Der Internationale Rat für Meeresforschung (ICES) empfiehlt Fangmengen für 1997

Based on the report of the most recent meeting of the ICES Advisory Committee on Fishery Management (ACFM), May 1996, brief uptodate information is given on the status of the fish stocks utilized by the German fleet and the relevant advice on TAC's to be fished in 1997.

Myxobolus aeglefini in Wittlingen (Merlangius merlangus)der Nordsee und der lrischen See

In June 1994 and 1995 stations in the North, Irish, Celtic Seas and the Channel were studied for the occurrence of Myxobolus aeglefini in whiting (Merlangius merlangus). The disease was visible externally as either white nodules of a few millimeters diameter in the upper mouth cavity, gill arches and the basis of pelvic fins and in severe cases also on the lower jaws or in the cornea and sclera of the eye. It was verified morphometrically in histological sections of infected eyes by size and shape of spores. Myxobolus aeglefini was present in low prevalences at two North Sea stations and high prevalences of up to 49 % in the Irish Sea (Solway Firth) during both cruises. Whiting between 23 and 55 cm were found to be infected. Neither length-age prevalences nor condition factors and gonado, spleen, liver somatic indices differed in diseased and healthy fishes.

Kontrollgeräte zur Überprüfung der Antriebsleistung von Fischereifahrzeugen - Entwicklungen im Institut für Fischereitechnik

Seit der Einführung der Plattfisch-Schutzzonen existiert das Problem der Kontrolle der maximalen Antriebsleistung von Fischkuttern. Nachdem in den letzten Jahren die Motoren der in den Schutzzonen zugelassenen Fahrzeuge zunehmend zu einer höhren Leistungsabgabe umgebaut wurden, entstanden zum Teil erhebliche Wettbewerbsverzerrungen in der EU- Flotte und eine nicht kontrollierte Steigerung des Fischereiaufwandes in den Schutzzonen durch Nichtbeachtung der Vorschriften.

Unerwartet niedrige Gehalte an toxischen Schwermetallen im Filet von Seefischen aus der Barentssee

Die 150. Reise des FFS "Walther Herwig III" wurde im Juli/August 1994 als Gemeinschaftsprojekt der Institute für Biochemie und Technologie und dem Institut für Fischereiökologie durchgeführt, um einen Überblick über die Schadstoffbelastung (anorganische und organische Schadstoffe, Radioaktivität) von Wasser, Sediment und Biota in der Barentssee zu erhalten. Das Institut für Biochemie und Technologie hat in diesem Forschungsprogramm den Teil "Bestimmung der Schwermetallgehalte im verzehrbaren Anteil (Filet) von Fischen und anderen Meerestieren" übernommen.

Struktur und Fänge der deutschen Fischereiflotte

In order to carry out the Multi-annual Guidance Programmes (MGP) the national fishing fleets of the EU were divided into mostly homogenous fleet segments. The current paper describes the single segments of thc German fishing fleet and summarizes their characteristics such as vessel capacity (tonnage in GRT), machine performance (power in kW) and vessel size (total length in m). Another table lists the averaged landings separated per stock and segment for the period from 1990 to 1994.

Situation wirtschaftlich wichtiger Grundfischbestände vor Norwegen, Spitzbergen und in der Barents-See

Assessments on NE-arctic stocks of cod, haddock, saith, redfish and Greenland halibut were carried out by the ICES 'Arctic Fisheries Working Group' in August 1996. Whereas stocks of cod, haddock, and saithe are presently in fairly good and stable condition the assessments show the stocks of beaked redfish and Greenland hailibut to be just the opposite. The status of the golden redfish stock seems to be stable. More detailed information is given in this report.

