IMPORTANCE OF WATER QUALITY IN CRAB FATTENING TO ENHANCE THE LIVELIHOOD OF FISHER FOLKS IN PAALAMEENMADU

Transcription

1 ERRATA

2

3 259 IMPORTANCE OF WATER QUALITY IN CRAB FATTENING TO ENHANCE THE LIVELIHOOD OF FISHER FOLKS IN PAALAMEENMADU P. Vinobaba and J.M. Harris Department of Zoology, Faculty of science, Eastern University, Sri Lanka Abstract Culturing of the mud crab Scylla serrata is not economical and hence the crab fattening is practiced. The water crabs at post-molt stage are fetching very low price in the market and are even rejected in the export market because of its poor meat content. If fattened, they fetch high price. However, local people prefer crab fattening in a participatory rural appraisal, conducted at a tsunami affected village namely Paalameenmadu of the Batticaloa District. In crab fattening, it is being treated as an alternative livelihood to reduce human pressure on mud crab from the mangrove ecosystem. Crab fattening in cages is economically viable. The cages were made out of wooden frame with Palmyra petiole basement. The four sides of the cages were perforated for the free circulation of water Trash fishes fed at the rate of 10% of the biomass of the crab at two intervals (morning and evening) every day. Crab fattening practices vary widely in different countries and have been rarely documented. The present study was conducted to how water quality parameters determine the growth, survival and production of mud crab. During fattening process in five different location the Turbidity ranges between FTU*, Salinity 4-20ppt, water temperature 31.6 C and 35.7 C, the ph value between 7.98 and The dissolved oxygen was ppm., Nitrate mg/L, Nitrite 23-81mg/L and Phosphate mg/L. The harvesting 35 days after fattening the maximum body weight is 1299g and minimum is 875g with a survival of 88%. In the case of algal fouling on the crab carapace, it was removed by brushing. Sometimes the barnacles also fouled the carapace and these were also removed. Keywords: Crab fattening, Nitrate, Post-molt, Scylla serrata, Turbidity Introduction Mud crabs (Scylla serrata) play a major role in the socioeconomics of the fisher folk and export market. Undersized (< 300 g female; < 350 g male) mud crabs have very low demand in the domestic market and are even rejected in the export market, they command a relatively low price. Hence, crab fattening in cages is a better alternative to enhance the livelihood of fisher folks. Because of their delicacy and

4 260 larger size, the live mud crabs are always in greater demand and fetch a higher price (Kathirvel, 1993). Economic indicators such as net profit, rate of return, pay back period and breakeven price indicate that crab fattening is much more profitable than any other coastal aquaculture operations currently in practice (Sathiadhas and. Najmudeen, 1991). In Sri Lanka, mud crabs have come into prominence since early eighties with the commencement of live crab export to the South East Asian countries which have created a renewed interest in the exploitation as well as in the production of mud crabs. The importance of live mud crabs as an export commodity has opened up great opportunities for crab fattening. It has high demand and price in the export market. Crab fattening is essentially a holding operation during which post-moult or water crabs are kept for a short period of 20 days until they 'flesh out'. Mud crabs grow to a very large size of about 22 cm in carapace and about 2 kg in weight. Mud crabs are highly tolerant to varying salinity conditions ranging between Salinity - 10 to 34 ppt, PH to 8.5, Temperature - 23o C to 30o C and Dissolved oxygen content - should be more than 3 ppm (SEAFDEC, 1997), so brackish water would be ideal for crab fattening operation. Several attempts at commercial culture of mud crab have been made, but, to date, low survival has been the major constraint to commercial operation (Gillespie and Mann 1991). Feeding activity and growth ceases in wet season, when temperatures below 20 C (Heasman 1980; Hill 1984 ). Salinity is important to control growth and survival of crabs. Each and every aquatic organism requires particular salinity for normal growth and survival. In higher and salinities, the animals are under stress. Koshio reported in 1990, weight gain was mainly depended on the nutritional quality of the water. However sudden change of water quality parameters negatively impact on the survival of the mud crab. From our experimentation period we can observed some death due to sudden salinity variation. This paper presents a broad but brief review of the mud crab fattening along with impacts of the water quality parameters on the growth and survival during the fattening cycle. There is no exclusive crab fattening method in Eastern province in order to meet the growing demand in the international market, which is entirely dependent on the capture fishery. The case of crab fattening as an alternative livelihood option to reduce human pressure on mud crab from the mangrove ecosystem. Therefore, this crab fattening activity has been initiated in the village of Paalameenmadu in order to use the available resources wisely and to assist the villagers, particularly fisher women to earn additional income. Although resources are available for crab fattening from Paalameenmadu to Vakarai coastal area in Eastern province. But fisher folks are not concerned about crab fattening due to lack of awareness and proper technology. Therefore we are initiated crab fattening in wooden cages at Paalameenmadu through the CIDA restore project. It is designed to know the how water quality parameters impacts on mud crab (Scylla serrata) fattening process for better weight gain and survival of crab

