A brief report on a survey of the fish and fisheries of the Tana river, with special reference to the probable effects of the proposed barrages

The construction of several barrages in order to develop the hydroelectric and irrigation potential of the Tana river has been proposed and the probable effects of these developments upon the fish and fisheries of the area' has been investigated. Briefly in the highest reaches the sport fishery will be unaffected, in the middle reaches the sparse subsistence fisheries will be only slightly inconvenienced but in the terminal reaches of the river the subsistence and commercial fishing enterprises are expected to be seriously reduced by the progressive re-regulation of river-flow. However each new dam will support a new and productive reservoir fishery and with proper development the annual yield of fish from the Tana basin is expected to increase considerably

A preliminary report on a survey of the fisheries of the Tana river, Kenya

Various departments of the Kenya Government, together with FAO consultants are co-operating in the United Nations Special Fund Scheme for developing hydro-electric and irrigation potential on the Tana River. The irrigation scheme is sited ON the south bank of the lower reaches below Garissa where a shallow but large reservoir dam will be constructed at Korakora (see Fig. C1). Hqwever, because of the limited capacity of such dam further reservoir dams are also considered in more suitable sites up-stream including Koreh Falls, Adamson's Falls, Mutijwa, Grand Falls, Mutonga confluence,Umbee Hill, Kindaruma, Gtaru, Thiba and Tana Reservoi

The Fisheries of Lake Rukwa, Tanganyika

This survey of the fisheries of Lake Rukwa, Tanganyika, describes results obtained during 1963-1964, and includes comparative material given by previous workers, in particular surveys conducted in 1936 by Ricardo and, in 1946 by Swynnerton. Data is given on the general hydrology of the Lake including chemical analyses, seasonal and annual fluctuations of volume. Cyclical variations of lake level occur every 20/30 years and the level now reaching a new maximum is expected to fall again during the next decade. The record of fish species from the Rukwa basin is enlarged by 3 genera: Polypterus, Protopterus and Chiloglanis; a summary of the biology and commercial exploitation of 20 species of fish is given. An historical account of the fish production from the lake and its subsequent marketing concludes that in 1963/64 some 5,328 tons of dried fish products are marketed annually; between 10-6;10 of this trade is directed towards the Rhodesias and the remainder is absorbed within Tanganyika. The state of the indigenous fishing enterprise is discussed, and for the improvement of the industry recommendations are given that the marketing of fish products should be immediately investigated and encouraged both abroad and within, Tanganyika. Further suggestions include the improvement of water-transport on the lake, the development of improved fishing-craft, fishing-methods, processing methods and further investigation of the biology of the fish-fauna

Evaluations of the pelagic resources in the Burundi waters of Lake Tanganyika and the evolution of the fisheries

The important pelagic fishery resources of northern Lake Tanganyika were identified after a preliminary scientific evaluation, and in Burundi, with governmental assistance they were rapidly developed and exploited more intensively until overfishing was thought to have occurred. At this point, legal measures were introduced in order to protect the resource by restricting fishing effort and maintaining the total yield near the apparent maximum sustained limit. Complementary biological research on the fish stocks did not accompany the rapid fishery development and now an intensive stock assessment programme has been launched by the Government and UNDP in order to define more precisely the available fish stocks and to consider, with the co-operation of the neighbouring lacustrine states, suitable ways of ensuring optimum levels of fish harvest from year to year

A translation of certain extracts from: "Les genres des poissons d'eau douce de l'Afrique" (The genera of freshwater fish from Africa) by M. Poll. (1957) Ann. Mus. Roy. Congo Belge. Ser. 8, Zool. 54: 1-191.

