Status of Grouper Aquaculture and Live Marine Fish
Trade
in Sri Lanka
S. C. Jayamanne[1]
Abstract
Sri
Lanka is an island with a coastline of 1,585 km. The coastal ecosystems provide ideal habitats for marine
fishes. Juveniles of marine fishes such
as groupers (serranids), rabbitfishes (siganids), wrasses (labrids) and
snappers (lutjanids) are marine fishes that are exploited and exported to
Taiwan, Hong Kong, Malaysia and Thailand for aquaculture industries and the
aquarium trade. The trade of these
marine fishes, which began in 1986, was variable in numbers and value. Trade had peaks in abundance and value in
1989 and 1993. In 1996, exports of
these fishes were valued at 2,000,000 rupees.
While lucrative and providing employment for many people, trade in live
marine fishes has caused high exploitation rate and habitat destruction. It is believed that aquaculture will address
some of these problems and the variability of the catch for exports. At present, the major constraint for the
development of aquaculture is the lack of knowledge on the life histories of marine
fisheries. The other limitations are
lack of technical knowledge in the mass-breeding and rearing of juveniles, lack
of adequate resources, and other facilities.
To address these constraints, the National Aquatic Resources Research
and Development Agency (NARA) has identified research on early life history,
behaviour, and ecology of high priority.
Sea-farming and mass-breeding for marine fishes are also planned with
external assistance. Training of research personnel is desired through regional
co-operative programmes.
Introduction
Sri Lanka is an island
located 40 km off the southeast coast of India in the Indian Ocean (Figure
1). The maritime waters around the
island are 230,000 km2 and are greater than its land area
(65,000). The coastline is about 1,585
km and supports highly productive ecosystems such as the mangroves, marshlands,
coral reefs, and seagrass beds. There
are 45 river basin estuaries and 40 lagoons that lined with mangroves and cover
about 160,000 ha. All the coral reefs
and seagrass beds are located within 25 to 30 km from the shore and contribute
to the fisheries production. In terms
of species richness, there are 39 species of serranids, 7 siganids, 33 labrids,
42 lutjanids, and 2 latids that were recorded in Sri Lanka that are contribute
to the fisheries production (de Bruin et al., 1995).
The climate in Sri Lanka is
driven by the monsoons. The southwest
monsoon, that prevails from May to September, brings rains to south and west
coasts while the northeast monsoon, brings rains to east and north coasts from
November to March.
Since the last decade, the
coastal ecosystems were exploited for ornamental fishes that were
exported. The seagrass beds were also
exploited for juveniles of marine fishes that may be cultured and then
exported. Majority of these species
that were exported for the aquarium and aquaculture belong to the family
Serranidae. In addition, Scatophagus
argus (Scatophagidae) and Monodactylus argentius (Monodactylidae)
are also being exported as ornamental fishes.
Juveniles of these two species and some serranids are found in shallow
seagrass beds of the lagoons and estuaries.
They are caught by gears such as brush parks and push nets.
Figure 1. Important recorded coral reef locations in
Sri Lanka surveyed by NARA.
Overview of the live marine fish trade and marine fish
aquaculture
The history of live marine
fish trade in Sri Lanka began in the 1950s.
The export of marine fishes was followed by the export of juveniles of
estuarine species, the Monodactylus argentius and Scatophagus argus. These two species were exported as
ornamental fishes. Export of edible
marine fishes started in 1987 and the trade increased due to high demand in the
world market. Today, Sri Lanka is a
regular supplier of live marine fish to the international market (Directory of
the Asso. Trop. Fish Exporters of Sri Lanka, 1992).
Aquaculture of marine fishes
is not practised in Sri Lanka. The
government, however, has recognized the potential for marine fish aquaculture
and has included sea farming as one of the areas for future development. Research into development of technology for
mass breeding of M. argentius and S. argus has already started
this year. Lates calcarifer
and Epinephelus tauvina have also been identified as the two major species
to be cultured.
As such, the present live
fish trade in Sri Lanka is based primarily on wild-caught fish and
mass-breeding of fishes. Most serranid
species are exported for both the live fish trade and for the aquarium trade. Breeding of these fishes is also done during
the onset of monsoonal rains. Fishermen
catch juvenile marine fishes from the south and west coasts from October to
April while the catches for the remaining months come for the east coast. This ensures a regular supply for the export
market. Unfortunately, no statutory
body maintains accurate records of species numbers of fishes exported.
