ALBERT

Description: research

Description: Chlorofluorocarbon-11 inventories for the deep Southern Ocean appear to confirm physical oceanographic and geochemical studies in the Southern Ocean, which suggest that no more than 5 × 106 cubic meters per second of ventilated deep water is currently being produced. This result conflicts with conclusions based on the distributions of the carbon-14/carbon ratio and a quasi-conservative property, PO4 *, in the deep sea, which seem to require an average of about 15 × 106cubic meters per second of Southern Ocean deep ventilation over about the past 800 years. A major reduction in Southern Ocean deep water production during the 20th century (from high rates during the Little Ice Age) may explain this apparent discordance. If this is true, a seesawing of deep water production between the northern Atlantic and Southern oceans may lie at the heart of the 1500-year ice-rafting cycle.

Description: A coral reef represents the net accumulation of calcium carbonate (CaCO3) produced by corals and other calcifying organisms. If calcification declines, then reef-building capacity also declines. Coral reef calcification depends on the saturation state of the carbonate mineral aragonite of surface waters. By the middle of the next century, an increased concentration of carbon dioxide will decrease the aragonite saturation state in the tropics by 30 percent and biogenic aragonite precipitation by 14 to 30 percent. Coral reefs are particularly threatened, because reef-building organisms secrete metastable forms of CaCO3, but the biogeochemical consequences on other calcifying marine ecosystems may be equally severe.

Description: Rayleigh fractionation is an important, open system process that involves the progressive removal of a fractional increment of a trace substance from a larger reservoir. A consistent relationship, such as a distribution coefficient, equilibrium constant, or a fractionation factor, is maintained between the reservoir and each increment at the instant of its formation, but, once formed, each increment is thereafter removed or otherwise isolated from the system. The mathematical constraints of this process include the distribution coefficient along with a statement of material balance in the shrinking system. These constraints may be combined into a single differential equation that may be integrated to a well-known relationship discovered by Rayleigh (1902). Examples of this common process include condensation, distillation, and the formation of crystals from a melt or a solution. As shown in the following, Rayleigh fractionation explains many different characteristics of meteoric waters, and provides a first-order explanation of the MWL

Description: Bringer of storms and droughts, the El Niño∕Southern Oscillation results from the complex, sometimes chaotic interplay of ocean and atmosphere.

Description: Length-frequency data on squid (Loligo forbesi) collected during trawling surveys in Scottish waters from 1980 to 1994 were analysed to describe temporal and spatial patterns in abundance and to examine the prospects for using survey abundance to forecast fishery abundance. Loligo was patchily distributed in space and time. Distribution patterns in the North Sea in February appeared to be strongly related to bottom temperature (squid avoided waters 〈7°C) and, to a lesser extent, salinity (more squid in more saline water). For other areas and times, no temperature or salinity data were available, but there were trends for squid on the west coast to be more abundant in westerly areas and higher latitudes, and for squid at Rockall to be more abundant in shallow water. Inter-annual trends in abundance differed between the North Sea, west coast and Rockall, but average survey abundances for the North Sea and west coast tended to be positively correlated. For the North Sea and west coast, survey abundance was positively correlated with fishery abundance for the same month and area, and average abundance for the February North Sea survey was a reasonable predictor of commercial CPUE in the autumn of the same year (the peak of the fishery). Some of the observed trends were consistent with the existence of a stock-recruitment relationship but may indicate that abundance in a given calendar year is linked to climatic factors.

Description: An investigation was carried out on the recently discovered ‘giant’ extra large (XL) form of the squid Sthenoteuthis oualaniensis from the Arabian Sea. The sample consisted of 2 males, which have not been previously described, and 13 females. Diet composition, parasite loading, sucker ring dentition, biolumi-nescence and sexual dimorphism were examined and compared to known parameters of the medium (M) form. Reproductive strategy, potential fecundity, egg size distribution in the ovary and oviducts were examined in mature XL females. Evidence of multiple spawning in the giant form was also investigated. Overall body shape, bioluminescent structures and coloration of the giant form were similar to the M form, though the XL form had a smaller fin angle than the M form. The mature female XL form has a dorsal mantle length about twice that of a mature female M form. Adult females of the XL form have a dorsal mantle length about twice that of adult males of the same form. Differences between males and females were found in arm sucker ring dentition and parasite load, suggesting a difference in diet. This could be linked to size differences between the sexes. A strong correlation between ovary mass and mantle length was found (r2 = 0.64). Poor correlation was found between mantle length and oviduct mass (r2 = 0.128) and potential fecundity (r2 = 0.07). Potential fecundity ranged between 2–5 million eggs and the holding capacity of the oviducts was approximately 300, 000 eggs. This combined with the presence of spermatangia and the presence of food in the stomach suggest that the XL form is a multiple spawner. S. oualaniensis appears to have a plastic phenotype and has adapted to the Arabian Sea conditions by evolving the capacity to grow to a giant size.

Description: Stomach contents of a resident community of bottlenose dolphins (Tursiops truncatus) from the Sarasota Bay area of the westcentral coast of Florida were studied to examine potential factors leading to patterns of habitat use. Composition and size of prey were analyzed and correlated with feeding behavior of individual dolphins of known histories. Examination of stomach contents of 16 stranded dolphins revealed a diet composed exclusively of fish (15 species), most of which were associated with seagrasses in varying degrees. Observational records for 21 years showed that feeding typically occurred in shallow (2–3 m) waters and in the vicinity of seagrasses in 23% of cases. Dolphins usually fed alone or in small groups and on non-obligate schooling prey. The main species of prey were soniferous, an indication that passive listening may be important in detection of prey. The close agreement between species of fishes represented in stomach contents and habitat of prey, as indicated by observations of feeding, suggests that analysis of stomach contents is a reasonable approach for studying prey and feeding patterns of dolphins. Meadows of seagrass are one of the habitats of importance to dolphins in the Sarasota Bay area, and their protection is important for conservation of these animals.

Description: The sexual cycle of the cuttlefish, Sepia officinalis, from the northern part of the Bay of Biscay was followed over several years (1988 to 1990 and 1992 to 1993). Sucessive maturity stages are reached at the same time regardless of site in the northern part of the Bay. In this area, the majority of cuttlefish reproduce during their second year of life (group II) whereas the remainder reproduce in their first year (group I). The first visible signs of sexual development concern the testis in males and the genital tract in females. Males mature earlier than females: the first spermatophores appear in July (group II) and October (group I) while mature eggs appear from December (group II) and March (group I). The breeding season lasts from about mid-March to late June (3.5 months).

Description: Parsimony analysis of 29 finned and finless octopod taxa considered 66 anatomical and morphological characters to discover synapomorphies that unite monophyletic groups. The resultant cladogram (177 equally parsimonious trees at 191 steps, CI 0.429) resolved all relationships except those among the 16 exemplars of the Octopodidae included and those among Tremoctopus, Ocythoe and Argonauta. Bootstrap values of over 90% support the monophyly of the finned and finless octopods, relationships among the finned octopods, the bolitaenids and the monophyly of Haliphron, Tremoctopus, Ocythoe and Argonauta; bootstrap values for other nodes range from 57 to 79%. Among finned octopods, specimens representing Grimpoteuthis are basal, as Voss (1988a) suggested. Specimens of Opisthoteuthis represent a distinct lineage, and are sister taxon, in this analysis, of Cirroteuthis (although specimens of Stauroteuthis could not be included). New definitions of the genera Opisthoteuthis and Grimpoteuthis are provided to reflect their separate evolutionary histories rather than their overt morphological similarity. Among finless octopods, bolitaenids are basal. The monophyletic Octopodidae is the sister taxon to the clade containing the sister taxa Vitreledonella and Amphitretus, and Haliphron, Tremoctopus, Ocythoe and Argonauta. The Ctenoglossa and Heteroglossa, families grouped by shared radular dentition, are diphyletic and paraphyletic, respectively. The cladistic relationships demonstrate that both the Vitrele-donellidae and Idioctopodidae are junior synonyms of the Amphitretidae; despite conspicuous morphological differences separating these taxa, they share a recent evolutionary history.

