IJERD – International Journal of Environmental and Rural Development (2012) 3-2

Research articleerd

Status of Blue Swimmer Crab (Portunus spp.) Fishing inChang Hoan and Kep Thmey Fisheries Community,
Kampot Province
VICHAR CHHOM*Royal University of Agriculture, Phnom Penh, Cambodia
Email: chhomvichar@gmail.com

KUONG KOV
Fisheries Administration, Phnom Penh , Cambodia

VANARITH KY
Fisheries Administration, Phnom Penh, Cambodia

KONGHEANG HUOT
Royal University of Agriculture, Phnom Penh, Cambodia
Received 17 December 2011

Accepted 12 March 2012(*: Corresponding Author)

Abstract Blue swimmer crab plays a significant role for the people living around thecoastal zone which provides foods, income for livelihood. Unsustainable use of fishery resources and lack of food security by human activities and environment factors drove thedegradation of these species. So, the study aimed to: identify the kind of fishing gears andthe way of fishing blue swimmer crab, identify the average yield of blue swimmer crab,
and show the blue swimmer crab market. The study selected 2 different Community Fisheries (CFi) from 2 communes and 14 fishermen from Keb Thmey Fisheries Communityand 25 fishermen from Chang Hoan CFi, 10 middlemen, 2 chief communities from eachFisheries Communities were interviewed. The simple yields, moreover, were recorded inChang Hoan CFi every morning and Keb Thmey CFi in the evening for 4 months. The results showed that crab trap and trawling have been used in both areas for catching blue
swimmer crab, but trawling is not commonly used. In Keb Thmey CFi, the average yields
per day of blue swimmer crabs were caught by crab trap: 15.77 kg/boat in March, 16.45kg/boat in April, 13.93 kg/boat in May, and 8.09 kg/boat in June. On the other hand, trawling was used to collect blue swimmer crab in Chang Hoan CFi; in average were 1.01
kg/boat in March, 1.09 kg/boat in April, and 0.89 kg/boat in May. Whereas the yield fromthe crab traps were 6.72 kg/boat in March, 5.05 kg/boat in April, 5.05 kg/boat in May and4.44 kg/boat in June. Usually, blue swimmer crabs were classified into 3 classes. The firstand second classes were purchased by middlemen who delivered to the crab strip shop, retailer and Kampot and Vealrihn markets. The third class was sold to the crab peelers. Inconclusion, crab trap is commonly used for catching crab all year round. The variation oftotal is according to time, weather, place and the number of fishing gears. The averagecatch in March and April is more than that in May and June.
Keywords blue swimmer crab, crab trap, trawling, fishery community.

INTRODUCTION
Cambodia’s   coastal zone is an ecological system which provides high potential of mangroves,aquatic plants, fishes, water birds, mollusks, mammals, reptiles and so on that support to economics
such as tourism sector, industry sector, ports, navigation. Furthermore, this area has been providing
the local livelihood through fishing. Blue swimmer crab is considered as a kind of zooplankton
which lives in the marine water that is attractively fished nowadays as it is highly economic both inⒸISERD133

IJERD – International Journal of Environmental and Rural Development (2012) 3-2

local and international market. However, these species are decreasing both in size and in quantitywith the modern fishing gears as well as technologies, which affects the livelihood of people in thearea. So the study proposed to: (1) identify the kind of fishing gears and the way of fishing of blue
swimmer crab; (2) identify the average yield of blue swimmer crab; and (3) show the blue swimmer crab market.
METHODOLOGY
Study site: Two community fisheries such as Chang Hoan and Keb Thmey CFi which are locatedin Prek Thnot and Teuk Chhou district, Kampot Province were selected to conduct the research,
because it is the place where people fish blue swimmer crab and also the place for blue swimmer
crab market process.