5 261 moreover to find out the impact of sudden changing water quality parameters on survival of mud crab. Material and methodology The inmates of Paalameenmadu area were given series of awareness program for how crab fattening could be made profitable and alternative livelihood. Therefore we selected the most interest and poorest village folks for fattening. Women showed keen interest in learning the maintenance of the crabs, collecting live feed of the fish offals and chicken manure. The training programmes executed for 20 fisher women by our resource persons include cage construction, feeding, maintenance, harvesting, species identification, culture and fattening, importance of water quality in crab fattening and executing innovative alternative livelihood schemes for coastal fisher folk. The cages were made out of wooden frame with Palmyra petiole basement. crab cages are set up into the shallow water fronts of the Batticaloa lagoon at different location shown in fig. 1. We have selected only 5 cages for our studies out of 20 cages. Each cages seeded with 10 crab lings. Trash fishes fed at the rate of 10% of the biomass of the crab at two intervals (morning and evening) every day. Five independent experiments on mud crab (S. serrata) fattening were conducted simultaneously in wooden cages for 30 days. Sampling of crabs was done on weekly. The Body Weight (BW), Carapace Length (CL) and percentage of survival crabs were calculated from the total harvest along with Salinity, Dissolved oxygen, ph, Nitrate, Nitrite, Phosphate, Turbidity and Temperature. In our experiment, mean number of crabs surviving and mean number of crabs declined (mortality) were calculated over time (months) in all the five cages. The means were obtained by averaging the number crabs. Weights of crabs at the time of harvest were measured from this average weight gained was calculated and percentage weight gain was calculated. In addition water quality parameters measured by Hanna instruments, electronic balance was used to measure weight gain.

6 262 Figure 1: Location of experimental cages Figure 2: Taking measurement Figure 3: Taking weight

7 263 Results Table 1: Body Weight (BW) and Carapace Length (CL) variation during the fattening cycle Week Cage 1 Cage 2 Cage 3 Cage 4 Cage 5 BW CL BW CL BW CL BW CL BW CL Table 2: Water quality parameters variation during the fattening cycle in different cages Parameters Average for 4 weeks during the fattening Cage 1 Cage 2 Cage 3 Cage 4 Cage 5 ph Dissolved Oxygen Turbidity Salinity Temperature Nitrate Nitrite Phosphate Figure 3: Cage number 4 Figure 4: Crabs were died at Cage no 4

8 264 In order to find out the relation between the water quality parameters and Body weight, Carapace Length, Pearson Correlation test were performed. The results shows only strong and statistically significant correlation found in Salinity and Phosphate, However Two way ANOVA results indicate there is interaction found between the Salinity, Dissolved oxygen, ph and Nitrate along with different locations (P<0.05) Figure 5: Variation of Carapace width with different salinities

9 265 Figure 6: Variation of Carapace width with different salinities Discussion The discussions are based on the finding of investigations during our experimentation period. From the obtained results, it showed maximum average Body Weight (BW) was 1229g, maximum average Carapace Length (CL) 17.4cm. The average survival rate was 88% from all 5 cages. Moreover showed the relationship between Carapace width (CW) and Body Weight (BW) and also with water quality parameters. The fattening period may vary from a few days to a month depending on the water quality of the fattening site. However, an accelerated rate of growth and survival was noticed in our experiment in higher salinity levels. Another previous study indicated the Syclla serrata from tropical areas may tolerate high temperatures and salinity more than those from other regions. Salinity is the measure of the salt content in the water. In general, salinity of the lagoon and estuaries varies with the spoatiallity, the salinity on the surface will be different from the bottom. Salinity changes in the sediments takes place much more slowly than the overlying water surface. Sudden change of salinity below 8 ppt resulted in death,(brick 1974; Hill 1974; and Ong 1964). However S. serrata is known to occur in water bodies having a range of salinity from to 45 ppt zero (Jones and Sujansinghani 1952). The optimum salinity for best survival is not known. The lower survival rates ( per cent) were recorded at 8-10 ppt without acclimation and at 51 ppt with acclimation (12.5 per cent survival). However, 100 per cent survival was recorded in the crab without acclimation at ppt, which was indicating the euryhaline nature of the species (Nair,1974 & Marichamy 1996

10 266 The main reason for the sudden mortality due to the sudden change of salinity. Wide differences observed in Salinity during our study period because of heavy shower. It ranges between 18 to 6 therefore we are experienced with sudden mortality of the cage number 4. The Batticaloa lagoon is the direct recipient water body of about 19 tanks, 5 major lakes and 11 rivers numerous irrigational channels and many drainage basins and has become dominate morphological features of the watershed (Shanmugapriyan and Vinobaba 2001) and Eight small rives enter Batticaloa lagoon. Therefore salinity ranges vary time to time however this not effect the grab fattening process. Natural seasonal changes in water flow and salinity of the lagoon are notably altered by the inflow of drainage from the Gal Oya and from several local irrigation systems (Shanmugaratnam,1995). The variation of nutrients in the fattening sites followed a seasonal trend. Nutrient (nitrates & phosphates) were higher during the rainy season October to December as compared to the dry season, February - March and July - August period. The ph values measured in the fattening sites did not vary much fluctuated, and ranged from 7.98 to 8.65 during our experimentation period. However water hyacinth seasonal abundant in our experimentation sites. This gathered lot of amount and decomposed near our experimentation sites, it takes oxygen from the water body as result alters the ph and dissolved oxygen suddenly. These factors might have negative impact on the fattening. Heasman (1980) reported that fluctuation of temperature might have an impact on survival rate of mud crab. But in our study there is no strong fluctuation of Temperature. Crab fattening is profitable due to the fast turnover rate and good survival. It is also very suitable for small-scale operations as an extra income source for fisher folk. Its expansion will be constrained by seed shortages as well as feed. principally trash fish. Most operations failed due to heavy mortalities resulting and wide salinity fluctuations and the general lack of knowledge about certain aspects of water quality requirements and maintenance of speeding up efforts to improve the existing mud crab fattening techniques along with water quality monitoring is essential in order to support a continued and sustained alternative livelihood option in the Paalameenmadu. This is the first time in the country that a community-based crab fattening project has been implemented for alternative livelihood purposes especially for women fisher folk. This has proved to be a great success not only in terms of generating extra income to the family through the but also in creating an awareness among fisher folk about the value of marine resources and the needs for sustainable utilization. Today the Paalamenmadu fishing village has become a role model for the establishment of similar projects in the other fishing villages along the eastern coast of Sri Lanka

