fish, shrimp, etc.---)

Reproductive Capability

No Management for Fisheries Resources

Depleted Fisheries Resources

Appropriate Fisheries Resource Management

Sustainable Use of (Fisheries) Resources

Mineral Resources (Oil, Coal, etc. ---)


Características de los Recursos

Pesqueros No-renovables

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Recursos orgánicos [Vivientes](Peces, camarones, etc.---)


Ningún Manejo para el Recurso Pesquero

Disminución del Recurso Pesquero

Apropiado Manejo del Recurso Pesquero

Uso Sostenible del Recurso (Pesquero)

Recursos minerales (Gasolina, carbón, etc. ---)

Capacidad Reproductiva

Fisheries Resources

Looking back the history on utilization and development of fisheries resources, the necessity of permanent utilization is quite obvious.

The major aim of fisheries resources conservation and management strategies is to make possible of permanent utilization of the resources.

We must grasp the strategies of fisheries resources conservation and management from three aspects.

The first aspect is a biological aspect, the second is a fisheries aspect, and the third is a economic aspect.

Biological Aspect: Growth law and survival law

The growth law shows the corresponding body weight increases as the cohort ages. WHILE,

Nu

mb

er o

r W

eigh

t

Age

Growth Curve

Survival Curve

The survival law demonstrates the decline in survival as a function of the age of the cohort.

Biological Aspect: Biomass curve

In the natural environment, the relationship of the two laws can be shown as a biomass curve.

Nu

mb

er o

r W

eigh

t

Age

X

The first half of the curve draws an exponential growth in total body weight of fish and as maturity is reached the maximum biomass , and will be at Point X.

Beyond this point little growth occurs and natural mortality begins to set in.

Simplified migration circuit

For maintain the resources on target species, proper measures for protection of nursery and spawning areas should be taken.

Adult Stock

Migration

Spawning Area

Migration / Drifting

Nursery Area

Recruitment

Fisheries Aspect: Selectivity curve 1.0

0.5

0.0

Body Size Y

Mes

h S

elec

tivi

ty Y

X

The selectivity curve is influenced by mesh size whereby as mesh size decreases, the curve moves to the left resulting in a smaller-sized catch.

Increasing the mesh size shifts the curve to the right, thus yielding a larger-sized catch. To maximize a catch, mesh size targeting the desired individuals should be used.

Fisheries Aspect: Discontinuous selectivity of an ideal gear

Previous mentioned relationship is drawn as a discontinuous selectivity curve (ideal gear if available)

1.0

0.5

0.0

Body Size

Mes

h S

elec

tivi

ty

No smaller fishes caught

Commercial sized fishes caught

Fisheries Aspect: Selectivity curve of diamond and square mesh

The mesh type is equally important as illustrated in above.

1.0

0.5

0.0

Body Size

M

esh

Sel

ecti

vity

Diamond Mesh

Square Mesh

At a given mesh size, square mesh is more effective in catching larger-sized fish than a diamond mesh.

In practice, this is a useful technique in catch selectivity.

Economic Aspect: Relationship between cost and Yield

MSY: Maximum Sustainable Yield

Fishing Effort

A

mou

nt

of M

oney

Yield

Cost MSY

MEY

MEY: Maximum Economic Yield

Objective

Target point at the time

Observation of present state

Evaluation of the difference from the target point

Judgment of method to approach target point

Decision on measure to be taken

Fisheries resource management at the target area

Monitoring of results

Scientific research

Fisheries Resource Management System in General

Flow chart of the measures for

sustainable use of the fisheries resources Fishermen (Fishers)

Fishermen want to catch fish, shrimp, shellfish, etc. as possible as they can.

Paid the heavy effort for the fisheries resources without management measures.

Depleted fisheries resources

Fishermen can’t be survived as fishermen & no fish will be provided to the consumers.

Appropriate fisheries management measures have to be promoted for sustainable use of the fisheries resources.

Establish Fisheries Resource Management Committee.

Policy makerResearcherFisheries industry

Intelligent persons in the fisheries science


Diagrama de flujo de las medidas para un

uso sostenible de los Recursos Pesqueros Pescador (Pescadores)

El pescador quiere capturar peces, camarones, moluscos, etc. tantos como ellos puedan.

Pago por el fuerte esfuerzo por los recursos pesqueros sin medidas de manejo.

Disminución de los recursos pesqueros

Pescador no puede sobrevivir como tal y los peces no son suministrados a los consumidores.


Establecen un Comité de Manejo de los Recursos Pesqueros.

Vigilancia

InvestigaciónIndustria pesqueraPersonas Inteligentes en la Ciencia pesquera

Apropiadas medidas de manejo pesquero deben ser promovidas para un uso sostenible de los recursos pesqueros.

