Review of Sampling Strategies, Data Needs and Estimation Procedures for Monitoring the Sri Lankan Fishery for Large Pelagic Species

Table of Contents

FI:TCP/SRL/2251
Field Document 1

TECHNICAL COOPERATION PROGRAM

ESTABLISHMENT OF A MONITORING SYSTEM FOR CATCHES OF ARTISANAL DRIFTNET AND LONGLINE FISHING

SRI LANKA

FIELD DOCUMENT 1:
REVIEW OF SAMPLING STRATEGIES, DATA NEEDS AND ESTIMATION PROCEDURES FOR MONITORING THE SRI LANKAN FISHERY FOR LARGE PELAGIC SPECIES

Report prepared for
the Government of Sri Lanka
by
the Food and Agriculture Organisation of the United Nations

Howel Williams

FOOD AND AGRICULTURE ORGANISATION OF THE UNITED NATIONS
Colombo, 1995

This electronic document has been scanned using optical character recognition (OCR) software and careful manual recorrection. Even if the quality of digitalisation is high, the FAO declines all responsibility for any discrepancies that may exist between the present document and its original printed version.

Table of Contents

1. INTRODUCTION

1.1 Project overview

2. REVIEW OF THE SPECIES COVERAGE

3. REVIEW OF EFFORT INDICES

4. VESSEL DESCRIPTIONS

5. REVIEW OF FORMS

5.1 Description of forms

A. LARGE PELAGICS FISHERY MONITORING PROGRAM
B. LARGE PELAGICS FISHERY MONITORING PROGRAM SUPERVISOR'S CHECK SHEET
C. SMALL PELAGICS FISHERY MONITORING PROGRAM
D. SMALL PELAGICS FISHERY MONITORING PROGRAM SUPERVISOR'S CHECK SHEET
E. CATCH SAMPLING FORM - FISHERY MONITORING PROGRAM

6. REVIEW OF ESTIMATING PROCEDURES AND RAISING FACTORS

6.1 The current method for estimating national annual production

A. THE SAMPLING PROTOCOL
B. STRATIFICATION OF SAMPLES
C. CALCULATION OF NATIONAL PRODUCTION

6.2 Review of the method for estimating national annual production

A. THE SAMPLING PROTOCOL
B. STRATIFICATION
C. CALCULATION OF NATIONAL PRODUCTION

7. REVIEW OF DATABASE

7.1 Original data base structure
7.2 The new data base structure

ATTACHMENT 1 - Current sample sites and samplers

ATTACHMENT 2 - Current species codes, FAO codes and recommended codes for the species categories proposed

ATTACHMENT 3 - Data sheets

1. INTRODUCTION

1.1 Project overview

The objectives of the project are:

· establish a reliable system for collecting and processing data on the catch and effort of the driftnet and longline fisheries for large pelagic species,

· in association with this system collect biological information on catch composition, bycatch species and length distributions of the principle species,

· establish a basis for estimating national catches of large pelagics and their bycatch,

· produce and document routine reporting systems that will provide analyses for researchers and managers.

The Technical Co-operative Program (TCP) project operated for 12 months after which the monitoring program would be continued with the support of the national government.

There are a number of issues linked to this project. Principal amongst these are:

· United Nations Resolution (44/225) sought a moratorium on all large scale pelagic driftnet fishing and encouraged coastal states to collect and submit scientific information on driftnet fisheries within their EEZs.

· Sri Lanka requested FAO assistance to study its driftnet fishery at the twenty-third session of the Indo-Pacific Fisheries Commission (IPFC).

· the Indian Ocean Fisheries Commission (IOFC) Tuna Committee recommended that the TCP project should receive a high priority.

· with the formation of the Indian Ocean Tuna Commission (IOTC), the Sri Lankan government is obliged to take on the national monitoring component currently supported by the Indo-Pacific Tuna Management and Development Program (IPTP).

The TCP project was delayed in starting by nearly two years. In the interim, some related projects were conducted to address urgent issues arising from the activities of the fishery. These studies were conducted by the National Aquatic Resources Agency (NARA) and the Bay of Bengal Program (BOBP) and included a critical appraisal of the catch of dolphins by the fishery and some basic socio-economic surveys of the fishery.

The accuracy of production estimates is dependant on accurate estimates of catch rates and of raising factors (the number of vessels in the national fleet). It is anticipated that the latter will be provided from a census conducted by a related FAO project SRL/91/022. Following this census, it is understood that the information used to estimate raising factors will then be routinely updated by the Ministry of Fisheries and Aquatic Resources (MOFAR)

2. REVIEW OF THE SPECIES COVERAGE

At present the data collected on catch compositions may be divided into the following categories on the data sheets and within the database:

Data sheet & database code	Category name	Scientific name
YFS	Yellowfin tuna (small)	Thunnus albacares
YFM	Yellowfin tuna (medium)
YFL	Yellowfin tuna (large)
SKS	Skipjack tuna (small)	Katsuwonus pelamis
SKM	Skipjack tuna (medium)
SKL	Skipjack tuna (large)
KAW	Kawakawa	Euthynnus affinis
FRI	Frigate tuna	Auxis thazard
BLT	Bullet tuna	Auxis rocheii
LOT	Longtail tuna	Thunnus tonngol
BET	Bigeye tuna	Thunnus obesus
BIP	Indo-Pacific bonito	Sarda orientalis
DOT	Dogtooth tuna	Gymnosarda unicolor
COM	Narrow-barred king mackerel	Scomberomorus commerson
WAH	Wahoo	Acanthocybium solandri
GUT	Indo-Pacific king mackerel	Scomberomorus guttatus
STS	Streaked seerfish	Scomberomorus lineolatus
BLM	Black marlin	Makaria indica
BUM	Indo-Pacific blue marlin	Makaria mazara
SAI	Indo-Pacific sailfish	Istiophorus platypterus
SWO	Swordfish	Xiphias gladius
MLS	Striped marlin	Tetrapturus audax
SSP	Shortbill spearfish	Tetrapturus augustirostris
REQ	Requiem sharks	Family CHARCHARINIDAE
LAM	Mackerel, mako sharks	Family LAMNIDAE
HAM	Hammerhead sharks	Family SPHYRNIDAE
ALO	Thresher sharks	Family ALOPIIDAE
ELA	Other elasmobranchs (not in the above families)
PEL	Other pelagics (not in above categories)
DEM	Demersals (not in above categories)
MAM	Marine mammals (dolphins, porpoises, whales)

In reviewing these categories consideration was given to the following:

· the need to keep the number of categories to the minimum to reduce inefficiency placed on the samplers and the potential for sampler and data entry errors,

· the growing importance of shark catches as a component of the pelagic fishery and hence a need to collect more detailed and meaningful statistics on landings for biological assessment,

· the need to collect information on important bycatch species,

· the potential for species which are currently infrequent in catches to become more significant as new fishing techniques are adopted.

