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: 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.

Description: Distribution and abundance of fish larvae collected from December 1964 to April 1965 in the Arabian Sea and the Persian Gulf are described. Deviations in the composition of the fish larvae fauna were due to kind of net used as well as to day time and to geographical area. Ecological differences were mostly pronounced when comparing the samples taken in the areas off East Africa, off India and in the Persian Gulf. Larvae of fishes which might be of economic importance were less abundant than larvae of fish species living mainly in the mesopelagic zone.