Description: The microstructure, morphology and ontogenetic development of statoliths and age and growth of 405 planktonic paralarvae and 117 juveniles belonging to 10 species of gonatid squids (Cephalopoda, Oegopsida) were studied in the region of the continental slope in the western part of the Bering Sea (57°00′–61°30′N, 163°00′E–179°20′W). The statolith microstructure of all species was characterized by the presence of a large droplet-shaped nucleus and bipartite postnuclear zone divided into two by the first stress check, except for Berryteuthis magister which had only one stress check and an undivided postnuclear zone. In Gonatus spp., completion of development of the postnuclear zone coincided with full development of the central hook on the tentacular club. Daily periodicity of statolith growth increments was validated by maintaining 13 paralarvae of the four most abundant species in captivity. All species might be subdivided into two groups based on statolith microstructure, i.e. species with a central position of the nucleus within the first statolith check (Gonatopsis spp., Egonatus tinro and B.magister) and species with the nucleus shifted to the inner side of the first statolith check (Gonatus spp.). Comparative analysis of statolith morphology showed that paralarval statoliths have species-specific characters that allowed the construction of keys to identify species of gonatid paralarvae based on their statoliths. Analysis of paralarval growth using statoliths revealed that these cold-water planktonic gonatid paralarvae have fast growth rates, attaining a mantle length of 7–10 mm at 15–20 days and 20–25 mm at 35–70 days.

Description: During glacial cycles, different parts of the Earth cool by different amounts. A growing collection of evidence has begun to show that cooling in the tropical oceans was greater than previously thought. In his Perspective, Broecker discusses the oxygen isotope evidence reported by Schrag et al. (p. 1930) that indicates that the cooling in deep tropical water was close to the freezing point.

Description: Statolith microstructure was studied in two abundant planktonic cranchiids, Cranchia scabra (56 specimens, 38-127mm mantle lengh, ML) and Liocranchia reinhardti (34 specimens, 99-205mm ML) sampled in epipelagic waters of the western part of the Gulf of Guinea (tropical Atlantic). Growth increments were revealed in ground statoliths of both species. It was possible to distinguish two growth zones in statolith microstructure by their colour in reflected light of the microscope: the translucent postnuclear zone and pale white opaque zone. Assuming that growth increments in statoliths were produced daily, ages of the largest immature C. scabra and L. reinhardti were 166 and 146 days, respectively. Both cranchiids are fast-growing squids with growth rates in length resembling those of juveniles of tropical ommastrephids and Thysanoteuthis rhombus. Liocranchia reinhardti grows faster: its growth rate in ML is approximately twice that of same-aged C. scabra. The life cycle of both cranchiids consists of two phases. During their epipelagic phase, C. scabra and L. reinhardti feed and grow rapidly from paralarvae to immature young in the epipelagic waters, attaining 120-130 and 170-200 mm ML by ages of 4-5 months, respectively. Then they change their life style to a deepwater phase.

Description: Age composition and growth rates of the squid Loligo vulgaris (Lamark, 1797) were studied by examination of growth increments within statoliths of 419 specimens (mantle length, ML, ranging from 32 to 400mm). The squid were obtained by monthly sampling from the catches of commercial trawls off southern Portugal between March and September, 1993. The total number of growth increments in the mounted and ground statoliths was counted using a semi-automatic image analysis system. ML was significantly correlated with both the statolith length, TSL and the number of increments, NI. The female statolith was slightly larger than the male statolith for the same mantle size. Growth rates of individuals showed high variability with an average estimated at 34.6mm month-1 for males and 33.5mm month-1 for females. Growth in length between 70 and 280 days was best described by a power function for both sexes. The growth index of the statolith (TSL/NI) decreased with individual growth. The result may be related with the onset of sexual maturation. L. vulgaris hatched throughout the year with two distinct peaks, in spring which is the main breeding period, and in autumn. The life cycle of the L. vulgaris population on the south Portugese shelf was completed in one year.

Description: research

Description: research

Description: Greenland ice-core data have revealed large decadal climate variations over the North Atlantic that can be related to a major source of low-frequency variability, the North Atlantic Oscillation. Over the past decade, the Oscillation has remained in one extreme phase during the winters, contributing significantly to the recent wintertime warmth across Europe and to cold conditions in the northwest Atlantic. An evaluation of the atmospheric moisture budget reveals coherent large-scale changes since 1980 that are linked to recent dry conditions over southern Europe and the Mediterranean, whereas northern Europe and parts of Scandinavia have generally experienced wetter than normal conditions.

Description: A study of individual and group growth rates based on a method of growth determination using the gladius was carried out in two populations of the purple-back flying squid (Sthenoteuthis oualaniesis) in the Arabian Sea. The duration of the life cycle in all populations and size groups examined was approximately one year. The growth pattern of linear increase was either slightly S-shaped or almost linear, while growth in weight followed a power-type pattern. Generally, females grew faster than males. Use of the gladius as a recording structure makes it possible to study the real growth of a specimen, rather than the statistical correlation of length/weight versus age, as in the commonly used statolith method. Analysis of individual growth rates in large-sized sawning females revealed growth rhythm with roughly a one-month periodicity in which phases of rapid growth (17-21 days; 1.6-3,6mm per day) alternate with phases of slow growth (12-14 days; 0.4-1.2mm per day). This new method is simple to use and may be applied even on board a vessel during research cruises.

Description: research

Description: research

Description: research

Description: research

Description: research

Description: research

Description: The strontium to calcium ratio of skeletal aragonite in three genera of reef-building corals varies as a simple function of temperature and the strontium to calcium ratio of the incubation water. The strontiumlcalcium distribution coefficients of coral aragonite apparently differ from the corresponding coefficient of inorganically precipitated aragonite. With some care, coral skeletons can be used as recording thermometers.

Description: The pollen record of three marine late Quaternary cores off Senegal shows a juxtaposition of Mediterranean, Northern Saharan, Central Saharan elements, which are considered transported by the trade winds from a winter-rainfall area, and Sahelian, Soudanese, Soudano-Guinean elements, considered transported both by winds and mostly by the Senegal River, and coming from the monsoonal, summer tropical rainfall area of southern West Africa. Littoral vegetation is either the edaphically dry and saline Chenopodiaceae from sebkhas at the time of the main regression, or the warm tropical humid mangrove with Rhizophora during the humid optimum period. Four stratigraphic zones reflect, from basis to top: Zone 4. A semi-arid period with a balanced pollen input. Zone 3. A very arid period with the disappearance of monsoonal pollen, probably from the disappearance of the Senegal River, a very saline littoral plain with Chenopodiaceae, a larger input of northern Saharan pollen from intensified trade winds. Zone 2. A quite humid period, much more so than today, very suddenly established, with a northward extension of the monsoonal areas, a rich littoral mangrove, and weakening of the trade winds. Zone 1. A slow and steady evolution toward the present semi-humid conditions with regression of the mangrove, and of the monsoonal areas toward the south. Tentative datations and correlations with the Tchad area suggested: zone 4: 22,500 to 19,000 years BP; zone 3: 19,000 to 12,500 years BP; zone 2: 12,500 to 5,500 years BP; zone l: 5,500 years BP to top of core. Dinoflagellate cysts display a tropical assemblage wwith mostly estuarine neritic elements and also a weak oceanic component, mostly in the lower slope core 47. Cosmopolitan taxa dominate the assemblage and only a few species point to more specialized environments. Quantitative variations of the assemblage are the basis of stratigraphy which is not similar to the pollen stratigraphy, and an inshore-outshore gradient has to be taken into account to correlate the three cores.