Major information needed for fisheries resource management (ⅰ) Biological Information (ⅱ) Technical Information (ⅲ) Economic Information (ⅳ) Social Information and (ⅴ) Institutional Information

– Source: FAO, RAPA Rep., 1987/10 Information mentioned above is obtained from

many sources such as universities, extension agents and so on.

For the more effective use of sources of information and increasing supply to information, some possible approaches suggested are as follow:

(ⅰ) Increasing contact with fishermen by facilitating establishment of fishermen’s groups or organizations or by making greater use of extension agents.

(ⅱ) Improved communication between decision-makers and scientists through the establishment of consultative meetings etc.

For the more effective use of sources of information:

(ⅲ) Better coordination between fisheries statistical services and other government agencies.

(ⅳ) Integrating the collection of economic and social data into catch assessment surveys.

For the more effective use of sources of information:

(ⅴ) Development and testing of surrogate-indicators for detailed information (e.g., changes in shares paid for labour or in lease fees for vessels as indicators of health of fisheries).

(ⅵ) Greater involvement of universities in multi-disciplinary fisheries research of direct relevance for decision-making.

(ⅶ) Improved contacts between private fishing industry and

fishery administrators.

(ⅷ) Others.

DEFINE THE FISHERY- GEOGRAPHICAL BOUNDARIES- FISHING METHODS- FISH SPECIES (ONLY IF ESSENTIAL)

ESTABLISH AN INDUSTRY/GOVERNMENT TASK FORCE

DETERMINE THE OBJECTIVE FOR MANAGEMENT OF THE FISHERY

CONSOLIDATE AND ANALYSE AVAILABLE BIOLOGICAL, ECONOMIC AND LICENSING INFORMATON

PREPARE MANAGEMENT OPTIONS PAPER SETTING OUT:- DESCRIPTION OF FISHERY- OBJECTIVES- ASSESSMENT OF BIOLOGICAL AND ECONOMIC DATA- ASSESSMENT OF MANAGEMENT OPTIONS UNDER FOLLOWING HEADINGS .. OPEN ACCESS .. TAXES ON INPUTS OR OUTPUTS .. LIMITED ENTRY .. INDIVIDUAL TRANSFERABLE QUOTAS

DRAFT MANAGEMENT PROPOSALS FOR CONSIDERATION BY INDUSTRY

SUBMISSION O RECOMMENDATIONS TO GOVERNMENT

ESTABLISHMENT OF INDUSTRY/GOVERNMENT MANAGEMENT ADVISORY COMMITTEE

IMPLEMENTATION OF MANAGEMENT PLAN

ONGOING EVALUATION OF MANAGEMENT PLAN AND INTRODUCTION OF ADDITIONAL MANAGEMENT MEASURES

An example of ‘Process of formulation of fisheries resource management plan’ is shown as follows (FAO, RAPA Rep., 1987/10)

Fisheries Resource Management Ideas for Small-scale Fisheries

Fishery BiologyFishery Biology

Stock AssessmentStock Assessment

Policy and MeasuresPolicy and Measures

Interaction of FisheriesInteraction of Fisheries

Resource EnhancementResource Enhancement

Fisheries StatisticsFisheries Statistics

Items should be done for the stock assessment and fisheries

resource management for the small-scale fisheries is as follow (Modified from Saila and Roedel, 1979):

(ⅰ) Collaborative Research, First Priority

① Comparative Studies – Productivity ② Comparative Studies - Catch ③ Comparative Assessment Models ④ Policy and Decision-making Structures ⑤ Biosocioeconomic Models



( ) Collaborative Research, Second Priorityⅱ

① Data Analysis Systems ② Surveys – Direct Census ③ Surveys - Acoustics



( ) Collaborative Research, Third Priorityⅲ

① Age and Growth Studies ② Surveys – Remote Sensing ③ Surveys – Capture ④ Surveys – Eggs and Larvae



( ) Supportive Research Activities ⅳ

① Inventory of Exploited Resources ② Inventory of Human and Institutional Resources

③ Inventory of Ecosystem Response ④ Inventory of Life Histories ⑤ Surveys - Effort



( ) Supportive Development Activities ⅴ

① Information Dissemination ② Training - Data

Stock Structure: Single-speciesS T O C K I

(Single-species)

Species A Regional Form a

Regional

Form b

Biological features on Form a

Biological features on Form b

Biological features on Species A

Resource evaluation on Stock I

Discrimination between Form a and Form b

(Resource evaluation on Form a)

(Resource evaluation on Form b)

Stock Structure: Multi-species

S T O C K II (Multi-species)

Species B

Species C

Biological features on Species B

Biological features on Species C

Resource evaluation on Stock II

(Resource evaluation on Species B)

(Resource evaluation on Species C)

Stock Discrimination

The stock or shoal discrimination studies are mainly based on the followings:

Morphology Ecology Catch fluctuation Genetics

Stock Discrimination Stock characters are as follows:

Body length and weight composition Growth rate Age composition Fatness Egg-diameter Fecundity Scale features