The Association of Tropical
Fish Exporters of Sri Lanka has gathered and kept information on the
trade. There are five private
enterprises in the country that engaged in the export of live marine fish for
aquaculture. The major species that are
exported are Epinephelus malabaricus and E. tauvina that are
exported to Singapore, Taiwan, Hong Kong and Malaysia. Exports are variable, indicating catches are
from the wild, and peaked in 1989 and 1993 (Table 1; data from *Aqua Blue
Lagoon, **Wet Pet (pvt) Ltd.). The
groupers exported ranged from 2.54 cm to 20.32 cm but demand is highest for the
small sizes that ranged from 2.54 to 10.16 cm.
Table 1.
Export data of grouper fry and juveniles during past decade
Year
|
Number Exported* |
Value (in SLR) |
Number Exported** |
Value (in SLR) |
|
1986 |
125,000 |
750,000 |
NA |
|
|
1987 |
150,000 |
1,000,000 |
NA |
|
|
1988 |
250,000 |
1,500,000 |
NA |
|
|
1989 |
1,800,000 |
9,000,000 |
NA |
|
|
1990 |
140,000 |
1,000,000 |
NA |
|
|
1991 |
100,000 |
600,000 |
NA |
|
|
1992 |
130,000 |
800,000 |
NA |
|
|
1993 |
920,000 |
5,500,000 |
150,000 |
900,000 |
|
1994 |
100,000 |
700,000 |
80,00 |
500,000 |
|
1995 |
125,000 |
800,000 |
40,000 |
200,000 |
|
1996 |
330,000 |
2,000,000 |
Nil |
Nil |
A wide variety of serranids
and coral reef fishes are exported by Sri Lanka for the aquarium fish trade (de
Bruin et al., 1995; pers. comm.).
These species are found in coral reefs, sandstones, muddy bottoms and
other nearshore habitats (Table 2; data from De Bruin et al., 1995 and
personal communication from fish live marine fish exporters).
Table 2.
List of the species of live marine fish exported from Sri Lanka for
ornamental trade.
|
Family |
Species |
Habitat |
|
Serranidae |
Aethaloperca rogaa |
Hard bottom |
|
|
Cephalopholis argus |
Coral and sponge banks |
|
|
C. aurantia |
Rocky and coral bottoms |
|
|
C. boenak |
Coral reefs and Sandstone flats |
|
|
C. formosa |
Hard bottom of Coral |
|
|
C. leopardus |
hard bottom of coral |
|
|
C. miniata |
Coral reefs |
|
|
C. sexmaculata |
Coral and Sandstones |
|
|
C. sonnerati |
Coral and Sandstones |
|
|
C. urodeta |
Coral reefs |
|
|
Cromileptes altivelis |
Coral and sandstones |
|
|
Epinephelus areolatus |
Coral and hard sandstones |
|
|
E. bleekeri |
Coral reefs and deeper sandstones |
|
|
E. caeruleopunctatus |
Coral reef and sandstone banks |
|
|
E. chlorostigma |
Sandstones and corals |
|
|
E. coioides |
Hard and soft bottoms |
|
|
E. diacanthus |
Muddy bottoms |
|
|
E. erythrurus |
Muddy bottoms |
|
|
E. fasciatus |
Coral and sandstones |
|
|
E. faveatus |
Coral reefs |
|
|
E. flavocaeruleus |
Coral reefs and sandstones |
|
|
E. fuscoguttatus |
Coral reefs |
|
|
E. hexagonatus |
Coral reefs |
|
|
E. lanceolatus |
Hard bottoms and caves in sandstones |
|
|
E. latifasciatus |
Coastal areas and mud bottoms |
|
|
E. longispinis |
Coral reefs and rocky substrata |
|
|
E. merra |
Coral and sandstones |
|
|
E. poecilonotus |
Deeper water |
|
|
E. radiatus |
Deeper water |
|
|
E. tukula |
Sandstone reefs near great basses |
|
|
E. undulosus |
Sandstones and Coral reefs |
|
|
Grammistes sexlineatus |
Coral reefs |
|
|
Plectropomus laevis |
Coral and sponge reefs |
|
|
P. pessuliferus |
Coral and sponge reefs |
|
Siganidae |
Siganus javus |
Sand stones and coral reefs |
|
|
S. canaliculatus |
Demersal neritic |
|
|
S. vermiculatus |
Demersal neritic, juveniles in lagoons |
|
Labridae |
Anampses meleagrides |
Coral reefs |
|
|
Cheilio inermis |
Coral reef and weed banks |
|
|
Coris africana |
Coral reefs and weeds |
|
|
C. ayqaimardgula |
Coral reefs and weed banks |
|
|
C. frerei |
Coral reefs and weed banks |
|
|
Gomphosus caeruleus |
Coral and rocky reefs |
|
|
Labroides dimidiatus |
Coral and rocky reefs |
|
Lutjanidae |
Lutjanus sebae |
Coral and sandstones |
|
|
Macolor sp. |
Shallow Coral reefs |
Environmental
impacts and management
Exploitation of ornamental
and culturable fish from natural habitats has caused a considerable damage to
the seagrass. The use of push nets and
dragnets in collecting juveniles of Epinephelus sp. from the shallow
areas and seagrass beds of the lagoons and estuaries are damaging. The extent of damage caused by these nets on
the seagrass beds are not known.