Description: Surface sediments from 5 profiles between 30 and 3000 m water depth off W Africa (12-19° N) have been studied for their sand fraction composition and their total calcium carbonate and organic matter contents to evaluate the effect of climatic and hydrographic factors on actual sedimentation. On the shelf and upper slope (〈 500 m), currents prevent the deposition of significant amounts of finegrained material. The sediments forming here are characterized by high sand contents (〉 60 % ; in most samples 〉 80 %), low organic carbon contents (in most samples 〈 0.8 %), high median diameters of the sand fraction (120-500 μm), and by a predominance of quartz and biogenic relict shells (most abundant: molluscs and bryozoans) in the sand fraction. Median diameters of total sand fraction and of major biogenic sand fraction components (biogenic relict material, benthonic molluscs, benthonic and planktonic foraminifers) co-vary to some extent and show maximum values in 100-300 m water depth, reflecting the sorting effect of currents (perhaps the northward flowing undercurrent; MITTELSTAEDT 1976). In this water depth, biogenic relict material is considerably enriched relative to quartz, the second dominating sand fraction component on the shelf and upper slope, resulting in distinct calcium carbonate maxima of the bulk sediments. The influence of the undercurrent is also reflected in a northward transport of finegrained river load and perhaps in the distribution of the red stained, coarse silt and sand-sized clay aggregates, which show maxima in 300-500 m water depth. They probably originate from tropical soils. Abundant coarse red-stained quartz on the shelf off Cape Roxo (12-13° N) suggests a southward extension of last glacial dune fields to this latitude. Below about 500 m water depth, current influence becomes negligible - as indicated by a strong decrease in sand content, a concomitant increase in sedimentary organic carbon contents (up to 2.5-3.5 %), and the occurrence of high mica/quartz ratios in the sand fraction. Downslope transport, presumably due to the bioturbation mechanism proposed by BEIN & FüTTERER (1977), is indicated by the presence of coarse shelfborne particles (glauconite, relict shells) down to about 1000 m water depth. The fine/coarse ratio (clay + silt/sand) of the sediments from water depths 〉 500 m never exceeds a value of 11 in northern latitudes (19°-26° N), but shows distinct maxima, ranging from 50 to 120, at latitudes 18°, 17°, 15° 30', and 14° N in about 2000 m water depth. This distribution is attributed to the deposition of fine-grained river load at the continental slope between 18° and 14° N, brought into the sea by the Senegal and southern rivers and transported northward by the undercurrent. Strang calcium carbonate dissolution is indicated by the complete disappearance of pteropods (aragonite) and high fragmentation of planktonic foraminifers (calcite) in sediments from water depths 〉 300-600 m. Fragmentation ratios of planktonic foraminifers were found to depend on the organic carbon/carbonate ratio of the sediment suggesting that calcite dissolution at the sea bottom may also be significant in shelf and continental slope water depths if the organic matter/carbonate ratio of the surface sediment is high and the tests remain long enough within the oxidizing layer on top of the sulfate reduction zone. The fact that in the region under study intensity and annual duration of upwelling decrease from north to south is neither reflected in the composition of the sand fraction (i. e. radiolarian and fish debris contents, radiolarian/planktonic foraminiferal ratios, benthos/plankton ratios of foraminifers), nor in the sedimentary organic carbon distribution. On the contrary, these parameters even show in comparable water depths a tendency for highest values in the south, partly because primaty production rates remain high in the whole region, particularly on the shelf, due to the nutrient input by rivers in the south (SCHEMAINDA et al. 1975). In addition, several hydrographic, sedimentological and climatic factors severely affect their distribution - for example currents, dissolution, grain size composition, deposition of river load, and bulk sedimentation rates.

Description: The Baie du Lévrier (some 800 km2, 〈 20 m deep) lies at about 21° N. The climate is arid. Hydrographie conditions are controlled by (1) Trade winds, which largely determine wave base, (2) tidal currents, and (3) upwelling on the shelf nearby. Sediments range from carbonate-poor silty muds to carbonate-rich sands. Below wa ve base sediments characteristically have 〈 30% sand, sand medians 〈 125 μm and 55-80% silt, whereas wave-washed sediments have 〉 70% sand with medians 〉 400 μm. Other dynamic factors, notably tidal currents, may blur the distinction between these two populations. Sources for the terrigenous components are (1) modern aeolian dunes whose sands enter the sea to form a prograding coastal sediment wedge; (2) wind dust deposited as silty muds below wave base; (3) sub-Recent relict material on the seafloor; ( 4) cliff and bank erosion (local); (5) sea bed-load, significant in current-washed areas. Non-terrigenous components include pellets, ooids and skeletal debris. Pellets, incompletely indurated and mainly faecal, form up to 2/3 of the sand fraction in muds below wave base. Relict pellets are rare. Superficial ooids occur in trace quantities in some beach and nearshore samples. Skeletal debris accounts for most of the carbonate sand and also contributes significant quantities of biogenic opal and phosphatic material. Relict and mineralized (goethite and Fe-silicates) skeletal grains are locally important. Like the modern skeletals they are of foramol type. In the modern skeletal sand molluscan material is ubiquitous ( 〈 20% to 〉 90% of skeletal sand) but, as little can be identified further, molluscs as a whole have little interpretative value. Other skeletals form two groups: ( 1) typical of the banks and flanks of the bay, includes barnacles, worm tubes, calcareous red algae, bryozoans and alcyonarian spicules (the two lattcr tend to occur close to rather than on the banks and to lie below wave base rather than in the wave zone as the others do); (2) found in "basinal" sediments below wave base, includes calcarcous, opalinc and phosphatic forms: foraminifers (benthonic and planktonic), echinoderms, ostracodes, sponge spicules, diatoms (planktonic and benthonic) and fish remains. From the relationships between the bank and "basinal" groups five skeletal grain assemblages are recognized and shown to be related to sedimentary facies (ranging from carbonate-poor, silty mud facies with foraminifers, sponge spicules, diatoms and fish remains, to carbonate-rich sand facies characterized by bank group skeletals, particularly barnacles). Within some of the assemblages there are marked and systematic lateral shifts in relative importance of skeletal components. All these features can be interpreted in terms of source and transportability of the grains, some (e.g. barnacle) being moved principally as bed load, while others are carried in suspension. Laterally graded suspensions are proposed to explain the distribution of the components of the "basinal" group and also, near banks (or flanks), of alcyonarian spicules and bryozoans. Proximity to oceanic influences is expressed particularly in fine-grained "basinal" sediments by relative increase of echinoderms, ostracodes and molluscs (particularly Pinna needles) as well as of planktonic foraminifers and diatoms relative to benthonic ones. Significant regional environmental features are expressed in the sediments as follows: Aridity limits terrigenous sediments to a coastal wedge of dune-derived sands, aeolian dust in silty muds below wave base, and products of local cliff erosion. By precluding freshwater "dilution" it allows evaporation to increase salinity and a few ooids form. Combination of offshore upwelling and the Canary Current accounts for the presence of the foramol skeletal association in the tropics, and for the unusually high percentage of biogenic opal (up to 〉 12% of total sample), (cool-water) planktonic foraminifers (up to 〉 25% of total foraminifers), fish debris, and perhaps also of ostracodes. The general water temperature and salinity regime is such that the Baie du Lévrier lies in a critical position on or near the boundaries between major provinces of carbonate sedimentation both for skeletal (foramol, but chloralgal known 150 km to south) and non-skeletal components (normally pellet, but oolithaggregate locally reached).

