Assessment of post-harvest losses in Nigeria fishery: the Kainji Lake model

The paper provides a description of a methodology used for quantitative assessment of post harvest losses in the Kainji Lake Fishery (Nigeria). The sample population was made up of 314 fisherfolk, 115 processors, 125 fish buyers and 111 fish sellers. For the determination of handling losses, 24,839 fishes weighing 2,389.31 kg belonging to 43 species were examined of which 10% by number and 9% by weight deteriorated at checking and 4% by number and 3% by weight at landing. Processing losses recorded 22% by number and 16% by weight deteriorated prior to and during smoking with the traditional 'Banda' kiln. During marketing, 16% of fish sold had deteriorated and 6% by weight of fish bought also deteriorated, mainly due to insect infestation during storage. Based on the 1995 yield estimate for Kainji Lake fishery, approximately 1000 tons of fish estimated at 80 million Naira were lost during handling alone. This figure would be much higher if the level of losses during processing and marketing are included. This assessment technique is recommended for use in obtaining quantifiable data on post harvest losses from other water bodies in Nigeria

An appraisal of the efficiency of fish marketing system in Lake Chad basin

Fish products from the Chad Basin Lake play important role in meeting fish protein needs of Nigeria: they contribute not less than 25% of the total domestic fish supply and are significant in determining the availability of processed products and reduction of post-harvest losses. Processors, marketers and consumers are the major actors in appraising a marketing system. The results show that most sellers (4-7.5%) are within the age range of 30-39 years. Desires for more earnings led the markets to diversify their business activities to food stuff trading (37.5%), dried meat/livestock sales (37.5%), farming (12.5%), and transportation (12.5%). 65% of traders dispose off their products mostly in the mornings and evenings, 70% of the products are sold smoked while 50% of products are sold to individual consumers. Lake Chad fish products have a long distribution chain. There is also a high degree of buyers and sellers concentration in the primary fish markets and secondary (urban) markets. The products have a vertical regional movement with southern traders (82.5%) dominating the business, thus making the products popular all over Nigeria. Product differentiation with imperfect pricing policy is common occurrence. Lake Chad fish marketing system has distortions that impede its efficiency, recommendations are made on how to ensure a better efficiency of the system

Fischereilich-ökonomische Überlegungen zu Chancen und Risiken in der Garnelenfischerei - am Beispiel des Schollendiscards (Ein Thesenpapier auf der Basis von EU-Studien und Langzeitreihen)

Though economic research is not one of the tasks of the German Federal Research Centre for Fisheries, basic in-formation for such work is available from biologic studies on fish biomass, discards and seasonal abundance of species. Results from EU-studies on brown shrimp fisheries show the effect of discarding juvenile fish, especially plaice, the possibly lost numbers and value of this fish as well as chances of reducing these losses by a timely effort reduction in summer and the use of selective nets throughout most parts of the year. However, it is also made clear, that these costly measures may have no effect on the stocks due to biological compensatory effects observed in strong year classes of plaice e. g. 1996, with high landings and collapsing prices. Therefore sound biological and economic data and methods are needed to assess the economic effects of management measures on fishermen’s situation and markets. Compensations for catch limitations may become inevitable.

Winterfischerei auf Garnelen. Die Anteile der europäischen Garnelenflotten an den Anlandungen von Crangon crangon im Zeitraum Januar bis März der Jahre 1990 bis 1999

„Winter fishery“ on brown shrimp does not imply a special type of fishery. It merely means the continuation of the standard fishing procedure of parts of the fleet during wintertime, when the majority of the mostly smaller vessels stay in harbour due to generally unfavourable weather conditions for their activity. During 1990 to 1999 mean European wide landings in January and February summedup to 854 tonnes making up to only 4 % of the mean annual landings (21 805 t). While German vessels landed0.7 % (68.7 t) of their mean annual landings during that period, the other countries caught about 7 % of their individual, mean annual landings at the same time. The Netherlands and Denmark contributed highest tonnages of 580and 110 tonnes, respectively, to the total European landings, making up 81 % of them. As about 70 % of brown shrimp may carry eggs in January, the winter fishery took a mean total of about 2.15 x 1012brown shrimp eggs out of the stocks in that period annually. As there is no reliable assessment available concerning the brown shrimp stocks, it is despite of these high losses of eggs not possible to trace a negative effect of the winter fishery in scientific terms. However, precautional catch reductions in winter would be in favour of higher survival rates of eggs, which are the carrying source for the recruitment of brown shrimp stocks and catches in forthcoming summer and autumn seasons according to Dutch investigations.

A photographic record of a pre- and post-lake creation event from World War II at Valley, Isle of Anglesey, UK

The article compares a recent aerial photograph of the lowlands of the Isle of Anglesey area with a German surveillance photograph from 1941. The authors aim to infer the environmental changes made to this sand dune and lake system as a direct consequence of constructing the airfield. Part of Tywyn Trewan, the extensive sand dune system, was completely destroyed in order to create runways and the technical and domestic accommodation to house a strategic airfield. As part of the dredging, six new water bodies with a combined surface area of approximately 6 ha were created.