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.

Ichthyoplanktonaufnahmen als Beitrag zu Biodiversitätsuntersuchungen in der westlichen Ostsee

Ichthyoplankton material provides information on the species composition in an area of investigation and leads to a better understanding of the entire fish community. Since 1993 every year in May and/or June an ichthyoplankton survey in ICES-Subdivision 22 and 24 has been performed to sample the plankton community of fishery resources in the western Baltic Sea. One objective was to get signs of possible changes in the natural structures of this fish community. The time series derived from the Bongo-Net samples does not show a clear trend in larval densities. Values varied, but up to now samplings in the western Baltic Sea yielded only low mean densities. According to the kind of reproductive biology the fish species were divided in three major groups: • Fish species with a long developmental phase in the plankton community • Small short living species with benthic eggs and a reduced plankton phase • Guests without local spawning populations. Species could be identified, which were absent in the fish larvae catches of the western Baltic Sea in the 60s and 70s.

Deutsche und internationale Dorschfischerei in der Ostsee im Jahr 1998

In 1998 the longtime series of the standardized bottom trawl surveys conducted in the western Baltic (ICES Sub-division (SD) 22 and 24 since 1978) during spring and autumn and also in the eastern Baltic (ICES Sub-division since 1993) during spring were continued. The results of the surveys as well as those of a sampling programme carried out on board of commercial cutters (mainly financed by an EU study project) and on the market, the investigation of the survival rate of the discards, and the landing statistics are the basis of the analysis of the German and international cod fishery in 1998. The German cod fishery was concentrated on the ICES SD 22 and 24 (total landings 9722 t). The total landings from the fishing grounds east off Bornholm, the traditional German fishing ground, amounted only to about 1270 t. The German cod quota was utilized at 64 %. The fishery in the ICES SD 22 and 24 was characterized by a discard rate of undersized cod of 13 %. That corresponds to about 7.3 million specimens of 0-group, one- and two-years-old youngfish, respectively. The total international cod landings of the Baltic amounted to 101 500 t. In comparison with 1997 (total landings 129 600 t) the landing decreased by 23 %. The percentage utilization of the cod TAC (1998: 140 000 t) amounted to 74 % in 1998.

Fangtechnische Möglichkeiten zur Reduzierung des Beifangs von Meeresenten in der Dorschfischerei mit stationären Fanggeräten

The present contribution summarizes results of fishery investigations with gillnets and longlines in the winter cod fishery which had been carried out in the western Baltic region from 1996 to 1999 by the Bundesforschungsanstalt für Fischerei with financial aid of the country Schleswig-Holstein. The main goal of these investigations was to point out technological possibilities for a reduction of unwanted bycatches of sea ducks in gillnetting. As it is obviously impossible to reduce the local and temporal bycatch problem by means of different gillnet constructions or tactical measurements, only the temporary avoidance of fishing grounds with high abundance of ducks or the change to longlining as catch method with reduced duck bycatches may be an effective solution.

Entwicklung des Aufwandes in der deutschen Garnelenfischerei

The German brown shrimp fishery experienced considerable changes during the recent four decades. Contrarily to the decline in number of vessels the technical standard and size of the shrimping vessels improved and the fishing power as well as the effort of the single boats have strongly increased. As fishing effort by the whole fleet may be calculated different ways, trends in total effort may differ according to the relevant author´s approach. The present study tries to estimate the total trawled area by the fleet in the mid fifties as well as in 1996. The result is that there seems to be no change in the order of magnitude of the total trawled area for the German shrimping fleet itself, though shifts in geographical areas as within seasons were reported. However, the development of the Danish and Dutch shrimping fleets have contributed to an increase in terms of annually trawled area. Therefore pooled fishing effort must have increased considerably.

Discards in der deutsche Seelachsfischerei

The saithe fishery in the Northern North Sea includes unused by-catches, that usually represent 6.1 % of the total catch. Although this relates clearly to single to species and year classes this fishery is comparatively “clean”. If such catches were better used, i.e. if the marketable fish of legal length were also landed, one could certify that the saithe fishery could be carried out without ecological concern.

Historie und aktueller Stand des Internationalen Heringslarvensurveys in der Nordsee

Since years the International Herring Larvae Survey Program (IHLS) is an important and internationally established survey program in the North Sea. The IHLS serves the calibration of stock abundance estimates based on information from the commercial fishery and the method of Integrated Catch Analysis (ICA) which is a specific derivate of the Virtual Population Analysis (VPA). Meanwhile the IHLS database has been transferred from Aberdeen to Kiel and it has been agreed that the Institut für Meereskunde Kiel should continue to maintain this database and provide the abundance indices to be utilized by the ICES Herring Assessment Working Group as one of the means for assessing the state of the herring stock in the North Sea. For establishing the calculation procedure at Kiel, it was necessary to optimize both, the survey design and the index calculation. This article gives an overview over the survey’s history, it’s geography, the sampling design, the information content of the IHLS data base and the various methods of calculating the different indices necessary for the calibration.