With regard to categories that could be amalgamated, it was considered that catches of longtail tuna, Indo-Pacific bonito and dogtooth tuna were small and infrequent and could therefore be incorporated into an 'other tuna' category. Whilst catches of bigeye tuna are currently rare it was considered that the potential existed for catches to increase in the near future as new longline techniques are adopted by the Sri Lankan fishing industry. The bigeye tuna should retain a separate category for this contingency.

The catches of Indo-Pacific king mackerel and streaked seerfish were also small and could be incorporated into an 'other seerfish' category. The catches of striped marlin and shortbill spearfish are also rare and could be incorporated in an 'other billfish' category. The pelagic and demersal categories are ill-defined and it is difficult to see how they would be used meaningfully in assessments. It is suggested that they could be combined into an 'other bonyfish' category.

Elasmobranch landings have become significant, if not the major component of landings at some centres. However the categories covering these landings are not sufficient to permit basic assessments of the contribution of the main species. To rectify this it is suggested that the Charcharhinid category (the major component of elasmobranch catches) be split into four categories (silky shark, blue shark, oceanic white tip and other requiem). Species belonging to these categories are readily identifiable and are sorted at the landing sites. Samplers should therefore find it easier to collect this information rather than having to pool information for the current category.

The other families of sharks are comprised of fewer principle species, however scope for confusion in identification exists and so identification to the family level only should remain. The catch of skates and rays is significant and it is anticipated that the catch of deep water dogfish will increase significantly in the near future. At present catches from either of these sources would be recorded in the one category and so valuable information on the respective fisheries is confounded. It is suggested that the current 'other elasmobranch' category, be split into 'other sharks' and 'skates & rays'.

For the non-fish bycatch, it is suggested that the 'marine mammal' category remain for recording catches of dolphins and whales. The NARA have indicated that it would be desirable to collect information on other vertebrate catches such as turtles It is suggested that for this purpose a remarks column be included with provision to record anecdotal reports of turtle entanglements. The landing of turtles is illegal in Sri Lanka although a black market exists for incidental catches. Catches cannot be reliably assessed by monitoring conventional landings however, it is believed that fishermen will readily provide advice on the number and type of entanglements that they may have experienced during a trip

Finally, in considering the impact of these changes on the ability of field samplers to collect reliable information, it is considered that the new categories can achieve identification of the major species caught (including sharks) down to the species level Other catches will be identified at either a family, order or class level. The changes proposed can be achieved without increasing the current number of categories and will therefore, not increase the complexity of the forms significantly.

Where possible the FAO species codes have been used. A table of the current code used by IPTP or NARA, the FAO code and the code recommended is at Attachment 2. The following categories are proposed:

Data sheet & database code	Category name	Scientific name
YFS	Yellowfin tuna (small)	Thunnus albacares
YFM	Yellowfin tuna (medium)
YFL	Yellowfin tuna (large)
SKS	Skipjack tuna (small)	Katsuwonus pelamis
SKM	Skipjack tuna (medium)
SKL	Skipjack tuna (large)
KAW	Kawakawa	Euthynnus affinis
FRI	Frigate tuna	Auxis thazard
BLT	Bullet tuna	Auxix rocheii
BET	Bigeye tuna	Thunnus obesus
TUX	Other tuna
COM	Narrow-barred king mackerel	Scomberomorus commerson
WAH	Wahoo	Acanthocybium solandri
KGX	Other seerfish
MAR	Marlin	Black, blue and striped marlin
SFA	Indo-Pacific sailfish	Istiophorus platypterus
SWO	Swordfish	Xiphias gladius
BIL	Other billfish
MZZ	Other bony fish (not in the above categories)
FAL	Silky shark	Charcharhinus falciformis
BSH	Blue shark	Prionace glauca
OWT	Oceanic while tip	Charcharhinus longimanus
RSK	Other requiem sharks
MSK	Mackerel, mako sharks	Family LAMNIDAE
HAM	Hammerhead sharks	Family SPHYRNIDAE
ALO	Thresher sharks	Family ALOPIIDAE
SKH	Other sharks (not in the above families)
SRX	Skates & rays
MAM	Marine mammals (dolphins, porpoises, whales)

In addition to these changes to the species list on the large pelagic data sheets, it is suggested that data recording for the small pelagics monitoring program be made more flexible to accommodate information on incidental catches of large pelagics. This can be achieved quite easily by including unlabelled lines in the species list on the small pelagics data sheet so that if significant species are encountered they can be recorded.

3. REVIEW OF EFFORT INDICES

The current program, estimates effort in units of days fished for each of the vessel classes. The form has provision for only one duration to be logged and that duration is ambiguous - it is not clear whether it is the length of the trip or the number of days on which fishing occurred during the trip. Improvements in the effort indices could be achieved if effort was partitioned by the gear types used and by estimating the quantities of gear in use during each trip.

The IPTP database for the Sri Lankan fishery for large pelagics, has recorded eight gear types and 23 combinations of gears in use since 1986. The gear types used and their codes on the database are:

Gear code	Alternative code	Gear name
BB	B	Pole and line
GN	G	Gillnel (drift)
HAR	Z	Harpoon
HL	H	Handline
LL	L	Longline
PS		Purse seine
RN		Ringnet
TL	T	Troll line

The gear combinations in use since 1986, and the use of those combinations as a proportion of all samples stored on the database for the years 1986 and 1991-92 are:

Gear combination	Explanation	% 1986	% 1991-92
BB	pole and line	0	0.41
BxT	pole and line & troll	0	0.04
GN	gillnet	91.40	25.07
GxB	gillnet & pole and line	0	0.01
GxH	gillnet & handline	0.52	0.45
GxHxL	gillnet & handline & longline	0	14.69
GxHxT	gillnet & handline & troll	0	0.01
GxL	gillnet & longline	4.77	38.52
GxLxT	gillnet & longline & troll	0	2.41
GxLxZ	gillnet & longline & harpoon	0	0.29
GxT	gillnet & troll	0	0.04
HAR	harpoon	0	0.09
HL	handline	3.13	6.50
HxB	handline & pole and line	0	0.01
HxL	handline & longline	0	0.04
HxT	handline & troll	0	0.01
LL	longline	0.16	4.84
LxB	longline & pole and line	0	0
LxZ	longline & harpoon	0	0.02
PS	purse seine	0.02	0.09
RN	ringnet	0	0.36
TL	troll	0.00	5.93
TxL	troll & longline	0.00	0.15

It appears that in the mid 1980's individual boats were using only one type of gear during a fishing trip. Gillnets alone account for 91% of samples collected in 1986. Fishing techniques have become quite diverse since that time with the wide adoption of longline fishing (and to a lesser extent, handlining and trolling) as an adjunct to gillnetting. Combinations of gillnetting and/or longlining with the other subsidiary gear types account for 87% of the gear combinations sampled in 1991-92.

