11 UPPER SHIRE RIVER: THE FISH RESOURCES AND THEIR EXPLOITATION

11.1 CURRENT STATUS OF EXPLOITATION

Total annual catches from the Upper Shire River have declined from more than 1,200 tonnes in the early 1980s to the recent levels of around 500 tonnes (Table 11.1). This is due to a 10-fold decline in chambo catches, from 900 to less than 100 tonnes. Catches of other species have remained fairly constant, at around 250–400 tonnes. Since the mid-1980s, the number of fishing craft has fallen by half, while two-thirds of the chambo seine operators have dropped out the fishery.

Table 11.1 Trends in the fisheries of the Upper Shire River

Notes: catch (CAS) and craft (frame survey) estimates are 3-year running means; gear counts for 1982, 1987 are extrapolated and are not available prior to 1981. Column “Total” includes other fish caught.

The collapse of the chambo stock directly parallels that of Lake Malombe, probably because the chambo fishery of the Upper Shire was based on a stock of fish migrating from Lake Malawi into Lake Malombe. However, in Malombe, increased kambuzi catches have provided compensation for the decline of chambo. In the Upper Shire, by contrast, the whole fishery has declined. It is apparent that the fishery had expanded to a level which far exceeded the sustainability of the river's own production. The productivity of the river has probably been further reduced by the elimination, by seining, of weed beds and reeds (D. Tweddle, pers. comm.) which provided refuges for fish fry and helped to maintain benthic production by the trapping of silt. Since it appears that the small kambuzi species do not migrate through the river, the whole fishery has declined.

11.2 EFFECTIVENESS OF PREVIOUS MANAGEMENT STRATEGIES

Enforcement of fisheries regulations has been spectacularly unsuccessful on the Upper Shire river. Headline lengths, mesh sizes and depths of seines are all restricted on the river. All chambo seines, most nkacha nets and half of the kambuzi seines presently operating are illegal. In addition, the river is closed to seining for 5 months, from November to March. The closed season is not observed. The principal gear in use on the river is a short chambo seine, with a headline length of less than 300m (97%), and a mesh size of 76–90mm (100%). Only 18% of chambo seines in the south-east arm of Lake Malawi and Lake Malombe have such short headlines, and most of these have smaller meshes. It is likely that in the lakes, large chambo are too far offshore to be economically exploited by gears of the dimensions used in the river. Thus, during the closed season, fishermen are unable to move their gears elsewhere. Given that the closed season occurs during the months of greatest economic hardship, prior to the harvest, and during the months of peak chambo density in the river (Seisay et al., 1992b), it is not surprising that enforcement has proved unworkable.

11.3 SOCIAL AND ECONOMIC CONSEQUENCES OF THE DECLINE OF THE FISHERY

The project frame survey in January 1990 (Alimoso et al., 1990) recorded 111 craft and 113 gear and craft owners operating on the Upper Shire River - thus the number of craft accurately reflects the number of entrepreneurs. It is probable that half of the entrepreneurs previously operating on the river had to move or give up fishing (Table 11.1).

In 1991, chambo seines required an average of 9 crew members, and kambuzi and nkacha seines 5.5. Employment in gillnet and trap fisheries is negligible (10–20 people for the whole river). Using the 1991 figures on crew size, a comparison of the averages of 1990–91 and 1985–86 frame surveys indicates that approximately 1,000 crew members, about 57% of the total, have lost their employment, or been forced to move. There is no indication that the decline in chambo catches has been arrested. At present, 60% of fisherman-entrepreneurs are fully, and 9% partly, dependent on chambo-catching gear (chambo seines and gillnets), which employ 70% of the crew members.

The total value of the catch (in 1991 prices) has declined from around MK 1.5 million in the early 1980s to approximately MK 300,000 - a drop of 80%. The average earnings per fishing craft has declined from MK 14,000 to MK 3,000 per annum. However, earnings are not spread evenly across all types of fishing activities: the nkacha fishery accounts for 60% of the total cash value of the catch of the river, and the chambo seine 39%.

Although a detailed cost breakdown of fishing operations of the Upper Shire is not available, this was derived from data for similar operations on Lake Malombe (Table 11.2a). Even assuming that fishing activity has been under-recorded during closed season months (Table 11.2b), kambuzi seine and gillnet operations appear to run at a loss. The profitability of the chambo seine, the main employer on the river, is marginal. The estimated crew incomes for gillnet, chambo seine and kambuzi seine operations are extremely low. However, the reduction in employment in the river fisheries may have made crew members more willing to accept low wages. Nevertheless, it is inconceivable that crew members would work for MK 8 per year, and it seems likely that this is the explanation for the low activities of the chambo and kambuzi seines.