11 267 Recommendation 1. Any commercial development in this direction needs further studies along with water quality parameters. These observations call for an immediate focus on the effective monitoring water quality parameters during the fattening period. 2. Crabs can achieve higher growth rates and less mortality with good quality than those obtained in metal cages. It is therefore recommended, that fattening should be done on floating wooden cages rather than submersion into the pond bottom. 3. Optimal weight for stocking should be g because crab of this size can gain a substantial weight and yield a reasonable return within a month. This would also, indirectly, preserve the resource of small crab. Acknowledgement Authors are thankful to Canadian International Development Agency (CIDA) for their keen interest and infrastructure facilities for the project and we wish to pay our sincere thanks to District Fisheries Extensions Office, Assistant Director Fisheries, Fisheries Inspector and also women fisher folks of the Paalameenmadu for their kind participation, and valuable help in various ways to carry out the project work successfully. Bibliography Brick, R.W. (1974). Effects of water quality, antibiotics, phytoplankton and food on survival and development of larvae of S c y l l a serrata (Crustacea: Portunidae). Aqua Gillespie, N.C. and Burke, J.B. (1991). Mud crab storage and transport in Australian commerce. A paper presented at Regional Sem. on Mud Crab Cult. and Trade in the Bay of Bengal Region. November S at Surat Thani. Thailand Heasman, M.P. (1980). Aspect of the general biology and fishery of the mudcrab Scylla serrata (Forskal) in Moreton Bay. Queensland. 506 p Hill, B.J. (1974). Salinity and temperature tolerance of zoea of the portunid crab Scylla serrata. Mar. Biol., 25( 1):

12 268 Hill, B.J. (1984). Effect of temperature on feeding activity in the crab Scylla serrata. Mar. Biol (ed). The Queensland mud crab fishery. Fish. Res. Br. Qld. Dept. of P. I., Brisbane, Australia. Jones, S. and Sujansinghani, K.H. (1950). Notes on the crab fishery of the Chilka Lake. J. Bombay Nat. Hist Soc. 51(1): Kathirvel, M. (1980). Abundance of portunid crab seeds in Cochin Backwater. IN: Proc. Svmp. on Coastal Aqua. Mar. Biol. Ass. Ind., Abs. No 94. Marichamy, R. (1996). Mud crab culture and hatchery. Bulletin of Central Marine Fisheries Research Institute, 48: Mudcrab culture. SEAFDEC Asian Aquaculture 19 (3, August 1997): p Nair, R.V., Bensam, P. and Marichamy, R. (1974). Possibility of marine fish culture in the salt pan area at Tuticorin. Ind J. Fish. 21 (1): 120 Ong Kah Sin. (1964). The early development stage of Scylla serrata Forskal (Crustacea Portunidae). reared in the laboratory. Proc. IPFC 11th session. Kuala Lumpur. IPFC 11(II): Sathiadhas, R. and Najmudeen, T M. (1991). Country Review, Abstract of Economic evaluation of mud crab farming under different production systems in India, Central Marine Fisheries Research Institute, Indian Council of Agricultural Research, Kerala, India. p-1 THE MUD CRAB, A report on the Seminar convened, for fisheries development, bay of bangal programe, in Surat Thani, Thailand, November 5-8, 1991 Vinobaba, P. and Shamugapiriyan, S. (2001). Studies on variation of some water quality parameters with the surface water movement from the selected sites of the Batticaloa lagoon. This was presented at the seventh annual sessions of the Sri Lanka Association for Fisheries and Aquatic Resources. 7: p14. Shanmugaratnam, N. (1995). The need for and steps towards a master plan for suitable utilization of the Batticaloa lagoon, Report to NORAD, pp1