Partitioning effort between these principal gear types (gillnet and longline) could be accomplished in a crude way by recording the amount of gear in either category taken on the trip. This could then be multiplied by the number of fishing days to give an index of the number of gear unit days fished. Subsidiary gear types are not a significant part of the fishery, however it is suggested that whilst information on the use of gillnets and longlines is always collected, some provision should be given to record a third gear type if used.

The question on the form referring to duration should be more explicit and refer to either the numbers of days fished or be split into two and report both the duration of the trip and the number of days fished. The former is preferred as it will be used in calculations of effort. Whilst information on the duration of a fishing trip is interesting, and can be used to draw inferences on the area fished, it is not routinely used within the database or in calculations of national production.

4. VESSEL DESCRIPTIONS

There are currently four vessel codes in use for the large pelagic fishery and the types of vessels which they describe are as follows:

Code	Description	Typical boat types
UN1	5.5 to 7.2 in LOA FRP dinghy with outboard motor (to 30 hp). Generally single day fishing trips.	18' 24'
UN2	8.8 to 9.8 m LOA. inboard motor (to 40 lip) displacement vessel. Variable construction (wood and/or FRP) and configuration of fish hold and accommodation. Typically multi-day fishing trips.	28' single day 32' (modernised 28') with ice box
UN3	9.8 m and over LOA. inboard motor (GO lip) displacement vessel. Variable construction (FRP and/or wood) and configuration of fish hold and accommodation. Multi-day fishing trips.	Trawler ?? hp Abu Dhabi Modified UN2 with large fish hold. gear hold and wheel house/accommodation 34' 36'
UN4	Traditional boat with outboard motor. Generally single day fishing trips.	Orru Vellum

The vessel categories UN1, UN2 and UN3 were originally formulated to classify a simple fleet of mechanised boats comprising of three basic designs Subsequent developments within the fishing and boat building industry have led to greater flexibility in the design and layout of vessels and the categories are now less narrowly defined. In addition the equipment installed on vessels varies within a length class depending on the fishery in which they operate The UN2 category is comprised of single day boats fishing for tunas in coastal waters and multi-day boats fishing in offshore waters. The latter are modified to include insulated fish holds and some navigational and fish finding aids.

The present UN3 category originally described the vessels designed and built by the Abu Dhabi North-West Fisheries Development Project (then the largest vessels in use in Sri Lanka). There is no upper size limit set for the UN3 category and so it is assigned to any vessel that is larger than a UN2. The development of the Sri Lankan large pelagic fishing fleet continues rapidly. New and replacement vessels are tending to be larger than their predecessors and to be custom built rather than based on a few basic plans. The UN3 category is increasingly being assigned to vessels that do not conform to the original definition. If continued tills will lead to valuable information on the development of the fleet being lost and a decline in the quality of the estimates of catch rates for that vessel class.

During the course of the TCP project, the Ministry requested NARA to produce catch statistics partitioning catches on the basis of coastal and offshore production. The easiest basis on which to partition catches is by looking at the multi-day boats as an offshore fleet and the single day boats as a coastal (near shore) fleet. This partitioning could be easily accommodated within the database if it were included as one of the attributes used in describing vessel categories.

The small pelagic program uses vessel categories with the code TR1, TR2 etc., TR standing for 'traditional'. However additional categories have recently been added and this naming convention has not been followed. Rather the new categories have been called UN4 and UN5. There is some confusion between the two programs and of course it is a logical progression for new categories of larger tuna fishing vessels to use the UN code.

Based on work conducted by NARA the following categories are suggested.

Category	Description
UN1	5.5-7.2m (17'-21') FRP dinghy Outboard engine - 8-70 HP (usually 15-25 HP) Single day boats - assumed to be fishing in COASTAL WATERS"
UN2A	8.8 - 9.8 m (28'-34') displacement hull. FRP or wooden. Inboard engine (single) - 40 HP No ice box or insulated fish hold only - no gear hauler, nav or acoustic equipment. Single day boats - assumed to be fishing in COASTAL WATERS"
UN2B	8.8 - 9.8 m (28'-34') displacement hull. FRP or wooden. Inboard engine (single) - 40 HP Insulated fish hold - no gear hauler, may have GPS/sounder/fish finder Multi-day boats - assumed to be fishing in OFFSHORE WATERS"
UN3A	9.8 - 12.2 m (34'-40') displacement hull. FRP or wooden. Inboard engine (single) - 60 HP - (includes Abu Dhabi vessels) Insulated fish hold and may have gear hauler/GPS/sounder/fish finder Multi-day boats - assumed to be fishing in OFFSHORE WATERS"
UN3B	12.2m- (40'-) displacement hull FRP or wooden. Inboard engine (single) - 60 + HP Insulated fish hold and may have freezer facilities. Gear hauler/GPS/sounder/fish finder Multi-day boats - assumed to be fishing in OFFSHORE WATERS"
UN4	Reserved for vessel category eg. 15.2 - 18.3 m (50'-60')"
UN5	Reserved for vessel category eg. 18.3m+ (60'+)"

It is suggested that the codes referring to categories of vessels in the small pelagic fleet use the suffix 'TR'. This will prevent confusion between the two sets of data and should simplify data recording for the field samplers. Accordingly it is recommended that the current code for the motorised orru be changed from UN4 to TR5.

5. REVIEW OF FORMS

5.1 Description of forms

In reviewing the forms it became apparent that there is considerable confusion and overlap between sampling for the large pelagics fishery and the small pelagics fishery. It has not been entirely clear to the samplers how to record information from the respective fleets. In most cases, no distinction has been made between vessels operating in the respective fisheries and so estimates of the number of vessels in port, operated and sampled will refer to boats from both fleets. This may have rendered the data collected to date, inadequate for estimating the size of either the large pelagic or small pelagic fleet participating in the fishery.