The object of this paper is to facilitate the identification of the families and genera of African freshwater fish known to date from the vast zoogeographical Ethiopian region south of the Sahara. This Ethiopian region really stretches ever the whole of Africa with the exception of North Africa (Morocco, Algeria, Tunisia) whose fauna has mainly European affinities. (Only the endemic Cichlid genera from Lake Nyasa cannot be determined from this work. The key for the identification of these fish can be found in the excellent monograph by Trewavas, 1935: "The Cichlid Fishes of Lake Nyasa" Ann. Mag.Nat.Hist. (10) 16: 65-118). The keys are convenient and are designed to simplify the identification as far as possible. Certain of these. keys are original, while others have been constructed from the works of several other ichthyologists: Boulenger, Pellegrin, Regan, Trewavas, Myers, Daget, Greenwood, as well as my own earlier publications

A resume of the evolution of the tilapia fisheries of lake Victoria up to the year 1960

A very useful account of the history of the fishing industry on Lake Victoria up to 1960 has been given by GARROD, however this paper is no longer readily available and a summary of his account, together with additional remarks by other authors is given here as a preamble to the review of the progress of the industry during the last decade

Laboratory capture, isolation and analysis of microparticles in aerogel: Preparation for the return of Stardust

We present observations from the laboratory capture of particles in aerogel. The paper focuses on a possible extraction technique and the bulk mineral characterization of the captured material using non-destructive analytical techniques

A translation of certain extracts from "Les genres des poissons d'eau douce de l'Afrique" (The genera of freshwater fish from Africa) by M. Poll (1957)

At present there is no convenient key in English for the identification of the species of freshwater fish from the East African political region which includes Kenya, Tanzania and Uganda. Whilst Boulenger (1909-16), Lockley (1949), Copley (1952 and 1958) and Greenwood (1953-1958 and 1966) give keys on descriptive data relevant to this fauna, their accounts do not give complete coverage for the region. Norman's (c 1944) draft synopsis of the orders, families and genera of recent fishes unfortunately excludes the Ostariophysi and the Cichlidae, thus does not cover 12 of the most important families of African freshwater fish. Moreover Norman's key employs, for the remaining families and genera, detailed anatomical characters which are not convenient to use in the field

Phase-referenced Interferometry and Narrow-angle Astrometry with SUSI

This thesis describes the development of an astrometric facility at the Sydney University Stellar Interferometer (SUSI) with an aim to measure at high precision the relative astrometry of bright close binary stars and ultimately to detect the presence of exoplanets within those binary star systems through observations of the systems’ perturbed motion. At the core of the facility is a new beam combiner that is phase-referenced to an existing primary beam combiner in the visible wave- length regime. The latter provides post-processed fringe-tracking information to the former for fringe stabilization and coherent integration of pre-recorded stellar fringes using newly developed data reduction software. Interference fringe packets of a binary star are recorded alternately; first the fringe packet of the primary, then the secondary, finally back to the primary again. The measurement of the fringe packet separation is facilitated by an air-filled differential delay line and a network of interferometer-based metrology systems. Characterizations and initial astronomical observations carried out with the dual beam combiner setup demonstrated for the first time the success of the dual-star phase-referencing technique in visible (~1μm) wavelengths. The current astrometric precision is larger than 100μas while the long term astrometric accuracy is yet to be characterized. In a parallel development, a complementary observing method using only the primary beam combiner is also demonstrated in this thesis. Relative astrometry of binary stars up to ~0.8” separation with this technique has been demonstrated to have precision of better than 100μas. A simple detection limit analysis based on a list of target binary stars estimates up to two exoplanet detections can be achieved with SUSI if the new astrometric facility attains precision of 10μas while the primary beam combiner operates at its designed peak performance. Finally, one new stellar companion was resolved and a preliminary astrometry for another suspected companion was estimated from the astronomical observation data collected throughout the course of this thesis

Classical and Thermodynamic Stability of Black Branes

It is argued that many non-extremal black branes exhibit a classical Gregory-Laflamme instability if, and only if, they are locally thermodynamically unstable. For some black branes, the Gregory-Laflamme instability must therefore disappear near extremality. For the black $p$-branes of the type II supergravity theories, the Gregory-Laflamme instability disappears near extremality for $p=1,2,4$ but persists all the way down to extremality for $p=5,6$ (the black D3-brane is not covered by the analysis of this paper). This implies that the instability also vanishes for the near-extremal black M2 and M5-brane solutions.Comment: 21 pages, LaTeX. v2: Various points clarified, typos corrected and reference adde