Fisheries Research 77 (2006) 60–71

Monitoring small-scale marine fisheries: An examplefrom Thailand’s Ko Chang archipelago

Kristin E. Lunn∗, Philip DeardenDepartment of Geography, University of Victoria, P.O. Box 3050, Victoria, BC, Canada V8W 3P5

Received 22 March 2005; received in revised form 9 August 2005; accepted 19 August 2005

Abstract

Small-scale fisheries provide food and income to millions of people worldwide, yet these fisheries are generally poorly documentedand their impacts not well understood. Improved documentation of these fisheries is needed to gauge global trends, identify the threats totheir sustainability, and assess management options. Combining semi-structured interviews and participant observation, this study providesbaseline information about the nature and scale of small-scale fisheries in the Ko Chang archipelago, Thailand, as a first step towards insti-tuting a monitoring and management strategy for the area. Although the area has been designated as a “no-take” Marine National Park,small-scale fisheries have continued virtually unabated within the park’s boundaries. Small-scale fishers living in the park are involvedp le fishingb g/year oft n average of4 nding sug-g ants. Givent zoning bec©

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rimarily in the shrimp trammel net, squid trap, crab trap, fish gill net, hook-and-line, and reef fish trap fisheries. Small-scaoats operating out of villages on Ko Chang and Ko Maisi Yai worked for an estimated 38,000 days/year and took 330,000 k

arget fish and invertebrates, based on extrapolations from interviews. Observed catches of target species were, however, a2–64% lower than fishers’ reported catches for the fisheries in which both data collection methods could be used. Such a fiests that future monitoring should rely on observational techniques to assess the catches and efforts of small-scale particip

he area’s status as a national park, regular monitoring of the small-scale fisheries should be undertaken and multiple-useonsidered.2005 Elsevier B.V. All rights reserved.

eywords: Small-scale fisheries; Resource management; Monitoring; Sustainable use; Marine protected areas

. Introduction

Small-scale marine fisheries provide an important sourcef food and income to coastal communities worldwide.early 23 million people around the world earn their living

rom marine capture fisheries, with 83% of fishers residing insia (FAO, 2002). In Thailand, official statistics reveal that7,000 households were involved in small-scale fishing activ-

ties in 1995—four times the number of participants operat-ng in the large-scale fleet (Boonchuwong, 1998). Althoughmall-scale fishing boats are individually able to catch fewersh than their large-scale counterparts, small-scale marinesheries reportedly account for 40% of the marine fish takenor human food (FAO, 1998). Unlike the large-scale industry,

∗ Corresponding author. Tel.: +1 250 472 4624; fax: +1 250 721 6216.E-mail address: klunn@office.geog.uvic.ca (K.E. Lunn).

aimed at providing high-valued species (e.g. tuna) to the inational market, artisanal fishers tend to supply local mawith lower-valued fish and invertebrate catches (King, 1991).Such small-scale fisheries products provide an imposource of protein to people throughout the developing w(Saila, 1988; King, 1991; Nickerson-Tietze, 2000).

Small-scale fishing activities have, however, beenrelated to reductions in the biomass, abundance, andvidual sizes of target fish and invertebrate speciesAlcala, 1988; Polunin and Roberts, 1993; Jennings e1995; McClanahan et al., 1999). Large predatory fishe(e.g. groupers) are considered the most susceptible toexploitation (Russ and Alcala, 1998), and as a result, are oftdepleted first (e.g.Watson et al., 1997). The removal of topredators can, furthermore, lead to trophic cascades, dthe complex interactions among marine species (Colemanand Williams, 2002; Daskalov, 2002; Pauly et al., 20

165-7836/$ – see front matter © 2005 Elsevier B.V. All rights reserved.oi:10.1016/j.fishres.2005.08.009

K.E. Lunn, P. Dearden / Fisheries Research 77 (2006) 60–71 61

Dulvy et al., 2004). As a result of the pressures imposedby over-fishing, the use of destructive fishing practices, andthe lack of adequate management, the Southeast Asian seashave faced extensive reductions in the quantity and qualityof once productive and valued habitats, including coral reefs,mangroves, and seagrasses (ADB, 2000; Talaue-McManus,2000; UP-MSI et al., 2002).

Assessing the relative sustainability of fisheries requiresinformation on the catch and effort of fishers, the state ofexploited populations, and the changes in these factors overtime. Landings and effort data for tropical small-scale fish-eries are notoriously sparse and inaccurate (Saila, 1988),possibly due to the complex nature of these fisheries and thehigh costs of collecting data. Small-scale fisheries typicallyinvolve a wide variety of target species, gear types, landingareas, and distribution routes, making it virtually impossibleto collect reliable and comprehensive statistics for the vastmajority of fisheries (King and Lambeth, 2000). The Foodand Agriculture Organization of the United Nations (FAO)acknowledges that “the frequent lack of basic data on subsis-tence and small-scale fisheries. . . contributes to failures inmanagement and policy-making directed at preventing over-exploitation, stock decline, and exacerbations to rural foodinsecurity and poverty” (FAO, 2002).

Like many nations worldwide, Thailand has seen the rapiddevelopment and subsequent decline of many marine fish-e ,1 il-l d in2 eirp lves,t atis-t s,f ore)s 1s ghert uatek fish-e orlyu t docu hai-l s tofi hai-l tiond

areai tionf sh-e tic toe e, iti hesefi tionsi ase-l pro-g com-p on.