13 269 AN ATTEMPT TO FARM GRACILARIA SP. IN PAALAMEENMADU AND THE LESSONS LEARNED FROM IT P. Vinobaba and J.M. Harris Department of Zoology, Faculty of science, Eastern University, Sri Lanka Abstract Marine macro algal flora of Sri Lanka comprise of 396 species within 147 genera and 56 families. Gracilaria, belong to the Phylum Rhodophyta, agar yielding red seaweed, is geographically distributed between 50 North latitude and 50 South latitude. In the eastern coast of Sri Lanka Gracilaria verrucosa and Graclilaria edulis were recorded from Trincomalee, Sinnakalappu, Kalkuddah, Passikuddah. Seaweed farming could be considered as an alternative livelihood for fishermen, because the short culture period can last for 45 days. Unlike other aquaculture ventures see weed farming is an environmentally friendly option in sedimentation tanks of the shrimp ponds where it removes excessive nutrients such as phosphates and nitrates. The nutritional benefits of seaweed consumption were considered as a source of micro-nutrients (vitamins and trace elements). In the present day the extracts from certain seaweeds are used as stabilizers, gelling agents or emulsifiers, dental moulds, cloth dyes, toothpaste, salad dressings, flavoured milks, cosmetics. Agar, the jelly found in some red seaweeds, is irreplaceable as a medium on which to culture fungi and bacteria for medical testing and research in microbiology. The dried product of Ceylon moss (Gracilaria) is popular for seaweed porridge and jelly that has been common in the local diet. This paper examines the in situ suspended farming of Gracilaria using stake long line cultivation under different conditions. The growth of this alga enhances the aggregation of fish such as Siganus oramin, Siganus lineatus, Signaus javus at its post larval stages where the sap of the algae is soft and permits the immature stage to feed on the thalus. Keywords: Gracilaria, Nitrates, Nutrients, Phosphates, Siganus sp Introduction The term seaweed refers to the large marine algae that grow almost exclusively in the shallow waters at the edge of the oceans. Sri Lanka has a rich marine algal flora along its coastal belt. Marine macro algal flora of Sri Lanka comprise of 396 species within 147 genera and 56 families (Silva et al.1996). Gracilaria, belong to the phylum Rhodophyta an agar yielding red seaweed (Usitalo, J. 1986), is

14 270 geographically distributed between 50 North latitude and 50 South latitude. In the eastern coast of Sri lanka, Gracilaria verrucosa and Gracilaria edulis were recorded (Durairatnam, M nd Pahalawattearachchi, 2003). Seaweed farming could be a source of alternative income for fishermen to that of fishing. The culture period is short and can last for 45 days (SEAFDEC-AQD, 2000) on the other hand there is an environmental friendly farming method (de Silva and Rahman, 2001). Seaweeds for direct human consumption are worth more than those destined for industrial use. The nutritional benefits of seaweed consumption were considered as a source of micro-nutrients (vitamins and trace elements) and their content of polysaccharides. Seaweed farming requires no more inputs, if there is periodic visitation two or three times a week (Samonte GPB, 1993). Because of the increasing demand for agarophytes, cultivation of Gracilaria has become more important during recent times. Nowadays we use extracts from certain seaweeds as stabilizers, gelling agents or emulsifiers, in thousands of everyday products from pet food to dental moulds, cloth dyes, tooth paste, salad dressings, flavoured milks, cosmetics, welding rods, and pizza toppings (Smith, 1980). Agar, the jelly found in some red seaweeds, is irreplaceable as a medium on which to culture fungi and bacteria for medical testing and research in microbiology. The dried product from Gracilaria, Ceylon moss is popular for seaweed porridge and jelly that has been common in the local diet (Subasinghe and Jayasuriya, 1989). In addition implementation of seaweed farming has been contributed to lift the rural economy (Luxton and Luxton, 1999) and has been found to be a sustainable activity, both environmentally and socially. The national knowledge of seaweed farming in Sri Lanka is limited. There this farming carried out only on a small scale as community based seaweed farming. In order to enhance Paalameenmadu fishermen livelihood we are first attempting experimental farming of Gracilaria in Paalameenmadu though the CIDA restore project. Although initial results were promising, the culture work will take up on a commercial scale with the sufficient marketing for seaweeds. This paper examines the in situ suspended farming of Gracilaria using stake long line cultivation under different conditions and it can also be ascertained whether the aggregation of herbivorous fish occurs. Materials and methods The CIDA restore projects implementation sites are Puthukudyiruppu and Paaalameenmadu. We did an initial water quality survey to select the most suitable site for Gracilaria farming. According to our survey Paalameenmadu was found to be the most suitable place to implement the project. The people living around this area were given awareness program how Gracilaria farming could be made profitable and alternative livelihood and other uses of the Gracilaria. This type of farming was introduced very recently into this area through the CIDA restore project and it has been carried out on a small scale on an experimental basis.

