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Fisheries Research 82 (2006) 280–289

The traditional shark fisheries of southwest Madagascar:A study in the Toliara region

Angus R. McVean ∗, Ryan C.J. Walker 1, Eibleis FanningSociety for Environmental Exploration, 50-52 Rivington Street, London EC2A 3QP, United Kingdom

Received 17 November 2004; received in revised form 17 May 2006; accepted 1 June 2006

bstract

Traditional shark fisheries in Africa are largely poorly documented. Fisheries management plans for fisheries targeting chondrichthyanpecies are typically based on studies with limited spatial resolution or detail, compromising their efficacy and potentially reducing theffectiveness of national and regional plans. Southwest Madagascar is an area poorly documented with regard to many of its marine resources.his study presents a detailed investigation of the directed shark fisheries of two villages south of Toliara – Soalara and Maromena – presentingdescription of the fishery in these villages and catch data for periods of 13 and 10 months, respectively. Results from a total of 1164 catch

ecords, including members of at least 13 species, with an estimated total wet weight of over 123 mt are reported, with hammerhead sharks

Sphyrna spp.) representing 29% of sharks caught and 24% of the total wet weight. There is an active export market for the fins resulting fromhe fisheries, indicating a considerable social and economic importance in this impoverished region of Madagascar. The fisheries are showingigns of decline, possibly as a result of changing to less selective fishing gear, as a result of the intervention from outside agencies.

2006 Elsevier B.V. All rights reserved.

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eywords: Traditional fisheries; Sharks; Madagascar; Toliara

. Introduction

The industrial, artisanal and traditional shark fisheries ofadagascar have been the subjects of studies dating back as

ar as 1930 (Petit, 1930). In the past decade the emphasisf this work has shifted from investigations of the speciesnvolved towards assessing the scale of these fisheries, thetatus of shark stocks involved and discussions of the man-gement implications of these findings (Smale, 1998; Cooke,997; du Feu, 1998; Cooke et al., 2003). The majority of thesetudies have focussed on fisheries in the North of Madagas-ar, with limited information available for the region south

f Toliara, especially concerning the traditional, canoe-based,sheries. Information available for this region consists largelyf fishery descriptions, details of species fished and reported

∗ Corresponding author at: 15 The Rise, Sevenoaks, Kent TN13 1RG,nited Kingdom. Tel.: +44 7771 573 895; fax: +44 20 7613 2992.

E-mail address: gus mcvean@yahoo.co.uk (A.R. McVean).1 Present address: Oak House, Pond Lane, Greetham, Rutland LE15 7NW,nited Kingdom.

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165-7836/$ – see front matter © 2006 Elsevier B.V. All rights reserved.oi:10.1016/j.fishres.2006.06.016

arine production statistics that are known to be of vari-ble completeness for reasons of periodic political instabilityithin Madagascar (Cooke, 1997; FAO, 1998).The aim of this study was to conduct an extended investi-

ation into the traditional (here taken as “fishing conducted onoot or in non-motorised vehicles” as defined by the Mala-asy fisheries law (93-022) and outlined in Cooke, 1997)hark fisheries of two villages south of Toliara – Soalara andaromena – in southwest Madagascar (Fig. 1), through the

ollection of catch data directly from the villages themselves.he study produced surprising results regarding the scalef the shark fisheries and highlighted the changes that haveccurred within these fisheries since they were last surveyedn 1995 (Salimo et al., 1995, referred to in Cooke, 1997),argely as a result of the intervention of external agencies.he scale of these fisheries and anecdotal reports of changes

n catch composition and reductions in catch per unit effort

uggest that the shark fishery in this region may be in decline.uch a decline could have significant consequences for the

ocal communities due to the socio-economic importance ofhark fishing to the villages surveyed.