2. Methods

2.1. Study site

The Ko Chang archipelago, comprised of more than40 islands, is located in the northeastern Gulf of Thai-land (Fig. 1). Ko Chang and the surrounding islandsexperience tropical climatic conditions, dominated by thesouthwest monsoon (wet; May–October), winter (cool anddry; November–February), and summer (hot and dry;March–April) seasons. Storms and large waves are commonon the west and southwest sides of Ko Chang during the wetseason, while the remainder of the year is typically calm andclear. Development of the archipelago is limited to fishingand farming communities on the north, east, and south coastsof Ko Chang – the area’s largest island – and intensive tourismactivities on the west coast. Residents of the archipelago livealmost exclusively on Ko Chang, with only one seasonal fish-ing camp on the island of Ko Maisi Yai. Local residents of thearchipelago, numbering roughly 5000 people, rely primarilyon farming, fishing, tourism, and retail sales for their liveli-hoods (Ko Chang Sub-District Office, unpublished data).

The area was designated as a Marine National Park in1982, and all fishing activities thereby outlawed. However,small-scale fishing activities continue unabated within thepark’s boundaries. Small-scale fishing boat owners tend toe nitym closet all-s ntsw entsa ies,i krills meln fish-i t netsa morec anda y theM ifea ov-e ent.T F)i ivityi 3 kmo

2

ringt arch2 iest usinga panto adsa ang

ries, particularly when targeting larger species (Christensen998). Official statistics for Thailand reveal that 2.6 m

ion tonnes of marine fisheries products were lande003 (FAO, 2005). Since many small-scale fishers sell throducts locally and/or consume their catches themse

heir landings are often under-represented in official stics (Seilert and Sangchan, 2001). Thai government recordor example, characteristically under-report (or even ignmall-scale fishers’ landings (Masae and Bussabong, 200),uggesting that total landings could in fact be much hihan FAO’s estimates for the country. Without adeqnowledge of the nature and magnitude of small-scaleries in Thailand, the impacts of such fisheries remain ponderstood. This paper describes a case study aimed amenting the characteristics of small-scale fisheries in T

and’s Ko Chang archipelago. In so doing, the study helpll the information gap about small-scale fisheries in Tand and contributes to the global paucity of informaescribed above.

The study is particularly significant in that the chosens one of Thailand’s 26 Marine National Parks. Legislaorbids fishing in the park, but restrictions to small-scale firies have never been enforced. Although it is unrealisxpect that this will change significantly in the near futur

s vitally important to understand the nature and scale of tsheries in order to develop workable management solun the face of limited resources. This study provides the bine data against which the results of future monitoringrams can be compared and, furthermore, applies andares two different approaches to fisheries data collecti

-

ngage family members, or occasionally other commuembers, as crew and usually fish in nearshore waters

o their own villages. Local residents’ participation in smcale fisheries is highly dynamic, with fishing informaorking in up to four fisheries throughout the year. Residre involved in many types of small-scale fishing activit

ncluding the coastal gill net, crab trap, hook-and-line,coop net, reef fish trap, shellfish gleaning, shrimp tramet, small trawl net, and squid trap fisheries. Large-scale

ng vessels using anchovy purse seines and squid caslso operate within the protected area, despite beinglosely monitored by local authorities. Both terrestrialquatic areas of the Ko Chang MNP are managed barine National Park Division of the Department of Wildlnd Plant Conservation (DWPC), part of the Royal Thai Grnment’s Ministry of Natural Resources and Environmhe Ministry of Agriculture’s Department of Fisheries (Do

s responsible for monitoring and managing fishing actn the marine areas surrounding the park boundaries (>ffshore).

.2. Data collection

Data were collected in the Ko Chang archipelago duhe wet (May–July 2002) and dry seasons (January–M003), allowing for the documentation of fishing activit

hrough the key fishing seasons. Data were gatheredcombination of semi-structured interviews and particibservation. Interviews were conducted with village hend small-scale fishers in every fishing village on Ko Ch

62 K.E. Lunn, P. Dearden / Fisheries Research 77 (2006) 60–71

Fig. 1. Map of the Ko Chang archipelago, with park boundaries represented as dotted lines (courtesy of O. Heggen).

and Ko Maisi Yai. Participant observation was used to esti-mate the number of boats operating in each fishery and tocross-check the fisheries data collected in interviews.

Fishers were considered part of the small-scale fleet iftheir boat was less than 15 m in length. Small-scale fishingrespondents were selected from a range of age classes, socialgroups, experience levels, fisheries, and villages, as a way ofdeducing average fishing effort and catch of the local fleet.Village headmen provided basic information about each ofthe main small-scale fisheries and suggested key fishers tointerview in each village. Additional contacts were foundusing a snowball sampling approach (Miles and Huberman,

1994). Selected fishers were asked about their background infisheries (e.g. age, experience), target species (e.g. identity oftarget and dominant species in their catches, seasonal and his-torical variations), fishing effort (e.g. type and dimensions ofequipment, length of fishing day), and catches (e.g. averagedaily catch, seasonal and intra-seasonal variations in catch).Interviews were conducted with the help of English-speakingThai interpreters, trained in fisheries science and capable oftranslating technical terminology. Interviews lasted for aslong as respondents remained interested, usually between20 min and 2 h. Respondents’ answers were written downduring the interview and transcribed into a computer file at

K.E. Lunn, P. Dearden / Fisheries Research 77 (2006) 60–71 63

the end of each day. Thai species names were translatedto taxonomic families using species identification guides.Catch-per-unit-effort (CPUE) was calculated, depending onthe type of fishery, using either effective fishing time, definedas the amount of time when fishers’ gear was actively in use,or the number of hauls. Respondents were not always asked,or could answer, every question, leading to the highly variablesample sizes (n) reported throughout the text.