One of the principal concerns in reviewing the forms has been to remove this confusion. It has therefore been necessary to also review the small pelagics forms, to provide scope for recording incidental catches of large pelagic species by boats targeting small pelagics. It is intended that the respective forms only be used to collect information pertaining to the specific fleets. Drafts of the catch and effort data sheets (large pelagic fishery and small pelagic fishery) and the length frequency data sheet are provided at Attachment 3(a-c) respectively.

It is also desirable to collect subsidiary information by staff who are supervising the work of the samplers This information is important for several reasons Firstly, it provides a means of monitoring the activities and practices of the samplers. Secondly, it can be used to provide independent information on factors being recorded by the samplers Finally, it can provide important additional information that is not being collected by the samplers. A draft of a quality control check sheet for supervisory staff is also attached [Attachment 3(d)]

With regard to bio-economic information, users advised that monthly estimates of costs and fish prices would be adequate for routine monitoring. On investigation it was found that the MOFAR currently collects this type of information from all major centres through the District Fisheries Officers. It is desirable to keep the collection of bio-economic data separate from the collection of fishery monitoring data. Both sets of information may be sensitive, and combining them may reduce the co-operation of fishermen or the reliability of the information volunteered. It is recommended that the monitoring and bio-economic information systems continue to be separated and that the MOFAR system for collecting bio-economic data be used.

5.1 Description of forms

A. LARGE PELAGICS FISHERY MONITORING PROGRAM
B. LARGE PELAGICS FISHERY MONITORING PROGRAM SUPERVISOR'S CHECK SHEET
C. SMALL PELAGICS FISHERY MONITORING PROGRAM
D. SMALL PELAGICS FISHERY MONITORING PROGRAM SUPERVISOR'S CHECK SHEET
E. CATCH SAMPLING FORM - FISHERY MONITORING PROGRAM

A. LARGE PELAGICS FISHERY MONITORING PROGRAM

One form to be completed for each sampling day, and if there is not sufficient room on the sheet for information from all the boats sampled then additional sheets can be used.

The form is divided into three basic parts. The first is a header that identifies the date of sampling and the site that was sampled. An indication is also given as to whether there is more than one page of information.

The second section deals with a description of the fleet landing and the sample size. It is intended that estimates of the number of boats 'operated' refers only to those boats operating in the large pelagics fishery and landing at that site on the sampling day.

The third section is the most detailed and aims to collect information on catch and effort on a boat by boat basis. Each column of information relates to one vessel. The type of boat refers to the vessel class (UN1-UN4), days fished is the number of days that the boat was actively engaged in fishing less the number days spent steaming or laying to. Gillnet fishing effort is indicated by the number of pieces of net that were carried on the boat and similarly longline fishing effort is indicated by the number of baskets of hooks. Another field has been included for recording and other auxiliary fishing methods that may have been used. This information will be. recorded using the existing alphabetic codes. The main bait type used for hook fishing is also included.

The catch/landing details are set out according to the species categories discussed in an earlier section. There are two major divisions in the type of information, bony fish landings are generally recorded in numbers and elasmobranchs in weight. Weight is the unit of preference for all species and should be recorded when they are available, possible,

B. LARGE PELAGICS FISHERY MONITORING PROGRAM SUPERVISOR'S CHECK SHEET

The attached quality control sheets have provision to collect information on the total number of landings made by a vessel in a month and the total number of fishing days undertaken. These data will improve the procedure for estimating the raising factor for monthly catches by vessel type. The total number of vessels participating in the fishery for large pelagics in the port, by the vessel categories, is also recorded. This information will be useful in estimating raising factors for fleet size, it will also provide information on the relative movements of vessels between ports.

C. SMALL PELAGICS FISHERY MONITORING PROGRAM

Designed to the specifications provided by the researchers responsible for this project within NARA.

D. SMALL PELAGICS FISHERY MONITORING PROGRAM SUPERVISOR'S CHECK SHEET

Designed to the specifications provided by the researchers responsible for this project within NARA.

E. CATCH SAMPLING FORM - FISHERY MONITORING PROGRAM

Data sheet for recording individual fish lengths from landings by boats sampled. Data is recorded here for species for which numbers and not weights are available It is not essential that the lengths be from any particular vessel. What is important is that the sample is representative of the size offish landed at the site on the day sampled. Care should also be. taken to ensure that any subsampling of a landing is done on a random basis.

6. REVIEW OF ESTIMATING PROCEDURES AND RAISING FACTORS

6.1 The current method for estimating national annual production
6.2 Review of the method for estimating national annual production

6.1 The current method for estimating national annual production

A. THE SAMPLING PROTOCOL
B. STRATIFICATION OF SAMPLES
C. CALCULATION OF NATIONAL PRODUCTION

A. THE SAMPLING PROTOCOL

Foremost in the design of the current sampling program is the allocation of equal sampling priority to the small pelagic and large pelagic fisheries. As well as the sampling time being evenly split between the two fisheries, an attempt is also made to sample ports which are important for both large and/or small pelagic fish landings.

The following table gives the sites sampled and the zones in which they are grouped. An assessment is also given of the relative importance of landings from the large and small pelagic fishery to each site.

Zone	Site	Large pelagic fishery		Small pelagic fishery
		Primary	Secondary	Primary
W	Negombo	x		x
SW	Beruwala	x
S	Weligama	x
	Mirissa		x
	Dondra	x		x
	Gandra	x		x
	Kottegoda		x
SE	Kudawella	x		x
	Tangalle	x		x
	Hambantota			x
E	Kalmunai	x
	Batticoloa	x
NE	Trincomalee	x		x

A sampling schedule for each zone is developed on a monthly basis with sampling days for the large pelagic and small pelagic fisheries alternating (so that there are about 10 days of large pelagic sampling in each zone per month). In those zones in which there is more than one sampling site, the sites have been defined as large pelagic, small pelagic or both. The sampling schedule is then determined by alternating the sites for those days set aside for either large or small pelagic sampling. One sampling day will be spent at one sampling site (except for Mirissa and Weligama which are sampled on the same day). In this way the number of sampling clays are equally distributed between sites.

The samplers attend the landing site on the day assigned by the schedule. At the site they conduct the vessel counts requested on the form and then start sampling landings. It is up to the interpretation of the sampler (and the nature of the vessels at a site) as to whether the vessel count relates to those boats participating in the large pelagics fishery or relates to all boats at the site. The selection of landings for sampling is on an ad hoc basis and may vary from site to site depending on the way in which fish are landed.