Description: Geophysical and geological surveys by R.V. "Meteor" (1967, 1975, 1977) and R.V. "Vema" (1973) revealed new information on the seismic stratigraphy and geological evolution of the Mazagan Marginal Plateau. Fragments of a light-colored, mylonitic granite were recovered from the base of the escarpment and interpreted as slivers of foundered continental basement, pushed upwards along landward dipping thrust faults. The upbuilding of a 〉 2 km thick carbonate platform during (? pre-)Oxfordian to middle Cretaceous times kept pace with its fast subsidence (up to 80 m/m.y.). At the foot of the 27-38° steep escarpment we dredged an Oxfordian well sorted algal and foraminiferal limestone which is devoid of any terrigenous components and full of shallow-water organisms; it indicates an euphotic, sublittoral, perireefal environment. Upslope on the escarpment, we infer outcrops of middle Aptian to early Albian quartzose, calcareous and siliceous nanno claystones which reflect an outer shelf setting. Below the outer Mazagan Plateau, seismic evidence suggests that individual reefal bioherms continued to grow above a mid-Cretaceous unconformity, while the underlying carbonate platform subsided below wave base and was covered by Late Cretaceous pelagic sediments. A Paleogene (? Paleocene) and an Oligocene unconformity can be distinguished on seismic records and correlated to Cretaceous and Tertiary outcrops on the shelf off EI Jadida. Paleogene glauconitic marls and thin Neogene hemipelagic sediments top the plateau and represent a slope environment of deposition.

Description: Taxonomical study of the Bryozoa collected during the cruises of R. V. "Meteor" near the French coast (Atlantic and Channel) and the coastline of Mauritania. First indications of Arachnoidea annosciae n'HONDT and GERACI, 1976, Onychocella antiqua (BUSK, 1858) and Cribrilaria flabellifera (KIRKPATRICK, 1888) in the temperate region of the North Atlantic.

Description: A study of recent publications on ichthyoneuston of subtropical seas showed that this fauna is neither regionally nor seasonally uniform. Available material of abundant and characteristic species off Northwest Africa was re-examined under this aspect. This material was collected during five German expeditions (1967-1973) between 20° and 36° N and between the coast and 30° W. It includes 366 hauls that could be utilized for qualitative analysis; out of these 333 hauls yielded quantitative information. Based upon variation in geographical and hydrographical factors, distribution of sampling locations and zoogeographical considerations, the study area was divided into five subregions (two neritic and three oceanic), each represented by a different number of samples. A clear faunistic boundary appears between neritic and oceanic subregions. This boundary is related to water depth and distance from shore. It is sharp for neritic species. It is also sharp for mesopelagic fishes as they do not occur in water shallower than the slope, whereas oceanic-epipelagic taxa are less affected by this boundary. Latitudinal zonation is also evident as it is a function of hydrographic factors, especially temperature, probably showing seasonal variations. The latitudinal boundary is less pronounced than the neriticoceanic one; simplified it is assumed as running through the Canary Islands region. In all subregions, ichthyoneuston abundances appear to be highest during winter months. Maximum of abundance is produced by spawning that is restricted in many species to this season. The five most common species constituted more than 80% of the total catch during winter. Their proportion decreased to less than 60% in warmer months due to the immigration of less common (largely tropical) species and the mortality and ontogenetic emigration of animals born during winter. Seasonal differences in diversity did not prove significant as species number in ichthyoneuston catches is generally high. Seasonal trends are conspicuous for typical species only and are discussed. The northwest African current system probably causes considerable drift in ichthyoplankton. This raises the question as to how stocks survive despite drift of early life stages. This problem is discussed for characteristic taxa. Depending on the species, several mechanisms acting either singly or in combination are possible: 1. Adults of tropical neustonic forms actively migrate into the study area in summer, passive southward transport of early stages being a necessary condition for survival during other seasons. 2. Southward transport of species performing diurnal vertical migrations may, in certain areas, be reduced if such species reach the poleward undercurrent and remain in it during part of the day. 3. South of Cape Blanc, inshore eddies and the temporary surface countercurrent may permit a longer stay or return transport. This mechanism is probably effective for neritic euneustonic animals.

Description: This paper deals with the presence and distribution of Thecosomatous Pteropods in the Indian Ocean. 122 plankton-samples, taken by R.V. "Meteor" during the International Indian Ocean Expedition (IIOE) in 1964-65 were investigated. They contain a total number of about 45000 Thecosomata, belonging to 22 species and 5 families. Some species (e.g. Creseis acicula and Limacina inflata) are common in the entire area, others (e.g. Creseis chierchiae and Desmopterus gardinieri) show a quite distinct distribution. From several species only one single specimen was captured, others are completely lacking in the collection though they have been reported frequently from the same area by other expeditions. This may be due to seasonal variations and to the fact that to bathial tows were taken. In spite of these restrictions the extensive material from a relatively small area offers the possibility to compare specific and nonspecific features in related species and to question their taxonomic value.

Description: research

Description: research

Description: Oceanographic measurements by groups from the Federal Republic of Germany contributed mainly to the C-Scale Experiment (centered at 9° N, 23° W) and the Equatoria1 Experiment. In this paper the data are presented that were obtained from the moorings F 1 and F 2 in the C-area. After a short discussion of instrument problems, data processing and statistical analysis, the data are presented graphically as time series, progressive vector diagrams, frequency distributions and spectra of horizontal kinetic energy and of temperature variance.

Description: The results of measurements on currents and stratification obtained by FRV "Anton Dohrn" during the GATE-Equatorial Experiment are presented in graphical form. Remarks on data processing arid errors involved are made accordingly.

Description: We report, numerically and in graphical form, measured tritium concentrations from five hydrographic stations in the North Atlantic. Fairly homogeneous concentrations are observed in a surface layer typically 400 m deep. In the thermocline, concentrations decrease steadily down to the a σθ = 27.3 density horizon, and are more variable further down. The tritium in the lower part of the thermocline originates from the Subarctic Intermediate Water and the Mediterranean Water. There is a relative tritium maximum associated with the Mediterranean Water on the easternmost station of the section. In the deep water (σθ 〉 27.8), concentrations east of the Midatlantic Ridge are close to the limit of detection down to 2500 m, and undetectable further down, while west of the ridge tritium is found throughout the water column. The deep water tritium is associated with the deep-water advective cores of Arctic origin. The present tritium data can serve as northern boundary values in attempts to use tritium in studies of the North Atlantic main thermocline dynamics. The present data together with data from the literature point to a general division of the North Atlantic main thermocline into two layers separated by an isopycnal surface near σθ = 27.3.

Description: During the international "Overflow-Expedition" 1973 on R.V. "Meteor" oxygen concentrations in surface layers were measured in order to determine the oxygen gradients within the First two meters and to add some informations to the mechanisms of oxygen exchange at the air-sea interface. These investigations may be interesting also with regard to long-term-observations of the oxygen distribution in the Atlantic, especially the problem of the A.O.U. (apparent oxygen utilization) determination. To measure oxygen gradients a special sampler was built which is able to take water samples each 20 cm of the First 2 meters. These data were supplemented by further samples down to 150 m, taken by conventional water samplers, from which samples were also taken to measure N2/02-relations. By comparing these relations with theoretical relations in air-saturated water the influence of biological production and consumption on the oxygen contents in water could be estimated. A simple glass apparatus was built to extract gas from the water samples, and hereafter the N2/02-relations were determined by mass spectrometry. Most distributions of the oxygen anomaly show a negative oxygen balance which varies largely, probably due to strong mixing processes in the Iceland-Färö ridge area. The distribution of surface oxygen saturation values are of two different types. The values of the stations 260, 262 and 270 stem from mixed water and show homogeneous supersaturations, as can be found instantly when whitecaps appear. The values of 9 other stations are from water, sampled during calm periods which has been mixed and supersaturated before. They show a decreasing oxygen saturation towards the sea surface and often undersaturation in the upper decimeters up to 98% and even 91%. So at the air-sea interface even less initial oxygen saturation than 100% can be found after supersaturation during heavy weather periods.