At present, only the nkacha fishery is operating at a reasonable profit margin - most of these nets are based on the southern part of the river, and probably fish mainly in Lake Malombe.

Thus, all fisheries on the river are operating uneconomically, and their continuing operation probably depends largely on transfer of funds from other business activities on the part of the entrepreneurs, in the hope of a recovery in the future. Further declines in fishing effort are likely, and most chambo and kambuzi seines will probably cease operations in the near future - leading to unemployment of perhaps 70% of the present crew numbers. The majority of chambo seines on use in the river are short, large-meshed nets, which are rarely employed elsewhere, presumably because in other areas chambo are not caught in inshore water in such large numbers as was formerly the case in the river. Thus, entrepreneurs will be unable to transfer their operations to Lakes Malawi or Malombe, without investing in new gears.

Table 11.2 Annual estimates of activity and economic performance of fishing on the Upper Shire River.

Notes: assumes 2/3 share for owner, costs for chambo seine are as for kambuzi seine in Lake Malombe, crew numbers GN=2, CS=9, KS=6, NK=5, extrapolation to closed season months where gears not recorded, was using mean activity level and earnings for rest of year.

11.4 EFFECTS OF THE CLOSURE OF THE MIDDLE SHIRE RIVER

The Middle Shire river is closed to fishing from its origin in Lake Malombe until the southern boundary of Liwonde National Park, a few hundred meters north of Liwonde Barrage. There is strong circumstantial evidence that the closure of this stretch of river have a beneficial effect on the fisheries of Lake Malombe. At present, all remaining chambo seines operating in Lake Malombe are located at the southern tip of the lake, in the vicinity of the river outflow, whereas previously they were distributed throughout the lake. In 1991 these nets caught 31 tonnes of chambo and 22 tonnes of other species. In the southeastern part of the lake, there is an important seasonal gillnet fishery for nchila (Labeo mesops): 250 tonnes of this species were caught in 1991. This is the last remaining fishery for what was, prior to its collapse in the 1960s, the second most important fish species caught in Lakes Malawi and Malombe. Thus, the existence of these two fisheries, which yield an equivalent of 60% of the total of the Upper Shire river catch, can be attributed to the closure of the Middle Shire river, and the protection of its catchment area. In addition, the gillnet fisheries (for chambo, other tilapias and catfish), and the kambuzi/nkacha fisheries almost certainly benefit from the reserve, while a lucrative small-scale fishery for high value cyprinids, catfish & tilapiine species is conspicuously active (but unmonitored) on the Liwonde Barrage itself.

Thus, it seems probable that the closed stretch of the Middle Shire contributes at least as much to the overall fish catch of Malawi as does the heavily-fished Upper Shire, while conserving many fish species whose populations are severely reduced in other areas.

11.5 SUMMARY AND RECOMMENDATIONS

The yield of the seine net fisheries of the Upper Shire has declined, with disastrous social and economic consequences, as a result of the collapse of the chambo stock. The fishery is presently uneconomical and will probably continue to decline. Previous regulations were unenforced and largely impracticable. The residual fishery is likely to inhibit any recovery by chambo stocks in Lake Malombe. Considering the beneficial effects of the closure of a stretch of the Middle Shire river on Lake Malombe's fisheries, it is recommended that all seining should be effects of the closure of a stretch of the Middle Shire river on Lake Malombe's fisheries, it is recommended that all seining should be prohibited on the Upper Shire river. Gillnets, traps and angling should be permitted. Existing nkacha units should be permitted to move to Lake Malombe, where they would be subject to the mesh size and headline length restrictions operating for that lake.

Figure 12.1 Lake Malawi, south-east arm. All gears. Relationship between chambo catch and effort for 1976–81 and 1987–91. Data for 1982–86 are exceptionally high for uncertain reasons and have been left out of the relationship (Schaefer: gillnet CPUE = 5.75 - 0.002 effort, r = -0.94, MSY = 4180, f_msy = 1450. Fox: elog gillnet CPUE = 2.0 - 0.0007 effort, r = -0.95, MSY = 4020, f_msy = 1480).

Figure 12.2 Prediction of yield curves for the fisheries on the three chambo species: Oreochromis lidole, O. squamipinnis and O. karongae based on the Thompson and Bell model. Effort is expressed as a percentage of the present effort level (= 100%). MSY, in all cases, is reached at effort levels lower than the present. Lake Malawi, south-east arm.