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. Materials and methods

.1. Study area

The study was carried out from October 2001 to October002. Initially only one village was selected for this study,Soalara-Bas” (hereafter referred to only as Soalara), situatedpproximately 30 km South of Toliara (23◦35′S, 43◦44′E),outhwest Madagascar (Fig. 1). The migratory nature of theshers studied, however, resulted in this study being extended

n January 2002 to the villages of Maromena and Befasyapproximately 30 and 35 km South of Soalara, respectively)Fig. 1). Both Maromena and Befasy share the same fishingrounds and so catch data were combined for the purposef this study. Catch data were also obtained for the villagef Beheloka (approximately 45 km South of Soalara, 50 kmouth of Toliara) (Fig. 1) for the month of January 2002.

.2. Research techniques

The study was carried out using three different tech-iques; firstly, semi-structured interviews were conducted

ith 12 fishers and three shark-fin collectors (agents of a

hark fin export company operating out of Toliara). Due to theature of the Vezo (the local seafaring ethnic group engagedn the fishery), extracting information though formal ques-

Fig. 1. Map of southwest Madagascar showing villages surveyed.

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earch 82 (2006) 280–289 281

ioning was impossible, so a more subtle, semi-structuredethod of questioning needed to be undertaken over time

uring the study. Questioning centred on obtaining informa-ion that could not be gleaned through direct observation.he main focus of the questioning centred on the trade ofharks produced by the fishery, obtaining information on thealues of different shark products to the fishers and deter-ining the criteria used by fin collectors to assess value of

he fins purchased. Direct observation of fishing practicesere undertaken through accompanying at least one fishingoat on a weekly basis throughout the period of the study tobtain descriptive information regarding the fishing practicessed.

In addition to this, a basic questionnaire was distributedmongst the fishers of the 15 shark fishing boats in Soalarand the 32 boats of Maromena and Befasy. The question-aires consisted of five questions regarding size, sex andpecies of sharks landed and were distributed to fishers on aeekly basis for the collection of simple catch data (Table 1).efore the study commenced a fisher from each boat wasiven thorough instructions on how to fill out the question-aire and how to take the standard length measurements ofach shark caught. Time was also spent with each of theseshers obtaining species local names with the aid field iden-

ification guides including Bauchot and Bianchi (1984) andompagno et al. (1989) and through direct questioning as

harks were removed from landed boats. The results of theuestionnaires were validated by picking a sample of boatsach week and directly measuring and identifying each indi-idual shark in the catch as the boats landed the catch, thenomparing these data to the results of questionnaires for theoat returned at the end of the week. Unreliable data wereherefore able to be discounted and an indication of reliabil-ty for each boat able to be ascertained over time, with lesseliable boats data able to be questioned and discounted asecessary.

.3. Wet weight calculations

Calculations used the following formula: weight (g) = a ×ength (cm)b. Calculations were made using length–weightonversion data obtained from the website FishBase

http://www.fishbase.org/). The values of a and b used, asell as length–length conversions used to convert standard

engths (SL) to either fork length (FL) or total length (TL),ncluding primary reference sources are given in Table 2.

able 1uestionnaire distributed to fishers to record details of every shark caught,

ncluding English translations

y andro ao anatin’ny herinandro (day of the week)arazany (local name of shark)naran’ny mpanjono nanjonaazy (name of fisherman)y halavau’ny Akio (hehibe antonony nakely) (size, standard length [SL])aly sa Vavy (male or female)

282 A.R. McVean et al. / Fisheries Research 82 (2006) 280–289

Table 2Length–length and length–weight conversion formulas used to estimate wet weights for the 11 most commonly landed shark species

Local name Latin name Length conversion formula Length type a b References

Bevombotse Carcharhinus plumbeus FL = 1.011 SL FL 0.0109 3.012 Kohler et al. (1995)Boriloha C. leucas TL = 1.2759 SL TL 0.0175 2.840 Garcıa-Arteaga et al. (1997)Fotyrambo C. albimarginatus N/A SL 0.00305 3.243 Brouard and Grandperrin (1984)Mbato C. brachyurus TL = 1.1944 SL TL 0.0104 2.900 van der Elst (1981)Gofo C. falciformis N/A SL 0.0464 2.750 Brouard and Grandperrin (1984)Tomanimanente C. amblyrhynchos TL = 1.1971 SL TL 0.00878 3.050 Letourneur et al. (1998)Vorotse Galeocerdo cuvier TL = 1.2937 SL TL 0.00141 3.240 Branstetter (1987)Maintepate N/A but taken as C. brevipinna TL = 1.2799 SL TL 0.00751 2.970 Branstetter (1987)Jinganify Isurus spp. FL = 1.082 SL FL 0.0052 3.141 Kohler et al. (1995)Santira Alopias vulpinus N/A SL 0.008995 3.020 http://www.fishbase.orgV