Prek Tnout
KepThmey
ChangHoanBoeung
Touk

National road
PrekTnout
BoeungTouk

Fig. 1 Map of study area (JICA, 2005)
Sampling size and method: There were two different methods of data collection: conducting
interview and yields recording. Also, 3 kinds of questionnaire had been created for householdinterview including 39 fishermen (14 and 25 fishermen from Kep Thmey and Chang Hoan CFi,respectively), 10 middlemen, and 2 community chiefs from each CFi. These questionnaires wereused to compare on the concept and understanding of the fishermen and community chiefs as well
as middlemen in the area.
On other hand, the data of blue swimmer crab yields were recording every day during fourmonths with the all of the fishermen who fish blue swimmer crab. The data was recorded in themorning in Chang Hoan FCi from 7 fishermen by using trawling and 3 fishermen by using crab
traps. Moreover, 15 fishermen from Kep Thmey CFi were selected to record the yields which holdin the evening. Both primary and secondary data had been collected and analysed by using MS Excel.
RESULTS AND DISCUSSION
Blue swimming crab fishing
In the Chang Hoan CFi, fishermen have been using crab trap and trawling to catch blue swimmer
crabs and other fish species. However, fishermen in Kep Thmey CFi use only crab trap as a fishinggear to catch blue swimmer crabs. These fishing gears can be bought from the market or middlemen.
The technique of crab trap using
In the early morning about 4 or 5 a.m., the fishermen drive their boat to the fishing place. A boatowner is responsible for driving and other two crews are responsible for laying the traps into water
until completed (in the crab traps they put bait to attract crabs). In order to avoid the traps damageⒸISERD134

IJERD – International Journal of Environmental and Rural Development (2012) 3-2

by other fishing boat, the fishing gave any signal (at the beginning of string and the end of thestring). After laying the traps, fishermen park their board for relaxing 4 to 5 hours, then they start tocollect their traps, tie the crab with the rubber band, keep it in net, and come back to landing side.
After selling crabs to middlemen, fishermen prepared traps and facilities for fishing next day.

Fig. 3 TrawlingFig. 2 Crab trap
Technique of trawling using

At about 5 p.m., the fishermen go to their usual fishing place. They start to operate their task as
they have been doing for catching fishes. First, the fishermen opened the stick and tie it. Second,
they dropped the tail of trawling into water until finished. Next, the fishermen starts to drop wooden boards into the water and tie the rope with two sticks to open trawling surface and drove a bite
faster than before. To continue, they untied the rope from the sticks and lie on the water and allowing the boat to operate faster. This task took about 3 hours, then the fishermen drive slowly to lift
the trawling on the boat and come back to landing side. After selling crabs to the middlemen, fishermen prepared trawling and any facilities for fishing tomorrow.
Time and duration of fishing
The crab trap and trawling can be used all year round: night and day times. For the crab trap, mostly fishermen in the Kep Thmey CFi do their fishing activities a time per day. Generally, they gofishing early morning around 4 to 5 a.m. and come back around 4 to 5 p.m. Although, fishermen inChang Hoan CFi operate crab catching twice times a day. In the morning, fishermen go to fisharound 4 to 5 a.m. and come back around 8 to 9 a.m. About 1 or 2 p.m. fishermen go fishing again
and come back about 5 to 6 p.m. in the evening. For trawling fishing gear, fishermen usually gofishing at night from 4 p.m. to 6 a.m.
Table 1 The number of fishing days in the four monthsMonths

Number of fishing daysby crab trap (Kep Thmey)

Number of fishing days bycrab trap(Chang Hoan)

Number of fishing days bytrawling (Chang Hoan)

151618April

15

16

17May

20

18

17June1325-Total

63

75

52

16

1917MarchMean

Fishermen did not go to fishing every day during conducted research. In Kep Thmey CFi, thehighest number of fishing days was in May about 20 days while the lowest was 13 days. In contrast,
the highest number of fishing days in Chang Hoan CFi by crab trap was 25 days June which theⒸISERD

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trawling was about 18 days in March (there was no data in June) (Table.1). According to the survey,
the two major factors that affect the number of fishing days were climate conditions and holidays(New Year, weddings and other ceremonies) as well as lack of baits ( for crab trap activities).
Blue swimmer crab yield
The yield of blue swimmer crab by crab trap in Kep Thmey CFi: Fig.4 shows the averagecatches of blue swimmer crab from March, April and May were not different (15.77 kg/boat/day,
16.45 kg/boat/day, and 13.93 kg/boat/day, respectively), while the average catches in June was decreased ( about 8.09 kg/boat/day). During data collection period, which during rainy season, thetemperature and salinity were declined between May and June so most crabs move to the depth sea
or other places. In March, the average catches of second and third classes of blue swimmer crabs
were increased about 8 and 4 kg/boat/day while the first class was decreased about 2 kg/boat/day(fig.5). The average catches of crab size were changed in April, May and June. The variety of average catches by size is depending on life cycle and biology of blue swimmer crab.

