Erste Ergebnisse zum Verlauf der Laichsaison von Dorschen in der westlichen Ostsee 1997

Investigations concerning the intensity and duration of spawning seasons of cod stocks are parts of the work of the reproductions ecology of commercial fish stocks in the Baltic Sea. The Institute of Baltic Fisheries Rostock has sampled and analysed data for this goal since 1992. The first data analyses for the spawning season 1997, sampled in the areas Kiel Bay, Mecklenburg Bay and Arkona Sea showed that the process of the spawning season is different compared to the years before. The spawning process starts earlier than the other years in Kiel Bay and Mecklenburg Bay. The results show that a high proportion of the spawning stock was part of the spawning process in this area. The Arkona Sea cod are regarded by ICES definition as belonging to the western cod stock. In this ICES sub-division only a low number of spawned cod was observed in March, the main spawning time of the western cod stock. Opposite to the theory of the stock units intensive spawning activities were observed in June as in the years before in the Arkona Sea.

Die Entwicklung wichtiger Fischbestände in der Nordsee und im Nordatlantik. Ergebnisse der Herbstsitzung des Advisory Committees for Fishery Management des internationalen Rates für Meeresforschung

The October meeting of the ACFM of ICES gave advice for a number of North-Atlantic fish stocks. The results of the most important stocks are given here from the perspective of German fishery management. The are chiefly North Sea plaice and sole, for which a reduction of 25 % of the fishing mortality (F) is recommended for 1998, North Sea saithe (minus 20 % in F), while North Sea cod is in the process of recovery and North Sea haddock is inside safe biological limits. The mackerel stock of the North Sea has not yet recovered, while the western mackerel stock as an entity has stabilised at a level of about 2.3 million t.

Neue Erkenntnisse zur Verteilung des Nordseeherings auf die Gebiete der EU und Norwegens

A study by K.R. Patterson of the Marine Lab, Aberdeen, Scottland, presented to the EU comission in June 1997, investigated the distribution of Herring in the North Sea, i. e. the zonal attachment of the stock to EU and Norwegian waters, respectively. Evaluation of data from the ICES International Bottom Trawl Surveys and Herring Acoustic Surveys conducted in the last 10 years showed a wide variation in biomass and zonal attachment, depending on the type of survey used and the season sampled. However, a mean share of 16 % was estimated to be attached to the Norwegian waters . In contrast to earlier analyses based on commercial catches there is little support that this proportion increases with increasing stock size. It is expected that this study will give rise to some discussion on the forthcoming EU-Norwegian consultations on North Sea herring.

Über die Herkunft des starken Kabeljau-Jahrgangs 1996 in der Nordsee

Cod in the North Sea is expected to reach „Safe biological limit“ due to a strong 1996 year-class. The cod fry was seen first as 5 cm fingerlings in the catches during a hydroacoustic survey in the southeastern North Sea. Back-calculations of the water drift show with high probability that the respective spawning ground was situated in the southwestern North Sea.

Zur Fang- und Bestandssituation von Hering und Sprott in der Ostsee

Information is given on the landings of herring and sprat in the Skagerrak/Kattegat and Baltic Sea. Based on assessment units used by the ‘Herring Assessment Working Group for the Area South of 62° N’ and the ‘Baltic Fisheries Assessment’ working group, the total landings are shown for the years 1974 to 1996. Further the quarterly landings for 1996 are listed on national basis by area/Sub-Division. In addition an actual description of the national fleets operating in the Skagerrak/Kattegat and Baltic Sea is given. At least the actual stock development and the catch options estimated by the corresponding working groups for different assessment units is presented.

Radioaktives Cäsium im Fisch der Barentssee weiterhin abnehmend

A decrease of 137Cs concentration in cod flesh from Barents Sea is shown by six years random sampling. This reduction runs parallel to reduced emissions from the nuclear fuel reprocessing plant Sellafield (Great Britain). It must be emphasized that even the highest values from 1992 are lower than comparable ones from the North Sea and from the Baltic. Although there is no increase of the radiation dose on people by consuming these fishes further monitoring should not be stopped. Potential risk arises from radioactive wastes of the russian nuclear navy in their coastal area. Obviously a safe storage seams almost too expensive.

