Neues aus der Selektionsforschung am Ostseedorsch

In account of the decision of the IBSFC (International Baltic Sea Fisheries Commission) to admit alternative codend constructions to the presently legal of diamond meshes with 120 mm mesh opening, since seven years a vivid research activity is encouraged at the fishing technology institutions around the Baltic. Though a center of gravity in this field of research lies in the EUproject BACOMA (participants Finland Sweden, Denmark) also the corresponding national institutes of other Baltic countries (Germany, Poland, Russia) have been active with similar investigations. German experiments in 1999 dealt with the effect of the use of netting made of double instead of single yarn on the selectivity. Further research was done on modifications of codends made from netting turned 90° from its original orientation and on simplified versions of the so-called Multipanel codend which consists of three equal diamond and three square mesh panels. The experiments demonstrated on the one hand a definite deterioration of the selective properties in a codend made from double instead of single yarn. Constructional changes in codends made from netting turned 90° on the other hand brought a further improvement of the selectivity of such codends. Finally, the investigations on the Multipanel codend revealed the overwhelming influence of the square mesh panels on the selectivity success. If in a conventional diamond codend three windows are cut out starting 50 cm from the real end of the codend in such a way that the remaining parts have the same breadth as the square mesh panels to insert, the selective effect of such a codend is remarkably improved. According to further preliminary tests this seems to be nearly independent from the type of material used.

Nachhaltige Entwicklung der Hochseefischerei

The poor situation of fish stocks worldwide pointed out by FAO has led to a reconsideration of fishing concepts internationally. A brief outline of the world fishing situation is given, as well as that of the EU and Germany. Explanations of basic fishing parameters like catch, recruitment and fishing mortality are given and used to expound and graphically show the relation to overfishing and the new concept of the ”precautionary priciple” and ”precautionary approach” for the goal of a sustainable fishery. This leads to recommendations for research and actions in respect to selectivity, adjustment of fishing capacity and new concepts of utilisation.

Der Krill im Südatlantik. Entwicklung der Bestände, der Fischerei und des Bestandsmanagements

Since 1976 the Institute of Sea Fisheries of the Federal Research Center for Fisheries, Hamburg, has been conducting long-term monitoring research on Antarctic krill in order to manage the stocks according to the precautionary approach. The krill stocks of the South Atlantic fluctuate seasonally as well as inter-annually in biomass and recruitment success. Following high densities in the late 1970s, the stocks are recently declining. Shortly after the onset of a commercial fishery the catches reached a maximum of around 500 000 t annually, but stabilized around 100 000 t during recent years. Actual survey results indicate mean krill densities in the South Atlantic of 21.4 g/m2, corresponding to 44 Mio. t. The potential yield and maximum catch rate was set at 4.0 Mio. t per year subdivided for the various CCAMLR Subareas. CCAMLR is expected to introduce further conservation measures to control the fishery in the convention area in the near future, however, there is still room for developing a krill fishery in the Antarctic.

Laichgebiete des Dorschs in der westlichen Ostsee

Analyses of the previous years showed that the reproduction of the Belt Sea cod stock (Gadus morhua morhua) is also very important for the cod stock of the central Baltic Sea (Gadus morhua calarias). Oeberst (1999, 2000) proved, that between 20 % and 50 % of the cods caught in the Bornholm Sea at the age of 2 or 3 years between 1994 and 1998, were spawned in the Belt Sea. On account of this large significance of the Belt Sea cod stock, information regarding the reproduction process are important. The goal of the article presented is the description of the actual spawning areas of the Belt Sea cod stock by means of the spatial distribution of the spawners based on characteristic parameters as the maturity stages and the proportion of the sexes. The basis for these analyses are data sampled between 1992 and 1999. The analyses showed that the actual main spawning areas in the western Baltic Sea were the deeper regions of the Kiel Bay, of the Fehmarn Bay and of the western Mecklenburg Bay. In these regions spawning cods were regularly observed with high intensity. Furthermore, the deeper basin of the Arkona Sea is an important spawning area.

Schwacher Nachwuchsjahrgang 2000 des Herings in der westlichen Ostsee

Several fishery independent estimates of the year-class strength are necessary for the assessment and the management of the total fish stock. An index for the year-class strength of the spring spawning herring in the western Baltic Sea is estimated on the basis of larvae surveys in the most important spawning ground. The results of this year’s herring larvae survey indicate a weak year-class 2000.