Fig. 4 The average yield of blue swimmer
crab in 4 months

Fig. 5 The average yield of blue swimmer
crab by size in average in 4 months

The yield of blue swimmer crab by crab trap in Chang Hoan CFi: Fig. 6 shows that the average catches of blue swimmer crab by crab traps in Chang Hoan CFi were increased in March andApril around 7 kg/boat/day, but this yield was declined in May and June around 5 kg/boat/day. The
third class of blue swimmer crab was highest amount of all classes because fishermen operated at
the shallow water areas (Fig. 7).

Fig. 6 The average yield of blue swimmer
crab in 4 months

Fig. 7 The average yield of blue swimmer
crab by size in average in 4 months

The yield of blue swimmer crab by trawling in Chang Hoan CFi: By using trawling, the average catches of blue swimmer crab in Chang Hoan CFi were not different in three months about 1kg/boat/day (Fig.8). According to climate conditions, fishermen did not go fishing in June. In addition, most yields were first class (Fig.9). The total catches of blue swimmer crab by trawl gear wasⒸISERD136

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not high compared with crab trap, because the purpose of trawl activities does not catch only crabs
but also shrimp, squid, and other fish species.

Fig. 8 The average yield of blue swimmer
crab in 4 months

Fig. 9 The average yield of blue swimmer
crab by size in average in 3 months

Blue swimmer crab market
Blue swimmer crab market framework (Fig. 10) is related to fishermen, middlemen, crab strip shop
owner, consumers, and exportation middlemen.
Kep Thmey CFi Fishermen

Chang Hoan CFi Fishermen

2%Middlemen

Middlemen

18.77%
58%

Crab Strip
Shop

8.12%

76.67%

13.21%

13%

KampotMarketVealrihn
MarketCrab Peelers

All classes
Third classes, small andother crabs
First and second classes
Thailand andVietnam

SihanoukvilleConsumers

Fig. 10 Blue swimmer crab framework

Blue swimmer crab priceⒸISERD137

Crab meat

IJERD – International Journal of Environmental and Rural Development (2012) 3-2

Crabs were priced by the middlemen and it was rarely changed because most fishermen received
loans or fishery gears from them. Thus, the crabs should be sold out to the loaners who were themiddlemen.
Yet, other fishermen who did not get any loans also sold their crabs to the same person easierthan selling it by themselves or selling to others. The prices were different between the fishermen
who got loans and did not get loans. The middlemen sold to Kampot and Vealrihn market in higher
price. However, the price was not too different between buying from fishermen and selling to thecrab strip shop. Generally, the market price for the consumers and crabmeat selling are highest(Table 2).
Table 2 Price change of blue swimmer crab
MarketFirst Class(riel/kg)

SecondClass(riel/kg)

Third Class(riel/kg)

Small Crab(riel/kg)

Bought from fishermen ( loan)

15,0008,500

4,500500

Bought from fishermen ( no loan)

17,000

9,000

4,500

500

Sold to retailers at Kampot market

1,900

10,000--Sold to retailers at Vealrign market

1,900

10,000--Sold to crab strip shop

15,3008,800--

Sold to crab strip shop (no loan)

17,5009,500--

Sold to consumers

30,00015,000--Crabmeat selling

32,00025,00020,00010,000Price

CONCLUSION
Crab trap is a fishing gear that fishermen in the Kampot Province prefer to use in order to catchblue swimmer crabs. Although, the purpose if trawling is to catch shrimps and squids, but somecrabs can be caught by this gear too. The variation of total yield is according to time, weather,place and the number of fishing gears. Moreover, these gears can be use all year round dependingon time, place and climate conditions. According to local people surveyed, shows that the cause ofblue swimmer crab yields have declined because of fishermen using the small size of crab trap
mesh (2a = 4 cm) and the number of crab traps has been increasing in the last few years. Likewise,
the use of beach seine is a major cause of destroying the habitats and foods for crab and otheraquatic plants and animals. Blue swimmer crabs are clarified into three classes. The first and second classes are counted into high price to sell in markets and the crab strip shop by middlemen andthird class are sold to crab peelers. Middlemen play an important role in market finding to fishermen and loan.
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