Description: The first expedition planned for 1970 was conducted in the ocean area between the Iberian and West African coasts (north of 15 ° N and 30 ° W, see map). The first three sections of the expedition were devoted mainly to biological questions. The fourth and last cruise-section was concentrated on geological and geophysical problems relating to the exploration of the Iberian shelf and shelf margin. Since the activation of R.V. "Meteor" in 1964, biological work has predominantly centred round two questions: a) comparative studies on nutrient dynamics in poor and rich areas and b) communities in the open ocean and their diurnal periodic migrations. It was the purpose of the Canaries Basin expedition to supplement the data collected during previous research cruises, particularly the Atlantic Seamount cruises ("Meteor" cruise 8 and 9) in 1967 and the West African expedition ("Meteor" cruise 13) in 1968. Research work in the various disciplines of marine biology was carried out simultaneously with the collecting of chemical and physical data indispensable for the understanding of productivity, transport and decomposition of organic matter as well as affording an opportunity to observe biogenic sedimentation. In planning the cruise, special emphasis was laid on ensuring as close a coordination as possible between the individual working programmes; it was decided that of the vast number of problems presently confronting marine science, particularly in the biological field, only a few should be selected and these approached from diverse sides. Each cruise section was directed at one focal point, around which other investigations were grouped. Cruise section I. Nutrient dynamics in an upwelling water body off the West African coast. Cruise section II. Communities and environmental conditions in the region of the Great Meteor Seamount. Cruise section III. Metabolism and communities on the Iberian deep-sea bed. Cruise section IV. Testing of geophysical gear. Moreover, investigations on two important questions that for a considerable length of time have occupied the attention of planktologists and geologists at various German institutes covered several cruise sections: a) The structure of communities in the oceanic deep scattering layers and at the sea surface; an insight into the feeding migrations of these organisms is essential for an understanding of the vertical transport of organic matter in the open sea. b) The origin of sediments in the deep sea and on the Iberian shelf in relation to organic productivity and climatic and oceanographic fluctuations. The Canaries Basin expedition 1970 inaugurated the "Cooperative Investigations of the Northeastern Central Atlantic" (CINECA), a programme coordinated by the International Council for the Exploration of the Sea (ICES) on the recommendation of the FAO and IOC.

Description: The expedition "Auftrieb '72" was conducted in the NW African Upwelling Region off the Banc d' Arguin and included two geological profiles off Cap Blanc and off Villa Cisneros. R.V. "Meteor" and R.V. "Planet", the research plane "Canberra" and the tourist vessel M.S. "Regina Maris" participated in the expedition. Several components added up to a coordinated programme of different disciplines: Current meter moorings, large-scale oceanography and intensive studies of frontal zones were the task of R.V. "Planet". Medium-scale oceanography, chemistry and various disciplines of marine biology were performed with R.V. "Meteor", while the airplane and M.S. "Regina Maris" supplied background oceanographic information for the whole programme. The work done with R.V. "Meteor" is reported here. lt has been organised in three sections: Cruise section I. Nutrient dynamics in upwelling water bodies, in continuation of the work done during the "Roßbreiten-Expedition 1970". Cruise section II. Circulation in an upwelling system, including direct measurements of the vertical velocity; mixing processes in an upwelling system. Cruise section III. Sediment and benthos in areas of strong and weak upwelling. The approach to the study of these processes varied according to the problem. During cruise section I a number of drift experiments similar to the experiment conducted during the "Roßbreiten-Expedition 1970" was performed, consisting of a regular station programme at a freely drifting buoy which served for marking a patch of upwelling water. Cruise section II consisted of repeated sections in the vicinity of the vertical current meters and the current meter moorings. Cruise section III concentrated on two profiles perpendicular to the coast off Cap Blanc and Villa Cisneros.