15 271 Therefore we selected the most interest and poorest village folks for farming. Though the maintenance work was carried out by the inmates the readings were taken down by us. Wooden poles were inserted into the sandy bottom down to a depth of about 1m Coir lines were stretched between the poles and the lines were supported every five meters by another lines running perpendicular to the main line. Vegetative cuttings of Gracilaria plants, which were collected from Sinnakalappu and the cuttings are used as the inoculums to start the raft farming. In the stake long line method, there are 34 plants/line of 10m long line. The average weight of seed stock is 20 grams each which is tied to the line at 1ft interval. The stakes are spaced 1 ft apart. The average weight of seed stock was estimated at 0.7kg /meter of grow out line. Grow-out lines were spaced at intervals varying between 0.2m. Grow-out time was three months. The study was carried out July 2008 to September The growth rate was monitored each week and the water quality parameters for growth monitored weekly including salinity, temperature, ph, rainfall, water flow rate, turbidity and dissolved. Dirt that was clinging to the seaweeds was removed thrice in a week. Once seaweeds are 2 ½ to 3 months old, once can start harvesting them. During the farming time one can collect fishes in the surrounding area by using fish traps and once that was done, their length was measured. Objective The main objective of this project is to find out whether Gracilaria farming could be used as an alternative livelihood of fisher folk of this area in relation to economical feasibility. By the Gracilaria farming in a particular location there is a possibility of increasing herbivores fish stock due to the growth of new Gracilaria stock naturally, by the settlement of zoo spores on the bottom. In addition, we sought to find out the impact on the water quality parameters on the Gracilaria farming. The feasibility of implementing this project on a commercial scale has to be studied further.

16 Sampling # DO (mg/l) Salinity (ppt) Temp (ºC) PH Nitrate (mg/l) Phosphate (mg/l) Nitrite (mg/l) Turbidity (FTU) 272 Results Table 3: Sampling dates and readings of Water quality parameters Date 1 2 nd July th July th July rd July th July th August th August rd August th August th September th September nd September * Highlighted row is sudden change of Salinity by heavy shower and fresh water inputs

17 273 Sites have enough water current, preferable sandy bottom 0.5 meters with depth. All water quality parameters except salinity are satisfied for optimal growth. Due to the heavy shower and fresh water inputs suddenly changes the salinity. Figure 7: Seaweed long lines Figure 8: Growing Seaweed in lines Figure 9: Monitoring the growth Figure 10: Harvesting Seaweed Figure 11: Bordering the Seaweed by net to protect Siganus sp. Figure 12: Siganus javus main grazer of Seaweed

18 274 Table 4: Growth rate and Water quality parameters Date Growth rate/ week Salinity DO Turbidity ph % % % % % % % % % % % % Data analysis and statistics Data has been analyzed to find out whether there is any correlation between the growth rate of Gracilaria and existing water quality parameters changes in open water staked long line method. The statistical analysis (Minitab 14.0) showed a variety of fish having most affinity to aggregate towards to Gracilaria. There is strong Pearson correlation found between the growth rate of Gracilaria and salinity, while no correlation was found in the other parameters. Table 5: Summary of the statistics Parameter Correlation value Correlation type P value Salinity Strong correlation Dissolved Oxygen Weak correlation ph Negative correlation Turbidity Negative correlation * Correlation value - Pearson correlation value, P value Probability value

19 275 Figure 13: Variation of salinity and growth rate during the sampling period Figure 14: Variation of dissolved oxygen and growth rate during the sampling period

20 276 Figure 15: Variation of ph and growth rate during the sampling period Figure 16: Variation of turbidity and growth rate during the sampling period

21 277 Discussion Seaweed culture is an exciting option for fishermen as an additional income to thei8r fishing because it offers much more income opportunity than growing other agricultural crops on land. The soil in Paalameenamadu village not suitable for agriculture. On the positive side this such farming would require little capital investment but high return, the trials clearly showed that fisher folk are capable of implementing the technology of Gracilaria culture by themselves. The farming aspects include spore-setting and vegetative propagation along with leaving the pieces to grow as big thallus. Gracilaria verrucosa and Gracilaria edulis from natural stocks collected from Kinniya of Trincomalee district were exported from Sri Lanka already. Under the right conditions, the crop grows quickly with a harvest every 45 days and the thallus of Gracilaria is unspecialized, so any piece taken from it can be vegetatively propagated whereas, without spending much time for this type of culture earn more income. At 45 days to a month old, branches of seaweeds start to fall off due to the water current. In order to save them from drifting away, a nylon net should be placed as a fence around the area that is perpendicular to the water current. Seaweed also has a steady and growing market, internationally, for food and the cosmetics industry. In 2006 Hurtado-Ponce AQ, Luhan MaRJ and Guanzon NG Jr, reported that seaweed farming has contributed positively to the rural economy. This could be considered as a sustainable activity, both environmentally and socially also as it provides employment for poor fishermen. At an early stage in the trials, it was apparent that value-added processing would be required to achieve an adequate return on investment. Various technical problems arose during the implementation of the two pilot projects, but information on current experience with Gracilaria production and marketing in our region was not readily available because of people prefer imported products. If we implemented proper post harvest and extraction techniques this will pave the way get more profit from this culture. Post harvest activity which determines the quality and shelf life of the seaweed (Doty and Fisher, 1987). In the past, the quality of seaweed was poor due to the lack of knowledge about the way to handle the seaweed culture. They, for example, usually just put the seaweed on the sand to dry up. If we give proper training about better ways to dry the seaweed we will get much better prices. Exposure to the sun or heat during transport should be avoided to insure the freshness of the produce. During transport, it was not always possible to keep the seaweed wet and cool. Washing was minimized to avoid stressing the plants and causing premature spore release. In our culture method seaweed was repeatedly washed; plants and spores might have consequently been damaged and released before the actual spore setting took place.