Description: Records of currents and temperature on the upper edge of the continental slope off Sierra Leone show a significant energy peak between 0.3 and 2 cph in the bottom near layer. The fluctuations of temperature and velocity are interpreted as internal waves over a critical bottom slope. Since they seem to receive their energy mainly from the barotropic tide, the phenomenon is of interest in the dissipation cascade of tidal waves. The high frequency current amplitudes are occasionally strong enough to affect sediment deposition and related benthic processes. Inspection of current meter records from other regions of the NW-African continental slope reveal the similar effect of intensified bottom current fluctuations.

Description: This paper presents a compilation of the data sets obtained by CTDs and profiling current meters on board the ships "Meteor" and "Planet" during GATE in the B- and C-Scale Areas (7°-10 °N, 22°-25°W, June 17 to September 24, 1974). The bulk of the CTD data is displayed in the form of isopleths. Selected sets of profiles, outlining special phenomena observed, and profiles of the mean and standard deviation of temperature and salinity are given additionally. Besides examples of actual current profiles, isopleths of the 25 hour mean current components, and isopleths of the vertical shear are presented. The mean current components and their standard deviations are also displayed. Time series presented are suitable for comparison with moored current measurements. The presentation of the data is preceded by a summary of the editing procedures and by a discussion of the data quality.

Description: One main point of our atmospheric-electric measurements over the Atlantic Ocean 1973 was the investigation of the air-earth current density above the sea. In addition to direct measurements at the water surface with a floating net, we calculated the air-earth current density from the electric field and the air conductivity measured simultaneously on board of the ship and during particular ascents in the free atmosphere. During all five ascents the air-earth current density did not change with altitude. For pure maritime air-conditions, the mean air-earth current density was found to be 2.9 pA/m2. The mean hourly air-earth current density over the Atlantic shows nearly the same 24-hour pattern as measured by COBB (1977) at the South Pole at the same time. When dust-loaden air masses of African origin reached the ship as well as under continental influence the mean air-earth current density was reduced to 2.1pA/m2. The global 24-hour pattern was modified by this continental influences. Finally, it is shown that the values of the air conductivity measured on board R. V. "Meteor" during our earlier expeditions have been influenced by the exhaust of the ship and must therefore be corrected. With this correction, our new mean values of the air-earth current density over the Atlantic are 2.6 pA/m2 in 1965 and 2.0 pA/m2 in 1969. From all measurements, the global air-earth current is estimated to be about 1250 A.

Description: The fluxes of momentum, heat, and water vapour have been obtained by the aerodynamic profile method. Within the frame work of GATE variation of fluxes with disturbed conditions are of special interest. The time traces of surface layer parameters repeatedly showed definite instationarities marked by a sudden drop of temperature by a few degrees centigrade. For these pronounced instationarities, equilibrium state of the profiles was regained after a few minutes, in agreement with scale considerations. For fluxes properly nondimensionalized in terms of surface layer parameters, no systematic deviations have been found under disturbed conditions compared with undisturbed conditions. Due to systematic variations of parameters, the energy exchange between sea and atmosphere was enhanced by about 30 % under disturbed conditions. From the above evidence it is concluded that for larger scale investigations reliable determination of fluxes from surface layer mean variables is possible.

Description: The Aitken particle size distribution in background aerosols was measured with a newly developed Diffusion Analyzer System. The measuring system and the inversion method is discussed critically. The several hundreds of measurements indicate that several maxima in the size distribution are present. Particles as small as 10-3 µm in radius are constantly observed. Measurements of other authors indicate similar results.

Description: Size distributions of Aitken nuclei were measured in the middle and western part of the North Atlantic between 38 through 22° N and 36 through 63° W. The apparatus comprised diffusion batteries and an especially designed condensation nuclei counter. The measurements cover the size range from about 3·10-1 through to 1·10-5 cm aerodynamically equivalent particle radius. There are some indications on the trend of particle numbers above 1·10-5 cm but no reliable number distributions. The size spectra were bimodal in the north eastern part of the cruise. Closer to the Caribbean the contribution of very small particles was enhanced and the peaks shifted to larger sizes to a certain extent.

Description: On board of the German research vessels "Meteor" and "Anton Dohrn" the components of shortwave and longwave radiation budgets have been measured over the Fladenground area during a short period in 1975 (13.-19. August) and the Fladenground-Experiment (FLEX, 25 March 1976-13 June 1976). The data show that in spring and in the beginning of summer, when the ocean water is still cool, the daily incident solar radiation exceeds the net thermal radiation loss of the water to the atmosphere. In August, however, the water emission has increased to such a level that on disturbed days the daily mean radiation balance is negative. The monthly averages of the radiation budget and the global radiation derived from the shipborn measurements agree surprisingly well with those derived by several authors from climatological data. A simple scheme has been developed to parameterize the global radiation with respect to the observed cloudiness.

Description: The Th content of the sediment samples from "Meteor" core 12310 (3080 m water depth, off NW Africa) on a carbonate-free basis lies around the average of 12.4 ppm and is similar to the average content of the earth crust. On the contrary, uranium was found to be up to 3.5-fold enriched in the core section between 60 and 330 cm (within the Würm Glacial) where reducing conditions occur, due to deposition of authigenic uranium (9 µg/cm2 1000 yrs.). The authigenic uranium content is correlated to the organic matter content (U/Corg ratio = 6 · 10-4). On the basis of the uranium content of the oxidized section uranium was split into a detritic and an authigenic component and the amount of supported ionium was calculated. From the profile of the specific I0.excess act1v1ty Io-total - Io-supported) with depth, average sedimentation rates of 3.3 ± 0.6 cm/1000 yrs. for the warmer stages and of 5 ± 1 cm/1000 yrs. for the cooler periods were estimated.

Description: A rapid procedure for Io (Th230) dating of sediments with accumulation rates in the range of several cm/1000 years is described. Studying of large sample populations with very small Io-excess activity is possible as the counting time (around 1500 min/sample) are 2 to 5 times shorter than with the standard Io-excess method. Improved sensitivity of the Io-excess measurement is achieved by: 1) extraction (~90%) of the authigenic Io-excess with EDTA, with minor leaching (~30%) of the allogenic Th232 and Io-supported, 2) processing samples as large as 10 g or more. The procedure was applied to sediments from the Caribbean (V 12-122) and from the Ionian Sea (22M48 and 17M17). In the case of the standard core V 12-122 our results are in good agreement with previous time-consuming Io determinations. The resulting average accumulation rates of 2.0 ± 0.3 cm/1000 years for the Ionian Sea cores are close to the average derived from magnetic reversal studies of a nearby core.

Description: A preliminary study was carried out on the ostracode fauna obtained from marine sediments off the Sahara Desert. The ostracodes are divided into two distinct associations: Association A - shallow water (100-483 m); Association B - deep water (470-2859 m). The deep water association differs from that of the shallow water by its low diversity and by the predominance of somewhat larger "blind" ostracodes in it. The depth of the boundary between the two associations corresponds closely to the general universally recognized 500 m boundary, below which psychrospheric conditions prevail and dictate the appearance of typical deepwater ostracode fauna.