Description: Um die Artengemeinschaft der Fische in Brackgewässern der Ostsee näher zu analysieren, wurde für die Süßwasserfische eine Liste aller Arten, die das Niederungsgebiet der Norddeutschen Tiefebene besiedeln, für die Seefische eine Liste aller sich noch im Bornholmbecken fortpflanzenden Arten zugrunde gelegt. Es zeigt sich, daß von 42 Süßwasserarten 11 als rheophil angesehen werden können, diese fehlen im Brackwasser. Die Mehrzahl der Süßwasserfische ist aber in diesem Biotop anzutreffen, nur ein geringer Teil geht über einen Salzgehalt von über 5‰ nicht hinaus. Etwa die Hälfte der in Frage kommenden Arten dringt in die mesohaline Salzwasserzone vor, davon wieder die meisten bis ins α-Mesohalinikum. Alle Süßwasserfischarten, außer dem Dreistachligen Stichling, vermögen sich nach den bisherigen Kenntnissen nicht im Brackwasser von über 5‰ fortzupflanzen. So betrachtet fehlt es weitgehend an limnisch-euryhalinen Arten in unserem Gebiet. Unter den Seefischen gibt es verhältnismäßig viele Arten, die sich auch im mesohalinen Bereich fortpflanzen, aber nur wenige sind in einem Brackgewässer wie der Schlei zu finden, weil der Mehrzahl der Biotop nicht zusagt. Nur zwei Arten finden in küstenexponierten Brackgewässern optimale Fortpflanzungsverhältnisse: der Frühjahrshering und der Strandküling. Vergleiche von fischereichlich genutzten Brackgewässern untereinander zeigen, daß die fischereilichen Auswirkungen der ökologischen Situation in Strandseen dahin gehen, daß sie von einem bestimmten Salzgehalt ab - trotz mannigfacher Ähnlichkeit mit eutrophen Flachwasserseen der Tiefebene - keine entsprechenden Erträge an Süßwasserfischen liefern, da für diese die Fortpflanzungsmöglichkeit stark eingeschränkt ist. Dort wo die Vorbedingungen für einen Laicheinzug des Frühjahrsherings gegeben sind, bestimmen diese mit ihren Erträgen das Anlandungsbild. Ungünstige fischereiliche Produktionsverhältnisse liegen dann vor, wenn in einem Gewässer ein Salzgehalt herrscht, der einerseits zu hoch ist, um die Fortpflanzung der Süßwasserfische zu ermöglichen, andererseits zu niedrig, um einen Einzug von Laichheringen zu gestatten. Als Beispiel hierfür kann das Frische Haff gelten. Grundsätzlich gilt für die ökologische Situation der Fischfauna in Bezug auf den Salzgehalt das gleiche wie für die Evertebratenfauna, wenn man die Fortpflanzungsfähigkeit als Kriterium bei der Eroberung eines neuen Lebensraumes an die erste Stelle setzt: Die Empfindlichkeit von limnischen Arten gegen eine Zunahme des Salzgehalts ist stärker als die Empfindlichkeit von marinen Arten gegen eine Abnahme des Salzgehaltes.

Description: A. The influence of the Great Meteor Seamount on the distribution of fish larvae and net plankton biomass is shown. The amount of biomass was significantly less in hauls from above the seamount than at stations beside it. The same was valid for fish larvae belonging to mesopelagic species. in addition the average length of such larvae was smaller in specimen caught above the seamount compared to those caught above the surrounding deep sea. The distribution of neritic, epipelagic, and euneustic forms seemed not to be disturbed by the seamount. Larvae of a neritic species were even more abundant above the plateau. The influence of the seamount on the oceanic biotope is discussed under faunistical aspects and under aspects of productivity. B. Horizontal plankton hauls from a depth of 25 m distinctly showed another composition of fish larvae species than oblique tows down to a depth of 100 and 200 m. All hauls were from the oceanic area beside the seamount. Probably due to internal waves the fish larvae fauna in three of the horizontal hauls showed a surprising deviation from the other nine hauls.