ALBERT

Description: Non-technical summary Scenarios compatible with the Paris agreement's temperature goal of 1.5 °C involve carbon dioxide removal measures - measures that actively remove CO2 from the atmosphere - on a massive scale. Such large-scale implementations raise significant ethical problems. Van Vuuren et al. (2018), as well as the current IPCC scenarios, show that reduction in energy and or food demand could reduce the need for such activities. There is some reluctance to discuss such societal changes. However, we argue that policy measures enabling societal changes are not necessarily ethically problematic. Therefore, they should be discussed alongside techno-optimistic approaches in any kind of discussions about how to respond to climate change. Technical summary The 1.5 °C goal has given impetus to carbon dioxide removal (CDR) measures, such as bioenergy combined with carbon capture and storage, or afforestation. However, land-based CDR options compete with food production and biodiversity protection. Van Vuuren et al. (2018) looked at alternative pathways including lifestyle changes, low-population projections, or non-CO2 greenhouse gas mitigation, to reach the 1.5 °C temperature objective. Underlined by the recently published IPCC AR6 WGIII report, they show that demand-side management measures are likely to reduce the need for CDR. Yet, policy measures entailed in these scenarios could be associated with ethical problems themselves. In this paper, we therefore investigate ethical implications of four alternative pathways as proposed by Van Vuuren et al. (2018). We find that emission reduction options such as lifestyle changes and reducing population, which are typically perceived as ethically problematic, might be less so on further inspection. In contrast, options associated with less societal transformation and more techno-optimistic approaches turn out to be in need of further scrutiny. The vast majority of emission reduction options considered are not intrinsically ethically problematic; rather everything rests on the precise implementation. Explicitly addressing ethical considerations when developing, advancing, and using integrated assessment scenarios could reignite debates about previously overlooked topics and thereby support necessary societal discourse. Social media summary Policy measures enabling societal changes are not necessarily as ethically problematic as commonly presumed and reduce the need for large-scale CDR

Description: The Falkland Shelf is a highly productive ecosystem in the Southwest Atlantic Ocean. It is characterized by upwelling oceanographic dynamics and displays a wasp-waist structure, with few intermediate trophic-level species and many top predators that migrate on the shelf for feeding. One of these resident intermediate trophic-level species, the Patagonian longfin-squid Doryteuthis gahi, is abundant and plays an important role in the ecosystem. We used two methods to estimate the trophic structure of the Falkland Shelf food web, focusing on the trophic niche of D. gahi and its impacts on other species and functional groups to highlight the importance of D. gahi in the ecosystem. First, stable isotope measurements served to calculate trophic levels based on an established nitrogen baseline. Second, an Ecopath model was built to corroborate trophic levels derived from stable isotopes and inform about trophic interactions of D. gahi with other functional groups. The results of both methods placed D. gahi in the centre of the ecosystem with a trophic level of ∼ 3. The Ecopath model predicted high impacts and therefore a high keystoneness for both seasonal cohorts of D. gahi. Our results show that the Falkland Shelf is not only controlled by species feeding at the top and the bottom of the trophic chain. The importance of species feeding at the third trophic level (e.g. D. gahi and Patagonotothen ramsayi) and observed architecture of energy flows confirm the ecosystem's wasp-waist structure with middle-out control mechanisms at play.

Description: Increases in ocean temperatures in the Filchner Ronne region of Antarctica are likely to result in increased ice mass loss and sea level rise. We constrain projections of the 21st century sea level contribution of this region using process-based ice-sheet modeling, with model parameters controlling ice dynamics calibrated using observed surface speeds and Markov-chain Monte Carlo sampling. We use climate forcing from Representative Concentration Pathway (RCP) scenarios as well as a set of hypothetical scenarios of deep ocean warming to evaluate the sensitivity of this region to ocean temperatures. Projected changes in regional ice mass correspond to a decrease in global mean sea level of 24±7 mm over 2015–2100 under RCP 2.6 and 28±9 mm under RCP 8.5. Increased regional inland surface accumulation related to higher warming levels in RCP 8.5 leads to more ice above flotation, offsetting increased ice shelf basal melt. The tests involving step changes in ocean temperatures with constant surface forcing show that one degree of ocean warming from present results in an additional +11 mm contribution to sea level by 2100 and 1% of the ice-covered area in the domain becomes ungrounded (23 200 km2). The rate of mass loss with temperature increases at higher temperatures.

