Die europäischen Krabbenanlandungen der letzten Jahre: Deutschland Nr. 1

Fishery on brown shrimp has developed towards one of the most important fisheries in the North Sea area in economic terms. Statistical data on European wide landings have been gathered by a working group of the International Council for the Exploration of the Sea. They show relatively stable shares of approximately 50% for Germany, 38% for the Netherlands and 8% for Denmark. Further production originates from Great Britain, France and Belgium. The new log-book regulation of the EU will give similar data improved by better information on fishing areas and fishing effort.

Die Anteile von Sieb- und Futtergarnelen in deutschen Garnelenfängen im Jahre 2000

The German shrimp fisheries land different types of pro-duce. Besides cooked shrimp for human consumption small (undersized), raw shrimp (industrial shrimp) are landed regionally in the second half of each year for animal feedstuff purposes. They are dried in special plants and form sellable secession from sieving processes aboard shrimping vessels. Grading the cooked shrimp ashore gives the non-marketable fraction of too small shrimp, which is not meant for shelling. That fraction is produced all year alongside landings of shrimp and is used for feed-stuff as well. Both extra fractions are listed in the official statistics since 2000 for the first time. That year industrial shrimp made up 6 % of the total landings while the non-marketable, small cooked shrimp summed up to 7 %, respectively. Though being essential for specialised animal feeds they are commercially of very little value, making up to hardly 2 ‰ of the total turnover of the German shrimp fisheries.

Winterfischerei auf Garnelen. Die Anteile der europäischen Garnelenflotten an den Anlandungen von Crangon crangon im Zeitraum Januar bis März der Jahre 1990 bis 1999

„Winter fishery“ on brown shrimp does not imply a special type of fishery. It merely means the continuation of the standard fishing procedure of parts of the fleet during wintertime, when the majority of the mostly smaller vessels stay in harbour due to generally unfavourable weather conditions for their activity. During 1990 to 1999 mean European wide landings in January and February summedup to 854 tonnes making up to only 4 % of the mean annual landings (21 805 t). While German vessels landed0.7 % (68.7 t) of their mean annual landings during that period, the other countries caught about 7 % of their individual, mean annual landings at the same time. The Netherlands and Denmark contributed highest tonnages of 580and 110 tonnes, respectively, to the total European landings, making up 81 % of them. As about 70 % of brown shrimp may carry eggs in January, the winter fishery took a mean total of about 2.15 x 1012brown shrimp eggs out of the stocks in that period annually. As there is no reliable assessment available concerning the brown shrimp stocks, it is despite of these high losses of eggs not possible to trace a negative effect of the winter fishery in scientific terms. However, precautional catch reductions in winter would be in favour of higher survival rates of eggs, which are the carrying source for the recruitment of brown shrimp stocks and catches in forthcoming summer and autumn seasons according to Dutch investigations.

Die Lage der Fischbestände in Nordostatlantik, Nord- und Ostsee. Einschätzungen des Internationalen Rates für Meeresforschung im Frühjahr 2001

The spring session of ACFM gave advice for a number of stocks in the North Atlantic, North Sea and Baltic. The present assessment of the situation is given here for stocks of importance for the German fishery. These are: Blue Whiting: the stock size is rapidly decreasing due to high catches; ICES recommends a closure of the fishery. Herring (Atlanto-Scandian, Norwegian spring spawner): Stock is within save biological limits, weak recruitment of the recent years will lead to a further reduction of biomass. Herring (North Sea): revision of the assessment led to a different perception of the stock: SSB was in 2000 below Blim. Excellent recruitment will lead to an increase of SSB over Blim within this year, but ICES recommends to reduce fishing mortality on adults significantly. Herring (Baltic spring spawner in 22–24, IIIa): Still no increasing tendency is detectable. Herring (VIaNorth): stable. Redfish: generally further decreasing tendency observed, a reduction of the fishery is recommended. Signs of recovery visible only for two units. Greenland Halibut: State of the stock not quite clear, but slightly positive tendencies. The present fishing intensity should be reduced. Cod (Kattegat): Weak recruitment, outside safe biological limits. ICES recommends a closure of the fishery. Cod (22–24, Western Baltic): Stock situation unclear due to extensive migrations. F should be reduced by at least 10%.