Erfolgreiche Fischereiforschung im Jahr 1998 zur Sicherung der Ressourcen

Das Aufgabengebiet der Bundesforschungsanstalt für Fischerei umfasst alle Forschungsaktivitäten, die zur Erreichung der politischen Ziele des Bundesministeriums für Ernährung, Landwirtschaft und Forsten (BML) im Bereich der Fischerei und ihrer Erzeugnisse erforderlich sind. Alle Arbeiten der Forschungsanstalt sind international eingebunden in die Ziele der gemeinsamen Fischereipolitik der EU, sowie die Arbeiten des Internationalen Rats für Meeresforschung. Die Bundesforschungsanstalt gliedert sich in fünf Institute.

Analyse der Beifangreduktion durch Gitternetze in der kommerziellen Garnelenfischerei

Trials for the determination of the magnitude of bycatch reduction by sorting grids used in the commercial brown shrimp fishery were carried out from September to December 1997. Trawls with 9 m beam length were used on different fishing grounds in the estuary of the Elbe River near Cuxhaven. The sorting grids tested were made of stainless steel bars spaced at 18, 20, 22, 26 and 30 mm, built into a cylindrical stainless steel frame with a diameter of 65 cm at an angle of attack of 45 degrees. This frame was positioned between the forenet and codend. Simultaneous hauls were made with a trawl of equal construction but without a sorting grid, and the weighed catch components (fish, discard shrimps and commercial size shrimps) separated by means of a riddle were compared. The composition of the sorted out part of the catch of the sorting grid net could be calculated by comparise the corresponding catch components in both the standard trawl and the sorting grid trawl. According to this the total catch of the beam trawl with the sorting grid is reduced by 18 to 38 % depending on the space between the bars. 7 to 31 % of the sorted out part of the catch consists of fish. The use of the sorting grid, however, also leads to losses of 4 to 12 % in Oktober. Per hour of towing this means a loss of 10,3 % commerical size shrimps with a sorting grid of 18 mm space between the bars and of 12,4 % for a 26 mm grid.

Beurteilung der Frische von Fischen. Ergebnisse und Empfehlungen einer Konzentierten Aktion im Rahmen von FAIR

Von Anfang 1995 bis Anfang 1998 wurde eine Konzertierte Aktion (CA) mit dem Titel „Evaluation of Fish Freshness“ (Bewertung der Frische von Fisch) mit Mitteln der Kommission der Europäischen Union im Rahmen des 4. Europäischen Forschungsrahmenprogramms (FAIR) unter Beteiligung von 18 zumeist staatlichen oder universitären Fischereiforschunginstituten aus 14 europäischen Ländern durchgeführt.

Fischbestände der Ostsee, ihre Entwicklung in den Jahren seit 1970 und Schlussfolgerungen für ihre fischereiliche Nutzung. Teil 1: Dorsch

On the basis of the ”Gdansk Convention on Preservation of Living Resources of the Baltic Sea” the International Baltic Sea Fishery Commission (IBSFC) has been regulating catches of most important fish species in the area since 1974. This article reviews, in a first step for Baltic Sea cod, the development of stocks and fishery since 1970 in the light of respective catch regulations of IBSFC. TACs have been fixed by IBSFC by species for the whole Baltic Sea and resulting quotas have been split according to national and/or international fishery zones from 1975 up to now. The Baltic Sea cod is on biological background treated in scientific stock assessment as two separate stocks. Both stocks, in the western and eastern Baltic Sea, show clearly different developments over the period since 1970. After a short living peak in stock size of the eastern compartment about 20 years ago this stock has been on a very low level since the late 1980’s. During that period with increasing effort big cod catches have been landed.. The level of fishing effort is more or less the same still with much lower catches nowadays. A detailed description of development of stock sizes and recruitment is given. The conclusion is that with the present regime of regulation on the basis of one TAC for the total Baltic Sea and with high fishing capacity available for cod it will be impossible to meet the aim of good and stable yields.

Das deutsche Larvenprogramm im Hauptlaichgebiet des Herings der westlichen Ostsee - eine Forschungsaufgabe von internationaler Bedeutung

The German larvae surveys in the main spawning area of the herring of the western Baltic Sea - an international important program. The article gives an overview over the German herring larvae surveys in the Greifswalder Bodden and Strelasund. This program is performed under ecological points of view annually in the main spawning area of the herring of the western Baltic Sea and delivers indices, which are well suited as independent estimates of the herring year-class strength.