Description: Radiocarbon (14C) concentrations in the oceans are different from those in the atmosphere. Understanding these ocean-atmospheric 14C differences is important both to estimate the calendar ages of samples which obtained their 14C in the marine environment, and to investigate the carbon cycle. The Marine20 radiocarbon age calibration curve is created to address these dual aims by providing a global-scale surface ocean record of radiocarbon from 55,000–0 cal yr BP that accounts for the smoothed response of the ocean to variations in atmospheric 14C production rates and factors out the effect of known changes in global-scale palaeoclimatic variables. The curve also serves as a baseline to study regional oceanic 14C variation. Marine20 offers substantial improvements over the previous Marine13 curve. In response to community questions, we provide a short intuitive guide, intended for the lay-reader, on the construction and use of the Marine20 calibration curve. We describe the choices behind the making of Marine20, as well as the similarities and differences compared with the earlier Marine calibration curves. We also describe how to use the Marine20 curve for calibration and how to estimate ΔR—the localized variation in the oceanic 14C levels due to regional factors which are not incorporated in the global-scale Marine20 curve. To aid understanding, illustrative worked examples are provided.

Description: The Marine20 radiocarbon (14C) age calibration curve, and all earlier marine 14C calibration curves from the IntCal group, must be used extremely cautiously for the calibration of marine 14C samples from polar regions (outside ∼ 40ºS–40ºN) during glacial periods. Calibrating polar 14C marine samples from glacial periods against any Marine calibration curve (Marine20 or any earlier product) using an estimate of , the regional 14C depletion adjustment, that has been obtained from samples in the recent (non-glacial) past is likely to lead to bias and overconfidence in the calibrated age. We propose an approach to calibration that aims to address this by accounting for the possibility of additional, localized, glacial 14C depletion in polar oceans. We suggest, for a specific polar location, bounds on the value of during a glacial period. The lower bound may be based on 14C samples from the recent non-glacial (Holocene) past and corresponds to a low-depletion glacial scenario. The upper bound, , representing a high-depletion scenario is found by increasing according to the latitude of the 14C sample to be calibrated. The suggested increases to obtain are based upon simulations of the Hamburg Large Scale Geostrophic Ocean General Circulation Model (LSG OGCM). Calibrating against the Marine20 curve using the upper and lower bounds provide estimates of calibrated ages for glacial 14C samples in high- and low-depletion scenarios which should bracket the true calendar age of the sample. In some circumstances, users may be able to determine which depletion scenario is more appropriate using independent paleoclimatic or proxy evidence.

Description: Spatially variable basal conditions are thought to govern how ice sheets behave at glacial time scales (〉1000 years) and responsible for changes in dynamics between the core and peripheral regions of the Laurentide and Fennoscandian ice sheets. Basal motion is accomplished via the deformation of unconsolidated sediments, or via sliding of the ice over an undeformable bed. We present an ice sheet sliding module for the Parallel Ice Sheet Model (PISM) that takes into account changes in sediment cover and incorporates surface meltwater. This model routes meltwater, produced at the surface and base of the ice sheet, toward the margin of the ice sheet. Basal sliding is accomplished through the deformation of water saturated sediments, or sliding at the ice-bed interface. In areas with continuous, water saturated sediments, sliding is almost always accomplished through sediment deformation. In areas with incomplete cover, sliding has a stronger dependence on the supply of water. We find that the addition of surface meltwater to the base is a more important factor for ice sheet evolution than the style of sliding. In a glacial cycle simulation, our model causes a more rapid buildup of the Laurentide Ice Sheet.

Description: Although it is generally known that a combination of abiotic and biotic drivers shapes the distribution and abundance of parasites, our understanding of the interplay of these factors remains to be assessed for most marine host species. The present field survey investigated spatial patterns of richness, prevalence and abundance of parasites in Mytilus galloprovincialis along the coast of the northern Adriatic Sea. Herein, the relationships between biotic (host size, density and local parasite richness of mussel population) and abiotic (eutrophication and salinity) drivers and parasite richness of mussel individuals, prevalence and abundance were analysed. Local parasite richness was the most relevant factor driving parasite species richness in mussel individuals. Prevalence was mainly driven by eutrophication levels in 3 out of 4 parasite species analysed. Similarly, abundance was driven mainly by eutrophication in two parasite species. Mussel size, density and salinity had only minor contributions to the best fitting models. This study highlights that the influence of abiotic and biotic drivers on parasite infections in mussels can be differentially conveyed, depending on the infection measure applied, i.e., parasite richness, prevalence or abundance. Furthermore, it stresses the importance of eutrophication as a major factor influencing parasite prevalence and abundance in mussels in the Adriatic Sea

Description: Trematode prevalence and abundance in hosts are known to be affected by biotic drivers as well as by abiotic drivers. In this study, we used the unique salinity gradient found in the south-western Baltic Sea to: (i) investigate patterns of trematode infections in the first intermediate host, the periwinkle Littorina littorea and in the downstream host, the mussel Mytilus edulis, along a regional salinity gradient (from 13 to 22) and (ii) evaluate the effects of first intermediate host (periwinkle) density, host size and salinity on trematode infections in mussels. Two species dominated the trematode community, Renicola roscovita and Himasthla elongata. Salinity, mussel size and density of infected periwinkles were significantly correlated with R. roscovita, and salinity and density correlated with H. elongata abundance. These results suggest that salinity, first intermediate host density and host size play an important role in determining infection levels in mussels, with salinity being the main major driver. Under expected global change scenarios, the predicted freshening of the Baltic Sea might lead to reduced trematode transmission, which may be further enhanced by a potential decrease in periwinkle density and mussel size.