There do not appear to be any written instructions for the samplers, and this is starting to present some problems particularly with the interpretation of some of the questions on the forms and the assignment of codes (particularly vessel class codes) The recording of landings of large pelagics taken as incidental catches of other fisheries (e.g. demersal and small pelagic fishery) is unclear. They may be recorded as landings in the large pelagic fishery (even though there was no targeting), recorded on a specific fishery database (such as demersals) or not recorded at all.

On any sampling day the samplers aim to measure landings from approximately 25% of the vessels in each of the vessel classes represented at the site

The bony fish landings are measured in numbers of individuals and the elsmobranch catches in weight. Length frequencies for bony fish are collected to provide both biological information on the population and a means of converting numbers of fish landed to weight of fish landed. A length frequency sample will comprise around 20 individual fish lengths. Lengths are generally not taken for species measured by weight (the elasmobranchs)

B. STRATIFICATION OF SAMPLES

In the current program the primary stratification is made by grouping sampling sites into zones and sampling each zone independently. Where zones contain more than one sampling site the data from the sites are kept separate although the sampling protocol is the same for all sites (regardless of size, significance to the fishery etc.). Individual sampling sites are therefore not treated as separate strata. The sites sampled and the zones into which they are grouped are given at Attachment 1.

The rationale behind the regional stratification is largely based on dividing the fishery into units that can be serviced by teams of samplers. A secondary reason is that the fisheries of the regions (zones) are distinct as a consequence of the proximity of particular fishing grounds and the influence of local climatic conditions (such as the north east and south west monsoons).

Vessel type is another stratification that is made on the fishing Heel sampled at each site on any sampling day. Vessel type is determined on the basis of the size and construction of the vessel. The definitions are given in Section 5. The size of the sample taken from each vessel type strata is arbitrary with the only criteria being that all types that are recorded as having operated in a port must be sampled The following table gives the number of vessels sampled by the IPTP program in Sri Lanka during the period 1991-92. The contribution of samples from each of the vessel types to the total number of samples collected is also indicated

Type	no of samples	% of all samples
UN1	245	2.6
UN2	7861	82.5
UN3	1290	13.5
UN4	132	1.4

C. CALCULATION OF NATIONAL PRODUCTION

The estimation of national production is currently made in the following steps:

Step 1 - Estimate daily landing of one species of one site

[1]

where D_sl = production of species (s) at landing site (1) on sampling day
L_sbl ⁼ landing of species (s) by boat (b) at site (1)
N_vl = number of vessels of class (v) operated at site (1) that day
n_vl = number of vessels of class (v) sampled that day at site (1)

Step 2 - Estimate months landing of one species at one site

[2]

where M_sl = production of species (s) at site (1) during month
D_sdl ⁼ daily production on sample day (d) at site (1)
N_dl = number of landing days at site (1) in that month
n_dl = number of days sampled at site (1) in that month

Step 3 - Annual production of a species within a zone

[3]

where S_z = annual production of species in zone (z)
M_sml ⁼ months production of species (s) in month (m) at landing site (1)
N_UN2/UN3 ⁼ number of vessels of class UN2 and UN3 registered within the zone
n_v == number of vessels registered at the sites sampled
n_l = number of landing sites sampled in zone

Step 4 - National production

National production is estimated by summing the annual production of all zones.

Whilst the calculations are straight forward there are some problems with this process. For instance,

(i) in computation [2] it is assumed that fishermen have no preference for particular landing days and hence that any landing day in a month is representative of the. others,

(ii) the number of UN2 and UN3 vessels is pooled when calculating the raising factor used to estimate zone production in computation [3] - tins assumes that the two classes have similar catching power, an assumption that is not sound,

(iii) in computation [1] it is assumed that there is homogeneity within a vessel class (that is the different gear types are ignored),

(iv) the factor used in computation [3] to raise the estimate to the number of vessels within the zone is based on information gathered by the MOFAR in the late 1980's. This is now outdated and should not be used in current estimates.

(v) in calculating the raising factor used in computation [3] it is assumed that all UN2 and UN3 vessels registered within a zone are engaged in the large pelagic fishery.

6.2 Review of the method for estimating national annual production

A. THE SAMPLING PROTOCOL
B. STRATIFICATION
C. CALCULATION OF NATIONAL PRODUCTION

A. THE SAMPLING PROTOCOL

The objective of the large pelagic sampling program has been to gather information on which to base estimates of national production. The original program was developed by IPTP to address this objective and it has proved to be capable of giving reliable estimates. The same objective has been carried over from IPTP to NARA, however, it appears to have been broadened to encompass the small pelagic fishery too. Whilst the small pelagic sampling program has no explicit objective, the fact that it models itself on the large pelagic program suggests that it too strives to estimate national production. If this is the case then it would be advisable for the small pelagics program to review its objectives as the current program cannot provide adequate information for this outcome.

Estimating production and sustainable yields for small pelagics is not practicable or of great utility to the managers. Rather, information on trends in catch rates, the use of gears by the fishery, inter-annual variability and basic biological parameters such as yield per recruit, growth, size at age are of more immediate importance. These are quite different problems to that which the large pelagics program has been designed to address and the logistical support needed is quite different. Indeed the current program in trying to service both projects has some major inefficiencies which diminishes the effectiveness of the large pelagics program The two programs cannot successfully coexist in their present form with the current resources.

It would be advisable for the small pelagics program to formulate explicit objectives for the program being mindful of the priority of the program, the needs of the resource managers and the physical resources available. In the mean time it is suggested that the sampling period for the large pelagics program be increased to three weeks in every month and that the sites sampled be reppraised to ensure that those areas of most importance to the fishery are being adequately covered. It would also be advisable to allocate blocks of time to large pelagics sampling rather than the current procedure of alternating between small and large pelagics on a daily basis. This would allow the samplers more time at the respective sites rather than in travelling The remaining week in each month can be assigned to sampling for the small pelagic and/or demersal fisheries, and this sampling should concentrate on areas of significance to those fisheries. A reappraisal of the sites for sampling for the large pelagics program follows in the next section.

The fact that the large and small pelagics programs are separate needs to be stressed to the samplers. They should be made aware that information collected on the sampling forms should refer only to those vessels that are actively participating in the respective fisheries. For example, the vessel counts and landing details on the large pelagics form should refer only to vessels that have targeted large pelagics and should not be used to record information on the incidental catch of large pelagics in other fisheries.