Direct observations were made of the number of boatsoperating in each fishery and the catch and effort of selectedfishing boats. The number of boats in each fishery wascounted by making observations of the gear onboard smallfishing vessels in each village or, in the cases of more crypticgear types (e.g. hook-and-line), by asking community mem-bers to identify all of the families involved in these fisheries.Select fishers were observed on single-day fishing trips tocross-check the information provided in interviews. On eachfishing trip, the start and end times of the fishing trip, theamount of time when gear was inactive, the type of equipment(e.g. boat, engine, gear), and the number of crew memberswere recorded. At the end of each trip, fishers’ landings weresorted into different taxonomic families and weighed using10-kg capacity weight scales (accurate to 0.1 kg). Fishingtrips were observed throughout the lunar cycle, to reduce theeffect of lunar phase on the amount caught. When logisticsprevented us from accompanying fishers on their trips, totalfi rteda arep

3

and6 fish-e trips( aleb fleetd ively.I ofb ns of

TT er offi

S

CCHSSR

inter-v iewr

fishers’ catch and effort was made on∼18% of small-scalefishers’ boats.

3.1. Characterization of study participants

Fishing respondents, all male, varied widely in age, levelof experience, and background. Fishers actively engaged infishing ranged in age from 18 to 66 years old (40± 11 years;n = 46), and had 1–50 years of fishing experience (18± 12years;n = 46). Former fishers ranged in age from 52 to 82years old (64± 15 years;n = 4), and had each fished for20–60 years (38± 13 years;n = 4). While some respondentshad been fishing for their entire working careers, others hadentered the fisheries more recently, from fields as diverse asfarming, carpentry, military service, and ruby trading, report-edly because they hoped to earn a better living from fishingthan they had from previous career choices. Although womendid participate in fishing activities as crew on their husbands’boats, or more frequently in the processing and distributionof fisheries products, this study focused on boat owners, who(in this area) were exclusively male.

3.2. Equipment

Small-scale fishers used small, motorized boats and simplegear to collect nearshore species from Ko Chang’s coastala ins 5 hpe ets,t reef-a or ing twod withd ffortw lysis.

3

onK ted3 withl tob fish-i henc son.F am-m r ofb ffort.S bero

ies,w thel daysp edt rage2 rs

shing time was recorded and fishers’ landings were sond weighed upon their return to the dock. All meansresented as± the standard deviation.

. Results

Field data were gleaned from interviews with 64 activeformer small-scale fishers, operating in one or more

ries, and observations made on 34 single-day fishingTable 1). Direct observations of the number of small-scoats suggested that 187 and 123 boats worked in thisuring the wet and dry seasons of 2002–2003, respect

nterviews were, as a result, conducted with roughly 34%oat owners active in the small-scale fleet. Observatio

able 1he number of fishers interviewed from each fishery and the numbshing trips observed during each season

mall-scale fisheries No. interviewrespondentsa

No. observed fishing trips

Wet season Dry season

oastal fish gill net 14 1 4rab trap 16 8ook-and-line 12 2hrimp trammel net 32 5 6quid trap 22 8eef fish trap 16a Many fishers worked in several fisheries throughout the year, andiews included questions about all of their fishing activities. Intervespondents were therefore included in all applicable categories.

reas (Table 2). The longtail and flat-bed boats rangedize from 3 to 13 m long and were equipped with 3–16ngines (n = 64). Fishers used various combinations of n

raps, and hook-and-line to gather benthic, pelagic, andssociated fish and invertebrates. Fishers worked aloneroups of up to five people per boat. Crab fishers fell intoistinct classes – longtail and flat-bed boat operators –iffering fishing behaviours; these fishers’ catches and eere therefore considered separately throughout the ana

.3. Fishing effort

Small-scale fishing boats operating out of villageso Chang and Ko Maisi Yai worked for an estima8,000 days/year in 2002–2003, based on interviews

ocal boat owners (Table 3). Small-scale fishers appearede most active in the rainy season; 52% more small-scale

ng boats were operating in the rainy season of 2002, wompared with observations made the following dry seaishers were most commonly involved in the shrimp trel net fishery, which accounted for the largest numbeoats in each fishing season and the highest annual ehrimp boats accounted for roughly 42% of the total numf fishing days put in by small-scale fishing vessels.