Stock Discrimination

Stock characters are as follows:

Ratio of body measurements Meristic characters Serum protein Karyotypes Isozymes Mitochondria DNA

Parameters/Elements for Biological Features of Fish

Popular parameters/elements for biological features are as follow:

① 　 Geographic limits to the stock ② Migration pattern ③ Depth distribution ④ Size composition (mean length in catch,

maximum length and maturity size) ⑤ Spawning (season and area)



⑥ Nursery ground ⑦ Fecundity ⑧ Recruitment (season and body size) ⑨ Growth (growth rate) ⑩ Length-weight relationship



⑪ Mortality ⑫ Age and age determination ⑬ Sex ratio ⑭ Food and feeding habit ⑮ Predators

Parameters/Elements for Biological Features of Fish Additionally, meristic characters such as

number of vertebrae, number of fin spines and rays, number of mid-lateral scales and so on are very important elements, and morphometric characters are also important for the features of stock of fish.

Identification of Parameters for Studies on Stock and Population Dynamics

① Length-weight relationship: – Paired data of length and weight are required. – Data are obtained from measurements of fish

body.

② Growth curve: – Paired data of age and length are required. – Analyse age and measurements of fish body.


③ Natural mortality coefficient: – Longevity (analyse age, etc.), growth equation (analyse

age and fish body measurements), tagging data (analyse recapture data) and data of virgin stock (survey in unexploited area) are required.

④ Fishing mortality coefficient: – Age composition (analyse age), catch and effort (obtain

from operation record) and tagging data (analyse recapture data) are required.


⑤ Longevity: – Growth, sex ratio, survival rate, etc. are required.

– Analyse age, sex and etc.

⑥ Availability: – Species list and catch composition are required.

– Data are obtained from Fish Market Census or direct observation of fish market.


⑦ Reproductive mechanism: – Information on recruitment-parent relationship

is required. – Analyse age composition data for many years.

⑧ Sex ratio: – Frequency distribution of each sex is required. – Analyse numbers of male and female

determined by gonad.


⑨ Maturity rate: – Frequency distribution of gonad index is

required. – Examine the gonads.

⑩ Number of spawned eggs: – Number of incubation and spawning eggs is

required. – Examine the ovaries.


⑪ Age composition: – Frequency distribution of body length is

required. – Analyse age and body length frequency. Age

determination method is required.

⑫ Population index: – Fish density of each area is required. – Data are obtained from experimental surveys.


⑬ Effective overall fishing intensity: – Fish density of each area is required. – Data are obtained from experimental surveys.

⑭ Catchability coefficient: – Selectivity and escape rate are required. – Data are obtained from experimental surveys.


⑮ Selectivity: – Mesh size selectivity data are required. – Data are obtained from experimental surveys.

⑯ Escape rate: – Hypothetical experiment is required.


⑰ Density of area: – Experimental survey is required.

⑱ Catch per year: – Fisheries statistics is required.

Possible Measures for Fisheries Management (Closed Season)

During this period Fishing activities are prohibited To protect spawning adults during the

spawning season Or To rehabilitate depleted stocks

Possible Measures for Fisheries Management (Closed Area)

An area/habitat is closed to fishing activities, For example, to protect spawning grounds or

juveniles This does not affect fishing effort It can be relocated to other areas But it can limit its effectiveness on fishing

effort

Possible Measures for Fisheries Management (Fishing Gear and Methods)

Certain types of fishing gear will be prohibited

Also the number of fishing gear will be restricted on this scheme

Mesh size restriction for certain fishing gear is also one of the popular measures

Possible Measures for Fisheries Management (Size Limit)

On the fishing and selling of fish Under a set size limit must be prohibited For conserving the resources Fish caught less than a set size limit It must be released into the sea At good condition.

Possible Measures for Fisheries Management (Fishing Sub-gear)

Fishing sub-gear such as fish luring (aggregative) lamp

It is sometimes restricted of its electric power Intensity of the lamps tends to be strengthened

gradually in order to get more catches But intensity of lamps is strengthened,

catchability is not improved so much Regulations regarding such fishing sub-gear is

necessary to avoid excessive competitions among fishermen.

Possible Measures for Fisheries Management (Total Catch by Species)

Stemming from the international law of the sea, as of November 1993, a country may set a total allowable catch (TAC) of the total catch by species as its upper limit.

Other countries, therefore, may only catch the difference between the TAC and actual catches, thus limiting the catches beyond the TAC.

Catch quota system is also one of the methods of restriction of the catches.

Possible Measures for Fisheries Management (Boat and Operation)

Capacity for Number of Fishing Boats and Duration of Fishing Operations

Many fishing activities are regulated by a licensing system

This is direct control on the level of exploitation Because, catches can be significantly increased

when there is an increase in efficiency and operation frequencies

Fundamentals of Fisheries Resource Management

Thank You

fundamentals of fisheries resource management ramon carcamo fisheries expert

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