Aquaculture, 105 ( 1992) 233-240 Elsevier Science Publishers B.V., Amsterdam

233

AQUA 40003

A.Q. Hurtado-Ponce, G.PB. Samonte, Ma.R. Luhan and N. Guanzon Jr. SEAFDEC, Aquaculture Department, Iklilo, Philippines

(Accepted 2 1 November 199 1)

ABSTRACT

Hurtado-Ponce, A.Q., Samonte, G.PB., Luhan, Ma.R. and Guanzon, Jr., N.G., 1992. Gracilaria (Rhodophyta) farming in Panay, Western Visayas, Philippines. Aquaculfure, 105: 233-240.

Interviews were conducted among eight Grucitaria growers in Panay, Western Visayas, Philippines from March to July 1990 using a structured questionnaire. The “rice planting” method was employed by farmers growing seaweeds in natural drainage canals and ponds. Initial harvests are made 15-60 days after planting. Higher production [7-14 t (dry) ha-’ year-‘] are obtained from cultures in canals than in ponds [ 3-4 t (dry) ha-’ year-‘]. The net income derived from culture in ponds i; estimated at f698/crop or f6313/year (US$234/year). A higher net income of f4936/crop or f41 766/year (US% 1547/year) was generated from Grucilaria farming in canals. Returns on invest- ment (ROI) from farming in ponds and canals are 39W and 908% respectively. Payha.ck period is 2 months in canal farming and 1 .X years in pond farming.

INTRODUCTION

An annual production of 25 000-30 000 metric tonnes of Gracilaria is har- vested from the wild in Chile, Argentina, Brazil, and South Africa and from fishpond culture in Taiwan and China (Santelices and Doty, 1989 ). In Pa- cific Asia, the Philippines is one of the producers of Gracilaria mainly from natural stock. An increasing annual production was recorded in the Philip- pines from 1982 (299 t ) to 1986 (728 t ), but there was a decline in 1987 (434 t ) (Fishery Statistics of the Philippines, 1987), believed to be caused by depletion of stocks due to unregulated harvesting practices.

Commercial pond farming of Gracilaria is now successful in Hainan, China (Wang et al., 1984; Liu, 1988 ) and Taiwan (Shang, 1976; Chiang, 198 l)* Encouraging results were obtained from cultivation of Gracihia on lines (Kim and IIumm, 1965; Raju and Thomas, 197 1; Smith et al., 1984; Doty,

Correspondence to: Dr. A.Q. Hurtado-Ponce, Southeast Asian Fisheries Development Center, Aquaculture Department, P.O. Box 256, Iloilo City 5000, Philippines.

0044-8486/92/$05.00 0 1992 Elsevier Science Publishers B.V. All rights reserved.

234 A.Q. HURTADO-PONCE ET AL.

1986; Camara-Netto, 1987; Barraca, 1990; Hurtado-Ponce, 1990)) rafts (Li et al., 1984; Ren et al., 1984), floating bags (Saunders and Lindsay, 1979), raceways (Fralick et al., 198 1 ), and tanks (Lapointe et al., 1976; Lapointe and Ryther, 1978; Lignell et al., 1987). Techniques have yet to be improved in order to achieve maximum production at a low production cost.

Although Gracilaria has been farmed in Panay for more than 10 years (Hurtado-Ponce, 1988), there is no literature describing farming practices and economics. The present study was undertaken to document the farming of Gracilaria in Panay and to estimate the costs and returns of the industry.

MATERIALS ANT\ METHODS

A survey was conducted from March to July 1990 among Gracilaria grow- ers in three municipalities in the provinces of Iloilo and Capiz, Panay, West- em Visayas, Philippines (Fig. 1). Eight growers were interviewed using a structured questionnaire. Data gathered were interpreted in percentages. Eco- n,*rlic implicators used were return on investment (ROI) and payback pe- riod. The average yield/ha obtained by six canal growers and two pond grow- ers was computed. Economic data were calculated as Philippine pesos. Current exchange rate is P 27 = US$ 1.

RESULTS

Farming practices Eight Gracilaria growers from three municipalities, namely, Leganes and

Villa in Iloilo and Pan-ay in Capiz, were interviewed. Two cultivate in brack- ish water fishponds (25%, both men) and six in canals (7S%, all women).

All growers use the “rice planting” method. The size of pond and canal farms ranged from 0.5 to 5.0 ha and 825 m2 to 7055 m2, respectively. The farmers used local stock of Gracilaria heteroclada as seedstocks. Gracilaria thalli of approximately 1 S-20 g and with a total length of 1 S-20 cm are used as seedstocks. One end of the bunch of thalli is staked into the sandy-muddy substrate. The bunches are spaced lo- 15 cm apart and left to grow for 1 S-20 days in canals or 45-60 days in ponds before the first harvest. Six farmers in Leganes farm Gracilaria for a period of 8- 12 months ( 75%) starting in June- July while the farmers in Villa and Pan-ay farm for a period of 6-8 months (25%) starting in November-December.

