Das europäisches Netzwerk zur Koordination der Altersbestimmung bei Fischen: European Fish Ageing Network (EFAN)

Financial support is going to be applied for from the European Commission in order to establish the European Fish Ageing Network (EFAN). The project, which was planned and initiated from Norway (Floedevigen) is supposed to be a concerted action from 14 European Countries involving about 35 institutions. The primary aim of the network is to coordinate the research in age reading, especially the improvement of data bases for reference material, the transformation of research (e.g. daily ring formation in otoliths) to each interested reader. Moreover, the applied financial support is supposed to be preliminary spent for travel of researcher and technicians to other institutes where the same fish species are aged. Reference material is supposed to be sent to the institutes for check-reading. Specific workshops will be held in cases where heterogeneous results occur from check-reading the reference material.

Fish species identification in Canned Tuna by DNA Analysis (PCR-SSCP)

DNA in canned tuna is degraded into short fragments of a rew hundred base pairs. The polymerase chain reaction (PCR) was used to amplify short sequences of mitochondrial DNA, which were denatured and analysed by polyacrylamide gel electrophoresis (native PAGE) for detection of single strand conformation polymorphisms. Species specific patterns of DNA bands were obtained for a number of tuna and bonito species. DE: In Thunfischkonserven liegt die DNA in Form kurzkettiger Fragmente von wenigen Hundert Basenpaaren Länge vor. Mit Hilfe der Polymerase-Kettenreaktion (PCR) wurden kurze Sequenzen der mitochondrialen DNA vervielfältigt. Anschließend wurde die gebildete DNA in Einzelsträngen überführt, die durch eine native Polyacrylamidgel-Elektrophorese (PAGE) aufgetrennt wurde. Für eine Reihe von Thunfischen und Boniten ergaben die Einzelstränge artspezifische Bandenmuster, die auf unterschiedliche Konformationen der DNA-Stränge der einzelnen Fischarten zurückzuführen sind.

Fish diversity of the wild and aquaculture water bodies in Singida Region

Tanzania Fisheries Research Institute being currently the only fisheries research institute in Tanzania has sole responsibility of marking the presence and distribution of fish species in the country. This work is expected to be completed by the year 2005. In order that this work can be accomplished, both published works and field observations (including geographical location using GPS) have to be compiled. Since the institute has centers in all the Great Lakes and one along the Indian Ocean coast, it is expected that field observations and identifications will be obtained and incorporated into the document to be produced by 2005. (PDF contains 15 pages)

The occurrence of two new plankton diatom populations in the English Lake District: Aulacoseira islandica

Samples of planktonic algae from major lakes in the English Lake District have been investigated over many years as part of a long-term monitoring programme set up by the Freshwater Biological Association and continued by the Institute For Ecology. Some lakes have been sampled regularly for long periods, others less frequently or only occasionally. Windermere north and south basins, and the neighbouring lakes Blelham Tarn and Esthwaite Water, have been under observation, mostly on a weekly basis, since the programme began in 1945. During this time diatoms have played a significant role in the population dynamics of these lakes.

The status of Arctic charr, Salvelinus alpinus (L.), in southern Scotland: a cause for concern

The objective of this article is to review the populations of Arctic charr in the south of Scotland which have become locally extinct, and the reasons for their demise. In the British Isles, the Arctic charr in individual lakes have been isolated from each other for thousands of years and have developed a variety of phenotypic characteristics which are probably genetically based. About 200 populations of Arctic charr have been recorded from different parts of the British Isles: approximately 12 in England, 50 in Ireland, 175 in Scotland and four in Wales. The threats to charr from acidification, afforestation, engineering schemes, angling and fish farming are assessed, and the establishment of new populations is proposed as a method of replacing extinct stocks or providing an additional safeguard for valuable stocks in threatened waters.

Coarse fish in Scotland: a threat or a resource?

This brief article summarizes the ecological role of non-salmonid fishes in Scottish fresh waters. Most government-sponsored research has focused on the ecologically valuable salmonids in this area, yet non-salmonid species are widely distributed in Scotland and play an important ecological role in freshwater ecosystems. The fish fauna of Scotland differs from other parts of the British Isles by being more impoverished following the end of the last Ice Age, ca. 10 000 years ago.

An annotated bibliography of research on coarse and salmonid fish (excluding salmon and trout) found in fresh water in Scotland

The authors provide an extensive annotated bibliography to a full list of species occurring in Scotland, to highlight what is known about them and to indicate potential areas for further research. The list of references brings together published research papers and numerous unpublished theses and reports, including experimental and laboratory studies conducted in Scotland, although some may not have unique application to the fish fauna in Scottish waters. There has been no attempt to include references that are made incidentally in the general literature intended for naturalists.

Habitat use by 0+ cyprinid fish in the River Great Ouse, East Anglia

This study was designed to examine the habitat use of several species of 0+ cyprinid in the regulated River Great Ouse and to determine the reasons for specific habitat use. In general, all fish species were found associated with the marginal zone, with little diel variation. Use of shallow habitats in the presence of macrophytes correlated well with the distribution of zooplankton in the river channel, the preferred food source of 0+ cyprinids. During the early to late larval phase, all species fed upon rotifers and diatoms. Cladocera, particularly Alona spp. and Chydorus spp., and early instar larvae of Chironomidae, then became prevalent in the diet along with small numbers of Copepoda. Models were developed to determine habitat availability over a range of discharges, using the physical habitat simulation (PHABSIM) component of the Instream Flow Incremental Methodology (IFIM). The results of this analysis revealed that habitat suitable for 0+ fishes comprised a relatively small percentage of the main channel and generally decreased with discharge.