Description: The last 85,000 years were characterized by high climate and environmental variability on the Yucatán Peninsula. Heinrich stadials are examples of abrupt climate transitions that involved shifts in regional temperatures and moisture availability. Thus, they serve as natural experiments to evaluate the contrasting responses of aquatic and terrestrial ecosystems. We used ostracodes and pollen preserved in a 75.9-m-long sediment core (PI-6, ~85 ka) recovered from Lake Petén Itzá, Guatemala, to assess the magnitude and velocity of community responses. Ostracodes are sensitive to changes in water temperature and conductivity. Vegetation responds to shifts in temperature and the ratio of evaporation to precipitation. Ostracodes display larger and more rapid community changes than does vegetation. Heinrich Stadial 5-1 (HS5-1) was cold and dry and is associated with lower ostracode and vegetation species richness and diversity. In contrast, the slightly warmer and dry conditions during HS6 and HS5a are reflected in higher ostracode species richness and diversity. Our paleoecological study revealed the greatest ecological turnover for ostracodes occurred from 62.5 to 51.0 ka; for pollen, it was at the Pleistocene/Holocene transition. Future studies should use various climate and environmental indicators from lake and marine sediment records to further explore late glacial paleoclimate causes and effects in the northern neotropics.

Description: Radiocarbon (14C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international 14C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable 14C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the 14C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine 14C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.

Description: The concentration of radiocarbon (14C) differs between ocean and atmosphere. Radiocarbon determinations from samples which obtained their 14C in the marine environment therefore need a marine-specific calibration curve and cannot be calibrated directly against the atmospheric-based IntCal20 curve. This paper presents Marine20, an update to the internationally agreed marine radiocarbon age calibration curve that provides a non-polar global-average marine record of radiocarbon from 0–55 cal kBP and serves as a baseline for regional oceanic variation. Marine20 is intended for calibration of marine radiocarbon samples from non-polar regions; it is not suitable for calibration in polar regions where variability in sea ice extent, ocean upwelling and air-sea gas exchange may have caused larger changes to concentrations of marine radiocarbon. The Marine20 curve is based upon 500 simulations with an ocean/atmosphere/biosphere box-model of the global carbon cycle that has been forced by posterior realizations of our Northern Hemispheric atmospheric IntCal20 14C curve and reconstructed changes in CO2 obtained from ice core data. These forcings enable us to incorporate carbon cycle dynamics and temporal changes in the atmospheric 14C level. The box-model simulations of the global-average marine radiocarbon reservoir age are similar to those of a more complex three-dimensional ocean general circulation model. However, simplicity and speed of the box model allow us to use a Monte Carlo approach to rigorously propagate the uncertainty in both the historic concentration of atmospheric 14C and other key parameters of the carbon cycle through to our final Marine20 calibration curve. This robust propagation of uncertainty is fundamental to providing reliable precision for the radiocarbon age calibration of marine based samples. We make a first step towards deconvolving the contributions of different processes to the total uncertainty; discuss the main differences of Marine20 from the previous age calibration curve Marine13; and identify the limitations of our approach together with key areas for further work. The updated values for ΔR, the regional marine radiocarbon reservoir age corrections required to calibrate against Marine20, can be found at the data base http://calib.org/marine/.

Description: A new carbon isotope record for two high-latitude sedimentary successions that span the Jurassic–Cretaceous boundary interval in the Sverdrup Basin of Arctic Canada is presented. This study, combined with other published Arctic data, shows a large negative isotopic excursion of organic carbon (δ13Corg) of 4‰ (V-PDB) and to a minimum of −30.7‰ in the probable middle Volgian Stage. This is followed by a return to less negative values of c. −27‰. A smaller positive excursion in the Valanginian Stage of c. 2‰, reaching maximum values of −24.6‰, is related to the Weissert Event. The Volgian isotopic trends are consistent with other high-latitude records but do not appear in δ13Ccarb records of Tethyan Tithonian strata. In the absence of any obvious definitive cause for the depleted δ13Corg anomaly, we suggest several possible contributing factors. The Sverdrup Basin and other Arctic areas may have experienced compositional evolution away from open-marine δ13C values during the Volgian Age due to low global or large-scale regional sea levels, and later become effectively coupled to global oceans by Valanginian time when sea level rose. A geologically sudden increase in volcanism may have caused the large negative δ13Corg values seen in the Arctic Volgian records but the lack of precise geochronological age control for the Jurassic–Cretaceous boundary precludes direct comparison with potentially coincident events, such as the Shatsky Rise. This study offers improved correlation constraints and a refined C-isotope curve for the Boreal region throughout latest Jurassic and earliest Cretaceous time.