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iko Sphyrna lewini FL = SL/0.907

. Results

.1. Description of the fishery

The shark fisheries of Soalara, Beheloka, Maromena andefasy employed 6–8 m long traditional sailing “pirogues”onsisting of a hull and outrigger with a square sail, crewed onverage by two fishers. Boats crews would go out to retrieveatch and re-bait there passive fishing gears on a daily basis,eather permitting, with fishers estimating approximately00 fishing days per year.

The fishing gears employed were static, surface-set,ong line sets (palangres) and gill nets (jarifas). Long linesonsisted of an anchor line 50–100 m long (depending onhe depth of water) and a buoyed surface line, 50–100 mong, with three 12 m long snoods approximately 25 mpart which was attached to the surface line. The snoodsere baited typically with jack (Carangidae), dog-tooth

una (Gymnosarda unicolor), narrow barred king mackerelScomberomorus commerson) or barracuda (Sphyraenidae),ith hooks attached via a wire trace. The gill nets used were

pproximately 50 m long and 4.5 m deep with a mesh size of

MMSl

able 3anding records by species including estimated biomass and standard length figure

ocal name Latin name No. of landed Average SL (cm

evombotse C. plumbeus 52 194oriloha C. leucas 30 159oty C. obscurus 13 204otyrambo C. albimarginatus 83 176bato C. brachyurus 56 178ofo C. falciformis 41 158omanimanente C. amblyrhynchos 149 212orotse G. cuvier 105 197aintepate N/A (see Table 5) 123 183

inganify Isurus spp. 72 188antira Alopias vulpinus 54 186iko Sphyrna spp. 340 161esotsy N/A 4 198aranoro N/A 34 135nknown N/A 8 201

FL 0.0078 3.067 http://www.fishbase.org

0–25 cm, typically bottom-set, in about 30 m of water andccasionally baited.

Soalara supported 15 shark fishing boats, employing 17ong line sets and five gill nets, with specific gears belongingo specific fishers/families. Both gill nets and long lines weresed in the same location, approximately 15 km southwestf Soalara near the island of Nosy Ve (Fig. 1) with longines set in 60–90 m of water and gill nets in around 30 m ofater. Gear was positioned in slightly deeper water duringctober–December, as the fishers perceived this to be moremore favourable fishing technique during this time of the

ear. The fishery in Maromena and Befasy operated approx-mately 32 pirogues that either regularly or occasionallyanded sharks, with fishing grounds located outside of theringing reef, just 6 km from shore. Due to the greater fishingctivity and that a number of fishers did not fish exclusivelyor sharks it was not possible to establish the exact numberf gears in operation in Maromena and Befasy (for ease,

aromena and Befasy will be referred to collectively asaromena from here on). As with the shark fishery of

oalara, both long lines and gill nets were used in the sameocation, but at different depths, with the long lines being

s

) Maximum SL (cm) Minimum SL (cm) Wet weight (kg)

400 100 5912285 100 2445305 100 N/A300 105 6194300 100 3772280 100 2429370 95 30290400 100 16931400 80 12703395 100 9255360 100 4197400 80 29399210 180 N/A280 40 N/A300 100 N/A

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A.R. McVean et al. / Fisher

et in 50 m of water whilst gill nets were set in just 30 m ofater.

