Report of the Frame Survey of Lake Albert conducted in May 2012

Lake Albert and Albert Nile are a major source of fisheries resources sustaining the riparian communities in Uganda and the Democratic Republic of Congo (DRC). Like all shared bodies of Uganda Lake Albert and Albert Nile fisheries are faced with immense exploitation pressure one time described as the tragedy of the commons. In Uganda, the lake is shared by five riparian districts namely: Buliisa, Bundibugyo, Hoima, Kibaale and Nebbi. The lake covers a total estimated surface area of 5,270 square kilometers with approximately 60% within Ugandan waters. It is located in the western part of the great rift-valley at an altitude of 618 m above Sea level. The central parts of the lake are characterized by steep escarpments whereas the northern and southern parts lie in a plain of the rift valley. The plains are gently sloping, resulting in shallow swampy inshore waters in many places. The major inflowing rivers are the Semliki and Kafu in the south, and the Victoria Nile at the northern tip. The lake has a diverse fish fauna with a gradient of multi-species fisheries in different parts of the lake. The overall objective of the Frame Survey was to provide information on the facilities and services at landing sites and the composition, magnitude and distribution of fishing effort to guide development and management of the fisheries resources of Lake Albert and Albert Nile. The specific objectives were to provide information on: a) The number of fish landing sites; b) The facilities available at the fish landing sites to service the sector including accessibility; c) The service providers especially fisheries staff at fish landing sites; d) The number of fishers; e) The number and types of fishing crafts and their mode of propulsion; f) The number, types and sizes of fishing gears used on the lake and their mode of operation.

Assessment and possible development of the fishery resources of Pedro Bank

Pedro Bank is about 1,300 square miles in extent and lies at the mouth of the Palk Strait close to the mainland, enabling smaller boats to exploit it. Trawl surveys indicated the presence of substantial demersal varieties on the Pedro Bank, but the results of the early commercial operations indicate that a 135-foot trawler may not be operated continuously on the bank without diminishing returns. Subsequent to the commercial operations extensive surveys with smaller boats and various types of gear were carried out. Of the various types of gear tried out, results from bottom long lining and hand lining operations were promising. Trials were carried out to compare these two types of gear. Though not extensive, these trials indicated that at the initial stages of exploitation of the Bank, hand lining, which is extensively practiced in Ceylon, may be better but as exploitation progresses; with more experience, it should be possible to overcome some of the present disadvantages of bottom long lining and eventually bottom long lining should produce better results. The recently introduced mechanised craft are exploiting only the fringe of the bank and it should be possible to exploit its stocks fully with slightly bigger boats with a 35-40 mile range.

A Contribution to the limnology of Colombo Lake

This paper records the results of investigations of plankton, benthic fauna and fish fauna carried out between 1957 and 1963. The standing crop of net plankton in the lake was found to be 249.6 Kg/ha. This plankton is not being fully utilized by the fish fauna in the lake. Stocking the lake with a plankton feeder like Chanos chanos (Forskal) is recommended. The figure of 24.37 Kg/ha obtained for the standing crop of bottom fauna in the lake was comparatively low. This indicates that the bottom fauna is being fully utilized by the fish. The introduction and establishment of Tilapia mossambica (Peters) had not wiped out a single indigenous species of fish from the lake that produces about 2,000 lbs. of fish per acre per year. This can be increased by the introduction of a plankton feeder (Chanos chanos), and by further exploitation of existing stock.

Predation of tuna longline catches in the Indian Ocean, by killer-whales and sharks

Since the inception of the tuna long line fishery in the Indian Ocean in 1952, an annual average of 10% of the number of tunas and spear fishes caught continues to be damaged by sharks. In spite of the fact that this method of fishing for tunas is also resulting in the exploitation of a significant quantity of the tuna-preying sharks, the extent of the damage by these predators continues to be fairly constant. Quite often the damaged tunas are acceptable to the market, especially for canning. On the other hand report of damage caused by killer-whales, occasional at the beginning of the fishery in the Indian Ocean, has been increasing in frequency each year and since 1960 tuna fishermen have been desperately calling for ways and means of reducing the damage caused by these mammals. Unlike sharks killer-whales do not get hooked on the tuna long line; and tunas damaged by killer-whales are almost always unfit even for canning. The problem of predation by killer-whales exists not only in the whole of the Indian Ocean including the Timor and Banda Seas but also in the Atlantic and Pacific Oceans, especially in the seas around New Guinea, Samoa, Caroline and Marshal Islands. The seriousness of this problem of predation was highlighted at the annual tuna research conference held in Kochi, Japan, in February 1963, and steps were taken to devote considerable attention to this problem.

