The smelt Osmerus eperlanus in Scotland

Smelt populations have been recorded since the 18th Century from at least 15 rivers in Scotland, but over the last Century the species has suffered a severe decline and has disappeared from all its former sites except the rivers Cree, Forth and Tay. These populations must now be regarded as having high conservation importance. There are probably several different reasons for this decline. In some rivers, such as the Clyde and the Stinchar, pollution in the lower reaches has prevented successful migration and reproduction. In other rivers, high weirs and barriers have completely cut off access to spawning grounds. In some estuaries and rivers, such as the Solway Firth, overfishing is believed to have been responsible for eliminating local stocks. A Species Action Plan for the smelt has been prepared and it is hoped that this will be the basis of a future conservation strategy for this species in Scotland.

Étude hydrologique du plateau continental Ivoirien

The authors give a picture of the average seasonal hydrographic situations over the Ivorian continental shelf using data provided by 26 cruises carried out from July 1969 to January 1972. They study meteorological conditions and the mechanism of setting of different types of hydrographic seasons defined as follows: a cold period related to an upwelling created by winds July to earlier October and a warm period divided in 2 parts in relation with haline variations: a low salinity period in November and December, and a high salinity period from January to May; this one sometimes cut off by short-timed drops in the temperature. Then precisions are given about seasonal and geographical variations using space-time diagrams: last, depth and intensity of the thermocline are examined.

Analysis of competition in the wholesale and retail markets for fish in Kisumu, Kenya

This study analyses competition in the wholesale and retail fish marketing system in Kisumu, which is Kenya's largest fish market. It is based on cross sectional and time series primary data collected in a survey involving 88 retailers and 47 wholesale traders of fish in the town. Stratified random sampling method was used in selecting the respondents, Concentration ratios, Lorenz curves and Gini coefficients are derived and evaluated for both markets. They demonstrate that market shares are unequally distributed among the wholesalers and retailers. The Gini coefficients are 0.37 and 0.45 for the whole and retail markets respectively. Based on a Gini coefficient cut-off level of 0.4, it is concluded that the wholesale fish market exhibits effective competition while the retail outlet has oligopolistic tendencies. The implication of this level of competition to price efficiency is discussed. Intervention measures to enhance competition in the market are recommended.