Daily fishing effort varied among small-scale fisherith fishers working the longest days, or hauling

argest numbers of traps, generally working the fewester month (Table 3). Flat-bed crab fishing boats work

he highest number of days per month, at an ave8± 3 days/month (n = 2), whereas hook-and-line fishe

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Table 2A description of the fishing gear and boats used in Ko Chang’s small-scale fisheries, based on interviews with local fishers

Small-scale fisheries Targets Gear description Method of operation Mesh diameter Bait Boat Numberof crew

Coastal fish gill net Mullets and shad Single-layered gill net, measuring1.5–5 m deep and 20–1000 mlong

Fishers encircled groups of fishwith their nets and, using loudnoises or lights, forced the fishinto their nets before hauling thegear 15–60 min later

1–5 cm None 5–8 m long with5–11 hp engines

1–3

Crab trap Swimming crabs,mud crabs, andstone crabs

Collapsible traps, measuring∼35 cm wide, 50 cm long, and15 cm deep, made with a metalframe and nylon mesh

Dropped close to the bottom andtied to floats at the surface

2 cm Non-commercialfishes

7–8 m longtail or 12 mflat-bed boat

1–4

Hook-and-line Spanish mackerel,barracuda, squid,trevallies, andfourfingerthreadfin

Still lines, measuring 10–15 m, ortrolling lines, measuring40–100 m, affixed with 1–3 largehooks (2.5 cm across, 7 cm long)

Still lines were attached to floatsand dropped directly below thesurface, whereas trolling lineswere attached to rods andextended behind fishers’ boats

N/A Artificial lures ornon-commercialfishes

5–8 m long with7–27 hp engines

1–2

Reef fish trap Live groupers andsnappers

Semi-cylindrical traps, made withwooden frames, measuring0.5–2.5 m long and 0.25–0.5 mwide

Traps were weighed to thebottom or hidden within crevices,purposely unmarked at thesurface

1.0–2.5 cm Smallnon-commercialfishes or unbaited

3–9 m long with3–100 hp engines

1–3

Shrimp trammel net White and dogprawns

Three-layered entangling net,measuring 1.5 m deep and40–1000 m long, withlight-weight sinkers lining thebase of the net and small floatsspread across the top

Designed to float vertically in thewater column, nets were tied tobamboo poles at either end andleft to drift in the current for10–90 min

4.2 cm for inner layerand 14 cm for outerlayers

None 4–13 m long with5–85 hp engines

1–5

Squid trap Big-fin reef squidand cuttlefish

Semi-cylindrical traps, madefrom bamboo and mesh netting

Held vertically in the water,about 1–2 m from the bottom,with a weighted line and a markerat the surface

Variable Squid eggs covered inpalm leaves

4–12 m long with11–165 hp engines

1–2

Fishers frequently described the lengths of their boats and the size of their fishing gear using the measurementswah andsog. Onewah is equal to an individual’s armspan, while onesog measures the distancebetween the tips of their fingers to their elbow. Although these measures vary among individuals, the units were converted to the metric scale using theapproximations 1wah = 2 m and 1sog = 0.5 m.

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Table 3Reported and observed fishing effort in small-scale fisheries, according to fishers’ interview responses and observations of their fishing trips

Fishing effort Data collectionmethod

Small-scale fisheries

Coastal fish gill net Crab trap Hook-and-line Reef fish trap Shrimp trammel net Squid trap

Longtail boats Flat-bed boats

Length of fishing trips (days/trip) Reported 1 1 4 1–3 1 1–2 1Frequency of fishing (days/month) Reported 26± 7 (n = 8) 25± 7 (n = 8) 28± 3 (n = 2) 16± 7 (n = 6) 30± 0 (n = 12)a 19± 5 (n = 14) 26± 7 (n = 9)

Total fishing time (h/day) Reported 5± 2 (n = 9) N/A N/A 10± 3 (n = 5) N/A 10± 3 (n = 15) N/AObserved 1.89± 0.49 (n = 5) N/A N/A 8.02± 8.41 (n = 2) N/A 7.13± 2.75 (n = 11) N/A

Effective fishing time (h/day) Observed 1.89± 0.49 (n = 5)b N/A N/A ?c N/A 5.86± 2.61 (n = 11) N/A

Number of traps deployed (hauls/day) Reported N/A 130± 80 (n = 10) 1000± 0 (n = 2) N/A 18± 10 (n = 11) N/A 60± 20 (n = 12)Observed N/A 60± 23 (n = 8) ?c N/A ?c N/A 33± 16 (n = 8)

Fuel expenditure (L/boat/day) Reported 3± 1 (n = 7) 4± 0 (n = 3) 30± 0 (n = 2) 8± 3 (n = 4) ? 11± 8 (n = 16) 24± 9 (n = 11)Number of boats (wet season)d Observed 9 24 8 0 3 142 1Number of boats (dry season)d Observed 15 21 8 12 16 33 18Total annual effort (days/year)e Extrapolated 4100 6700 2700 1300 4200 16,000 3400

a Reef trap fishers left their traps in the water continually, thus leading to constant effort throughout the month. These fishers only checked their traps, however, every 3–7 days (n = 11).b Total fishing time was considered the same as effective fishing time in this fishery because gill net fishers spent their travel time searching for schoolsof fish.c Hook-and-line, medium-sized crab trap, and reef fish trap fishers could not accommodate us on their fishing trips. In some cases, however, total fishing times and catch volumes could be measured at their

landing sites.d Fishers’ accounts of the timing and lengths of the wet and dry seasons varied slightly among fisheries; gill net (n = 6) and shrimp trammel net (n = 13) fishers reported 8-month dry seasons, while crab trap

(n = 5), hook-and-line (n = 7), and squid trap fishers (n = 10) reported 7-month dry seasons.e Total annual effort was calculated using the following formula: (number of fishing days per month× length of rainy season× number of boats operating in rainy season) + (number of fishing days per

month× length of dry season× number of boats operating in dry season).