.2. Catch trends and composition

Reliable catch data were collected by six boats from

oalara and seven from Maromena. This corresponded toatch data from 8 of the 17 long lines and 3 of the 5 gillets in Soalara, and 4 of the 5 long lines and 2 gill netsn Maromena. At least 13 species of shark from 5 fami-

sc(l

able 4ranslated local names for all sharks identified during interviews with fishers from

pecies name Thi

lopidae (Thresher Sharks)Alopias vulipnus (Thresher) SanA. superciliosus (Bigeye Thresher)

archarhinidae (Requiem Sharks)C. albimarginatus (Silvertip) FotC. amblyrhynchos (Grey Reef) TomC. brachyurus (Copper) MbC. brevipinna (Spinner) MaC. falciformis (Silky) GofC. leucas (Bull) BorC. limbatus (Blacktail) MaC. longimanus (Oceanic White-tip)C. melanopterus (Blacktip Reef) MaC. obscurus (Dusky) FotC. plumbeus (Sandbar) BevC. sorrah (Spot-tail) MaG. cuvier (Tiger) Vor

inglymostomatidae (Nurse Sharks)Ginglymostoma brevicaudatum (Short-tail nurse)Nebrius ferrugineus (Nurse)

amnidae (Mackerel Sharks)Carcharodon carcharias (Great White) FarIsurus spp. (Mako) Jing

dontaspidaeOdontaspis ferox (Small-tooth Sand Tiger)

phyrnidae (Hammerhead Sharks)Sphyrna lewini (Scalloped Hammerhead) VikS. mokarran (Great Hammerhead)S. zygaena (Smooth Hammerhead) Vik

tegastomatidae (Zebra Sharks)Stegastoma fasciatum (Zebra) Mir

emiscyllidaeChiloscyllium griseum (Grey Bamboo)

hinobatidae (Guitarfishes)Rhynchobatus djiddensis (Giant Guitarfish) Sor

dentifications to family level onlyHexanchidae (Cowsharks) BelDasyatidae (Whiptail Stingrays) Fay

Taeniura lymna (Bluespotted Stingray)Myliobatidae (Eaglerays) FayMobulidae (Devilrays) FayPristidae (Sawfishes) VavTorpedinidae (Torpedo Rays) Lej

nknown Garnknown Fes

earch 82 (2006) 280–289 283

ies were taken by the shark fisheries (Table 3). Of these,phyrnids were the most frequently caught, comprising 29%f the catch (n = 340). The exact species make up of theammerheads taken could not be determined as the fishersid not distinguish between scalloped (Sphyrna lewinii) andmooth hammerheads (S. zygaena). Other frequently caught

pecies included grey reef sharks (Carcharhinus amblyrhyn-hos), representing 13% of the catch (n = 149) and tiger sharksGaleocerdo cuvier), which represented 9% (n = 105). Theocal name maintepate was the third most frequently recorded

the villages of Anakao and Soalara

s study Cooke (1997), Toliara

tiraTomanimanente

yramboanimanente

atointepateoilohaintepate

Mesointepate Maintepateyombotseintepate/Meso Fesokeotse/Bemaso/Tsaka

VoritseValovombotse

ao/Masiakeanify/Mintseka/Sabonto Bevombotse

Foty

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oro Ntsaka

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obois

idake (three types)foty

FaimbalanytomilyMiangetsea Vavaa Leja

anoro/Keleterakeostsy/Mainte Voho

284 A.R. McVean et al. / Fisheries Res

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ig. 2. Graph showing number of sharks landed in Soalara and Maromenay month.

ame (n = 123, 11%), but this was used by the fishing com-unities for four or more different species of carcharhinid

hark (Table 4). Isurus oxyrichus and I. paucus were referredo as Isurus spp. on account of the only deciphering trait beinghe jaws and dentition, thus, making accurate identification topecies level unreliable. A further four local names appearingn the catch data could not be assigned to species using theuides available and were not observed by the authors duringny of the landings or fishing trips undertaken. Table 4 alsoncludes translations for a further six species that were notaught during the period of the survey and further speciesranslations obtained by Cooke (1997) for the Toliara regionuring his survey of the shark fisheries of Madagascar as ahole.Over 13 months, 1164 sharks were recorded, with peak

atches in January 2002 of 187, with 76 caught in Marom-na and 104 caught in Beheloka. From February to October002 the catch patterns for both Maromena and Soalara fol-