22 278 In order to maintain the freshness of Gracilaria the inner surface of each basket should be lined with a gunny sack, and several layers of fresh or dried banana leaves or fresh seaweeds. A topping of fresh seaweeds or banana leaves was then placed over the seaweeds, then the basket was finally covered with gunny sack which was secured by lacing it to the basket with tying materials. Siganus sp is the main grazers and they can literally wipe out Gracilaria culture (Coppen, 1990). It appears that juvenile Siganus are largely to blame. The fish began entering the plots, as evidenced by grazed seaweed. During our farming period the observed Siganus were less than 100 g, with the majority below 40 grams. Clearly, the seaweed farms were sited on the feeding grounds of the juveniles of the principal grazing species. Two methods were performed to protecting the Gracilaria from Siganus sp were tested in Paalameenmadu. First, making a net enclosure round the farming area traps are placed inside fenced plots. The second method making scare lines made of pieces of Palmyrah leaves. However, Siganus sp swam over the scare line and into the farm plot and all the seaweed was eaten by Siganus sp. These scare lines were totally ineffective. But in the net enclosure fence had to be buried in the sandy bottom to prevent it from lifting off the bottom by the water current and prevent it from allowing the entry of the grazer. The fence effectively excluded Siganus sp at Paalamenmadu. A few entered under the fence, but could be controlled with traps. Clearly, more trials are needed to find the alternative sites. Besides grazing, there were other problems, fouling by unwanted epiphytes and invertebrates may seriously affect the product quality. Water hyacinth (Eichchornia sp.) was seasonally abundant, particularly in Paalameenmadu. Large quantities often became entangled and alter the ph by decomposed water hyacinth which retarded growth and resulted in the death of some of the plants. Extremely low tides left some seaweed lines exposed to the sun, with consequent drying out. Some of the cuttings also started to decay and dropped off the ropes. Sedimentation and fouling were much more pronounced here. These problems were minor compared to the grazing problem and, therefore, several methods were tried to protect the seaweed from Siganus sp. Assessment of commercial feasibility requires both longterm trials and sufficient production capacity to evaluate economic, and technical costs. Gracilaria has the potential to remove inorganic nutrients from coastal areas. From our studies the growth of algae showed reduction of nitrate, nitrite and phosphate concentration in surrounding area. It was observed that the large-scale cultivation of Gracilaria could be effective in controlling eutrophication. Water temperature did not fluctuate much throughout the farming period, varied between C but salinity, ph varied due to the rainfall, decomposing of water hyacinth and fresh water input and deficit of the correct concentration of nutrients in

23 279 the water might have caused poor development of the spores. Small unidentified molluscs were frequently observed on out planted lines and could have grazed on the few plants which germinated. During the culture period spores fell down to the bottom and grew as a new Gracilaria bed. This will stimulate fish stocks to hide. These grounds act as feeding and spawning ground to many fish in this way enhance fish stocks as well as it could be maintain ecological balance and dynamics. A sudden change of the salinity affects the growth rate (P<0.05). However Siganus lineatus and Siganus javus severely grazed Gracilaria and reduced the net harvest. Gracilaria growth exhibits seasonal variations based on monsoonal effect. The best production was over 1 kg wet weight per meter. The weekly growth rate ranges from 2.5% to 8%. The results indicate that Gracilaria has the potential to remove excess nutrients from coastal areas. Constraints Seaweed farming is not flourishing because of the following constraints - Lack of proper transportation and marketing facilities. - Lack of buyer and market information. - Inadequate aircraft space and desired flights to importer countries. - Lack of technical knowhow to enable scientific production and the introduction of proper management systems. Because of these constraints, fishermen receive low prices for their products - mainly due to the lack of post harvest knowledge. Sometimes they have to sell the produce at minimal prices. Recommendations We recommend that there be: 1. An investigation of the natural stock of Gracilaria in inshore and offshore waters to assess the stock size. 2. An arrangement of marketing facilities. 3. Government participation in internal seaweed farming promotional activities. 4. An arrangement with the help of international agencies for the training of professional seaweed culture and processing techniques. 5. Research activities on seaweed biology to be given importance.

24 280 Acknowledgment We would like to express our profound gratitude to Canadian International Development Agency (CIDA) for their financial assistance. We are indebted to convey our heartfelt thanks to inmates of the Paalameenmadu for their kind cooperation and valuable help in various ways to carry out the project work successfully. Bibliography Causey, N.J.P., Prytherch, J., McCaskill, H.J., Hum, F.A., Wolf. (n.d.). Influence of environmental factors on the growth of Gracilaria. Bull. Duke Univ. Marine St. 3, Coppen, J. (1990). Production of agar from seaweed with special reference to India. In Symposium on Gracilaria production and utilization in the Bay of Bengal, October 23-27, 1989, Songkhla, Thailand. BOBP/REP/45: Bay of Bengal Programme, Madras. Doty, M.S. and Fisher, J. (1987). Experimental culture of seaweeds (Gracilaria Sp.) in Penang, Malaysia. BOBP/WP/52 :Bay of Bengal Programme, Madras. Durairatnam, M. (1961). Contribution to the study of the marine algae of Ceylon. Fisheries Research Station, Ceylon, Bulletin pp. Durairatnam, M. (1965). The Ecology of Gracilaria verrucosa (Hudson) Papenfuss [Formerly G. conferoides (L.) Greville] in Koddiyar Bay, Trincomalee. Bulletin for Fisheries Research Station, Ceylon 18, Hurtado-Ponce AQ, Luhan MaRJ, Guanzon NG Jr. (2006). Seaweeds of Panay (2 nd Ed.). SEAFDEC Aquaculture Department, Tigbauan, Iloilo. 50 p Jayasuriya, P.M.A. (1987). Socio-economic aspects of wild seaweed harvesters in Puttalam lagoon, 42 nd Ann. Sec. SLAAS. sec. F. Luxton, D.M. and Luxton, P.M. (1999). Development of commercial Kappaphycus production in the Line Islands, Central Pacific. HYDROBIOLOGIA 399, Pahalawattearachchi. (2003). Report on Pilot project on culture of seaweeds. National Aquatic Resources Research and Development Agency (NARA), Colombo, pp. 22