Internationaler Rotbarschsurvey auf den ozeanischen Sebastes mentella in der Irminger See unter isländischer, deutscher und russischer Beteiligung

A hydroacoustic survey on the oceanic redfish (oceanic Sebastes mentella) in the Irminger Sea and adjacent waters South and East of Greenland was carried out by Iceland, Germany and Russia. During this, about 250 000 nm2 were covered. The acoustic assessment yielded a stock size of approximately 1.6 x 10(6) tonnes or 2.6 x 10(9) individuals. This however, is considered to be an underestimation of the stock, as a result of partial mixing of the stock with the scattering layer. The oceanic redfish concentrations were densest at 200-300 m depth, mainly within temperatures of 3.5 °C to 5 °C. 61 % of the stock were males at an average length of 36 cm and an average weight of 582 g.

Untersuchungen der Industriefischerei 1995/96

Information on the impact of industrial fishery on sandeel and sprat is given. First results of experimental fishing on board RV "Walther Herwig III" and results of studies aboard commercial vessels within the German Economic Zone are presented.

Kabeljau-Discards in der Deutschen Bucht

The German trawlfishery on cod in the German Bight causes discards. Their amount since 1983 has been estimated. The losses of millions of fish finally is the reason for losses of thousands of tonnes of valuable landings. The fishermen therefore should improve the selection rate of their nets.

Die biologischen Voraussetzungen für einen guten Dorschnachwuchs verbesserten sich 1994 in der westlichen Ostsee

The investigations on the fecundity of cod from different areas of the Baltic Sea started in 1992. The samples were collected in ICES Sub-divisions 25 (Bornholm Sea). 24 (Arkona Sea) and 22 (Mecklenburg and Kiel Bay). This article surnmarizes the results of 435 analysed gonads from females of age groups 1 to 8 with total length of 24 - 116 cm of the years 1992 to 1995. The gonads were prepared and analysed according to the methods which were deseribed in Bleil and Oeberst (1993). The aim of the investigations is to estimate the reproduction potential of cod for different areas and years. For this reason the absolute and relative fecundity were analysed for estimating the dependence on the total length, for age groups and the weight of females. These data were estimated for the populations Gadus morhua morhua and Gadus morhua callarias. Preliminary results have shown that the absolute fecundity (fabs) is dependent on whole weight of the females. The influence of sub-divisions (SD) and years to the fecundity are very low. Additional to this data was calculated the population fecundity for the western Baltic Sea stock (SD 22 and 24). The numbers of produced ripe eggs within the western Baltic were estimated with 4055.59 x 10(9) for 1993 and 6949.85 x 10(9) for 1994.

Einfluß der Holtechnologie auf die Selektion von Grundschleppnetzen

A widespread belief among fishermen that sidetrawlers show a better selectivity than sterntrawlers was investigated in a comparative fishing exercise in the Baltic. In contrary to earlier observations during this experiment in May no essential differences with regard to the selectivity of the trawls used could be found for both types of fishing vessels. Possible explanations for the result are discussed.

Keine Erholung der westgrönländischen Grundfischbestände

Since 1991, the aggregate biomass of fish stocks inhabiting the West Greenland shelf stagnates at the lowest level. The latest survey results of cruise no. 152 conducted by FRV 'Walther Herwig III' do not indicate any improvements in state of the stocks, although no fishing effort was recently directed towards groundfish. The cod stock showed again a record low and is presently dominated by recruits of the year classes 1991 and 1993. Both year classes are considered to be weak and the cod stock is beyond the 'minimum biologically acceptable level'. Consequently, an increase in stock abundance is not expected either in short or long term. Other ecologically or economically important fish species, American plaice, redfish, wolffish and starry skate, were also found to have minimum stock abundances. By-catch estimates of juvenile groundfish taken by the shrimp fishery, operating at traditional grounds of cod and redfish fisheries, are indispensible. Analysis of climatological data from Nuuk/West Greenland indicates that climate during the past fourty years was characterized by two decades of anomalous warm conditions, and cooling which dominates the dimate since 1969. Anomalous cold events were encountered during 1983, 1984 and during 1992, 1993. Similar to the air temperature anomalies, autumn temperatures of the ocean surface layer indicate cold and warm periods during the past thirty years. In contrast to the colder than normal atmospheric conditions during the early nineties, however, the ocean conditions indicate intermediate warming.