66 K.E. Lunn, P. Dearden / Fisheries Research 77 (2006) 60–71

worked the least, averaging 16± 7 days/month (n = 6).Although reef fish trappers left their traps in the watercontinually, and therefore technically fished 30 days/month,these fishers only checked their traps an average of sixtimes per month (n = 11). Working the fewest numbersof days per month, hook-and-line and shrimp trammelnet fishers reported the longest fishing days, averaging10± 3 h/day. Such a comparison could not be made for trapfisheries, however, because the time invested in hauling trapsdepended on the fishery; for instance, reef trap fishers onlyreported hauling an average 18± 10 traps/day (n = 11), butemptying their traps required fishers to dive to the oceanfloor, sometimes with the assistance of hookah lines, andhaul the traps to the surface before replacing them in newlocations.

Fishers’ participation in local fisheries varied with theirexpected productivities. According to fishers, their invest-ment in small-scale fishing activities changed with the lunarphase and with local weather patterns, two factors reportedlylinked to their catch volumes. Reef fish trap and hook-and-line fishers generally reported not being able to work, orobtaining low catches, in stormy weather, whereas shrimp andcrab fishers reportedly yielded higher catches under such con-ditions. Similarly, fishers in the shrimp, squid, and hook-and-line fisheries reported that lunar phase affected the volumesof target and non-target species in their catches. Virtually alls wax-i e pullo rimpw -e UE,a eren ook-a n thef sa as ai

3

ter-v k atl non-t r-a s, at2 tsa ated9 lumeo 30%o ionso ver,t theira r-g hers’r col-l f fish

trap fishery could not be gathered using either data collectionmethod; respondents in the reef trap industry were unableto estimate their catch volumes over any time period andcould not accommodate us on their fishing trips. Data on non-targets were, furthermore, very sparse, with only flat-bed crabboat operators and shrimp fishers able to approximate theirdaily takes of non-target species. Hook-and-line and squidtrap fishers did note that their catches of non-target specieswere minimal.

Gill net fishers reported catching the highest diversity offish and invertebrate families (Table 4). Shrimp fishers were,on the other hand, responsible for landing the greatest numberof taxonomic families, based on our observations of fish-ing trips (Table 5). While non-target species comprised anaverage of only 1–13% of fishers’ catch volumes in the gillnet, crap trap, hook-and-line, and squid trap fisheries, thesespecies accounted for∼86% of shrimp fishers’ landings byweight. Fishers reported that non-commercial catches weretypically kept for food (n = 13), sold cheaply for bait, fer-tilizer, and/or fish feed (n = 8), kept for home aquaria or livefish cages (n = 7), thrown back alive (n = 4), or given to friends(n = 3). While non-target species yielded little market incomefor local fishers, these fishes and invertebrates often supplieda valuable source of subsistence income.

3.5. Sustainability of fisheries

boutd ty-sixp s haddt moree entsa theirm 0–15y ndi-v rtedd ok-a t 20y mon-p timesa ffort.A le toc againb iousy clinesi theira last1 ize ofg ted int

ernso ouldq sherr o, hew hen

hrimp fishing respondents stopped fishing during theng gibbous and waning crescent moon phases, when thf the current was reportedly lowest and therefore shere not easily caught in their nets (n = 16). Squid trap fishrs reported dropping fewer traps, or yielding lower CPround the new moon (n = 9), apparently because squid wot attracted to their traps at this time in the lunar cycle. Hnd-line fishers reported that they fished either betwee

ull and new moons (n = 2), or during the waxing gibbound waning crescent moon phases when the current w

ts lowest (n = 2).

.4. Catch volumes

Extrapolations from fishers’ responses during iniews suggested that small-scale fishing boats tooeast 330,000 kg of target species and 53,000 kg ofarget species per year (Table 4). Flat-bed crab boat opetors reported the highest volume of target specie5± 21 kg/boat/day (n = 2), whereas longtail crab boapparently gathered the least. Working an estim400 days/year, crab trappers collected the largest vof target species per year, together taking roughlyf the fleet’s total annual catch (by weight). Observatf small-scale fishers’ collection trips suggested, howe

hat interview respondents might have over-estimatedverage catch volumes (Table 5). Observed catches of taet species were, on average, 42–64% lower than fiseported catches in the five fisheries for which both dataection methods could be used. Catch data for the ree

t

Fishers targeting finfish were more concerned aecreasing catches than were invertebrate fishers. Eighercent of gill net respondents reported that their catcheecreased substantially in the last 10 years (n = 7), blaming

he decline on increased participation in the fishery andfficient gear (e.g. lights to track fish at night). Respondble to quantify the change reported that the volumes ofullet catches had dropped by 50–95% in the last 1

ears (n = 4); none reported any change in the size of iidual fish. Like the coastal gill net fishery, fishers repoeclines in the quantity of fish they could catch with hond-line. One long-time hook-and-line fisher told us thaears ago, before push nets and trawl boats became comlace around Ko Chang, he could catch seven to eights many Spanish mackerel for the same amount of enother fisher reported that just 2 years ago, he was abatch two to three times as many barracuda and squid,y expending the same level of effort that he had in prevears. Reef trappers generally reported concern over den their catches; three out of four respondents told us thatverage CPUE (kg/trap) had declined by up to 80% in the–10 years. The fourth said that both the number and sroupers he caught had remained stable since he star

he industry 5 years prior.Although some invertebrate fishers did voice conc

ver declining catches, few interview respondents cuantify these changes. A recently retired shrimp fieported that when he entered the fishery 50 years agas able to catch twice as many shrimp as he could w