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Description: Estimation of average Cenozoic sedimentation rates for the Atlantic, Indian, and Pacific oceans indicates global synchronous fluctuations. Paleocene-early Eocene and late Eocene-early Miocene rates are only a fraction of middle Eocene and middle Miocene-Recent rates. These changes must reflect significantly different modes of continental weathering, which may be due to alternate states of atmospheric circulation marked by reduction of global precipitation.

Description: The distribution of 210Pb and 210Po in dissolved ( 〈 0.4-micron) and particulate (〉 0.4-micron) phases has been measured at ten stations occupied during cruise 32 of F. S. "Meteor" in the tropical and eastern North Atlantic. Both radionuclides occur principally in the dissolved phase. Unsupported 210Pb activities, maintained by flux from the atmosphere, are present in the surface mixed layer and penetrate into the thermocline to depths of about 500 m. Dissolved 210Po is ordinarily present in the mixed layer at less than equilibrium concentrations, suggesting rapid biological removal of this nuclide. Particulate matter is enriched in 210Po, with 210Po/210Pb activity ratios greater than 1.0, similar to those reported for phytoplankton. At depths of 100-300m, 210Po maxima occur, and unsupported 210Po is frequently present, an observation that suggests rapid re-cycling within the thermocline. Comparison of the 210Pb distributions with those reported for 226Ra at nearby GEOSECS stations confirms the widespread existence of a 210Pb/226Ra disequilibrium in the deep sea. Close to the bottom, profiles of 210Pb and 226Ra usually diverge, and 210Pb concentrations frequently decrease with depth, suggesting a sink for 210Pb near the seafloor. Particulate 210Pb concentrations ordinarily show little systematic variation with depth. At depths greater than 1,000 m, dissolved 210Po activities are, on the average, less than those of 210Pb by 12 % . A corresponding 210Po enrichment in the particulate phase is found.

Description: Pelagic tar has been collected daily on a transsect from off Prtugal to south of the Canary Islands in January/February 1975. A new neuston sampler was used which may be towed at speeds between 7 and 10 knots (DERENBACH & EHRHARDT 1975). A total of 22 samples was taken. Dimensions of tar balls ranged from potatoe-size to small specks approximately 1 mm in diameter. Concentrations were found to vary between 20.5 and 0.007 mg/m2, except for one instance of an extremely high tar concentration of 2270 mg/m2. 49 GC analyses were made. 61% showed bimodal peak distributions characteristic of crude oil sludges. The composition of tar balls was independent of their size suggesting diffusion controlled degradation.

Description: During the International ICES Expedition "Overflow '73" a total of 174 samples from 18 stations were collected by R. V. "Meteor" in the waters of the Iceland-Faroe Ridge area. They were filtered on board ship (through 0.4 µm "Nuclepore" filters), then stored in 500 cm3 quartz bottles (at -20°C) and analyzed in air-filtered laboratories on land for zinc and cadmium by means of the differential pulse anodic stripping voltammetry technique and copper and iron by flameless atomic absorption spectrometry. The overall averages of 1.9 µg Zn l-1, 0.07 µg Cd l-1, 0.5 µg Cu l-1 and 0.9 µg Fe l-1 are in good agreement with recent "baseline" studies of open-ocean waters. The mixture of low salinity water masses from the North Iceland Shelf/Arctic Intermediate Waters seem to maintain distinctly lower concentration of Cd, Cu and Fe than the waters from the North Atlantic and the Norwegian Sea where quite similar mean values are found. There is only little evidence for the assumption that overflow events on the ridge are influencing the concentrations of dissolved metals in the near-bottom layers.

Description: The hydrodynamic roughness of the sea surface at low wind speeds (u10 〈 5 ms-1) is investigated according to the aerodynamic profile method. The wind, temperature, and humidity profiles were measured during GATE in 1974. In some earlier publications on this subject the density stratification has not been considered. Therefore apparent roughness parameters are found, which are smaller than those for a hydrodynamic smooth flow. In this paper the density stratification was determined from 10 m-values of wind, temperature, and humidity. From more than 1 OOO 10 min-profiles an average drag coefficient reduced to neutral stability of CD,N10 = (1.10 ± 0.32) · 10-3 for u10 〈 5 ms-1 is obtained. As the slight decrease of CD,NlO with increasing wind speed is not significant, CD,NlO can be regarded as independent of the wind speed. In the range of low wind speeds (1.75 ms-1 〈 t110 〈 5 ms-1) the sea surface is hydrodynamically rough. The validity of the Charnock formula z0 = u*2/ag cannot be verified. An influence of wind waves on the wind profile can be shown even for wave heights less than 0.75 m up to a level of 2 m above the sea surface. Therefore the drag coefficient was determined from wind values above 2 m height.

Description: During GATE 37 flights with radiometersondes to measure the infrared radiation were made from R.V. "Meteor" at 7.8° N, 22.1° W. This position was close to the ITCZ, very often high reaching convective clouds dominated. The profiles of the irradiances are dominating influenced by clouds. Examples are given, one showing the dependence on cirrus clouds, another that on dense altostratus and nimbostratus clouds. The goal of the measurements was to obtain mean profiles of infrared radiative heating rates, but due to the high variability of the clouds and due to the difficulty to assign the flights to distinct clouds, only three mean profiles could be calculated: - Average of all 37 flights, - Clear skies, - Skies overcast with medium clouds.

Description: The net flux of all irreversible fluxes of radiation and heat crossing the ocean surface is determined for phase III of GATE at position no. 27 (WFS "Planet", FRG). The radiation fluxes have been measured directly, while the heat fluxes have been parameterized with the bulk formula however with bulk coefficients depending on stability. The heat loss of the ocean due to warming of the cooler precipitation is included for the determination of the net flux at the ocean surface. Some examples of hourly mean values of different fluxes during different weather conditions are additionally shown.

Description: Spectral analysis of time series for hourly and three minutes surface observations of potential temperature, specific humidity and wind speed show significant differences between spectra for disturbed and undisturbed conditions in the period range between one and five days and 30 and 120 minutes. The spectrum of pot. temperature which was found to be a good indicator of convective activity showed that these differences are mainly caused by enhanced convection during disturbed conditions, as the cloud and subcloud layer are strongly coupled by updrafts and downdrafts. This convective mixing influences the near surface fields of pot. temperature, wind velocity, and to a lesser extent 0£ specific humidity. For moderate to depressed convection the cloud and subcloud layers are less coupled. The diurnal radiative forcing then determines the spectra. Convection seems not to be distinctly organized, while during enhanced convective activity, the individual clouds are organized on a larger scale, forming what is commonly called cloud clusters. Two modes are found in the long period range which could be determined with a certain significance. The first one in the range of 4 to 5 days the second one in the range of 30 to 40 hours. The analysis of the high resolution buoy measurements at "Meteor" shows a further maximum due to convective influences for periods of about 40 minutes.

Description: With a 6-channel integrating nephelometer spectral scattering properties of the atmospheric aerosol have been measured during the third part of the Atlantic Expedition 1969. A meridional cross section of light scattering integrals in the wavelength range 0.475 µm to 0.924 µm was recorded reaching from 10° S to 60° N along 30° W. With a new algorithm the time series of hourly scattering spectra was inverted yielding a first meridional cross section of the median radius of the number size distribution in situ. Three air mass regimes could be distinguished in the course of the experiment, the first one being the extremely clean air of the SE-trade south of the ITC. An abrupt increase in light scattering marked the hemispheric change when the ship entered the NE-trade which was heavily loaded with Sahara dust. North of the trade region the ship sailed through maritime North Atlantic air masses with highly variable light scattering and a slow decrease in median radius with latitude.