25 281 Report of the seminar on Gracilaria production and utilization in the Bay of Bengal, October 2-3, 1989, Songkhla, Thailand Samonte G.P.B., Hurtado-Ponce A.Q., Caturao R.D. (1993). Economic analysis of bottom line and raft monoline culture of Kappaphycus alvarezii var. tambalang in Western Visayas, Philippines. Aquaculture 110:1-11 Silva, P.C., Basson P.W. and. Moe R.L. (1996). Catalogue of benthic marine algae of the Indian Ocean. Published by the University of California Press. Smith, Allen. (1980). Finding Better Crops for Seaweed Farmers in the West Indies, Caribbean Natural Resources Institute, Out of Shell Vol. 6# 1, pp Subasinghe, S. and Jayasuriya, P.M.A. (1989). Seaweed Industry in Sri Lanka; A Study of the Present Status of the Seaweed Industry in Sri Lanka. National Aquatic Resource Agency, Colombo, pp. 62. Usitalo, J. (1986). Commercial seaweed collection and agar/alginate in Tamil Nadu, India: Seaweed cultivation as a solution to overexploitation of a natural resource. Swedish National Board of Fisheries, Gothenburg. Webography SEAFDEC-AQD, Seaweed culture, 2000, a 3-fold flyer downloadable from the SEAFDEC/AQD website

26 282 EVALUATING THE PERFORMANCE OF MUSHROOM PRODUCTION AMONG SELECTED MUSHROOM GROWERS OF MADIHE EAST K.L. Wasantha Kumara and H.W.L. Pushpakumari Department of Agricultural Biology, Faculty of Agriculture, University of Ruhuna, Mapalana, Kamburupitiya, Abstract Ten beneficiaries were selected based on their interest and potential for production of mushroom under the CIDA Restore project at Madiha East with the objectives of identifying the present status, production and marketing problems of their cultivation and to suggest mitigating measures to overcome the identified constraints. Selected growers were given complete package including technical knowhow and other materials such as complete mushroom units, basic materials, etc. to start their cultivation. Data were collected by a field survey using a questionnaire. The cultivation was started one year ago and only 80% is continuing mushroom cultivation at present and therefore, selected for the survey. Among selected ten mushroom growers, 90% are female which implies the women employment and empowerment. All the growers cultivate American oyster variety as it gives higher yield with frequent harvesting and due to higher market demand. Most of the growers (75%) prepare bags at a time. Average production cost for 100 mushroom packets sold at the market is approximately Rs All the growers engaged in the cultivation with the purpose of obtaining only an additional income. Seventy-five percent of the growers were willing to test new varieties in their production. All the growers used saw dust which is readily available in the area as the medium for the cultivation of mushroom. All of them used family labor while receiving initial investment from the project. Seventy five percent of growers encountered pest and disease problems so far however were able to overcome this problem may be due to the proper training received and correct technology application. Most (75%) of the growers faced problems of availability and quality of spawns and most of them explained marketing was the major problem in their mushroom cultivation and therefore, had not attempted to expand their production. It is also observed in the survey that none of the growers attempted any other kind of value addition to their production. Collective bargaining rather than individual bargaining via farmer organizations, providing training for value addition to enhance marketing can be suggested in this study to overcome the above constraints observed in the survey. Keywords: Mushroom cultivation, problems, prospects