Qualitat under Verwertung von Fruhjahrshering aus der Ostsee

The utilization of spring herring caught off the eastern German Baltic Sea coast in the waters around Rügen Island has a long tradition. Since 1991 there was a dramatic decrease in herring fisheries in this area. To promote the better use of this typical spring herring stock an exploratory fishery was started from January to May 1999 accompanied by quality investigations. The results show the possibilities of utilization according to length distribution, fat content and quality aspects.

Vierwöchige Gebietsschließung in der Deutschen Bucht - Eine Maßnahme zum Schutz des starken 1996er Kabeljaujahrgangs

End of January 1998 a real-time closed area has been established by the Federal Republic of Germany. As a case of emergency an area of 12 x 25 nm has been closed for trawling, to protect the mostly undersized 1996 cod year-class. The background and the valuation of this action is described.

Analyse der Beifangreduktion durch Trichternetze in der kommerziellen Garnelenfischerei

Trials for the determination of the magnitude of bycatch reduction by the sievenets used in the commercial brown shrimp fishery were carried out from September to December 1997. Trawls with 9 m beam length were the subjected to the investigation. They were used on different fishing grounds in the estuary of the Elbe near Cuxhaven. Sievenets with 50, 60 and 80 mm mesh opening were tested in 29 hauls and 31.6 h total duration. A trawl of equal construction without sievenets fished synchronously was used for comparison. The proportional catch composition in the codend was determined by weighing the catch components (fish, discard shrimps and commercial size shrimps) as separated by means of a riddle. The composition of the sorted out part of the catch could be calculated by comparison of the corresponding catch components both in standard trawl and sievenettrawl. According to this the total catch of a beam trawl with sievenet is diminished by 9 to 34 % depending on the mesh opening of the sievenet. 32 to 58 % of the sorted out part of the catch consists of fish. Use of a sievenet, however, also leads to a loss of 6 to 15 % of commercial size shrimps. Per hour of towing this means a loss of 8.7 kg commercial size shrimps with a sievenet of 60 mm mesh opening and of 1.8 kg for a mesh size of 80 mm.

Ergebnisse der 23. Jahrestagung der Internationalen Ostsee-Fischereikommission (IBSFC) vom 08.-12.09.1997 und Ausblick

Die Tagung fand in Warschau, dem Sitz des Sekretariats der IBSFC, statt. Arbeitsebenen der Tagung sind Plenarsitzungen und Sitzungen der beiden Ständigen Komitees „Regulierungsmaßnahmen“ und „Finanzen“. Die Plenarsitzungen und Sitzungen des Ständigen Komitees für Regulierungsmaßnahmen mit insgesamt 34 Tagungsordnungspunkten waren geprägt von der Analyse der nationalen Fischereien im Basiszeitraum, d.h. von der Ausnutzung der nationalen Quoten für 1996 und z.T. 1997, den Beratungen zum Fischereimanagement für 1998, aber auch vom Vorsorgeansatz im Fischereimanagement und den Auswirkungen der sogenannten Rio-Konferenz (UN-Konferenz über Umwelt und Entwicklung, Rio de Janeiro 1992) für den Ostseeraum.

Die Situation der Makrelen- und Stöckerbestände. Der deutsche Beitrag zur internationalen Bestandsabschätzung

The question has not yet been completely solved whether or not the mackerel and horse mackerel stocks in the waters from the Bay of Biscay to the Atlantic off the Norwegian coast are independent unit stocks or must be regarded rather as one stock with distinct stock components. The stock definition, however, is the basis for fishery management and is fundamental for the exploitation of the stocks. For this reason the extensive mackerel and horse mackerel egg survey carried out in 1998, is of high importance and significance for the fishery management of the two species. The survey has begun in January in Iberian waters and will eventually end in the autumn north of Scotland. To cope with this task research vessels of eight European nations are participating.

Aktuelle Entwicklung der Herings- und Sprottenbestände südlich des 62. Breitengrades

Information is given about the last meeting of the ICES “Herring Assessment Working Group for the Area South of 62° N”, conducted from 9.-18. March 1998 in Copenhagen. The actual stock development and the catch option estimations for different assessment units of herring and sprat are presented. The spawning stock size of North Sea herring was in 1997 still below the “Minimum Biological Acceptable Level” (MBAL) of 800 000 t. Keeping the fishing mortalities at the present level, the spawning stock size should reach a level of about 1.1 million tons by end of 1998. For the Western Baltic pring spawning herring stock no actual stock parameters were estimated. Due to uncertainties in splitting the catches in North sea autumn and Baltic spring spawners no analytical assessment was accepted.