FAO Fisheries Circular No. 920 FIRM/C920
REVIEW OF THE STATE OF WORLD FISHERY RESOURCES: MARINE FISHERIES
Marine Resources Service,
Fishery Resources Division,
FAO, Rome, Italy
9. EASTERN INDIAN OCEAN
FAO Statistical Area 57
The Eastern Indian Ocean (Figure B9.1) includes the Bay of Bengal in the north, the Andaman Sea and northern part of the Malacca Straits in the east, and the waters around the west and south of Australia. The main shelf areas include those of the Bays of Bengal and Martaban and the narrower shelf areas on the western and southern sides of Indonesia and Australia. Most of the coastal fisheries are concentrated in these shelf areas and are the main fisheries in the region. The resources range from typical tropical species found in the northern part of the area to temperate species in the waters of the southern latitudes west and south of Australia.
The fisheries of the Eastern Indian Ocean are characterized by increased fishing pressure, especially in inshore areas. The coastal areas off the east of India, the west of Thailand and the south coast of central Java are good examples of areas where fishing pressure has kept increasing. Knowledge of the fish stocks is generally poor and management actions taken have usually been on an ad hoc basis, in most cases with lack of scientific backup.
PROFILE OF CATCHES
Catches in this region have increased since 1950. In the mid 1970s the rate of increase nearly doubled and has remained at a higher level since, although catches in 1993 to 1994 were stabilized. Catches of five countries (India, Indonesia, Malaysia, Myanmar and Thailand) accounted for 90% of the total in 1994. The absence of Bangladesh as a major marine fishing nation, despite a large population, is due to the historical focus on the large freshwater fishery resources. The catches of Australia made up only 3% of total catches by weight but contributed a much higher proportion in terms of their economic value.
Seven major ISSCAAP Groups account for 84% of the total catches: miscellaneous
marine fishes (39); redfishes (33); herrings (35); jacks (34); mackerels (37);
tunas (36) and shrimps (45) (Figure B9.2 and Table
IX). The catch reported as miscellaneous fishes (principally made up of
small fishes and juveniles of some high-valued fishes) accounted for 39% of
the total catches in 1994. Although the continued increase of catch of this
group may indicate the augmented fishing pressure, the relatively high figure
has been also caused by the incomplete or poor statistical collection of some
member countries, on which assistance is needed.
|Figure B9.3||Figure B9.4|
The rate of increase of catches by ISSCAAP Groups generally shows the same trend as that of total catches, with a slow increase from 1950 to 1970, followed by a more rapid increase in the last 20 or so years. However, the rate of increase in catches of shrimp has slowed since the early 1980s while catches of shads have apparently climbed sharply since the early 1980s (Figure B9.5). The slowing rate of increases of shrimp catches is thought to be due to local overexploitation of the resource (see below). Shads are traditionally the main catches of marine fisheries in Bangladesh. The sudden increase in catches in the mid-1980s is an artifact caused by the fact that Bangladeshi statistics on shad catches started in 1984.
RESOURCE STATUS AND MANAGEMENT
Most of the catch from coastal fisheries is used for local consumption. Fish are generally considered an affordable source of protein by most people in the region. Shrimp and tuna are the main export commodities. Overexploitation of shrimp resources in coastal waters have reduced the amount of exports from capture fisheries, and there is a growing tendency for exports to come from the aquaculture sector in almost all countries in the region. While the majority of tuna catches are from coastal fisheries, the skipjack and yellowfin tuna, which form the major part of the tuna exports, are caught offshore. During the last decade some countries have developed offshore fishing for tuna, notably longlining in the case of Indonesia and purse seining in the case of Thailand.
Though squid is commercially important, its production is small, with only Thailand producing relatively high catches (40 000 t in 1994 compared to only 15 000 t in 1984). Thailand contributed more than 50% of the total catch. Some of the Thai fleets have also expanded to fish in other countries through various joint agreements. It is likely that potential for development of this fisheries exists in the region, although further work is still needed in assessing the resources, in addition to the familiarity with the fishing technique.
Overexploitation of the resources in coastal waters is very much related to the population pressure in the coastal area. With the limited access of waste treatment in most countries in the region, organic material and nutrification seems to be the major problem in aquatic pollution. The cyclones that enter the Bay of Bengal are a considerable natural hazard to fishers, particularly given the absence of good weather forecasts and the poor level of electronic equipment on most fishing vessels. There is a resulting high casualty among fishermen during the cyclone season.
The main fisheries in the southern part of the Eastern Indian Ocean are the fisheries off the west and southwest of Australia. The lobster fishery is one of the important fisheries in this area. The fisheries have been relatively steady since 1980s and the catch in 1994 amounted to 16 000 t. On the other hand, tuna catches that had climbed up and reached the peak of 19 700 t in 1985, have declined since, and the catch in 1994 amounted to 5 900 t. In response to the decline, Australia has promoted the management of the southern bluefin tuna where Japan and New Zealand have also participated. The trend in catches of the herrings group (ISSCAAP Group 35) showed a similar pattern as the tuna catch, with the peak in 1989 of 17 000 t after which the catch declined and in 1994 the catch was about 11 000 t. It is not clear whether the decline is attributable to either the increase of fishing pressure or environmental changes or both.
The trend of catches of miscellaneous fishes (ISSCAAP Group 39) shows an interesting feature. The peak catches of about 28 000 t occurred in 1975 and 1993 but in between the catch was as low as 1 000 t (in 1985). A similar pattern is seen in the catch of scallops (ISSCAAP Group 55), which showed peaks in 1984 and 1993 of about 27 000 t but in 1989 catches were down to 1 000 t. No clear explanation could be found for this pattern of catches of these two resource groups.