27 283 Introduction The livelihood of people in the Madiha East area was badly affected with Tsunami tribal waves in 26 th December The CIDA Restore project was established to implement a multi-sectorial approach to environmental restoration, sustainable livelihoods and community development in Tsunami affected six needy villages including Madiha East. The project focused mainly on restoring traditional livelihoods and developing alternative sustainable livelihoods among affected people. The some of the expected results especially from the livelihood part of the project in the selected villages are, enhancing quality of life and economic status of communities, diversification of livelihood opportunities, diversification and expansion of small scale industries, diversification and expansion of improved agriculture, and enhanced levels of empowerment and greater roles of women in community life. Most of the people were dependent on coir industry, handloom, limestones, aquaculture and tourism as their main income generation before Tsunami in Madiha east (Perera and Kumara, 2008). The mushroom cultivation is a profitable agribusiness and it has a great relevance to the rural development (Shah et al., 2004). Mushroom production can generate a good income for farmers, and utilize surplus manpower in rural areas which ideally fit with the major objectives of the project. In this view, it was identified from the project mushroom cultivation as a sub activity in upgrading livelihood of people in the area. The selected growers in the Madiha area were supported with complete technical package and the performance was evaluated one year after starting mushroom cultivation. This paper discusses the present status, production and marketing problems of the cultivation and suggests mitigating measures to overcome the identified constraints among beneficiaries of the CIDA restore project of the sub activity mushroom cultivation. Methodology Ten beneficiaries were selected based on their interest and potential for production of mushroom under the CIDA restore project at Madiha East. Selected growers were given complete package including technical knowhow and other materials such as complete mushroom units, basic materials, etc. to start their cultivation. Regular field visits were conducted to discuss the issues pertaining to the mushroom production. One year after starting mushroom cultivation, survey was conducted among all the beneficiaries with a field survey. Data were collected using a questionnaire. Out of 10 selected growers, only 8 were continuing mushroom cultivation and therefore, selected for the survey.

28 284 Since the number of beneficiaries surveyed is small (8), data were presented only in tables and figures and was unable to perform statistical analysis. Results and discussion The cultivation was started one year ago and only 80% are continuing cultivation at the moment. According to Illankoon (2002), although large number of people start cultivation of mushrooms, only a few continue their cultivation and others give up cultivation due to various cultivation problems encountered. Among selected 10 mushroom growers, 9 of them are females which implying the women employment and empowerment. All the growers cultivate American oyster variety. The reason for growing American oyster was the higher yield with frequent harvesting and high market demand. However, 3 out of 8 growers tried cultivation of Abalone variety as it also has high market demand according to their observation. Most of the growers (75%) prepare mushroom bags at a time (Fig. 17). Only one grower found producing more than 250 bags at a time. Time limitation due to involvement in main occupation may have restricted these growers from full time engagement in mushroom cultivation and they are satisfied with their current production % Bags 12.50% Bags to 120 to 130 Bags 250 to 500 Bags 75% Figure 17: Average mushroom bag production (at a time) by growers

29 285 Most of the growers produce bags only once in each month (Table 6). Lack of storage facilities for incubation of large numbers of bags and time limitations due to their main occupation has restricted them preparing bags more frequently. None of the growers attempted preparing bags every day. However, three growers found preparing bags every week or within less than a week. Those growers prepare bags more frequently to obtain regular harvest and to avoid wastage of large amounts of saw dust transported once. Table 6: Production frequency of mushrooms by growers Frequency Number of growers Percentage (%) Daily 0 0 Every other day Every 3 days Every week Every 2 weeks Every month Average production cost for 100 mushroom packets sold at the market is calculated as Rs Factors considered for calculating the cost of production of 100 packets were, cost of preparation of bags (Ingredients, polythene, etc.), transport cost, labour charges, water/electricity charges and packaging (Polythene, label, etc.). The monthly production and income generated through mushroom cultivation is presented in the table 6. It is observed from the table that only three growers receive more than Rs. 5000/= per month from the mushroom business. Three growers were satisfied with more or less equal to Rs. 3000/= per month and their production was 16 kg per month (Table 7). The main reason for the low income from mushroom cultivation among these growers was low production of mushrooms. It is observed that mushroom yields three times more income compared with the initial investment. To obtain more income, growers need to prepare more bags and be involved with the production frequently which is not seen among these growers. Table 7: Monthly production and income from mushroom cultivation Grower No. Packets /month Kg /month Income (Rs.)

30 NA NA - - Note: Grower no. 6 and no. 10 were not interviewed as they have already abandoned cultivation. All the growers engaged in the cultivation with the purpose of obtaining only an additional income apart from their main income from other occupations. Even though mushroom cultivation is considered a profitable industry, none of the growers wanted to engage in this as a main income source. The reasons for not attempting to expand their production are not clear. However, 87.5% in the opinion that mushroom cultivation is a profitable agribusiness and only one out of 8 (12.5%) in the indifference opinion. Seventy-five percent of the growers were willing to test new varieties in their production with the expectation of increased market opportunities, yield, demand and reduced cost of production. Unavailability of different spawn types and lack of technical knowhow may have restricted their attempt to test new mushroom types. At the same time, 25% of growers were not willing to take the risk of growing new varieties assuming low yield compared to currently grown variety, low demand, high cost of production and lack of knowledge of cultivating different types. All the growers used family labour while receiving initial investment from the project. They may not have found assistance from a labourer since their production was very small and were able to manage with one or two persons. Seventy five percent of the growers encountered some form of pests and disease problems so far however, were able to overcome those problems successfully thanks to the proper training received and correct technology application. It is common in many people in other areas that giving up the cultivation after finding difficulty in eliminating pests and disease problems. The complete mushroom hut with insect proof net would have restricted entry of mushroom pests into the cultivation and therefore, didn t find a major problem in their cultivation. Most of the growers believe that marketing is the major problem in their mushroom cultivation and therefore, had not attempted to expand their production. Four out of 8 growers sell their products to nearby shops and neighbors. Five of them sell produce to nearby shops and use for self consumption. Another 3 out of 8 sell the produce to nearby shops and getting regular orders. This indicates there is no proper