Incidences de la modification de la circulation des eaux sur l'hydrochimie et le degré de contamination bacterienne d'un estuaire eutrophe tropical

In order to control the proliferation of floating aquatic vegetation in Côte d'Ivoire, a coastal inlet, allowing a direct communication between the Comoe river and the ocean, was created in September 1987. The impact of this operation on the hydrochemistry (salinity, nutrients, algal biomass) and the bacterial contamination level was studied in the area close to the Vridi canal.

Sur la circulation d'eau a la surface du corps des Stomatopodes

A wide collection of Stomatopods of Indochina was studied from a morphological point of view.

L'oxygène dissous en Lagune Ebrié: Influences de l'hydroclimat et des pollutions

The hydrology of the Ebrie coastal lagoon in Abidjan area is summarized. The authors describe the oxygenation in that area during the two extreme seasons of the hydrological cycle: the low-water season (March-April) and the high-water season (Sept-Oct). The influences of the continental and oceanic waters, photosynthesis, exchanges with the atmosphere and pollution are considered. The oxigen consumption of primary organic pollution represents from 9 to 12% of the content of the waters that circulates in the area. It is geographically very heterogeneous. The central basin, swept by strong marine and fresh water currents, shows a rather high level of water oxygenation. In the peripheric bays, water circulation and mixing are less important and pollution accelerates the natural eutrophic processes. During the low-water season, a vertical stratification is responsible for a bottom anoxic layer and the deposit of reduced organic silts. On the contrary, supersaturations, up to 200%, are recorded on the surface layer. During the high-water season the break of the vertical stratification sets the loose reduced silts into suspension and partly reoxygenates the bottom waters. A classification of the different areas, based on the oxygen vertical profiles is proposed.

Tidal oscillations at the head of Monterey Submarine Canyon and their relation to oceanographic sampling and the circulation of water in Monterey Bay. Annual report, Part 6, September 1972

During a 25-hour hydrographic times series at two stations near the head of Monterey Submarine Canyon, an internal tide was observed with an amplitude of 80 to 115 m in water depths of 120 and 220 m respectively. These large oscillations produced daily variations in hydrographic and chemical parameters that were of the same magnitude as seasonal variations in Monterey Bay. Computed velocities associated with the internal tide were on the order of 10 em/sec, and this tidally induced circulation may have a significant role in the exchange of deep water between Monterey Submarine Canyon and the open ocean. (PDF contains 49 pages)

Modelling of the Subarctic North Pacific Circulation (Report of Working Group 7)

This review focuses on modelling ocean circulation and its variability in the subarctic North Pacific; it addresses issues specific to that region, and not the subject of ocean modelling in general. The performance of existing models is assessed in relation to observations in the upper ocean, intermediate waters and deep/abyssal waters. (PDF contains 87 pages)

Traité général des pesches : et histoire des poissons qu'elles fournissent tant pour la subsistance des hommes que pour plusieurs autres usages qui ont rapport aux arts et au commerce. [3 volumes bound in 2 parts in folio]

Early illustrated book about fish, fishing and fisheries by one of the preeminent scientific investigators of the French enlightenment. This work deals extensively with the species of fish found in Europe and beyond, their habits and habitats, techniques and equipment used in fishing and fish processing, and many other aspects of these endeavours. Roughly 185 engraved plates illustrate the text. The scans for this version come from 3 volumes bound in two parts in folio.

Tagungsbericht: 29. Sitzung des FAO-WHO-Codex-Alimentarius-Komitees für Fische und Fischereierzeugnisse

Der globale Handel mit Fischen und Fischereierzeugnissen funktioniert nur dann reibungslos, wenn sich die Handelspartner über die Qualität und Sicherheit der Produkte einig sind. Um diesen Handel zu erleichtern, tagen Experten aus aller Welt regelmäßig im CodexAlimentarius-Komitee für Fisch und Fischereierzeugnisse (CCFFP). Sie erarbeiten unter besonderer Beachtung des Gesundheitsschutzes der Verbraucher sowie der Sicherung fairer Praktiken im Handel internationale Lebensmittelstandards, Richtlinien und Vorschriften wie Codes of Practice. Die Mitarbeit in diesem Komitee ist auch aus dem Grunde besonders wichtig, da es eine Plattform dafür bietet, Ergebnisse aus eigener experimenteller forschender Tätigkeit direkt in hochrangige internationale Rechtsnormen umzusetzen, die unmittelbar dem Verbraucher und der betroffenen Lebensmittelindustrie zugute kommen, wie es beispielsweise bei der Grätendefinition, der Bestimmung des Fischkerngewichtes, der Bestimmung der Lebensfähigkeit von Nematoden, dem Heringsstandard, dem Standard für Fischstäbchen usw. der Fall war.

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.

