The Cape Verdean Senghor-Seamount rises up to 93 m below the surface, and lies within the Cape Verde Frontal Zone (CVFZ), and within the southwestward North Equatorial Current (NEC). The seamount and its oceanic surroundings were surveyed with Multiple-Opening-Closing Net (MCN) fish larval catches, Issacs-Kidd-Midwater-Trawl (IKMT) micronekton hauls, and an analysis of some Conductivity-Temperature-Depth (CTD) data (RV Poseidon cruise no. POS 320/2). The thermal and saline stratifications showed widely symmetrical uplifts near the summit. The larval fish community was diverse (H´ = 2.656) and composed mainly of larvae of meso-to bathypelagic species (91.5%). In IKMT 44.1% of the specimens originated from demersal parents (H´= 3.296), and mostly, albeit not entirely, from West African coastal waters, after advection along the CVFZ to and across this potential "stepping stone". Gross larval fish abundance (median 35.5 specimens/1m²) and composition agreed well with historical literature data from adjacent waters and seamounts north of the CVFZ, whilst south of the CVFZ and towards NW-Africa reported abundances were higher. Vertical distributions of larvae which generally live at greater depths showed a rise above the seamount, following the hydrographic uplift, accompanied by "thinning-out effects" through bathymetric disturbance. The extent to which findings at Senghor Seamount are representative for small, shallow and steep seamounts in the tropical NE-Atlantic is discussed.
The copepod fauna southwest of the British Isles includes a number of species which have their centre of distribution in the subtropical or tropical Atlantic. Among these, some species appear to be faunistically linked with the Iberian continental slope or slope waters even farther south along the NE Atlantic margin. It seems that these species reach their northeastern range by means of poleward-flowing currents. For example, CaEanoides carinatus has deep-living resting stages and ascends to surface waters only during its reproductive period, which is short at northern latitudes. Its main dwelling layers along the west Iberian continental slope cover the poleward-flowing undercurrent and the Mediterranean outflow water underneath. Part of the poleward flow regime tends to follow the slope bathymetry, i.e. it bends eastwards into the Bay of Biscay along northern Spain. Another part separates from the continental slope at Cape Finisterre and crosses the Bay of Eiiscay, approaching the continental slope at about 47" N, where it joins the north-westward flowing slope currents again. Because of its preference for the deeper layers during the long resting phase it is assumed that resting C. carinatus drifts mainly with the northward branch of the Mediterranean outflow water and penetrates only slightly into the inner Bay of Biscay. In contrast, Calanus helgolandicus has, on average, a shallower vertical distribution. Reproductively active individuals occur in the surface layers off western Iberia throughout the year. Here it drifts presumably northwards during late autumn and winter, but is recirculated southwards during late spring and summer. Due to advection with both the intermediatl-undercurrent and the variable near-surface currents, Calanus helgolandicus occurs more commonly in the inner IBay of Biscay than C. carinatus. 0 Elsevier, Paris Bay of Biscay I continental slope current I Mediterranean water I salinity minimum I copepod transport RCsumC-Transport de copCpodes par la circulation le long de la pente continentale du golfe de Gascogne. Au sudouest des iles Britanniques, la faune de copCpodes comprend de nombreuses espbces originaires de 1'Atlantique tropical ou subtropical. Certaines, likes B la faune de la pente continentale ibQique ou, plus au sud, B celle de la marge nord-est de l'titlantique, arriveraient avec les courants dirigCs vers le p81e. Ainsi, Calanoides carinatus se trouve en profondeur pendant ses pCriodes de repos et ne remonte dans les eaux de surface que pendant la ptriode de reproduction, b&e aux latitudes nord. Plongeant le long de la pente continentale & l'ouest de la pCninsule ibCrique, il atteint le sous-courant dirigC vers le p6le et les eaux sous-jacentes issues de la mer MtditerranCe. Une partie du flux suit la bathymktrie en direction de l'est et entre dans le golfe de Gascogne au nord de 1'Espagne. Une autre partie du flux quitte le talus continental au cap Finisterre et traverse le golfe de Gascogne pour retrouver, vers 47" N, la pente continentale et les courants orient& vers le
The Mauritanian Province, which comprises the area from the NW-African shelf to about 20 ~ and from Cape Timiris to Cape Verde, is redefined on the basis of fish larvae distribution patterns, direct and indirect current measurements, CTD-O2 hydrography and SST-remote sensing. Its northern and western boundaries coincide with the permanent, although not stationary, Cape-Verde-Frontal-Zone separating North-and South-Atlantic-Central-Water masses. Its southern boundary is characterized by tropical temperatures throughout the year. The oceanic Mauritanian Province is a myctophid dominated system that lacks genuine endemic species. Many deep-mesopelagic species of Myctophidae as well as other families are absent or rare in its centre, whilst some northern oceanic Myctophidae acquire a pseudoceanic character and prosper. On the other hand, tropical species of both oceanic and neritic origin co-occur alongside such cold-temperate Myctophidae. Distribution patterns of fish larvae were partly directly dependent on currents intruding into the province and partly indirectly on the impact of the circulation system on the local hydrography. Local hydrography could affect the survival capability of either larvae or adults. While an oxygen deficit southeast of the frontal zone is a limiting factor for subsurface-epipelagic and mesopelagic species, southwestward Ekman-drift and the related temperature deficit hampers the intrusion or survival of tropical fish larvae with neustonic or shallow vertical distribution. Southern, deep living or eurybathic species with lower temperature preferences are transported into or even beyond the province by northward currents. A transport model describing the input/output mechanisms of the province and defining its limiting features is presented and discussed in respect to recent literature.
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