ALBERT

Description: Cephalopod remains were collected from all of 12 dead Emperor penguin chicks [Aptenodytes forsteri (Gray)], from 76% of 29 living adult Emperor penguins, and from 18% of 105 living adult Adelie penguins [Pygoscelis adeliae (Hombron & Jacquinot)] from Adelie Land, Antarctica, in 1982. Of the seven species of squids represented by lower beaks, Psychroteuthis glacialis comprised 88% of the number in both Emperor chicks and Emperor adults and 100% in Adelie adults. From estimates of the weight of squids represented by lower beaks, Gonatus antarcticus and Kondakovia longimana contributed 18 and 14%, respectively, of the weight of squids in the diet of Emperor chicks and 27 and 21%, respectively, in the diet of Emperor adults. The data suggest that Psychroteuthis glacialis probably hatch in July–September and grow steadily for one year, and then spawn and die.

Description: An intertidal population of Octopus digueti Perrier and Rochebrune was sampled without apparent sex or size bias (except for the smallest size classes) by placing artificial shelters in the intertidal zone. Comparisons of captures between the octopuses' natural shelters, large gastropod shells, and the artificial shelters, glass bottles, revealed no differences in the sex or size of the octopuses captured. The bottle trap technique is an inexpensive means of sampling 0. digueti. The technique provides large numbers of untraumatized octopuses and can define the local species distribution in this potentially shelter-limited population.

Description: The Pantelleria Rift system is a wide zone of post-Miocene northwest-trending grabens and horsts beneath the Sicily Strait. The central grabens host volcanics of predominantly alkalic composition which are exposed on the islands of Pantelleria and Linosa. On the Maltese Islands, along the northeastern shoulder of the rift, an Oligocene-Miocene carbonate succession exposed above sea level allows structural analysis and determination of shallow crustal stresses within the otherwise largely submarine rift system. An older northeast-trending set of normal faults is probably the expression of an Oligocene-Miocene crustal extension event which produced continental rifts in western Europe and led to passive margin formation in the western Mediterranean. Younger northwest-trending grabens of the Pantelleria Rift system cut the older faults almost at right angles and define a zone of lithospheric stretching between Tunisia and Sicily. The northwest-trending grabens which subsided dramatically since the beginning of Pliocene time appear to be connected by east-trending dextral and, more rarely, north-trending sinistral transforms. Displacement along the transforms is probably in the order of a few kilometres. In-situ stress measurements carried out on the Maltese Islands show maximum horizontal compression (SH) parallel to the rift. This suggests that in general σ1 (vertical) and σ2 (horizontal and parallel to the rift) are of about the same magnitude; both exceed σ3 (Sh) which trends northeasterly. Slight intraplate convergence in a NW-SE direction seems to be more than balanced by extension in a NE-SW direction. Neotectonics of the region possibly reflects an asthenospheric flow pattern which became established during the Messinian salinity crisis. The mechanism of recent intraplate deformation of the Pelagian shelf has relevance for the understanding of more anciently subsided platforms of the Apulian Plate.

Description: The fur seal, Arctocephalus gazella, population at Mossman Peninsula (Laurie Island) was studied from 1985 to 1987. Weekly counts were carried out at a 4 km bachelor haul-out beach from December through June. Maxima of 2 240, 2 787 and 5 196 juvenile and adult males were counted during March of the respective years. Census data indicate an increase in the non-breeding population of 13.5% between 1985–1986 and 46.5% between 1986–1987.

Description: In the Antarctic there are large unexploited stocks of cephalopods with high potential commercial value and there are two important fisheries for squid in the cool temperate waters of the Southern Ocean, adjacent to the Antarctic, in the Atlantic and Pacific sectors. Squid fisheries can develop very rapidly, and if this were to happen in the Antarctic before adequate management plans could be established, there would be serious consequences for the squid stocks, and also for the vertebrate predator populations which depend on them. It is especially important to increase our knowledge of the Antarctic cephalopod species, their distribution and role in the food chain, and to understand their life cycles

Description: At ODP Site 661 from the continental margin of Northwest Africa, authigenic clinoptilolites were investigated in detail. Based on chemical data, crystal size and shape and their intergrowth with associated mineral phases, two types of clinoptilolite (type A and B) occur representing different diagenetic conditions under which the formation of zeolites took place. Clinoptilolite type A was found in a sediment section comprises numerous hiatuses and stratigraphically condensed sediments and could have been formed during early diagenesis. In contrast, clinoptilolite type B was precipitated in Campanian sediments during later diagenesis, after the transformation from opal-A to opal-CT had taken place. At Site 661, the silica source for the authigenesis of both clinoptilolite types is biogenic opal. Volcanic ash material occurs, but in low amounts and thus is not a prerequisite for the formation of clinoptilolite at Site 661.