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Table 4Reported identities and catch volumes for target and non-target families, based on fishers’ responses during interviews

Small-scale fisheries

Coastal fish gill net Crab trap Hook-and-line Shrimp trammel net Squid trap

Longtail boats Flat-bed boats

Target families Clupeidae Eriphiidae Portunidae Carangidae Penaeidae LoliginidaeMugilidae Menippidae Loliginidae Sepiidae

Portunidae PolynemidaeScombridaeSphyraenidae

Target CPUE 11± 9 kg/boat/day (n = 7) 5± 2 kg/boat/day (n = 10) 25± 21 kg/boat/day (n = 2) 8± 3 kg/boat/day (n = 6) 6± 3 kg/boat/day (n = 7) 22± 15 kg/boat/day (n = 6)4.465± 5.376 kg/boat/h (n = 5) 0.053± 0.034 kg/haul (n = 10) 0.025± 0.021 kg/haul (n = 2) 0.609± 0.298 kg/boat/h (n = 3) 0.684± 0.256 kg/boat/h (n = 7) 0.467± 0.405 kg/haul (n = 6)5.13± 3.84 kg/L (n = 5) 0.86± 0.20 kg/L (n = 2) 0.71± 0.71 kg/L (n = 2) 1.08± 0.10 kg/L (n = 4) 0.65± 0.70 kg/L (n = 8) 0.89± 0.27 kg/L (n = 5)

Total target catcha 45,000 kg/year 34,000 kg/year 68,000 kg/year 10,000 kg/year 96,000 kg/year 75,000 kg/year

Non-target families Belonidae Leiognathidae Plotosidae Belonidae Carangidae CarangidaeCarangidae Loliginidae Nemipteridae Istiophoridae Chirocentridae ChaetodontidaeClupeidae Lutjanidae Serranidae Clupeidae LobotidaeDasyatidae Nemipteridae Cynoglossidae LutjanidaeDrepanidae Sciaenidae Engraulidae OstraciidaeElasmobranchii Sepiidae Gerreidae PenaeidaeEphippidae Serranidae Harpodontidae PortunidaeGerreidae Sillaginidae Leiognathidae PriacanthidaeLeiognathidae Xanthidae Muricidae SerranidaeLoliginidae Myliobatidae SiganidaeLutjanidae PectinidaeMenippidae PortunidaePolynemidae SciaenidaePomacentridae ScombridaePortunidae ScyllaridaeSciaenidae SepiidaeScombridae SquillidaeSiganidaeSphyraenidae

Non-target CPUE ? ? 2 kg/boat/day (n = 1) None (n = 7) or minimal (n = 4) 3± 1 kg/boat/day (n = 4) None (n = 2) or minimal (n = 5)? ? 0.002 kg/haul (n = 1) ? 0.267± 0.064 kg/boat/h (n = 2) ?? ? 0.07 kg/L (n = 1) ? 0.76± 0.28 kg/L (n = 3) ?

Total non-target catcha ? ? 5400 kg/year ? 48,000 kg/year ?a Total target and non-target catches were calculated using the total annual effort presented inTable 3and the average daily catch (kg/boat/day).

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Table 5Catch data for observed fishing trips, with target families presented in plain font and non-target species initalics

Taxonomic families Catch volumes

Coastal fish gill net Crab trapa Hook-and-line Shrimp trammel net Squid trap

kg/boat/day kg/boat/h kg/boat/day kg/haul kg/boat/day kg/boat/h kg/boat/day kg/boat/h kg/boat/day kg/haul

InvertebratesEriphiidae 0.1± 0.1 0.001± 0.002Loliginidae 1.9 ± 0.1 ? 0.1 ± 0.1 0.006 ± 0.015 9.1 ± 11.8 0.226± 0.220Menippidae 0.1 ± 0.2 0.063 ± 0.127 0.3 ± 0.6 0.003± 0.006Octopodinae 0.1 ± 0.3 0.002 ± 0.005Pectinidae 0.3 ± 0.8 0.042 ± 0.092Penaeidae 2.8 ± 2.0 0.451± 0.210Portunidae 2.4± 1.3 0.040± 0.018 1.8 ± 2.3 0.282 ± 0.364Scyllaridae 0.6 ± 1.5 0.104 ± 0.291Sepiidae 0.3 ± 0.3 0.051 ± 0.060 1.4 ± 2.3 0.032± 0.044Squillidae 0.2± 0.3 0.003± 0.005 0.5 ± 0.5 0.093 ± 0.105Xanthidae 0.1 ± 0.3 0.001 ± 0.003