owed a similar trend, building to a peak in June for Soalaran = 89) and a second peak for Maromena in the same monthn = 75) and dropping again towards the end of the surveyith the exception of a second peak for Soalara (n = 72)

tbJa

able 5esults of wet weight calculations broken down by month and by village, including

onth Beheloka Maromena

kg kg gear−1

October – – –November – – –December – – –January 29918 15936 2656February – 800 133March – 3915 653April – 2888 481May – 4744 791June – 4797 800July – 3049 508August – 2299 383September – 3503 584October – 1286 214

otal 29918 43217 7203

earch 82 (2006) 280–289

n September 2002 (Fig. 2). As neither effort data relat-ng to soak-times for gears (as recommended by the FAO,000) nor number of days fishing were collected each month,nly basic catch per unit effort (CpUE) data of the form ofatch per gear per month were calculated for Soalara andaromena (Table 5), with CpUE peaking in January foraromena at 2656 kg gear−1 and September for Soalara with

70 kg gear−1. This increased CpUE for Maromena duringanuary is supported by Fig. 3, which shows that the largestf the four commonest groups of sharks were indeed landeduring this month. Wet weight of sharks landed resulted inoalara generally landing more weight of sharks each monthith the exception of January, but it must be considered thateheloka’s catch was included for this month (Fig. 4). Catch

ates were consistently higher for Maromena (with the excep-ion of February), peaking in January 2002 at 12.7 sharks perear (and again in June at 12.5 sharks per gear) as opposedo 8.1 sharks per gear in June 2002 for Soalara (Table 4).

.3. Catch weight calculations

Based on the translations of local names, calcula-ions of catch weight for sharks landed were made usingength–weight allometric relationships for 11 species rep-esenting 1105 of the 1164 sharks recorded. This yielded aotal catch weight of 123.5 mt. The results of these calcula-ions broken down by month, village and species are given inables 2 and 3. Catch weight peaked in January, with 47.6 mtf shark caught, over 4.5 times the amount landed in anyther month and 38% of the total landed during the coursef this study. Of this, 29.9 mt were landed by fishers fromeheloka, 15.9 mt by fishers from Maromena and just 1.7 mty fishers from Soalara. As can be seen from Fig. 4, whilst

he catch weight figures follow a similar pattern to the num-ers landed (Fig. 2), the noticeable peak in number caught forune 2002 compared to other months is absent, replaced byn approximately joint peak in the months of May and June

estimates of wet weight gear−1

Soalara Total

kg kg gear−1 kg kg gear−1

4309 392 4309 2534547 413 4547 2672183 198 2183 1281744 N/A 47598 N/A3220 293 4019 2363628 330 7544 4444582 417 7470 4395623 511 10367 6105095 463 9892 5823357 305 6406 3773450 314 5749 3386275 570 9778 5752378 216 3664 216

50392 4581 123527 7422

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A.R. McVean et al. / Fisheries Res

ig. 3. Box plots for the four commonest sharks showing the variation in length (uvier for the three villages across the study period.

earch 82 (2006) 280–289 285

±95%) of all landed Sphyrna spp., C. amblyrhynchos, maintepate and G.

286 A.R. McVean et al. / Fisheries Research 82 (2006) 280–289

(Contin

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(fi(5wstudy one fisher sold a set of 4 m mako (Isurus spp.) jawsfor 250,000 FMG (US$ 37) to a curio shop in Toliara. Of allthe shark products sold, the fins are of the greatest economicimportance to fishers.

Fig. 3.

10.4 and 9.9 mt, respectively). The peak in September, how-ver, is accentuated, being much closer to the peak in May andune (under 600 kg less) than was suggested by the numbersaught. In terms of species wet weight, C. amblyrhynchosatches during the study weighed almost 900 kg more thanhe commonest species landed; sphyrnids, at 30.3 mt, withhe two of these groups together accounting for 48% of theotal wet weight of sharks landed (Table 3). After these, G.uvier contributed the next highest catch weight with 16.9 mt,ollowed by Isurus spp. with 9.3 mt. These four togetherccounted for 57% of the sharks landed and 70% of the catcheight (Table 6).