Die Bedeutung biologischer Daten aus der deutschen Seelachsfischerei für Bestandsabschätzung und Management

Since 1999, the ICES Working Group on the Assessment of Demersal Stocks in the North Sea and Skagerrak assesses the saithe stock in the North Sea, Skagerrak and west of Scotland as a single stock unit. The sampling, evaluation and role of biological data from the German saithe fishery in the assessment are described. The German data showed similar trends as observed in French and Norwegian series. Based on these estimates, the spawning stock recovered to more than 200 000 t due to reductions in quotas and exploitation rates. Thus, the production of the stock increased also in combination with good recruitment and positive trends in spawning stock size and landings were projected for 2002. The biological data derived from the German saithe fishery dominated the assessment of stock size, structure and exploitation. This fact encourages a continuation of the described analyses based on sampling onboard fishing vessels and fish markets by the Institute for Sea Fisheries. The successful collaboration with the saithe fishing industry is judged as an important contribution to the sustainable management of fish stocks.

Die Fruchtbarkeit von Dorschen in der Ostsee - was verrät sie uns?

About 1500 ovaries of Baltic cod were prepared for estimating the potential absolute and relative individual fecundity. The female cod were sampled in the Belt Sea, ICES Subdivision (SD) 22, in the Arkona Sea, SD 24, and in the Bornholm Sea, SD 25. The investigations started in1992 and until 1999 cruises were carried out to catch female cod in the different sub-divisions every year. The results shows that the potential fecundity is not a stable biological parameter, and that significant changes are possible within a relative short period. It was demonstrated that the developments of the potential individual fecundity of the western (Gadus morhua morhua) and eastern Baltic cod stocks (Gadus morhua callarias) were different. In contrast to the stable individual fecundity of the western cod the absolute and relative fecundity of the eastern repeat spawners increased from 1993 to 1999, significantly. The reason of this development seems to be the dramatic decrease of the eastern cod stock and the more successful reproduction of individuals that produce oocytes with a lower dry weight in combination with a higher relative fecundity.

Nährstoff-Einträge aus der deutschen Aquakultur in die Ostsee

Es gibt vier bzw. fünf große Gewässereinzugsgebiete mit Bedeutung für die Fischzucht. Dies sind die Donau mit ihrem Abfluß in das Schwarze Meer, Rhein, Weser und Elbe, die in die Nordsee entwässern sowie die Oder, die in die Ostsee mündet. Daneben gibt es noch einige weitere kleinere Flüsse von Nordwesten bis Nordosten Deutschlands, die in Nordsee (z. B. Eider, Stör) oder Ostsee (z. B. Stebnitz) fließen und das Ablaufwasser von Fischzuchten transportieren können.

Die Fischereiressourcen im Hinblick auf deutsche Interessen

The North-European fish stocks are assessed annually by ICES working groups. The results are evaluated twice annually in two meetings of the Advisory Committee for Fisheries Management (ACFM) at ICES. Based on the working group assessments, ACFM formulates an advice for the fisheries management and suggests a total allowable catch (TAC) which is based strictly on biological grounds. The summaries of the state of some selected stocks which are given here, are derived from the ACFM advice, formulated during the most recent October 1999 meeting. For many of the fish stocks the precautionary approach has been implemented now, and for most of them the target reference points have been defined. As a result, most of the stocks are outside safe biological limits or are harvested in disaccordance with the precautionary approach. Only 10 stocks of those evaluated during this autumn meeting were found to be within safe biological limits.

Welche Faktoren beeinflussen die Stärke der Dorsch-Jahresklassen?

In the previous years extensive investigations were carried out concerning the reproduction biology of cod in the Baltic Sea. The analyses showed that the year class strength of the eastern Baltic cod stock is decisively determined by the bad oxygen conditions during the spawning season in the summer and by sprat as predator of the cod eggs. In the western Baltic Sea these factors have no importance. The year classes are mainly determined by the strong variations of the portions of female cods, which participated in the spawning activities in the region. The individuals within the length range from 35 cm to 45 cm have a special importance at this time, caused by the actual age structure of the cod stock.

Die Tiefseegarnele Pandalus borealis im Nordostatlantik. Biologie, Bestandssituation und fischereiliche Nutzung

One of the most common decapode in the North Atlantic is the “Northern” or “Pink shrimp” Pandalus borealis (Kröyeri). Due to decreasing fish stocks and catches the shrimp fishery was intensified during most recent years. In the North-East Atlantic, a profitable fishery on this species has been carried out by Norway and USSR/ Russia off Norway, in the Barents Sea and off Spitsbergen for about 30 years. For the first time, Germany started a shrimp fishery with FMV “Hannover” in this area in spring/summer 1999. This article gives information on the biology of Pandalus borealis. A brief description of the problems in stock analyses, stock assessment, and the TACs (Total Allowable Catches) for the entire North Atlantic are given.

