ALBERT

Description: Rowe proposed a stress–dilatancy relation for granular assemblies in a dense packing of the form Ė=tan2(¼π+½φμ). He used a minimum energy ratio principle to develop this relation. It is shown here that the same result is obtained by considering the same model of toothed separation planes as that treated by Rowe, and applying to that model the laws of friction only.

Description: Since organic chemistry began, the chemistry of natural products from terrestrial organisms such as plants and fungi has been studied intensively; in contrast, marine species have received relatively little attention. However, in the last decade research in the field of marine products has increased sbstantially. The heightened interest in this area is attested by the appearance of the monumental treatise of Halstead on Poisonous and Venomous Marine Animals in 1965 (108), Baslow’s review on “Marine Pharmacology” in 1969 (14) and Scheuer’s recent book “Chemistry of Marine Natural Products” (160) in 1973. In addition Premuzic’s review devoted to the Chemistry of Natural Products Derived from Marine Sources, was published in volume 29 of this series in 1971 (152).

Description: Turbulent fluxes have been measured in the atmospheric surface layer from a boom extending upwind from the Dutch offshore research platform Meetpost Noordwijk (MPN) during HEXMAX (Humidity Exchange over the Sea Main Experiment) in October–November, 1986. We started out to study eddy flux of water vapour, but discrepancies among simultaneous measurements made with three different anemometers led us to develop methods to correct eddy correlation measurements of wind stress for flow distortion by nearby objects. We then found excellent agreement among the corrected wind stress data sets from the three anemometers on the MPN boom and with eddy correlation measurements from a mast on a tripod. Inertial-dissipation techniques gave reliable estimates of wind stress from turbulence spectra, both at MPN and at a nearby ship. The data cover a range of wave ages and the results yield new insights into the variation of sea surface wind stress with sea state; two alternative formulas are given for the nondimensional surface roughness as a function of wave age.

Description: A culture of juvenile Sepia officinalis L. was kept during summer 1985 in the aquaria of the “Station Marine”, Wimereux, France. During the first four months of juvenile development, oxygen consumption under increasing hypoxia was measured with a closed respirometer. The experiments revealed a high regulatory capacity of juvenile S. officinalis. The critical oxygen concentrations were calculated and their ontogenetical evolution was studied. The critical oxygen concentration increased with increasing development. A linear relationship emerged between the critical oxygen concentration and the logarithm of the wet weight [COc (mg O2 l-1)=-0.393+0.893×log10(Ww)]. The decreasing regulatory capacity of growing S. officinalis is most probably related to adaptations to a changing ecological environment during development. Another possibility is a physiological change, most probably related to the shift from embryonic to adult hemocyanin.

Description: Squid regurgitated by Greyheaded and Yellownosed Albatrosses at the Prince Edward Islands were predominantly two onychoteuthid species, Kondakovia longimana and Moroteuthis knipovitchi. Both squid are characteristic of cold, Antarctic waters and may have been caught south of the Antarctic Convergence, some 350 km to the south of the breeding station. Both albatross species regurgitated similar squid (by species and size), and these squid were similar to those found in previous studies of the diet of Wandering, Sooty and Lightmantled Sooty Albatrosses at the Prince Edward Islands

Description: The diet of Northern Rockhopper Penguins Eudyptes chrysocome moseleyi breeding on Gough Island, south Atlantic Ocean was studied, during November 1984, 1985 and 1986 by stomach content analysis. Rockhopper Penguins fed chiefly on the euphausiids Thysanoessa gregaria, Euphausia lucens and E. similis. Fish and squid were of minor importance by mass but constituted the largest individual prey items.

Description: Ninety-three species of bony fishes were caught in 4 seasonal bottom-trawl surveys carried out between July 1986 and May 1987 on the outer shelf and upper slope (124 to 587 m depth) along the southern Brazilian coast (30°40' to 34"30' S). On the outer shelf (〈 179 m), the demersal- pelagic species Trichiurus lepturus, Trachurus lathami, Cynoscion guatucupa, Scomber japonicus, and Thyrsitops lepidopoides predominated and also to a lesser degree the demersal benthonic Umbrina canosai and Mullus argentinae. Antiyonia capros and Priacanthus arenatus were found associated with the relic coral hard bottoms of the shelf break (180 to 249 m). Further offshore, the demersal-pelagic species Ariomma bondi and Zenopsis conchifera and the demersal benthonic species Polyprion ameri- canus and Helicolenus lahillei were abundant, both associated with rocky bottoms. The macrourids Coelorinchus marinii and Malacocephalus occidentalis characterized deep-water hauls p450 m). Frequent and widespread, but less abundant in the catch, were Polymixia lowei, Urophycis mystacea and Merluccius hubbsi. Mean total catch (kg h-') decreased 6-fold and the number of species by more than half along the depth range, with a sharp step at 350 m. Both catch and number of species were slightly higher in the winter cruises. Most species occurred in both winter and summer-autumn cruises, but, with increasing depth, the relative abundance of species that occur year-round decreased, whereas fishes that occur mostly in winter increased. The catch of demersal-pelagic fish decreased sharply below 350 m and differed little among seasons; catches of demersal-benthonic fish were more evenly distributed across the depth range and were larger in winter and spring. The high number of species on the shelf break may be attributable to the higher variety of soft and consolidated substrates and the overlapping of different water masses along the water column. The north-south shift of the western boundary of the Subtropical Convergence appears to be mainly responsible for the seasonal changes in abundance of the species.

Description: Marine geophysical surveys employing Seabeam, multi- and single-channel seismic reflection, gravity and magnetic instruments were conducted at two locations along the continental slope of the Peru Trench during the Seaperc cruise of the R/V “Jean Charcot” in July 1986. These areas are centered around 5°30′S and 9°30′S off the coastal towns of Paita and Chimbote respectively. These data indicate that (1) the continental slope off Peru consists of three distinct morpho-structural domains (from west to east are the lower, middle and upper slopes) instead of just two as previously reported; (2) the middle slope has the characteristics of a zone of tectonic collapse at the front of a gently flexured upper slope; (3) the upper half of the lower slope appears to represent the product of mass wasting; (4) thrusting at the foot of the margin produces a continuous morphologic feature representing a deformation front where the products of mass-wasting are overprinted by a compressional tectonic fabric; (5) a change in the tectonic regime from tensional to compressional occurs at the mid-slope-lower slope boundary, the accretionary prism being restricted to the very base of the lower slope in the Paita area. The Andean margin off Peru is an “extensional active margin” or a “collapsing active margin” developing a subordinated accretionary complex induced by massive collapse of the middle slope area.