Simulierte Auswirkungen des mehrjährigen Bewirtschaftungsplans für die Dorschfischerei in der westlichen Ostsee und die Möglichkeit einer technischen Alternative

The cod stock in the Western Baltic Sea is assessed to be overfished regarding the definitions of the UN World Summit on Sustainable Development at Johannesburg in 2002. Thus, the European Fisheries Council enforced a multi-annual management plan in 2007. Our medium term simulations over the future 10 years assume similar stock productivity as compared with the past four decades and indicate that the goals of the management plan can be achieved through TAC and consistent effort regulations. Taking account of the uncertainty in the recruitment patterns, the target average fishing mortality of age groups 3 – 6 years of F = 0.6 per year as defined in the management plan is indicated to exceed sustainable levels consistent with high long term yields and low risk of depletion. The stipulated constraint of the annual TAC variations of ±15% will dominate future fisheries management and implies a high recovery potential of the stock through continued reductions in fishing mortality. The scientific assessment of sustainable levels of exploitation and consideration in the plan is strongly advised, taking account of uncertainties attributed to environmental and biological effects. We recommend our study to be complemented with economic impact assessments including effects on by-catch species, which have been disregarded in this study. It is further demonstrated, that the goals of the management plan can alternatively be achieved by mesh size adaptations. An alternative technical option of mesh size increases to realize the required reductions in fishing mortality provides avoidance of discards of undersized fish after a few years by means of improved selectivity, another important element of the Common Fisheries Policy. However, it is emphasized that technical regulations since 1990 failed to affect the by-catch and discards of juvenile cod. In any way, the meaningful implementation of the multiannual management plan through stringent control and enforcement appears critical.

Zustand und Entwicklung ausgewählter Fischbestände: Einschätzung des ICES im Herbst 2003

During the autumn session of the ICES Advisory Committee for Fisheries Management (ACFM) 58 stocks assessed in 7 Working Groups have been analyzed and reviewed, among these the demersal stocks in the North Sea and the Mackerel stock. As in previous years, ICES recommends a reduction in fishing mortality for a number of stocks or even the establishment of recovery and management plans, to safeguard a continuous development of the stocks towards safe biological limits. ICES reiterated last year’s recommendation to close the directed cod fishery and any fishery taking cod as by-catch in the North Sea, west of Scotland and in the Irish Sea. This year, the stocks of plaice in the North Sea, southern hake and southern anglers are (among others) in a critical state and in urgent need of protecting or rebuilding measures. This will again have an enormous impact on almost all mixed fisheries in the European Union.

10 Jahre Untersuchungen zur Reproduktionsbiologie des Dorsches im Institut für Ostseefischerei

The reproduction biology of cod is one of the main re-search topics of the Institute of Baltic Sea Fisheries at Rostock. It was defined 10 years ago when the Institute was formed. Since then results have been published in a number of publications. This paper summarizes the main results of the past decade ant outlines necessities for future research in cod reproduction biology in the Baltic Sea.

Zustand und Entwicklung ausgewählter Fischbestände - Einschätzung des ICES im Herbst 2002

During the autumn session of the ICES Advisory Committee for Fisheries Management (ACFM) 58 stocks assessed in six Working Groups have been analysed and reviewed, among these the demersal stocks in the North Sea and the Mackerel stock in the North East Atlantic. As in previous years, ICES recommends a reduction in fishing mortality for a number of stocks or even the establishment of recovery and management plans, to safeguard a continuous development of the stocks towards safe biological limits. ICES recommended the closure of the directed cod fishery and any fishery taking cod as by-catch in the North Sea, west of Scotland and in the Irish Sea. This will have a significant impact on the mixed round fish fisheries targeting haddock and whiting.

Reduzierung der Schädigung des Meeresbodens durch Baumkurren und Grundschleppnetze

An EU funded research project was started in 1998 by institutes from Ireland, Belgium, the Netherlands and Germany to reduce the adverse environmental impact of demersal trawls. In the frame of this project the Institute for Fishery Technique of the Federal Research Centre for Fisheries, Hamburg, is developing a jet beamtrawl replacing the heavy tickler chains of a traditional flatfish beam trawl by water jet nozzles placed at the lower side of the beam with the jets directed towards the sea bottom. First trials on the dutch research vessel “Tridens” were performed in March 1998. Catch and bycatch of a jet beamtrawl and a traditional beamtrawl were compared. The efficiency of the jet beamtrawl was not satisfactory and will have to be improved.