.4. Processing and sale of shark products

Sharks were processed immediately on the beach whenanded. This involved removing all fins of commercial valueusually the first dorsal, the pectorals and the upper caudalobe) and the jaws, if large enough to sell (usually frompecimens over 300 cm SL). The head, gills and intestinesere removed and discarded. The remaining meat was salted

nd/or dried in the sun and sold for human consumption.he fins of commercial value were either sold fresh, directly

o fin collectors, or dried and then sold. Shark meat was soldocally in the villages for 1000 Malagasy Francs (FMG) kg−1

FM

ued ).

US$ 0.15 kg) and the fins sold to one of three commercialn collectors operating out of Toliara, with large fresh fins>20 cm) commanding a mean price of 350,000 FMG (US$2 per kg) during the study. Neonate and juvenile fins wereorth a mean price of 6000 FMG (US$ 0.90). During the

ig. 4. Graph showing estimated wet weight of sharks landed in Soalara andaromena by month.

A.R. McVean et al. / Fisheries Research 82 (2006) 280–289 287

Table 6Number of sharks landed and recorded broken down by month and by village including monthly catch rates in sharks gear−1

Month Beheloka Maromena Soalara Total

Number Sharks gear−1 Number Sharks gear−1 Number Sharks gear-1

1 October – – – 58 5.3 58 5.31 November – – – 35 3.2 35 3.21 December – – – 13 1.2 13 1.22 January 104 76 12.7 7 N/A 187 N/A2 February – 9 1.5 36 3.3 45 2.62 March – 31 5.2 31 2.8 62 3.62 April – 40 6.7 66 6.0 106 6.22 May – 63 10.5 67 6.1 130 7.62 June – 75 12.5 89 8.1 164 9.62 July – 50 8.3 60 5.5 110 6.5222

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August – 42 7.0September – 49 8.2October – 27 4.5

. Discussion

The scale of these fisheries was largely unexpected,ith over 123 mt of sharks estimated to have been fishedithin 13 months. This figure greatly exceeds the estimatedean annual catch of 500 kg of elasmobranches per km

f coastline in Madagascar stated by Kroese and Sauer1998) in their review of African elasmobranch fisheries,worrying underestimate when you consider that there are

t least 14 other similar villages that exploit sharks within00 km of the study area (den Haring, pers. commun.). Ouresults show that the traditional shark fisheries of this regionre low-tech and reliant to a great extent on favourableeather conditions and the daily investment of considerable

ffort, in terms of man-hours, similar to those described byooke (1997). Resource utilisation is high compared to mostommercial shark fisheries, where up to 95% of the catch cane wasted in the case of some large-scale fining vessels. Theshing gears used by the fishers in this study, whilst simple

n design, are expensive by local standards. In his 1997eview of shark fisheries in Madagascar, Cooke states theost of gill nets, the commonest shark fisheries gear in use inadagascar, to be 1–2 million FMG (US$ 220–440 at that

ime). Our study showed that this gear preference had shiftedrom gill nets to long lines, with this prevalence of long linesn the southwest region largely due to the intervention ofhird parties. The Ministere de la Peche et des Ressourcesalieutiques (MPRH) (now the Direction des Peches of

he Ministere de l’Agriculture, Elevage et Peche (MAEP)),esponsible for fisheries policy in Madagascar, had, upntil 2004, regarded sharks as an under-utilised marineesource (Webster, pers. commun.). This, coupled with theigh value of shark fins and the seemingly inexhaustibleemand for these products in the Far East, resulted in theromotion of shark fisheries by development organisations

s a means of increasing income in coastal fishing communi-ies. For example, Projet MAG/9/008—Composante Pecherogramme Sectoriel Peche, a F.A.O. initiative, distributed

arge quantities of fishing equipment, including long line

tmwa

37 3.4 79 4.672 6.5 121 7.127 2.5 54 3.2

ear, to villages south of Toliara to promote the targeting oflasmobranches.