The exploitation of reef
fishes for the live marine fish trade is one of the major environmental
problems in the coral reefs. The indiscriminate use of nets and hand netting
while diving contribute to the high exploitation rate on reef fishes.
Furthermore, the coral reef fish populations are threatened by habitat
destruction with the use of explosives and coral mining.
Collection of live marine
fish for export has become a livelihood for many fishermen in the country. The latest statistics report that there are
800,000-1,000,000 people are involved in the marine fish trade. This includes divers, fishermen, and
suppliers of raw materials for live marine fish trade and their families.
In Sri Lanka, numerous
government institutes are involved in the control of activities within the
coastal areas. The government
institutes which are directly responsible for the development, conservation and
management of the marine ecosystems include the Coast Conservation Department
(CCD), Central Environmental Authority (CEA), Ministry of Fisheries and Aquatic
Resources (MOFAR), Department of Wild Life Conservation (DWLC), and National
Aquatic Resources Research and Development Agency (NARA). Protection of the
marine environment for sustainable development has been documented as a
national policy and priority since the creation of NARA and CCD in the early
1980s.
Environmental problems were
first addressed in the Coastal Zone Management Plan (CCD, 1990) and more
recently in the policy document entitled Coastal 2000: A Resource Management
Strategy for Sri Lanka’s Coastal Region (Olsen et al., 1992). The latter
document calls for a decentralised and participatory approach to management of
coral reefs and other resources.
One of the strategies in
dealing environmental problems in the coral reefs is by establishing marine
parks. The inter-ministerial committee
formed by NARA in the 1980s has identified more than 20 marine and coastal
sites around the island to be declared as marine reserves or sanctuaries. Only Hikkaduwa Marine Sanctuary in the
southwest coast and the Bar Reef Marine Sanctuary off the northwest coast are
legally protected. However, even in
these 2 parks, the destruction of the coral reefs continue due to lack of
proper enforcement strategies, adequate funds, and public concern (Rajasuriya
and White, 1995).
Constraints to
grouper and other coral reef fish aquaculture
Sri Lanka only recently
investigated the potential of developing aquaculture. It was found out that the lack of knowledge on life histories of
marine fishes was the major constraint in developing mass culture of these species. Technical skills on breeding and rearing of
juveniles and lack of adequate funds and facilities also remain as major
constraints in developing the aquaculture industry.
Recommendations
NARA has
identified steps in addressing the restrictions in developing aquaculture in
Sri Lanka. Research on the life
history, behaviour, and natural habitats of important marine fish species has
been identified as a priority. Sea-farming
is focusing on the culture and mass breeding of sea bass and commencing in 1997. Expansion of this project for other marine
species is anticipated through funding from external sources. Training of research personnel is expected
through regional co-operative programmes.
Literature Cited
Coastal
Conservation Department. 1990. Coastal zone management. CCD and Coastal Resources Management Project
of the University of Rhode Island Colombo Plan.
De Bruin, G.
H. P., B. C. Russel, and A. Bogusch.
1995. FAO Species identification
field guide for fishery purposes. The
marine fishery resources of Sri Lanka, Rome.
FAO. 400 pp. 32 plates.
Olsen, S., D.
Sadacharan, D., H. I. Samarakoon, A. T. White, H. J. M. Wickermeratne, and M.
S. Wijeratene. 1992. Coastal 2000: A resource management strategy
for Sri Lanka’s coastal region. 2 volumes. Coastal Resources Management Project and
CCD, Sri Lanka. 21-81 pp.
Rajasuriya,
A., and A. T. White. 1995. Coral reefs
of Sri Lanka: Review of their extent, condition, and management status. Coast.
Mgmt. 23: 77-90.
Rajasuriya,
A., N. W. R. N. de Silva, and M. C. Ohmen. 1995. Coral reefs of Sri Lanka: Human disturbance and management
issues. Ambio 24(7-8):428-437.
Samarakoon, J.
I. and L. Pinto. MS. Synthesis report for information on coastal
habitats in Sri Lanka, Coastal Conservation Department and Coastal Resources
Management Project, Colombo.
Wanniarachchi,
P. K. 1995. Controlled export through natural resources. Aquarist 1(April).