Description: Sediment cores from the continental slope off NW Africa (20-27° N) have been investigated by means of an analysis of clay minerals, of grajn size distribution of terrigenous material and of coarse fractions and CaC03 -contents. Deductions concerning Late Quaternary climatic variations could be made from the obtained results. The interglacial periods X and Z (stage 1 and 5 after SHACKLETON & OPDYKE 1973) had an arid climate, characterized by: a) presence of chlorite and attapulgite in noticeable amounts, these fragile minerals being preserved from weathering in dry climatic conditions, b) small grain size of terrigenous material, c) high desert quartz numbers, high CaC03-amounts of total sediment, small terrigenous input and low transport energy. The glacial periods Y and W (stage 2-4 and 6) had a humid climate. This is suggested by: a) the absence or rareness of chlorite and attapulgite and increasing amounts of mixed-layer minerals, b) high amounts of coarse-grained terrigenous material, indicating greater transport energy, c) low or disappearing desert quartz numbers, low CaC03-content and high terrigenous input. The cores from 27 and 20° N do not fit into this general scheme, because they are situated at climatic boundaries, the northern core lying at the actual boundary of mediterranean humid and arid climate, the southern core lying at the Würm boundary between humid and arid climate. Results of 40-63 μm sized desert quartz and amount of 〈6 respectively 20-63 μm fraction show sharp boundaries between stratigraphic zones, revealing rapid changes in climate. Clay mineralogical changes are less rapid, showing the progressive changes in soil formation and soil destruction. The origin of the clay minerals is exclusively detrital. Their quantitative variations show a differential settling with distance from coast, and a latitudinal zonation parallel to terrestrial soils.

Description: The 60 km wide shelf off Mauritania is cut by several submarine canyons. Its water-circulation is controlled by the cool Canary current and upwelling. Its Recent sediments show faunal assodations remarkably related to the grain size distribution which in water depths between 40 and 80 m is strongly influenced by reworldng of older coarse sand or sandstone. In this depth range a mixed biofades originating from Pleistocene and Recent material is encountered. The present lateral faunistic and sedimentological fades change, including horizons of mixed provenance, can be recognized in vertical sequences taken by vibro-coring. This correlation combined with 14C-datations on molluscs enable the reconstruction of the history of the last gladal regression and transgression. Due to the arid climate, the emerging calcareous shelf sediments are indurated and, therefore, protected from subaerial and submarine erosion. During low sea level eolian sand migrates over the shelf, but only about l/10 of this material remains there and is later incorporated into the sandy shelf sediments. The calculated average rate of total sedimentation during Holocene is 15 cm, and the production rate of carbonate is 5 cm/1000 years.

Description: In March 1974 combined refractional and reflectional seismic experiments were performed in the Cretan Sea. A total of 141 shots were fired along two lines, one parallel to the main structure striking nearly E-W between Karpathos and the SE-Peloponnese, the other perpendicular to it between Crete and Santorin (Thira). The shots were observed at 13 sites on land and by four buoy stations at sea. The seismic data reduced to time-distance plots and evaluated by direct and inverse ray theory methods revealed that: The Cretan Sea builds an E-W elongated dome of the upper mantle with maximum crustal attenuation at its central part and a thickness of nearly 20km. The vertical distribution of the P wave velocity is that of a continental crust that has been subjected to attenuation. The present distribution of sediments is mainly confined to the zone: SE-Peloponnese-Kithera-Antikithera-Crete-Karpathos, and also to small depressions within the central basin. In general they do not exceed 2 km in thickness. The uneven distribution of the sediments indicates the possibility of a two phase subsidence of the Cretan Sea. Areas with no or very thin sedimentary cover belong to the youngest tectonic phase. The morphology of the crystalline basement has been formed by intensive fragmentation, consisting mainly of normal faults, typical for tensional tectonism. The northern border of the Cretan Sea exhibits intensive volcanism along the line : Methana-Milos-Santorin-los. This zone is partly mobilized and intruded by surplus masses from the upper mantle as shown in the case of Santorin.

Description: This paper is a dcscription of the shallow structure of the Cretan Trough in the Aegean Sea as illustrated by continuous seismic profiles obtained by R. V. "Meteor" (1600 n.m., 1974), and R. R. S. "Shackleton" (1000 n.m., 1972, 1974). Study of this data shows an erosional unconformity between indurated rocks and sediments which over most of the Cretan Trough corresponds to erosion after the main Alpine orogeny and prior to the Upper Tortonian and in some places to the Upper Pliocene transgression. Thick sediments of up to 1.5 km have collected in local basins. Strong vertical movements on normal faults were responsible for the formation of the Cretan Trough and subsequently controlled the sedimentation. Sediments within the Trough have been deformed by Upper Pliocene/Pleistocene faulting and folding. Quaternary intrusions of volcanic? material are sporadically observed over the whole width of the Cretan Trough and do not suggest active seafloor spreading. Extensional processes are seen to be the dominant f eature in the tectonics of this area since ca. 10 m. y. A geodynamic process responsible for the observed structural data - mantle diapirism or subduction induced back-arc spreading - could not be derived from the reflection seismic data.

Description: Sediments sampled in three lateral traverses from the outer continental shelf to the continental rise off the Sahara Desert were analysed for their grain size distribution and composition. The carbonate content of the shelf and upper slope sediments increases from about 10-15 % in the south to about 50-90 % in the north and changes to about 40-45 % in deeper water. The high carbonate content in the north generally reflects the high proportion of relict material in the sediments. The main change in the composition of the sediments - defined mostly as hemipelagic - from the outer shelf to the rise is in an increase of coccoliths and clays and a decrease of quartz. The cumulative grain size curves indicate that each of the samples is a mixture of different proportions of two approximately log normal populations. The size of the truncation point between the populations, the proportion between the coarse and fine populations and the mean, sorting, skewness and kurtosis decrease with increasing depth. Correlations between the parameters indicate that the moments express mainly the mixture proportions of the two populations. The two populations may, however, indicate an artificial effect of deflocculation during sample treatment rather than reflecting some hydraulic factor. The cumulative grain size distribution curves of eolian dust collected on ship's surface during cruises along the Saharan shelf and that of other published data is divided into a two-population and a onepopulation type. The two populations may be attributed to either gravitational settling of larger dust particles and normal dust fall or to disaggregation effect. The moment statistics of the dust differ mainly from those of the marine sediments in that they have a lower standard deviation. The composition and the textural parameters, combined with modal analysis of the dust and the separated soluble and insoluble components of the sediments indicate that the downslope transportation of the coarser sediment particles is a result of marine currents rather than of wind. The distribution pattern of the relict material in the northern outer shelf and upper slope is attributed to an extinct current regime which was stronger than the present one. The gravitational settling of coarse dust, mainly over the shelf, most probably accounts for the principal input of sediment that is transported further downslope by marine currents. Part of the fine, as well as a small portion of the coarse terrigenous material may be derived from direct settling of dust over the open sea. The recent sedimentation process results in a continental margin prograding off the Sahara Desert. In the south sedimentation occurs on the outer shelf, slope and rise, whereas in the north main sedimentation occurs on the lower slope and rise. The deflection of the Canary current away from the Cape Blanc coast is proposed as an explanation for the apparent reduced deposition rate over the outer shelf and upper slope in the northern area.

Description: Light and electron microscopic examination of a number of dpecies previously attributed to the genus Syracosphaera LOHMANN show that three groups can be delimited, all of which warrant generic status. Caneosphaera GAARDER and Coronosphaera GAARDER are described, and the genus Syracosphaera with type species the two-layered S. pulchra LOHMANN is emended with redescription in terms of morphological features seen under light and electron microscope. New combinations are presented for five species.