Only two-thirds of the seaweeds are harvested by cropping; the remaining serve as seedstock for the next cultivation period. A total of 16-24 (75%) and 12-l 6 (25%) croppings are made for one farming period among canal and pond growers, respectively. The Gracilaria canal growers sell their har- vests at P80-loo/sack ( 1 sack=25 kg) and the dried harvest at I+ 7.OO/kg. The pond growers sell only their dried harvest atP4.50 toP9.0O/kg (average

GRACLLARIA FARMlNGINPANAY,PHILIPPINES 235

Fig. 1. Map of Panay, Western Visayas.

of F7.OO/kg). The harvests are sun-dried for 1 day only using old fish nets (75%) and bamboo slats (25%) as drying devices. Dried seaweeds are packed in plastic sacks and stored in warehouses for 2-3 months to accumulate a bigger volume and await a higher price.

Data gathered revealed that canal farming of Gracilaria produced approx-

236 A.Q. HURTADO-PONCE ET AL.

imately 7-l 4 t (dry) ha- * year- I or an average of 1.3 t/ha per crop while pond farming produced 3-4 t (dry) ha- * year- ’ or an average of 450 kg/ha per crop. Marketing of Gracilaria is done in two ways: ( 1) fresh harvests are either sold directly to traders or brought to local public markets; and (2) dried seaweeds are sold first to traders then to exporters or processors.

Economics The initial investment for Gracilaria culture for a l-ha pond and canal were

-P 16 000 (US$593 ) andP4600 (US$170), respectively (Table 1). This cov- ered the fixed asset outlay and working capital for the first cropping.

The total cost of production for succeeding crops wasp 1507/ha per crop or f)4.78/kg (US$O. 17/kg) for pond culture and -P 1434/ha per crop or -P 1.58/kg (US$O.OS/kg) for canal culture (Table 2). A projected costs and returns for pond farming is included to compare its profitability with canal farming. Total cost consisted of cash and non-cash expenses. For pond cul- ture, cash expense was 77% of the total cost with 23% being non-cash expense. For canal farming, non-cash expense comprised about 9 1% of the total1 costs while cash expense was only 9%. Unpaid family labor was the bulk of total expenses for Gracilaria culture in canals and comprised 84% of total costs. The annual net farm income derived from Gracilaria culture in ponds was -I+63 13/crap. Higher net farm income off,4 1 766/crap (US$1547/crop) was generated from Gracilaria farming in canals due to higher production yield obtained.

TABLE 1

investment requirement and depreciation for Gradaria culture in ponds and canals (peso/ha) (U%$1=?=27)

Item Pond

Amount Depreciation*

Canal

Amount Depreciation*

A. Capital asset Pond development Drying platform Dug=out Non-motorized boat

Sub-total

10 000 2000 1000 200 1000 200 1000 200 1000 200 2000 400 2000 400

14 000 2800 4000 800

B. Working capital 2000

c. Initial investment 16 000 4600

*Using the straight-line method, the annual depreciation was calculated by the formula: (P-L ) ln, where P is the initial cost of the asset, L is its value as scrap assumed to be zero, and n is its lifespan assumed to be 5 years.

GRACILARIA FARMING IN PANAY, PHILIPPINES 237

TABLE 2

Costs and returns of Gruciluriu culture in ponds and canals (peso/ha) (US% I =f27)

Item Pond

Actual (n=2)

Projected

Canal

Actual (n=6)

A. Seeding density (g/m* ) First crop Revenue: Yield (kg dry)

Unit selling price Total revenue

Cash expenses: Seed plants tf l.OO/kg)

Caretaker’s salary -. Hired labor (20 md,f40/md) Marketing expenses (2% of revenue) Land tax Permit

200 400 300 300 800 800 63 126 13 13

Sub-total 1376 1639 Non-cash expenses: Family labor (30 md,P40/md)

Depreciation

Sub-total Total cost Net cash income Net farm income

B. Succeeding crops Revenue: Yield (kg fresh )

Less: Seed allocation (30%) Net fresh yield (kg) Dry yield (kg, 7 : 1 wetmdry ratio) Unit selling price Total revenue

Cash expenses: Caretaker’salary

Hired labor (20 md,P40/md) Marketing expenses (2% of revenue) Land tax Permit

Sub-total Non-cash expenses: Family labor (30 md,P4O/md)

Depreciation

Sub-total Total cost Net cash income Net farm income

C. Profitability Annual net cash income ( 8 croppings ) Annual net farm income ( 8 croppings ) Return on investment Payback period (years)