The number of vessels operated and the number sampled should refer only to those vessels that are participating in the large pelagics fishery with large pelagic species as their principle targets. The Quality Control Check Sheet completed by supervisors will yield additional information on the fleet size at the sampling sites.

On a sampling day, samplers should aim to take information from at least five landings off vessels from each class operating at the site and a daily total of at least twenty vessels. Care should be taken to ensure that the whole landing from a vessel is recorded.

The current system is inflexible in the way in which catch quantities are measured, numbers only for bony fish and weights for sharks and rays. At some sites the landings are only measured by weight (Trincomalee, Negombo) and it is difficult to get a count of the number of individuals. Similarly the landings of sharks are sometimes not weighed or they are dismembered before weighing which presents the sampler with a difficult problem of accounting Where weight is taken at the landing site it is pointless to derive weights from the length frequency measurements. Similarly, by not collecting length frequency information on some species of shark, valuable biological information is being lost.

It is suggested that the database should be altered to allow the recording of either weight or number for any species in a landing. Where the weight of landings is available the samplers should record this in preference to numbers. Length frequency information should be collected for all of the principle species regardless of the method by which landing quantities are measured. It is also suggested that the samplers receive training in estimating weights particularly for making estimates of the weight of landings of shark species where there Is no facility for weighing at the landing site.

In the previous section problems with some of the assumptions implicit in the current raising factors were mentioned. One of those assumptions was that landing days were homogenous, that is that all landing days in a month had an equal probability of fishermen choosing to land and hence that measurements taken on sampling days were representative of all landing days. This assumption is not borne out in the field and it is only at the largest landing sites (Negombo and Beruwala) that it is likely to be true. At the smaller sites particular landing days are chosen in preference of others, for instance the day before poya days (each quarter of the moon) in Buddhist areas and Saturdays in Christian areas.

To overcome this problem it is suggested that the number of landings by a fisherman in a month should be determined as well as sampling individual landings In tins way the assumption becomes unnecessary as the estimate of average landings size in any month can be raised by the average number of landings made in a month. Samples of landings are therefore more representative of all other landings as they become independent of the day on which landings are made.

Where landings of the principle tunas are sorted before samplers have access to them provision has been made on the forms for recording numbers/weights in arbitrarily assigned classes (small, medium or large). Samplers should note that the classes are arbitrary and that there are no strict bounds to them - as a rule the samplers should not be concerned with the sorting. It is important that where a catch is assigned to a particular class then care should be taken to ensure that any associated length measurements are also assigned to that class (that is the species codes should correspond exactly).

With regard to the problems outlined earlier concerning the estimates and assumptions used in the raising factors for fleet size, several suggestions are offered. Firstly, it should be noted that the MOFAR (through the FAO sponsored fisheries management project) intend to conduct regular censuses of fleet size by village and district. Tills will revise the estimates used now which are outdated and provides for a regular cycle for updating the information on fleet size and distribution. Secondly, in developing the MOFAR census the needs of the large pelagics monitoring program are being considered and it is intended that information will include the class of the vessel (UN1-UN4) and the principal target fishery of the vessel.

B. STRATIFICATION

The regional grouping of sites is convenient for reference and there is no need to change the zones used. A departure from the principle of one team of samplers in each zone is suggested in those areas in which a team of samplers are in close proximity to a site in an adjacent zone - this is detailed later in tills section. Within zones the selection of sampling sites should be based on the overall contribution of the site to the fishery or the number of vessels landing at the site. The following table gives estimates of the number of large pelagics fishing vessels based at the landing centres and also notes peculiarities associated with the site and whether the site is used as a landing centre for boats fishing out of other sites.

Zone	Site	No. of vessels		Comment
		UN 2	UN 3
NW	Kandaculya	-	-	Seasonal centre, fleet size varies and is itinerant
W	Negombo	200	35
	Colombo (Mutwal)	-	15
SW	Berwala	300	50
	Galle	75	1	landing centre for large boats from Hikkaduwa
S	Weligama	65	-	main fishing method trolling
	Mirissa	170	28	landing centre for larger boats from Gandra and Kottegoda
	Dondra	140	12
	Matra	60	-	main method is pole and line
	Gandra	60	IS
	Kottegoda	72	-	single day boats
SE	Kundawella	42	-	mainly single clay boats
	Tangalle	50		landing centre for larger boats from Kudawella and Kalmetyia
	Kirinda	10
	Kalmetiya	25	20
E	Kalmunai	??	??
	Batticoloa	??	??
NE	Trincomalee	200	??	Seasonal influx of larger boats during NE monsoon.

Sites within the various zones which have some relevance to the large pelagic fishery are given in the following list. Sites are listed if they are in the current sampling program or if landings of large pelagics constitute the primary or secondary landings to the site. If the site is primarily a landing centre for small pelagic species this is also indicated

Zone	Site	In current program	Large pelagic fishery		Small pelagic fishery
			Primary	Secondary	Primary
NW	Kandaculya	opportunistic		x	x
	Chillaw	opportunistic		x	x
W	Negombo	yes	x
	Colombo (Mutwal)	no	x
SW	Beruwala	yes	x
	Galle	no	x
S	Weligama	yes	x		x
	Mirissa	yes
	Dondra	yes	x		x
	Matra	no		x	x
	Gandra	yes	x		x
	Kottegoda	yes	x
SE	Kudawella	yes	x		x
	Tangalle	yes	x		x
	Hambantota	yes			x
	Kirinda	no		x	x
	Kalmetiya	no	x
E	Kalmunai	yes	x		x
	Batticoloa	yes	x		x
	Valaichchenai	no
NE	Trincomalee	yes	x		x

Landing sites within the respective zones that are only significant to the fishery for small pelagics are provided in the following table.

Zone	Sites
NW	Kalpitiya, Taawilla, Nampura, Mukkutuduwawa, Puttalam, Sinapardu, Udappuwa, Muthiupanthiya, Karukupane, Iranawilla, Mattakotuwa, Thalwilla, Marawilla, Katuneriya, Wennappuwa
W	Elakanda
SW	Moratuwa, Panadura, Wadduwa, Kattukurunda, Maggona, Balapitya, Ambalangoda, Hikkaduwa, Dondanduwa
S	Dikwella, Hambantota, Ambalantota
SE	Welipatanwilla, Mawella, Armadura
Other	Mullaitiva, Jafna

In reviewing the sites for sampling, consideration was given to the need to optimise the coverage of the fishery by:

· choosing a few representative sampling sites for routine monitoring by the samplers,

· maximising the amount of time available for sampling on any day by minimising the amount of time spent in travelling between centres.