Description: Through correspondence, the authors determined that each possessed material of an undescribed wrasse of the genus Suezichthys SMITH. The first five specimens of this species were taken in December, 1964 by R. V. "Anton Bruun" while trawling in 78-82 m and in 70-80 m (2 and 3 specimens resp.) off the Somali Republic, East Africa; the next two were collected a month later by R. V. "Meteor" by trawl off Kenya in 124-130 m; the last two were trawled in July and October, 1972 by U. S. National Marine Fisheries Service research vessel "Townsend Cromwell" off Oahu, Hawaiian Islands in 119-168 m. These nine specimens form the basis for the description herein of this new labrid fish.

Description: 46 hydropolyp species of 28 genera and 10 families were sampled during the "Meteor" passage 1964/65 (IIOE) through the Red Sea and its northern and southern exits and on the occasion of several ecological investigations of 29 selected coral reef sections of the central Red Sea and the Gulf of Aqaba. These collections comprise 128 single records of hydropolyp species. Three species and two genera each with one species are doubtful. 25 species, seven genera, one family and one subfamily, together from 49 records have not previously been found in the Red Sea and its exits. Including these newly reported species, the total list increases from 64 species and 112 records (SCHMIDT 1972) to 89 species and 240 single records and 51 additional ones. Scanning microscopical photos, made for the first time for the illustration of the hydropolyps, have been shown to be suitable for a better characterization and diagnosis of the species. Qualified results on the reasons for the horizontal distribution of the species known from the Red Sea area cannot be given because of the low number of samples sporadically distributed through the whole area. In contrast with this fact, the vertical spread of the species sampled seems primarily to be regulated by water exchange and light intensity. For example, four species of hydropolyps are excellent indicators of certain abiotic factors or combinations of them: Gymnangium eximium reacts extremely stenophote-photophobe-rheophil, Eudendrium ramosum moderately stenophote-photophobe-rheophobe, Lytocmpus philippinus moderately stenophotephotophil-rheophil, and Halocordyle disticha var. australis extremely stenophote-photophil but moderately rheophil. Other species have been found throughout all the light zones. Combined with the small size of their colonies their euryphotic behaviour does not allow their use as indicator species.

Description: Four species of gammaridean Amphipoda are recorded from the Iberian deep sea basin at about 5000 m depth: Bathyceradocus iberiensis sp. n., Paracallisoma platepistomum sp. n., Parandaniexis cf. mirabilis SCHRELLENBERG, 1929, and Parargissa galatheae BARNARD, 1961. The biogeography of the four species is discussed.

Description: Using a Bongo-Net equipped with a multiple codend closing device, the vertical distribution of siphonophores has been observed in 100 m depth intervals at 13 stations off Cap Mirik (19° N) (from 0-500 m depth). The distributional pattern of the 15 siphonophores species found is discussed in relationship to the hydrography of this upwelling region. The following main features have been observed in comparison with the warmer oceanic water offshore: (1) a lower diversity, (2) a shallower distribution of some of the deep living species due to the lower temperature in the upper 300 m and a lower transparency, (3) no contribution to acoustic scattering by physonect siphonophores.

Description: From sublittoral silty sediments (118 m depth) of the North Sea (59° 0.5' N; 01° 20.5' E), Bathymacrostomum spirale n. gen. n. sp. is described on the basis of squeeze preparation. According to the organization of the cuticular apparatus of the bursal organ the species belongs to the family Dolichomacrostomidae RIEGER, 1971. The absence of an accessory gland organ and the simplicity of the penis stilet leads to the establishment of the subfamily Bathymacrostominae nov. subfam.

Description: Description of Acanthophmyngoides quintus nov. spec. (Desmodorinae) with discussion of the systematical relationship to Spiriniinae and Pseudonchinae, and description of Richtersia iberica nov. spec. with discussion of the relationship to Desmodorinae.

Description: The Great Meteor Seamount is situated in the subtropical NE Atlantic. The dimension of the plateau in the depth of 400m is 1465 km2 ; its lowest depth 275 m. 35 species have been caught above the plateau in 1967 and 1970 (voyages 9 c and 19; R. V. "Meteor") with a bottom trawl, the Agassiz-trawl, with BEYER's epibenthic closing net, the triangle-dredge and the chain-dredge. For comparison fishes of the same species were collected off Morocco, Mauretania and Senegal. The circular current system above the seamount and the low rates of the net transport are the reasons for the existence of the autochthonous demersal fish populations, in spite of the pelagic stages of development. A comparison of the populations of three species from the seamount and from the African shelf, using a multivariate method (linear discriminant function), indicates a genetical diverging development of the populations. An overlapping of the populations is only applicable for 1.7 % of the individuals. This argument for an autochthonus demersal fish fauna is corroborated by nearly the same composition of species in 1967 and 1970, the small differences in the dominance of the species and the great homogeneity of the fish fauna in the two years. The distribution of the species above the plateau is nearly uniform. The species Aulopus filamentosus, Phycis phycis, Macroramphosus scolopax, Anthias anthias, Antigonia capros, Capros aper, Callionymus phaeton and Arnoglossus rueppelli are characteristic for the fauna, as in 6 of 11 comparable catches these 8 species were present together. For the demersal fishes the plateau is a rather uniform biotope, for it is mainly covered with biogenic sand. The aggregations of the seamount's own plankton and nekton near the bottom in daytime is exclusively or partly the food for 94% of the fish species, while the bottom fauna is only utilized by 22% of the species. Only Callionymus phaeton feeds exclusively on bottom animals. Shrimps (predominantly Plesionika heterocarpus) are the favoured prey of the majority of fish species. Relative to the number of examined stomachs the small crustacea like ostracodes and copepods are most abundant. Fishes were found in the stomachs of 8 species. Moreover cuttle-fish are of some importance as food of the bigger fishes. A comparison of the food of respective species from the African shelf shows that the lower availability of food above the seamount has no influence on the feeding behaviour of the species. lt seems, that there is sufficient food at the seamount, so that the fishes must not put up with animals they disdain elsewhere. The fish fauna from the Great Meteor Seamount shows the greatest similarity with the demersal fish fauna of the African shelf between Gibraltar and Cap Blanc (28 species in common). The Great Meteor Seamount has only 24 species in common with Madeira and 17 with the Canary Islands. Two species suggest a possible influence of settlement from the Western Atlantic. These species also belong to the fauna of Madeira and the Josephine Seamount, while they are absent on the African shelf. The species Gnathophis codoniphorus, Callionymus sousai and probably also the ray of the genus Raja are endemic. The depth of the plateau (275-400 m) has a great influence on the composition of the fish fauna. Regarding the vertical distribution of the species in the rest of their distribution areas, the plateau of the Great Meteor Seamount is situated at the optimal depth.

Description: 85 species of polychaetes were collected, 72 of them were determined to species level. One genus (Palposyllis n. g.), four species (Pionosyllis gorringensis n. sp., Palposyllis prosostoma n. sp., Potamethus filiformis n. sp., Potamethus breviuncatus n. sp.), and one subspecies (Ophelina delapidans longicephala n. subsp.) were described as new taxa. The majority of the species collected during this cruise have their distribution in the Atlantic Ocean or are more widely distributed. Peisidice bermudensis was found the second time after its original description. Lepidastenia brunnea and Isolda whydahensis never have been found as far north off the coast of Portugal. The interstitial living species Pisione remota and Hesionides arenaria, usually common in shallow waters, were found in deeper water (72 m and 120-180 m) for the first time.