Exploiting variable-width features in large vocabulary speech recognition

The use of variable-width features (prosodics, broad structural information etc.) in large vocabulary speech recognition systems is discussed. Although the value of this sort of information has been recognized in the past, previous approaches have not been widely used in speech systems because either they have not been robust enough for realistic, large vocabulary tasks or they have been limited to certain recognizer architectures. A framework for the use of variable-width features is presented which employs the N-Best algorithm with the features being applied in a post-processing phase. The framework is flexible and widely applicable, giving greater scope for exploitation of the features than previous approaches. Large vocabulary speech recognition experiments using TIMIT show that the application of variable-width features has potential benefits.

A Preliminary survey of 21 Ceylon lakes. 1. Fisheries of two lakes, Parakrama Samudra and Minneriya Wewa

Fourteen species of indigenous fish and three species of introduced fish commonly used for food are present in Parakrama Samudra and Minneriya Wewa. Commercial fishing is done throughout the year in these two lakes by gill nets, shore-seines ("Ma-del" nets) and cast nets. From records of fish landings maintained from 1957 it is seen that the production of fish at Parakrama Samudra has increased from 41 pounds per acre per annum in 1957 to 117 pounds per acre per annum in 1962 and at Minneriya Wewa from 11 pounds per acre per annum in 1957 to 118 pounds per acre per annum in 1962. Tilapia mossambica formed the chief constituent of the catch at both these lakes and it was due to this fish that the commercial fisheries at both these places were successful. It is recommended that fishing effort be further increased in both these lakes and records be kept to note any tendency towards over-exploitation.

Resources of the Wadge and Pedro Banks

Sri Lanka's interest in trawler fishing dates back to 1902 when a Colombo merchant attempted to operate a trawler off Sri Lanka's waters. The next attempt was made in 1907. These attempts did not proceed any further. Between 1920 and 1923 a very comprehensive survey of the littoral waters around the island was carried out. One of the principal aims of the survey was to investigate the possibility of trawler fishing in the seas around. Malpas (1926) and Pearson and Malpas (1926) reporting the results of the survey indicated that the Wadge and Pedro banks were the only areas available for commercial trawler operations and indicated that the fish resources in the two banks could be profitably exploited. Commercial exploitation of the Wadge bank commenced in 1928 and a fishery is now firmly established in the bank. The Marine Biologist and the Director of fisheries in their administration reports and Sivalingam and Medcof (1957) and the author (1965) have reported on the progress of the Wadge bank fishery. Some of the trends indicated by an analysis of the records of the commercial trawling operations are further discussed in this paper.

Brackish-water fishery resources

Ceylon has about 300,000 acres of coastal brackish-water areas of which about 100,000 acres constitute shallow lagoons, tidal flats, mangrove swamps and saline marshes, and the rest deeper lagoons and estuaries. While the former represent a vast potential resource with regard to fish farming, the latter are the sites of important fisheries. W. H. Schuster (1951) estimated the average natural production of Ceylon’s brackish waters to be less than 20 lbs. per acre per annum. Since then estimates have been made by the author for a rich lagoon, the Negombo lagoon, a poorly productive lagoon, the Ratgama lake (Dodanduwa) and studies are in progress of some of the other lagoons. The natural production of the Ratgama lake was estimated in 1959 to be 18.5 lbs. per acre per annum while that of Negombo lagoon was estimated in 1960 to be 65 lbs. per acre per annum. It is reasonable to estimate the average production of Ceylon's brackish-waters to be 25 lbs. per acre per annum. Thus the total production is about 3,350 tons per annum. Considering the fact that the island's present total production is 90,000 tons per annum, the brackish-waters contribute 3.7% of it. Schuster (1951) further states that the natural production in the brackish-waters of other countries is around 80 lbs. per acre per annum. In order to increase our average natural production to this value it would seem necessary to consider the nature, biology and fish resources of the brackish-waters and draw some conclusions with regard to their proper exploitation.

New evidences on the distribution of predatory pelagic sharks in the tuna grounds of the Indian Ocean

Since the commencement of the exploitation of oceanic tuna resources of the Indian Ocean seventeen years ago, the hooked rates for the tuna species have declined in many areas of the Ocean but there are no evidences of such a trend in the case of the sharks. As a result, the percentage composition of sharks in the longline catches and the percentage of the tuna catch damaged by sharks show an increase. Hence there is an urgent need for innovation of the existing longline gear in order to increase the fishing efficiency for hooking the tuna species with a corresponding reduction in its efficiency for hooking sharks. At the beginning of this fishery, hooked sharks were discarded at sea, at a later stage the liver and fins were taken and the carcass discarded and presently the sharks are also brought along with the tuna catch. Though the shark meat has a very low market value it is brought in order to cover up for the declining tuna catches. Thus it has become very necessary to increase the demand for shark meat by developing products or by-products utilizing shark meat and ensuring the successful continuity of the tuna longline fishery. The pattern of distribution of shark species in the time grounds of the Pacific, Indian and Atlantic Oceans and also the predation of hooked tunas by sharks were discussed earlier (Sivasubranianiam 1963, 1964 and 1966). Some contribution to these studies is made in this paper based on new data become available.