Die Bruttoraumzahl als neue Einheit der Schiffsvermessung

The definition of the newly introduced dimensionless parameter for tonnage measurement (German: Bruttoraumzahl (BRZ) (English: Gross tonnage (GT)) instead of Gross register ton (GRT) (German: Bruttoregistertonne (BRT) doesn’t seem to be so clear, neither for specialists. The present article gives some explanations about the history of measurement of ships and the relation between BRT and BRZ, especially for fishing vessels.

Die lage der Fischbestände in Nordostatlantik, Nord- und Ostsee. Einschätzungen des Internationalen Rates für Meeresforschung im Frühjahr 2000

The spring session of ACFM gave advice for a number of stocks in the North Atlantic, North Sea and Baltic. The present assessment of the situation is given here for stocks of higher importance for the German fishery. These are: Blue Whiting: the stock is still relatively high, this, 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 22–24 (Baltic): stock is inside save biological limits. F, however, is above the recommendation of the IBSFC. Greenland Halibut: state of the stock not quite clear. The present fishing intensity seems to be sustainable. Herring (Atlanto- scandian, Norwegian spring spawner): stock is within safe biological limits, weak recruitment of the recent years will lead to a reduction of biomass. Herring: for Baltic spring spawner in 22–24 and IIIa still no increasing tendency detectable. North Sea Herring: further increasing tendency, with 900 000 t over B lim, good recruitment. Herring in VIa: stable. Redfish: generally decreasing tendency observed, a reduction of the fishery is recommended. Signs of recovery, however, visible for some units

Radioaktivität in Fischen und anderen Meerestieren aus der Nordsee. Auswirkung der 1994 geänderten Genehmigung für Sellafield auf die Strahlenexposition der Bevölkerung

A subject of a change of authorised limits in 1994 for the discharge of liquid radioactive waste by the reprocessing plant Sellafield (UK) was an increase of these limits for certain radionuclides (3H, 14C, 60Co, 99Tc and 129I). It is investigated now how the radioactivity in marine biota from the North Sea and subsequently the public radiation exposure by ingestion has developed in the years since 1994. This is based on a compartment model for the Northeast Atlantic. Discharges of the reprocessing plants Dounreay (UK) and La Hague (F) are included in the assessment. It is deduced that about 60 % of 137Cs in the North Sea originate presently in the remobilisation of old Sellafield discharges from the Irish Sea sediment. A comparison with measured biota data shows that the model is conservative in the most cases. The public radiation exposure from ingestion of fish, crustaceans and molluscs from the central North Sea as the sum over 12 considered radionuclides has decreased from 1992 to 1998 from 0,13 to 0,08 μSv·y–1. For the southward and northward joined regions it was a little bit smaller with a similar decreasing trend.

Ostseehering (Clupea harengus) - eine Rohwarenressource für die deutsche Fischwirtschaft?

Baltic Sea herring is a traditional raw material for the German fish processing industry and the fresh fish market. This applies also for the spring herring of the spawning population of the waters around the island of Rügen. Reduction of the fat content to about 5 % during the spawning cycle limits the processing possibilities of mature herring from this area. Failures in taste and odour (tainting), a common problem of the past have not been detected in the last 3 years. Infestation by nematodes are comparable to other herring stocks and contamination levels of organic and inorganic contaminants are well below allowable limits. The annual German fishing quota of about 85000 t of Baltic Sea herring is now utilised only to 10 %. For a stronger utilization of this stock as in the 70th and 80th , there are scarcely prerequisites. The project of a central processing plant on the island Rügen for about 50000 t of herring as raw material is not realistic. The answer to the question asked at the beginning of this article, whether Baltic Sea herring represents a raw material for the German fish processing industry, is YES, dispite some restrictions.

Fischerei auf die wichtigsten nordostatlantischen Grundfischbestände 1998

A short review of the actual assessments on the northeast atlantic groundfish stocks of cod, saithe, haddock, redfish and Greenland halibut provided by the ICES „Arctic Fisheries Working Group“is given. All these stocks are presently considered outside safe biological limits. For the first time since 5 years the cod stock is in an endangered situation, because the assessment was to optimistic and the TAC therefore set to high. According to the recent assessments necessary changes in the commercial fishery of the year 1998 off the Nowegian coast and in the Barent-Sea area are discussed. Information on distribution and fishery of cod, haddock, saithe and redfish is given. Biological investigations were carried out onboard the German factory trawler FMS „KIEL“ in January/March and September/ Occtober 1998 in order to collect data of the German fishery in that area. Aspects of length and age distributions, and stomach- and gonad investigation are represented.