Of the species or groups of species identified within thesheries, all but one, Isurus spp., were reef associated speciesnown to commonly frequent continental and insular shelves.his would be expected considering the positioning of theears, close to reefs and islands, in deep water and nearrop-offs ranging from 30 to 100 m in depth. The dominancef Sphyrna spp. (n = 340) followed by C. amblyrhynchosn = 149) differed to previously reported studies where theceanic whitetip (C. longimanus) and the smalltooth sandiger shark (Odontaspis ferox) both featured as commonlyshed in the Toliara region (Cooke, 1997), with neitherppearing in the catch figures presented here. In the casef O. ferox this could be due to differences in names, withooke (1997) giving Akio Foty as the local name whilst in this

tudy this name was attributed to C. obscurus (Table 4). For. longimanus, however, there is no readily available expla-ation as the name given by Cooke (1997) did not appear inny of our interviews and observed catches. The absence ofhe grey bamboo shark (Chiloscyllium griseus), zebra sharkStegastoma fasciatum) and of sawfishes (Pristis spp.) in ourtudy, but reported by Cooke (1997), is most likely due tohe positioning of fishing gears, which would seem to pre-lude the capture of bottom or estuary associated species suchs these. These differences do highlight the problems asso-iated with using local names, however, with names oftenarying between villages. This problem was avoided in thistudy, despite catch data being collected from two villages,s many of the fishers participating in the study in Maromenaere originally from Soalara. However, it was necessary toroup some species together due to the non-differentiation ofertain very similar species by the fishers.

January was the most important fishing month during thetudy in terms of wet weight and size of sharks landed, and

herefore also economically, with a massive peak during this

onth, even when excluding the data from Beheloka. Thisas due to an increase in the average size of sharks landed

s the number of sharks landed was only the sixth highest.

2 ries Res

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88 A.R. McVean et al. / Fishe

his implies an even greater economic significance for thisonth as larger individuals will yield larger fins capable

f obtaining a higher price. These results correspond withata collected in other regions suggesting high fishing sea-on between November and January (Cooke, 1997; du Feu,998) with a peak in shark fin exports during the same periodCooke et al., 2003). Conversely, whilst there was a definiteeak in numbers of sharks landed in June (n = 164), this wasot matched in size and catch weight figures with only 9.9 mtanded. Catch weight figures for both May and September002 were similar at 10.4 and 9.8 mt, respectively, despitehe lower catch figures of 130 and 121, respectively. There-ore, the indication is that there are intra-annual fluctuationsn both the numbers of sharks caught and the average sizesf these sharks, with fewer but larger sharks being caught inhe austral summer months and a greater number of smallerharks taken during the winter months.

The size ranges of individuals taken during this study wereonsiderable for the majority of species/groups landed (upo 320 cm), although the maximum recorded sizes for twopecies, C. plumbeus and C. amblyrhynchos, seem unlikelyt 400 cm SL for both, as previously reported maximumengths are just 250 and 255 cm TL, respectively (Nakaya,984; Randall et al., 1990). Of more concern, however, arehe minimum sizes for sharks landed of 80–105 cm SL forhe majority of species, with the Sphyrna spp. and maintepateanded during June and July regularly measuring around onlym in both Soalara and Maromena (Fig. 3). Prior to the intro-uction of static long-lines, only gill nets with a mesh sizef 20–25 cm were in use. This, due to the selectivity of thisype of fishing gear, would have limited the size classes thatould be taken for the majority of species with very small andery large individuals being protected. (A notable exceptiono this would be the Sphyrnidae, which, by virtue of their headhape, would have been vulnerable to capture over a widerize range.) Of the sharks recorded during the course of thistudy, however, 8% (n = 96) had SLs of 100 cm or less withhe smallest being just 40 cm (SL). Sharks of this size wouldave been unlikely to have been caught using gill nets alonendicating that the change in gears has probably resulted in ahift in the size range of sharks being taken by these fisheries.