An aerial survey for surface tuna resources in the seas around Ceylon

An aerial survey of the off shore range around Ceylon, for a quick evaluation of the potential surface tuna resources, for commercial exploitation, was organised by Mr. Manuel R. Cintas of Ocean Blazer Inc. (Commercial tuna), San Diego, California and his associate Mr. R. Perera. The organisers offered, through the Hon'ble Minister of Fisheries, to take an officer of the Fisheries Research Station, Ceylon, as an observer and the author participated in that capacity. Dr. V. Arkely served as the photographer. The survey period was within the South-West monsoon season and extremely bad weather with high speed winds were experienced particularly off the North-West and South coasts. Except during these two trips, an average altitude of 1,000 ft. and a flying speed of 110-115 m.p.h. were maintained. The program was to cover the off shore range between 15 miles and 50 miles, from shore. The total number of hours of flying was eighteen. Details of the flight plan are shown in figure 1.

Os recursos de algas marinhas de importáncia económica na República popular de Moçambique com especial referéncia para Euchema (Florideae) em Cabo Delgado

Composition, abundance and environmental characteristics of the sea-weed resources of Mozambique were investigated along the whole Mozambican sea shore between May, 1979 and November, 1980. The limits of distribution of tropical algae were identified and located close to parallel 21 degree 00'S. Important concentrations of sea-weeds were found in the southern region, but only the Euchema resource in the coast of Cabo Delgado looked promising for commercial exploitation. Biological studies of Euchema were undertaken, the results of which permit the recommendation of a strategy for immediate harvesting which could yield 400-500 tons annually. Further proposals for the culture of sea-weeds are also included.

On the Catch Assessement Survey (CAS) of Lake Victoria

If recent estimates are accurate the world’s human population can be expected to double in the next thirty years. The rate of growth will likely be even greater in many African nations, yet food supplies in these countries especially of essential animal proteins, are even not; inadequate Clearly increased production of food for domestic consumption must become a high- priority development goal. The inland fisheries of Africa will play an increasingly important role in augmenting protein supplies. In 1970, production of the inland fisheries was already-about 1.4 million metric tons, and had increased some 71 per cent in the previous six years. With further development and more affective fishery management a two-fold increase 1n output over the present level can reasonably be expected. Effective management of the fisheries at optimum exploitation levels end development of under utilized fish resources will neccessite major improvement in the stastistical systems employed to produce information on the fish stocks and fisheries. More reliable and detailed information on the catch, effort and other important aspect of the fishing enterprises will be required.

Avaliaçāo económica das medidas de gestāo da pescaria de camarāo do Banco de Sofala

The objective of this study is to recommend management measures for the industrial shallow-water shrimp fishery in Sofala Bank after estimating the economic affects considering different alternatives and assessing the level of exploitation of this fishery. The short-term economic analysis was based on the results of the total catch and average weight of the shrimp caught obtained by a simulation model in which different combinations of exploitation patterns and levels of fishing intensity were tasted. The variable parameters used were the mash size and the duration and period of the closed season, and all the remaining parameters were fixed. Economic and production data of the main industrial shrimp fishing companies for the period 1987-90 were also used.

Preliminary investigations on the population dynamics of Otolithes ruber (Sciaenidae) on Sofala Bank, Mozambique

Catch length-frequency data of Otolithes ruber (Schneider, 1801) obtained from the "Projecto de Pesca Experimental da RDA" on Sofala Bank, Mozambique, in 1987 were used to estimate growth parameters, mortalities and exploitation rates. The yield-and biomass-per-recruit analyses based thereon suggest that the stock is overfished.

National Agricultural Research Organisation. Fisheries Resources Research Institute Annual Report 2000/2001

It is now clear that fisheries resources are among the key assets contributing to the national development objective of poverty eradication through providing food, employment, income and export earnings. It was recently reported in the papers that monthly fish exports had increased by 23% and fetched about US$ 10 Million during the month of November 2001 alone. This value may be underestimated as it is based solely on recorded exports from fish processing factories numbering 12. Although fisheries resources are renewable they can be depleted through unsustainable exploitation. It is therefore important to ensure that there is guided development and management of this asset so that it can continue contributing to the livelihood of the people who depend on it. Therefore, FIRRI contributes to the fisheries sub-sector developmental objective of ensuring increased and sustainable fishery production and utilization by providing information to guide sustainable management of capture fisheries resources and development of aquaculture.