200 400 400

450 900 7 7

3150 6300

1300

910;

400

182

6

588

350 350

350 350 1726 1989 1775 4662 1425 4312

1200 100

1300 1888 8512 7212

3150 6300 945 1890

2205 4410 315 630

7 7 2205 4410

9100 2730 6370 910

637;

300 300 800 800 44 88 13 13

!27

1157 1201

6

134

._ 350

1200 100

350 1507 1048 698

350

350 1551 3209 2859

1300 1434 6236 4936

9113 27 127 52 166 6313 24 327 41 766

39% 152% 908% 1.76 0.59 0.11

238 A.Q. HURTADO-PONCE ET AL.

Major problems Farmers culturing Gracilaria in ponds and canals cited several problems:

low market price (SO%), predation (38%), presence of associated algae (25%), theft (25%), no accessible market outlet (25%), and poor farming technology (25%).

DISCUSSION

The canal system of cultivation is more productive than the pond system The low production in ponds may be attributed to low stocking density, poor water management, insufficient fertilization, grazing by herbivorous fishes (Oreochromis and Mugil), and presence of undesirable macroalgae (Rhizo- clonium, Chaetomorpha, Cladophora, Enteromorpha, and Ulva ) . The last two factors have been claimed by Shang ( 1976), Chen ( 1976, 1990) and Liu ( 1988) to be detrimental to the growth of Gracilaria. Production in canal farming is comparable to the results reported by Shang ( 1976) (7-12 t dry wt ha- * year- * ) and Liu ( 1988) (7.5 t dry wt ha-’ year-’ ) but below the values ( 16-43 t dry wt ha- * year’ I ) reported by Chiang ( 198 1) . As an open- water system is used by the canal growers in Leganes, nutrients are readily accessible to the seaweeds; hence there is constant replenishment for the plants, leading to faster growth.

Fertilization plays a significant role in aquaculture. The quality and quan- tity of the fertilizer are primary indices to high production. The rigIlt amount of animal manure is necessary in order to have a high production. One of the pond growers, however, had a low production despite the use of animal man- ure, due to poor water management.

The presence of metabolic wastes of oysters within the pond in Pan-ay, Capiz contributed to the luxuriant growth of Gracilaria. However, a minimal pro- duction was obtained due to poor farming techniques. Water replenishment was done only during spring tides. The pond does not hold water during neap tide due to damage and to seepages through the dike. As a consequence, Gra- ciiaria was exposed to the sun during neap tide which caused dessication and loss of pigment in the seaweeds. Gracilaria plants are sensitive to long expo- sure to sun and air ( McLachlan and Bird, 1986 ). Aquatic animal culture adds substantial nutrients to the environment in the form of metabolic wastes (Fralick, 1984) but these wastes can present a pollution problem if not con- trolled As Chiang ( 198 1) stressed, appropriate fertilization and water man- agement in Gracilaria farming are important.

Farming Gracilaria in canals gives a much higher net income than in ponds due to lower investment requirement and higher production. Labor is usually provided by the members of the family. The culture of Gracilaria is profitable in ponds and in canals. Canal culture, however, has a higher ROI and shorter payback period than pond culture.

GRAC’ILARIA FARMING IN PANAY. PHILIPPINES 239

Gracilaria sold fresh in the local markets of Western Visayas is mainly used as a source of human food. It is prepared as a vegetable salad garnished with vinegar, tomatoes, onions, ginger, and salt. When it is sold to local processors in dried form, it is manufactured into food-grade agar in the form of bars, mainly for local consumption. Exporters sell the raw materials to Japan and some European countries for the manufacture of pure agar. Agar (Barbaroux, 1990) is mainly used in the food industry (58Oh) as a strong gelling agent, thickener, and stabilizing agent; in pharmacy; bacteriological agar (28%); and in biotechnology.

Gracilaria production is a viable aquaculture venture in both ponds and canals, providing a good source of livelihood. This activity, however, needs serious attention. Gracilaria as an agarophyte should be developed in areas suitable for its commercial cultivation. The presence of several idle brackish- water fishponds, wide and protected mud flats, and the introduction of poly- culture techniques (Gradaria with finfish or shrimps) may lead to higher production in the region and in the country as well.

Pond production in Western Visayas can be increased by the following means: ( 1) proper pond preparation, (2) appropriate stocking density (5- 10 t/ha), (3) good water management, (4) accurate fertilization, and (5) absence of undesirable macroalgae and grazers.

ACKNOWLEDGEMENTS

The authors are thankful to RX Agbayani an Dr. G.C. Trono, Jr. for their critical review of the manuscript, and to R. Caturao for his technical assis- tance with the interview.

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