Declines are evident in both numbers of sharks landednd size, if one is to compare results with Cooke (1997)ata. This change in the size ranges of fished sharks couldave serious implications for the sustainability of thesesheries as population studies of coastal shark species have

ndicated that even a slight increase in juvenile mortality canreatly reduce the sustainability of coastal shark fisheriesCortes, 1998). For smaller species such as C. sorrah and C.elanopterus this minimum size of 80–100 cm SL represents

lose to or greater than the reported size for female maturity.s such the impact on juveniles will be limited providing

hat pregnant females are not caught in great numbers. Forll other species identified, such small sizes are considerablyelow documented sizes at maturity and as such any capturef these individuals will have an impact on juvenile stock

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evels with potentially damaging consequences for theustainability of fisheries for those species. The decline inhe number of larger individuals is probably accountableo fishing pressure, but the recent introduction of lesselective fishing gears has permitted the fishery to continuey enabling smaller individuals to be targeted.

Despite the risk of possible resource depletion, the poten-ially high returns of shark fishing due to the guaranteed pricef fins resulting from the inexhaustible demand supplied byhe export trade to the Far East, appears to suggest this willontinue to be an attractive livelihood in this impoverishedegion of the world. Unfortunately, however, whilst the highconomic returns of the fishery are in all likelihood contribut-ng to the development of the communities in which the sharkshers live, it is precisely these extremely high returns thatre driving the fishery past a sustainable level of exploita-ion. After the costs of purchasing the fishing gears the onlyosts associated with shark fishing are the maintenance of theears and the man-hours involved in travelling out to checkhe gears each day. Manpower is generally not a limiting fac-or in fishing villages in the south west of Madagascar andherefore the majority of earnings are “profit” which is usedo improve the lives of the fishers and their families. However,his also means that a considerable drop in earnings can bendured before the fishery ceases to be economically viablend fishers are forced to find a different source of income.ndeed, as fins become scarcer, the price paid is likely toncrease.

Between 1989 and 1995 the price paid to fishers for dryn increased from US$ 6 to US$ 45–67 per kg−1 for highestuality fins (Cooke, 1997). Since then the value of wet finsas increased further with 1 kg of fresh fin selling for US$ 52.his represents over a 100% increase in the value of fins since995 as 1 kg of dry fin weights about 36% the weight of freshns (Kreuzer and Ahmed, 1987). Furthermore, as the averageize of sharks landed decreases, the premium paid for largeharks with higher quality, more marketable fins is likely toncrease. Such a situation in an open access system such ashe one studied here could promote increased exploitationates to the point of collapse (Randall, 1987).

Therefore, the indications of this study are that whilst thedea of management is likely to be unpopular, it is importanthat some form of management be implemented in order tottempt to preserve the remaining shark populations and makehe fishery more sustainable in the long term. Such a planould need to be applied at a regional level with all villages on

he southwest coast included. Part of this will require a moren-depth study of the catches of the different fishing gears inse to determine how the fisheries can be managed to promoteustainable exploitation. Discussions with the fishers includ-ng presentations by the authors on the work conducted andn shark ecology and conservation were met with interest by

he fishers and concerns were raised about the future of theirsheries if current trends continued. Considering the relativealues of shark fins, however, an appropriate course of actionould seem to be to attempt to restrict captures to large indi-

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iduals only through more selective gear use. This would acto preserve income as much as possible as fins from smallerndividuals gain a far lower price. Therefore, by focussingfforts on larger individuals with higher value fins it willaximise incomes whilst at the same time protecting stocks

f smaller individuals, hopefully promoting stock recoverynd leading to a more sustainable fishery. Such a move wouldequire an education programme to be undertaken within theshing communities to explain the principles and aims ofuch a management plan. Education and scientific supportlso needs to be directed towards local development agencies,nforming them of the best means of promoting sustainablese of what is a very delicate group of species on which toase a fishery. Such agencies encouraged the exploitation ofharks when the fishery was in its infancy, therefore the mes-age they must pass on to the fishers is one of sustainability.

cknowledgements

We would like to acknowledge the help and support ofhe staff and research assistants of Frontier-Madagascar, aollaboration of L’Institut Halieutique et des Sciences Marinend the Society for Environmental Exploration. We wouldlso like to thank the fishermen and residents of the villagesurveyed for their co-operation and patience and Al Harris oflue Ventures for the map in Fig. 1. This work was fundedy the Society for Environmental Exploration.

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