It was also considered that as the industry develops and larger boats become more common then landings will become concentrated at larger centres where infrastructure to service the larger boats exists. The pace of development already appears to be quite rapid in the Sri Lankan industry and the fishery is becoming increasingly dependent on deeper water ports, ice factories and access to transport.

The proposed sites were selected on the basis of their importance within a zone as indicated by the number of large pelagics fishing vessels based at or landing to the site. Rather than allocating equal sampling time to each site within a zone it is proposed that sampling time should be proportional to the number of vessels at the sites covered by the sampling teams (not necessarily the same as the proportion of vessels at sites within a zone). In the following table the sampling sites are listed and the proportion of sampling time allocated is also indicated.

Zone	Site	% sampling days assigned	days per fortnight	sampling team
W	Negombo	100	10	W
	Colombo (Mutwal)	ad hoc	ad hoc
SW	Beruwala	100	10	SW
	Galle	20	2	S
S	Weligama	20	2	S
	Mirissa	60	6	S
	Dondra	60	6	SE
SE	Kudawella	20	2	SE
	Tangalle	20	2	SE
E	Kalmunai			E
	Ballicoloa			E
	Valaichchcnai	ad hoc	ad hoc
NE	Trincomalcc	100	10	NE

In proposing these changes to the sampling sites it was noted that the North West zone could continue to be sampled opportunistically by NARA Colombo stall. The Mutwal landing centre could either be sampled by NARA Colombo staff or the samplers based at Negombo, The landing site at Galle needs to be covered as it is already a significant landing centre (as indicated by the number of vessels it services) and it will become increasingly important as its infrastructure will be in increasing demand as the fleet develops. Galle is within the zone serviced by the samplers based at Beruwala, however as they are responsible for the largest sampling site (in terms of the fleet size) and as Galle is a long distance from Beruwala, it is recommended that the South zone team cover this centre. Similarly the Dondra site should be picked up by the. South East zone team to bring the number of sites covered by the South zone team back to three (four cannot be adequately covered by one team and two sites in the South East is too few).

The current sampling sites at Gandra and Kottegoda could be dropped for several reasons. The fleet sizes are smaller and the larger boats from these centres are landing to other centres that will be monitored. Access for the samplers to both the sites is also relatively difficult as they are remote from the main road. Both sites could continue to be monitored on an act hoc basis with occasional visits by NARA Colombo staff.

Hambantota should be dropped from the schedule as this site. is of no great significance to the large pelagic fishery.

Map

C. CALCULATION OF NATIONAL PRODUCTION

Step 1 - Estimate the mean landing by class of vessel of one species in one zone during month

[4]

where _svmz = mean landing size of species (s) in month (m) by vessels of class (v) in zone (z)
L_sbmz = landing size of species (s) in month (m) by boat (b) in zone (z)
n_vmz = number of vessels of class (v) sampled in month (m) in zone (z)

Step 2 - Estimate the number of landings by a class of vessels in a zone during month

[5]

where _vmz = mean number of landings in month (m) by vessels of class (v) in zone (z)
Q_bmz = number of landings in month (m) by boat (b) from zone (z)
n_vmz = number of vessels of class (v) sampled in month (m) in zone (z)

Step 3 - Estimate months production of one species from zone

[6]

where P_smz = production of species (s) in month (m) from zone (z)
N_vmz = number of vessels of class (v) actively fishing in the fishery in zone (z) during month (m) from MOFAR survey

Step 4 - Annual production of a species within a zone

[7]

where S_z = annual production of species in zone (z)

Step 5 - National production

National production is estimated by summing the annual production of all zones.

7. REVIEW OF DATABASE

7.1 Original data base structure
7.2 The new data base structure

7.1 Original data base structure

The existing database is a FoxPro application with the data structured in such a way that separate files are created for each month's samples at each site (i.e. up to 12 files for each site). The data for each month is stored as a large flat file, with one record for each vessel sampled. The site information is therefore repeated for each boat sampled, and species data (catches) are recorded in columns corresponding to particular species. Length measurements are also maintained is separate files for each site and month. Each record relates to a sampling of one species from one catch, multiple length samples are recorded on each record

The database does not take advantage of any of the relational features of contemporary database applications and so offers very little flexibility for accommodating changes that could be expected to be seen in the fishery such as new vessel types, additional species, supplementary biological information. As information is stored in separate files for each month and site, reporting and maintenance of the year's collection is tedious, requiring the operator to conduct the same action for every file generated that year. In addition the FoxPro database application is probably not the ideal application to use in the NARA context. FoxPro is ideal for application developers, and requires a high level of understanding of database principles and the FoxPro scripting language for effective use, NARA has no great depth in database development expertise and is therefore totally dependent on external agencies for software development in FoxPro There is no local training in FoxPro and so little prospect of this changing.

In reviewing the database, principal consideration was given to:

· encouraging NARA to be self-reliant in subsequent development and amendment of the database,

· providing an application that could easily accommodate the anticipated changes in the fishery,

· a more efficient application taking advantage of relational joins between records.

· a single 'container' for all of the data for one year, and hence more efficient system administration and maintenance.

7.2 The new data base structure

The database package Microsoft ACCESS was chosen for database development. ACCESS is an entry level product that supports relational databases in an object oriented environment. The product is supported by excellent on-line help, and design tools 10 simplify the development of the more complex functions. Training in ACCESS is available locally.

The basic design developed for the database, \vas to store all of the data for one year in one 'container'. Within that 'container' the sampling data was split into four tables linked by relational joins. The tables were for information on the clay's sample, information on the boat sampled that day, information on the species caught by the bum and the lengths of any individuals measured. There was a one-to-many relationship between each of the tables as the hierarchy was descended.

This design allows for recursive actions over the whole data collection for the year and simplifies maintenance (backup and modification). Details of the database design and maintenance instructions can be found in the Field Report Number 2.

The database structure was also sufficiently generalised so that is could be used for any of NARA's other catch and effort data collections.