Untersuchungen zu selektionsverbessernden technischen Maßnahmen in der Ostsee-Aalfischerei

With the aim to reduce unwanted bycatches and discards in small mesh size trawling for Baltic eel some technical measurements are described and investigated. They include as well sorting grids as the more selective technological alternative longlining.

Bestimmung der Begriffe Gesamtfang, Fang, Beifang und Rückwürfe

Due to the increasing environmental awareness of the public, marine environmental protection became a general interest. Since fishery is one of the strongest direct influences of man on the marine ecosystem, it became criticised, especially because of the discarding of unused fish, which is considered as a waste of the resource. In the different types of fisheries the calculation of the amounts of discards in relationship to the landings vary strongly. One of the reasons is, however, the different use of the terms 'bycatch' and 'discard'. Thus it is important to work with equal terms and definitions, so that fishermen, protectionists and ecologists talk the same language. This contribution tries to define the following terms achieving a generally acceptable terminology which is also explained by the attached diagram.

Perspektiven für die wichtigsten von der deutschen Fischerei genutzten Bestände für 1996

This article informs about the current status and development of fish stocks which are•of commercial importance for all branches of the German fisheries in the•entire North Atlantic. The information is based to a large extent on the reports of the Advisory Committee on Fishery Management (ACFM)of the International Council of the Sea(ICES) and in close connection with the results of scientific investigations of different institutes in Europe dealing with fish including the Institute for Sea Fisheries in Hamburg.

Technische Maßnahmen zur Schonung des Ostseedorschs - Gegenwärtige Ergebnisse der Selektionsforschung

Die gegenwärtige Situation der westlichen und östlichen Dorschbestände in der Ostsee wird von den Experten des Internationalen Rates für Meeresforschung, verglichen mit den 80er Jahren, als ungünstig beurteilt. Noch 1994 wurde daher kein Anlaß gesehen, trotz massiver Proteste der Praxis, die Empfehlung für eine moderate Befischung aufzuheben (Anon. 1994).

Der Einsatz von Flüssigrauch: eine neue Technologie Teil 3: Untersuchungen zur Lagerfähigkeit von mit Flüssigrauch hergestellten vakuumverpackten Räucherfischprodukten

The investigations showed that the shelf life of traditional smoked and vacuum-packed gutted mackerels, mackerel and herring fillets is similar to the corresponding vacuum-packed products smoked with liquid smoke. The storage temperature was 5 ± 0,5 °C. Under experimental conditions the storage time was 26 days for smoked gutted mackerels and more than 30 days for smoked fillets. Storage times of 20 to 25 days for these products are recommended. The microbiological and chemical results showed no differences between both technologies.

International Seafood Conference 25. Jahrestagung der WEFTA (West European Fish Technologists' Association)

The 25th annual meeting of WEFTA was held in Noordwijkerhout, The Netherlands, in November 1995 as an "International Seafood Conference". In 12 sessions 40 oral presentations and 60 posters were presented. The topics included among others: Quality assurance, consumer demands and behaviour, processing, packaging, distribution, nutrition, storage, analytical methodology. The conference was attended by 210 participants from 33 countries.

Biologische Verbindungen zwischen den Rotbarschbeständen Westgrönlands und der Irmingersee

Two redfish species are expected to live off western Greenland in a broad distribution area. Except for a small population of adults in the Godthab Fjord, only juvenile and adolescent specimens have been met there, tending to increase in age from the north to the south. As taxonomic identification of single specimens is difficult the distribution of species stocks cannot be clearly identified. This paper deals with spawning areas, migration and drifting routes around Greenland respectively in relation to distributional pattern of juvenile redfish off western Greenland.