ALBERT

Description: An abrupt lithofacies change between calcareous shale and noncalcareous shale occurs in strata deposited in the mid-Cretaceous Greenhorn Seaway in the southeastern corner of Montana. The facies were correlated lithostratigraphically using bentonites and calcarenites. The lithocorrelations were then refined using ammonites, foraminifera, and calcareous nannofossils. Twenty-five time slices were defined within the upper middle and lower upper Cenomanian strata. Biofacies analysis indicate that lithofacies changes record the boundary or oceanic front between two water masses with distinctly different paleoceanographic conditions. One water mass entered the seaway from the Arctic and the other from the Gulf of Mexico/Tethys. The microfauna and microflora permit interpretation of the environmental conditions in each water mass. At times when the front was near vertical, the two water masses were of the same density but of different temperatures and salinities.

Description: Serological methods for prey identification have been applied to detection of residues ofsandeel (Ammodytidae) protein in faeces of common seals (Phoca vitulina) and grey seals(Halichoerus grypus) from the Moray Firth, north-east Scotland. Antisera raised to muscleprotein from Ammodytes marinus were evaluated by testing their reactions with proteinextracts made from a range of North Sea fish species and protein residues in in vitro digestates,seal digestive tracts and seal faeces. It was concluded that, using fused rocketimmuno-electrophoresis, linkage of precipitin peaks from unknown samples with peaksfrom standard sandeel extract was a reliable indicator of the presence of sandeel in theunknown sample. Seasonal variation in the incidence of sandeels in common seal diet in theMoray Firth was examined by identifying otoliths, bones, and proteins, and all threemethods indicated that sandeels occurred in the majority of samples tested in the summer,but were less important during the winter. Proteins were detected in fewer samples thanotoliths, particularly in February and March. Possible reasons for this difference arediscussed. Serological identification of sandeel proteins is potentially applicable to dietarystudies on all marine predators.

Description: Age and growth were estimated in the European squid, Loligo vulgaris, by examining growth increments in the statoliths of 203 specimens collected from off the French Mediterranean coast. Length and increment data were analyzed assuming that the increments were formed daily. The relationships between age and length showed that: growth rate varied considerably among individuals; growth was double exponential; the squids grew on average to 240 mm ML at 240 d from hatching, with a maximum of 350 mm at 240 d; the life span is probably about one year.

Description: Some of the limits to the use of serology to identify prey species in the digestive tracts of cephalopods have been evaluated. Cuttlefish, Sepia officinalis, were given meals of krill slurry (Euphausia superba). Protein extracts of contents from four regions of the digestive tract, stomach, caecum, digestive gland and intestine, were tested for prey antigenicity. Digestion times (loss of antigenicity) ranged from 1 to 8 h depending on sampling site. Stomach and caecum emptied rapidly, but meal antigenicity persisted longer in the digestive gland. The Sepia experiments provide a basis for interpretation of results from natural predation by cephalopods).

Description: Alteration patterns in the lavas and dykes of the Troodos Ophiolite, Cyprus, record a complex history of axial hydrothermal alteration, crustal aging, and subsequent uplift and emplacement of the ophiolite. Field mapping shows that distribution of five alteration zones, each with distinct mineralogical, geochemical, and hydrologie characteristics, is influenced by igneous stratigraphy, structure, and the nature and thickness of the overlying sediments. Paragenetic sequences of secondary minerals indicate that alteration conditions changed progressively as the crust cooled and moved off-axis. Along spreading axes, low temperatures (≤50°C) were maintained by the rapid flow of seawater in and out of the lavas, and only minimal alteration took place. In contrast, lower water/rock ratios and higher temperatures (〉200°C) in the dykes promoted extensive seawater-rock interaction. Although the sharp rise in temperature between the two regimes generally coincides with the lava-dyke transition, late-stage intrusions or hydrothermal upwelling zones locally cause high-temperature alteration to extend upward into the lavas. As a segment of crust moved off-axis, temperatures remained low in the lavas and progressively decreased, from 〉250° to 〈80°C, in the dykes. High permeability in the uppermost lavas led to the downward migration of an oxidative alteration front whose thickness and spatial distribution was dependent upon the rate and nature of sedimentation and, thus, the original seafloor morphology. Although field relations show that alteration has a consistent vertical pattern in Troodos, the alteration zones are not laterally continuous, and the stratigraphie depth of their boundaries varies considerably.