FishApogonidae 0.1 ± 0.1 0.007 ± 0.017Bothidae 0.2 ± 0.3 0.043 ± 0.095Carangidae 0.1 ± 0.1 0.062 ± 0.090 0.7 ± 1.5 0.088 ± 0.174Clupeidae 2.2± 4.9 0.437± 0.976 0.7 ± 1.5 0.097 ± 0.173Cynoglossidae 0.4 ± 1.2 0.043 ± 0.141Dasyatidae 0.3 ± 0.5 0.039 ± 0.066Drepanidae 0.2 ± 0.3 0.148 ± 0.196Engraulidae 0.7 ± 0.6 0.142 ± 0.110Ephippidae 0.1 ± 0.1 0.002 ± 0.005Gerreidae 0.3 ± 0.4 0.218 ± 0.269 0.1 ± 0.2 0.008 ± 0.022Harpodontidae 0.8 ± 0.9 0.128 ± 0.140Leiognathidae 5.2 ± 11.6 0.682 ± 1.343Mugilidae 3.2± 3.6 1.902± 2.457Platycephalidae 0.1 ± 0.4 0.015 ± 0.049Sciaenidae 0.8 ± 0.8 0.146 ± 0.143Scombridae 2.9 ± 4.6 0.527 ± 0.879Serranidae 0.4 ± 0.5 0.042 ± 0.059Sillaginidae 0.1 ± 0.1 0.016 ± 0.032 0.2 ± 0.5 0.019 ± 0.064Sphyraenidae 1.0 ± 1.4Tetraodontidae 0.1 ± 0.3 0.017 ± 0.035

Unidentified 0.2 ± 0.5 0.003 ± 0.010 0.1 ± 0.2 0.007 ± 0.024

Target catch 5.4± 4.4 2.339± 2.217 2.9± 1.8 0.047± 0.021 2.9± 1.6 0.351± 0.178 2.8± 2.0 0.451± 0.211 10.4± 12.2 0.258± 0.220Non-target catch 0.8± 0.6 0.462± 0.394 0.4± 0.5 0.007± 0.011 0.4± 0.5 0.042± 0.059 16.9± 18.7 2.614± 2.214 0.1± 0.2 0.002± 0.005

Only families with average combined catches≥0.1 kg/day were included here.a Flat-bed boats could not be observed directly, as these boats could not accommodate us on their multi-day fishing trips. The values given here are exclusively for longtail crab boats.

K.E. Lunn, P. Dearden / Fisheries Research 77 (2006) 60–71 69

he stopped in 1998, despite fishing for the same amount oftime per day. The size of individual shrimp in his catcheshad, however, remained the same over time. A longtail crabfisher reported that 10 years ago he could catch 3–5 kg/daywith only 50 traps, whereas this year he needed 130–150traps to catch the same volume of crabs. In the past, smallcrabs of any species were, according to one respondent, con-sidered non-target, but as demand for crabs has increasedso too has fishers’ interest in small-sized crabs. Squid fish-ers did not report any changes to their catch volumes overtime.

Fishers used relatively non-destructive gear to collecttarget species, suggesting that small-scale fisheries posedminimal threat to the area’s physical habitats. None of therespondents in the live reef fish industry mentioned the use ofany chemicals to collect groupers and snappers from nearbyreefs, nor did any respondent note the presence of blast fish-ing activities in the area. One government official did report,however, that he heard rumours that fishers on Ko Kuud, alarge island south of Ko Chang, were using cyanide to collectlive reef fish.

4. Discussion and conclusion

Although the prevalence of destructive fishing methodsi ntion( nn,2 e ecol lled“ logyi ear,s esti-m least4 Witho le toe calefi of5 uchh ofl -linefi ount.A eren land-i ctivef

thati efforti atch-i eatere tic-i threet with

totalc

gill net, crap trap, hook-and-line, shrimp trammel net, andsquid trap fishers. Fishers reported working an average of25–165% longer per day than the fishing times recorded onfishing trips with gill net, hook-and-line, and shrimp tram-mel net fishers. Similarly, crab and squid trap fishers toldus they dropped 82–117% more traps per day than wereobserved on fishing trips. Discrepancies between these datasets could be attributed to fishers’ difficulties in estimatingcertain parameters (e.g. lengths of fishing days, frequency offishing trips), inter-annual variations in fishing patterns, anda culture that might encourage the over-estimation of catchesand/or effort. Interview data were, nonetheless, chosen togauge total catches and effort of the small-scale fleet, giventhat these data were more likely to reflect year-round varia-tion and could be gathered for more parameters (e.g. fuel use,monthly and annual effort).