Johann Heinrich von Thünen: Leben und Werk des Namenspatrons des neuen Bundesforschungsinstituts für Ländliche Räume, Wald und Fischerei

A new concept for resource oriented federal research within the competence of the German Ministry of Food, Agriculture and Consumer Protection was implemented in 2008. The Johann Heinrich von Thünen-Institute, Federal Research Institute for Rural Areas, Forestry and Fisheries is one of 4 newly established large scale federal research institutions. It comprises the former Federal Research Centre for Fisheries, the Federal Research Centre for Forestry and Forest Products and large parts of the Federal Agricultural Research Centre. The institute is named after Johann Heinrich von Thünen, a famous national economist and social reformer of the 19th century. He developed the first serious treatment of spatial economics (the so-called Thünen rings) and the basics of the theory of the natural pay.

Mögliche Ursachen des geringen Heringsnachwuchses in der Nordsee

Though the stocks of North Sea herring seemed to have recovered from small numbers since the mid-1990s we do recently observe a new decline in the spawning stock biomass. This is mainly caused by four consecutive years of small reproduction. Whilst the adults produce enough eggs and larvae only few survive until mature stages. The reasons for the bad recruitment are not clear. In this paper we investigate the influence of climate conditions, in particular the North Atlantic Oscillation (NAO) that obviously triggers the interaction between the size of the spawning stock and the abundance of larvae. We show that approximately 60 % of the recruitment variance can be explained by specific constellations of spawning stock size and climatic conditions. Beside physical factors we also discuss several working hypotheses shedding light on the influence of biological variables on the fluctuation of herring offspring.

Ein Vorschlag zur Senkung des Schlepppwiderstandes von Grundschleppnetzen

Mathematical modelling shows that the projection area of the trawl twine influencing its hydrodynamic resistance can be reduced by approx. 30 % through increasing the mesh size of the trawl wings and the conical parts of the trawls, in combi-nation with the use of thinner twine. The interrelation between fuel consumption and projection area of the trawl twine as well as the influence of the enlarged meshes of the wings and first panels on the catch composition can only be measured by trials on fishing boats.

Begrenzung des Fischereiaufwandes oder Erhöhung der Mindestmaschenöffnung – Ein Vergleich der Alternativen bei der Dorschfischerei in der Ostsee

The basis for a long-term profitable fishery is a precautionary and environment-compatible use of fish stocks. The fishery management presently models the exploitation through the parameters of fishing mortality and the age at first capture. These two parameters are translated into the technical measures of fishing effort and mesh openings and quotas, which are then used in practice for controlling the fishery. Stock protection can be achieved by reducing the fishing effort, by assigning smaller quotas, by reducing the number of days at sea, or by increasing the mesh opening. The respective protection measures have different effects on the development of the stocks but also on the revenue obtained by the fishery. These alternatives have been examined taking as an example the cod stock in the western Baltic. The optimization goal was the maximization of profit observing at the same time the prerequisites for stock protection according to the precaution approach. For these calculations the same models and data have been used as are beeing used in the stock management of the ACFM of ICES. The response of altered technical measures to the recruitment of cod stock was considered, and a proposal to overcome overfishing of cod in the western Baltic Sea was derived.

28. Sitzung des FAO/WHO-Codex-Alimentarius-Komitees für Fische und Fischereierzeugnisse

Die 28. Sitzung des Codex-Alimentarius-Komitees für Fische und Fischereierzeugnisse fand in Peking, China, vom 18. bis 22. September 2006 statt. Das Komitee folgte damit der in der letzten Sitzung ausgesprochenen Einladung der chinesischen Regierung und dem Ziel, die Codex-Sitzungen in verschiedenen Teilen der Welt abzuhalten. Geleitet wurde die Sitzung von Dr. Bjørn Røthe Knudsen, Regionaldirektor der norwegischen Behörde für Lebensmittelsicherheit. Professor Li Xiaochuan von der chinesischen Akademie für Fischforschung nahm die Rolle des Co-Chairman ein. Insgesamt 140 Delegierte, die 44 Mitgliedstaaten, die EU und eine internationale Organisation vertraten, nahmen an dieser Sitzung teil. Folgende Punkte wurden auf der diesjährigen Codex-Komitee-Sitzung diskutiert: 1. Erweiterung des Standards für Sardinen und sardinenähn-liche Erzeugnisse 2. Bearbeitung des Entwurfs eines Standards für Störkaviar 3. Überarbeitung des Entwurfs eines Standards für lebende und rohe Muscheln 4. Verhandlung über den Entwurf des Standards für geräu-cherten Fisch 5. Code of Practice für Fische und Fischereierzeugnisse 6. Zukünftige Arbeiten

30. Sitzung des Codex Alimentarius Komitees für Fische und Fischerzeugnisse in Agadir, Marokko, vom 28.9. bis 2.10.2009

The Codex Committee on Fish and Fishery Products held its 30th Session in Agadir, Morocco from 28 September to 2 October 2009, at the kind invitation of the Government of Morocco. The Session was chaired by Dr Bjørn Røthe Knudsen, Regional Director of the Norwegian Food Safety Authority. The Session was attended by 218 delegates representing 78 Member States, one Member Organization (EC) and 1 international organization.

Guter Nachwuchsjahrgang 2004 des Herings der westlichen Ostsee, des Kattegats und Skagerraks (ICES-Gebiete IIIa und 22 – 24)

Several fishery independent estimates of the year-class strength are necessary for the assessment and the ma-nagement 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 indicate a good year-class 2004.