ATTACHMENT 1 - Current sample sites and samplers

Zone	Centres sampled	Field samplers
SOUTH	Weligama Mirrisa Dondra Kottegoda Gandara	W. Palitha L. Ranawaka
SOUTH EAST	Kudawella Tangalle Hambantota	G. Malaviarchchi R. D. Jayawardana
NORTH EAST	Trincomalee	M. Jayathilaka
EAST	Kalmunai Batticoloa	M. N. Mohamad Failan M. S. Junaideen
SOUTH WEST	Beruwala	Bertrum Amila
WEST	Negombo	B. S. V. J. Perera J. A. Prasad
NORTH WEST	Kundakulya Chillaw	seasonal samples on ad hoc basis

ATTACHMENT 2 - Current species codes, FAO codes and recommended codes for the species categories proposed

IPTP/NARA	FAO	Recommended	Common name	Status
YFX	YFT	YFX	Yellowfin tuna	-
SKX	SKJ	SKX	Skipjack tuna	-
KAW	KAW	KAW	Kawakawa	-
FRI	FRZ	FRI	Frigate tuna	-
BLT	FRZ	BLT	Bullet tuna	-
BET	BET	BET	Bigeye tuna	-
-	TUX	TUX	Other tuna	x
COM	COM	COM	Narrow-barred king mackerel	-
WAH	WAH	WAH	Wahoo	-
-	KGX	KGX	Other seer	x
-	-	MAR	Marlin (all species)	x
SAI	SFA	SFA	Indo-Pacific sailfish	x
SWO	SWO	SWO	Swordfish	-
-	BIL	BIL	Other billfish	x
-	MZZ	MZZ	Other bony fish	x
-	FAL	FAL	Silky shark	x
-	BSH	BSH	Blue shark	x
-	-	OWT	Oceanic white tip	x
REQ	RSK	RSK	Other requieum	x
LAM	MSK	MSK	LAMNIDAE	x
HAM	-	HAM	SPHYRNIDAE	-
ALO	-	ALO	ALOPIIDAE	-
-	SKH	SKH	Other sharks	x
-	SRX	SRX	Skates and rays	x
MAM	MAM	MAM	Marine mammals	-
AMS	-	AMS	Ambyglaster sirm (Hurulla)	-
SAG	SAG	SAG	Sardinella gibbosa (Matta alaya)	-
SAA	-	SAA	White sardine (Sudaya)	-
SAS	-	SAS	Sardinella sudensis (Kalawanna)	-
SAO	SIX	SIX	Other sardinella	x
STH	-	STH	Stolephorus beterolobus (Handella)	-
STB	-	STB	S. betariensis (Potaya)	-
STO	STO	STO	Other anchovy (Stolephorus)	-
THR	-	THR	Thryssa spp (Lagga)	-
GAZ	-	GAZ	Gazza spp (Mas karalla)	-
LEO	-	LEO	Leiognathus sp (Katu karalla)	-
SEC	-	SEC	Secutor sp (Salli karalla)	-
PEL	PEO	PEO	Pellonna sp (Venganawa)	x
HER	HES	HES	Herklotsichthys quad. (Korabunma)	x
DUS	-	DUS	Dussumieria sp (Thonda hurulla)	-
OPL	-	OPL	Opisthopterus tardoone (Thottawa)	-
KOW	-	KOW	Escualosa thoracata (Vella sudaya)	-
CHI	DOB	DOB	Chirocentrus dorab (Katuwalla)	x
SPY	BAR	BAR	Sphyraena sp (Jeelawa)	x
DEC	-	DEC	Decapterus macarellus (Linna)	-
RAS	RAX	RAX	Rasterllinger sp (Kumbalawa)	x
FUS	FUS	FUS	Caesio sp (Ratta)	-
SEC	BIS	BIS	Selar crumenophthalmus (Bolla)	x

ATTACHMENT 3 - Data sheets

LARGE PELAGICS FISHERY MONITORING PROGRAM

DATE _____

LOCATION _____

PAGE _____

OF _____

FLEET DETAILS	UN1	UN2	UN3	UN4
Number operated
Number sampled

CATCH AND EFFORT BY BOAT IF GIVING WEIGHT OF FISH PLEASE CIRCLE EACH ENTRY

Boat number

Type of boat

Days fished

Pieces of net

Baskets of hooks

Other gear type

Main bait type

NUMBER OR WEIGHT OF FISH (circle if weight)

Yellow

YFS

S

YFM

M

YFL

L

Skipjack

SKS

S

SKM

M

SKL

L

Kawakawa

KAW

Frigate

FRI

Bullet

BLT

Bigeye

BET

Other tuna

TUX

Narrow barred

COM

Wahoo

WAH

Other seer

KGX

Marlin

MAR

Sailfish

SFA

Swordfish

SWO

Other billfish

BIL

Other bony fish

MZZ

Silky shark

FAL

Blue shark

BSH

White tip

OWT

Other requiem

RSK

Mako

MSK

Thresher

ALO

Hammerhead

HAM

Other sharks

SKH

Skates & rays

SRX

Mammals

MAM

Remarks (eg turtle entanglements)

COMMENTS

LARGE PELAGICS FISHERY MONITORING PROGRAM SUPERVISOR'S CHECK SHEET

DATE _____

LOCATION _____

SUPERVISOR _____

TIME SCHEDULE	Fish at market	Samplers	Supervisor
Arrived
Departed

FLEET DETAILS	UN1	UN2	UN3	UN4
Number operated
Number based at site

CATCH AND EFFORT BY BOAT

Boat number

Type of boat

Days fished

Gear combination

No. of crew

Target species

WEIGHT LANDED (KG)

Yellowfin

Skipjack

Other tuna

Seer

Billfish

Other bony fish

Requiem

Mako

Thresher

Hammerhead

Other sharks

Skates & rays

Mammals

IF VESSEL OPERATED AT THIS PORT LAST MONTH, THEN DURING THAT MONTH HOW MANY

Days were fished

Landings were made

COMMENTS

SMALL PELAGICS FISHERY MONITORING PROGRAM

DATE _____

LOCATION _____

PAGE _____

OF _____

FLEET DETAILS	TR1	TR2	UN1	UN2
Number operated
Number sampled

CATCH AND EFFORT BY BOAT

Boat number

Type of boat

No of trips

No. of operations

Departure time

Arrival time

Duration

Depth

Number of gear units by

mesh-

Beach seine

WEIGHT LANDED (KG)

Hurulla

AMS

Salaya

SAG

Sudaya

SAA

Kalawanna

SAS

Other sardines

SIX

Halmassa

STH

Pottaya

STB

Other anchovy

STO

Lagga

THR

Mas karalla

GAZ

Katu karalla

LEO

Salli karalla

SEC

Venganawa

PEO

Koraburuwa

HES

Thonda hurulla

DUS

Thottawa

OPL

Vella sudaya

KOW

Katuwalla

DOB

Jeelawa

BAR

Linna

DEC

Kumbalawa

RAX

Ratta

FUS

Bolla

BIS

Others