Description: An investigation was carried out on larvae of the oceanic tropical squid Sthenoteuthis pteropus in the equatorial Atlantic (2°30′N–7°S;12°W –8°30′E) The age of the larvae was calculated from the statolith microstructure of 20 larvae; mortality was estimated from the size structure of 1128 larvae. The larval stage lasts 32–38 days. At ages ranging from 14 to 38 days. the daily relative growth rates of mantle length decrease from 7.5 to 2.8% day −1 and from 14–16 to 5.8% of body weight day −1 At age 12–24 days, mortality rates were estimated using both raw catch data and corrected data accounting for net avoidance. The mean value of raw mortality rates was 0.189, the corrected value was 0.158. During the proboscis division (transformation of the larva into juvenile) at age 25–35 days, a sharp decrease in larval growth rates and a simultaneous increase in mortality rates (raw 0.443, corrected 0.379) were observed.

Description: Spirula spirula has stimulated considerable interest since it was first discovered. It is a member of one of the two genera of sepioids to frequent oceanic water (the other being Heteroteuthis); it has a unique spiral shell which acts as a buoyancy mechanism and can withstand considerable pressure (Denton, Gilpin-Brown & Howarth, 1967); and, until the capture by the Danish Oceanographical expeditions it was considered very rare, only 12 specimens having been captured. The Dana expeditions caught 193 individuals from 1909 to 1931 and these were described by Kerr (1931) and Bruun (1943,1955). Most of these were caught in the waters around the Canary Islands of the North Atlantic. Bruun (1943) arranged the specimens according to month and size and claimed that two size groups could be distinguished. The specimens were taken over a wide geographical area, in several years and during the months of February (1 specimen), March (40), April (3), May (8), June (1), August (1) and October (23). His conclusion concerning growth depends entirely upon his decision to split the March sample into two year-groups; those above 1.9 cm in ventral mantle length he put in a separate year-class to those below 1.9 cm in ventral mantle length. This division was arbitrary and, one suspects, based on a belief that a one-year life-span was likely. Clearly the growth of Spirula requires further study based on a larger collection and the present paper is an attempt to fulfil this need.

Description: In the western equatorial Pacific, the El Niño/Southern Oscillation (ENSO) phenomenon is characterized by precipitation variability associated with the migration of the Indonesian low pressure cell to the region of the date line and the equator. During ENSO events, Tarawa Atoll (1°N, 172°E) experiences heavy rainfall which has an estimated δ18O of about −8 to −10‰ δ18OSMOW. At Tarawa, sufficient precipitation of this composition falls during ENSO events to alter the δ18O and the salinity of the surface waters. Oxygen isotope records from two corals collected off the reef crest of Tarawa reflect rainfall variations associated with both weak and strong ENSO conditions, with approximately monthly resolution. Coral skeletal δ18O variations due to small sea surface temperature (SST) changes are secondary. These records demonstrate the remarkable ability of this technique to reconstruct variations in the position of the Indonesian Low from coral δ18O records in the western equatorial Pacific, a region which has few paleoclimatic records. The coral isotopic data correctly resolve the relative magnitudes of recent variations in the Southern Oscillation Index. Combining the Tarawa record with an oxygen isotopic history from a Galápagos Islands coral demonstrates the ability to distinguish the meteorologic (precipitation) and oceanographic (SST) anomalies that characterize ENSO events across the Pacific Basin over the period of common record (1960–1979). Comparison of the intensity of climatic anomalies at these two sites yields insight into the spatial variability of ENSO events. Isotope records from older corals can provide high-resolution, Pacific-wide reconstructions of ENSO behavior during periods of different climate boundary conditions.

Description: As shown by the work of Dansgaard and his colleagues, climate oscillations of one or so millennia duration punctuate much of glacial section of the Greenland ice cores. These oscillations are characterized by 5°C air temperature changes, severalfold dust content changes and 50 ppm CO2 changes. Both the temperature and CO2 change are best explained by changes in the mode of operation of the ocean. In this paper we provide evidence which suggests that oscillations in surface water conditions of similar duration are present in the record from a deep sea core at 50°N. Based on this finding, we suggest that the Greenland climate changes are driven by oscillations in the salinity of the Atlantic Ocean which modulate the strength of the Atlantic's conveyor circulation.

Description: The stomachsof 23 striped dolphins (Stenella coeruleoalba Meyen, 1833, Cetacea), stranded along the Ligurian coast (western Mediterranean Sea), contained 32 species of cephalopods, crustaceans and fishes, totalling an estimated 2,723 prey specimens representing about 36 kg in weight. Cephalopods and bony fishes were equally important in the diet (50%). Todarodes sagittatus (34.5%) and Micromesistius poutassou (25.9%) were found to be the most important food species. Other species belonging to six cephalopod families, three crustacean families and nine bony fish families, contributed to the diet with variable numbers, weights, and occurrences, demonstrating the opportunistic character of striped dolphin feeding.