Entwicklungstendenzen der Steinbuttfischerei in der Ostsee

The economical value of turbot (Psetta maxima) from the Baltic Sea has distinctly increased in the past decade. Compared to the eighties the catches of this species on the main fishing grounds increased threefold. Besides a more directed fishery on this species and an improved catch statistic the main reason for this fact is probably an increased stock size. Improved protection measures caused three consecutive strong year-classes. The main parameters of the turbot stock are presented.

28. Jahrestagung der "West European Fish Technologists´ Association" in Tromsø, Norwegen

In der 1970 gegründeten West European Fish Technologists’ Association (WEFTA) arbeiten zahlreiche europäische Institute, die sich mit Fischen als Lebensmittel bzw. Fischtechnologie befassen, zusammen. Sie wurde seinerzeit ins Leben gerufen, um jüngeren Wissenschaftlern zu ermöglichen, ihre Ergebnisse und Probleme einem größeren fachkundigen Publikum vorzustellen gegebenenfalls weiter weisende Impulse zu erhalten. In ihr wird aber auch der Sachverstand der Institute zusammengeführt, was zu zahlreichen bi- und multilateralen Absprachen geführt hat, aus denen EU-finanzierte Forschungsvorhaben entstanden sind. Die Jahrestagungen der WEFTA sind deshalb gute Gelegenheiten, bei denen Wissenschaftler und Technologen aus verschiedenen Ländern ihre Kenntnisse und Informationen austauschen können, um globale und öffentliche Fragestellungen zu diskutieren und durch gemeinsame Forschungsvorhaben zu klären.

Beurteilung der Fischbestände in Nordatlantik, Nord- und Ostsee. Einschätzung durch den Internationalen Rat für Meeresforschung vom Mai 1999

The spring session of ACFM gave advice for a number of stocks in the North Atlantic, North Sea and Baltic. The situation is given here for stocks of higher importance for the German fishery. These are: Blue Whiting: A short term upwards trend is observed, which, however, will not last very long, due to too intense fishing. Cod in Kattegat: Stock is outside safe biological limits. No immediate recovery in sight. Cod in Sub. Div. 22– 24 (Baltic): Stock is outside safe biological limits. Due to weak recruitment not immediate recovery in prospect. Greenland Halibut: Stock outside safe biological limits and still in downward trend. Herring (atlanto-scandian, Norw. spring spawner): Stock inside safe biological limits, weak recruitment of the past 5 years will, however, lead to a reduction of the biomass. Redfish: Generally decreasing tendency observed, a reduction of the fishery is recommended.

Zustand der Herings- und Sprottenbestände in Nord- und Ostsee, östlichem Kanal und westlichen britischen Gewässern. Beurteilung durch die Herings- und Ostsee-Arbeitsgruppe des ICES, März/April 1999

Information is given about the results of the latest meeting of the Herring Assessment Working Group for the Area South of 62° N and the Baltic Fisheries Assessment Working Group, which were conducted in March and April at ICES headquarters in Copenhagen. The actual stock development and the catch options estimated for different assessment units of herring and sprat are presented. The spawning stock size of North Sea herring reached in 1998 for the first time since 1991 a level above the Minimum Biological Acceptable Level (MBAL) of 800 000 t. Keeping the fishery at the present level the spawning stock size should reach in 1999 a level of about 1.2 mio. t. For the Western Baltic Spring spawning herring stock no actual stock estimate was presented. Due to uncertainties in splitting the catches in North Sea autumn and Baltic spring spawners no analytical assessment was accepted.

Die bewirtschafteten Fischbestände im Nordwestatlantik. Eine Einschätzung des Wissenschaftsrates der NAFO vom Juni 1999

Die Situation der bewirtschafteten Fischbestände im NAFO-Gebiet hat sich im Jahr 1998 im Vergleich zu 1997 nicht verändert. Alle Bestände auf der Grand bank (Gebiet 3LNO) bis auf die Gelbschwarzflunder, deren Bestand sich weiter vergrößerte, bleiben auf niedrigstem Niveau mit wenig Aussicht auf eine kurzfristige Erholung. Auch die Bestände auf der Flämischen Kappe (Gebiet 3M) sind mit Ausnahme der Garnelen (Pandalus boreals) in der gleichen Situation.