Determining the effects of such landings on the marineecosystem at Ko Chang would require further informationon the abundance and distribution of marine species in thearea. Since species and habitat inventories do not exist formost coastal areas in Thailand, even in the protected areasdesigned to conserve marine biodiversity (Chettamart andEmphandhu, 2002), it was not possible to calculate fishingmortality on target populations, nor to deduce the effects ofsmall-scale fishing on exploited stocks. Fishers did, however,report declines in their CPUE over time, particularly in theg for-m ratet nfishs ments lnera-b

ftenb ingp -t ble ofs cksh rge-s and( t beb thans ownt f ofT ited( ayf tain-a uid)c in-i oralr houtt e anu ncess ld bee ovens onalP

n Southeast Asia has received a great deal of attee.g. Pauly and Chua, 1988; McManus, 1997; Erdma000), further research has been needed to assess th

ogical impacts of small-scale fisheries employing so-canon-destructive” techniques. Despite the low technonvolved, and comparatively benign nature of their gmall-scale fishers in the Ko Chang area landed anated 330,000 kg/year of target species, comprising at2 families, according to fishing respondents’ accounts.nly flat-bed crab boat operators and shrimp fishers abstimate their daily take of non-target species, small-sshers’ non-target landings were placed at a minimum3,000 kg/year. Actual catches could have, in fact, been migher, if fishers’ discards1 and the non-target landings

ongtail crab fishers, squid and fish trappers, hook-andshers, and gill net fishers could have been taken into accpart from the shrimp trammel net fishery, however, whon-target species made up more than 80% of fishers’

ngs, small-scale fishing gear appeared relatively selerom our observations of fishing trips.

Observations of fishers’ trips in the area suggestnterview respondents over-estimated their catches andn the small-scale fleet. Fishers consistently reported cng larger quantities of target species and expending grffort than observed on our fishing trips with study par

pants. Reported catches were an average of two toimes greater than the catches observed on fishing trips

1 Worldwide, small-scale fishers discard an estimated 3.7% of theiratches (FAO, 2004).

-

ill net fishery. Although time-series fisheries data and ination on stock dynamics would be needed to corrobo

hese reports, fishers’ perceptions of declines in certain fipecies should warrant the adoption of fisheries managetrategies that reduce fishing pressure on especially vule marine species.

Long-lived finfish species, such as groupers, have oeen identified as particularly vulnerable to heavy fishressure (seeRuss and Alcala, 1998), while short-lived inver

ebrate species such as squid and shrimp might be capaustaining higher levels of fishing effort. Cephalopod stoave, for example, been relatively unaffected by the lacale development of trawl fisheries in the Gulf of ThailChristensen, 1998), suggesting that squid species mighetter able to support small-scale fisheries at Ko Changome finfish species. Shrimp have, similarly, been sho sustain “even very high fishing pressure” in the Gulhailand, provided that their predators are also explo

Christensen, 1998: 138). Shifting small-scale fishers awrom vulnerable species (e.g. grouper) towards the susble collection of more robust species (e.g. shrimp, sqould offer one of few feasible alternatives for maintang fishers’ livelihoods and protecting the area’s rich ceef ecosystems. Given that restricting fisheries throughe park has, 20 years after its designation, proven to bnrealistic goal, a multiple-use zoning strategy that balaustainable fisheries with ecosystem protection shouxplored, particularly since this type of approach has pruccessful in other parks in the region (e.g. Komodo Natiark, seePKA and TNC, 2000).

70 K.E. Lunn, P. Dearden / Fisheries Research 77 (2006) 60–71

Focusing on the small-scale fisheries of the Ko Changarchipelago, this case study provides valuable baseline datafor the conception and implementation of a co-operative fish-eries monitoring program at Ko Chang. The catch and effortdata collected in this study serves as a reference point forquantifying changes in local fisheries and, in the future, willhelp to assess the ecological implications of these fisheries.Results from this study, ranging widely between interviewand observational data sets, have, furthermore, drawn atten-tion to the role of data collection methods in influencingfisheries survey results. Developing an observation-basedsampling strategy that accounts for intra- and inter-monthlyvariation would likely offer the best approach for document-ing fishers’ catch and effort. The importance of interviewingshould, however, not be discounted, as the information pro-vided through this approach yielded an important overviewof the fisheries and provided an opportunity to build rela-tionships with local fishers. In addition to informing fisheriesmanagement at Ko Chang, the data gathered here will con-tribute to efforts already underway to document the trends insmall-scale fisheries worldwide (see Chuenpagdee and Pauly,unpublished data). “Without reliable information, no support-able decisions can be reached, no diagnoses on the state offisheries can be performed, and no prognoses on the effectsof management control can be made” (FAO, 2002: 59).

A

hangf l toA Anu-r ng,T eng,A asakY Wea ic-t ncilo andt ell ast ionalD forA itiesR RE.M au,a revi-o

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A hai-ment,

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B Fish-eries

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cknowledgements

A special thanks to the fishers and residents of Ko Cor their help, support, and generosity. We are gratefunukorn Boutson, Surachet Chettamart, Ole Heggen,

ak Loogon, Kullatida Muangkhum, Pongboon Pongtoom Reimchen, Cliff Robinson, Sitthichai Seereesongsapiwat Sretarugsa, Ekkawit Wongsrisung, and Weeringyuad for their roles in various stages of the project.ppreciate the institutional support of the University of V

oria, Kasetsart University, the National Research Couf Thailand, the Royal Forest Department of Thailand,

he Southeast Asian Fisheries Development Centre as whe financial support provided by the Canadian Internatevelopment Agency, the University of Victoria’s Centresia-Pacific Initiatives, the Social Sciences and Humanesearch Council of Canada, and PADI’s Project AWAany thanks to Michele-Lee Moore, Marie-Annick Morend two anonymous reviewers for their comments on pus drafts of this manuscript.

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