Description: The workshop on polar lows (PLs) and mesoscale weather extremes attracted 30 scientists from China, France, Germany, Japan, Norway, Russia, the United Kingdom, and the United States to present the most recent findings on PL research and to summarize our present understanding of PLs and mesocyclones (MCs) as well as mesoscale weather extremes in the Arctic and Antarctic (see sidebar for the definition of PLs). The workshop had the following main themes: PL studies using satellite data and in situ observations, climatological aspects, PLs in reanalyses and model simulations, environments for PL genesis and operational aspects, polar mesoscale weather phenomena, and air–ocean–ice interactions. The workshop was concluded by a roundtable discussion resulting in recommendations for future research and actions.

Description: Recent rapid retreat of glacial front lines and the loss of land ice along the Antarctic margins may play an important role in exporting suspended particulate matter (SPM) potentially rich in bioavailable (defined as ascorbate leachable) iron (FeA) to coastal areas of the Southern Ocean. Sediment ablation is an additional source of iron for this high-nutrient low-chlorophyll region. In Potter Cove, King George Island, meltwater streams discharge up to 18 000 mg l-1 (average 283 mg l-1) of slightly weathered, finely ground bedrock particles into coastal waters during the summer. Approximately 15% of this SPM is exported within a low-salinity surface plume into Bransfield Strait. Based on our data, an estimated 12 mg m-2 yr-1 of FeA is exported from the South Shetland Island land surface (ice-free and subglacial areas) to the surrounding coastal waters. Extrapolated to an area of 2.5x104 km2, this FeA input is comparable to the contribution from icebergs and c. 240-fold higher than aeolian input via dust. An observed rise in local sediment accumulation rates suggests that glacial erosion has been increasing over recent decades and that (sub-)glacially derived SPM is becoming more important as a source of iron to the Southern Ocean.

Description: Since the Last Glacial Maximum, ice has retreated through the fjords of the South Shetland Islands leaving a valuable record of submarine landforms behind. In this study, glacial landforms and sub-bottom characteristics have been mapped to investigate the late Holocene retreat behaviour of the Fourcade Glacier and to delineate past environmental processes in Potter Cove, King George Island. The comprehensive datasets include high-resolution swath bathymetry, shallow seismic profiling and one sediment core. Moraines, moraine incisions and glacial lineations were mapped on the sea floor in the inner part of the cove, whereas pockmarks, ice scour marks and channel structures were identified in the outer part. Sub-bottom characteristics have been assigned to different acoustic facies types indicating different depositional settings. The results reveal glacial recessions as well as stillstands and potential readvances during the late Holocene. Furthermore, the sediment record indicates that the Fourcade Glacier was situated inside the inner cove during the Little Ice Age (500–100 cal yr bp).

Description: Introduction. Today, most countries have accepted a 2 degrees Celsius temperature increase above preindustrial levels as the maximum tolerable limit for global warming. An exceedance probability of below 20 percent for this limit implies an emission budget of less than 250 GtC from 2000 until 2049, however, extrapolating from current global CO2 emissions, this budget will only last until 2024. This sobering math should wake us up to the reality that all options, including climate engineering, need to be considered to address climate change. Climate engineering options can be classified broadly into two categories: solar radiation management and carbon dioxide removal measures. Solar radiation management schemes seek to decrease the incoming solar radiation or to increase the reflection of incoming solar radiation. These approaches can generate fast climate responses, but do not immediately address the cause of the problem. Carbon dioxide removal measures seek to decrease atmospheric carbon concentrations by enhancing or substituting natural carbon sinks. The terrestrial carbon sink can be enhanced by means of forestation; the oceanic sink may, in some regions, be enhanced by means of fertilization, for example by artificially enhanced upwelling of macronutrients or by purposeful addition of the micronutrient iron; the mineral carbon sink can be enhanced by means of chemically accelerated weathering. Some analysts have expressed doubts about the potential of mitigating climate change by sink enhancement, because of concerns about whether carbon can be stored permanently. Nevertheless, terrestrial vegetation sinks have entered the Kyoto Protocol (KP) as offsets for anthropogenic greenhouse gas emissions, but ocean sinks have not.

Description: The Water and Global Change (WATCH) forcing datasets have been created to support the use of hydrological and land surface models for the assessment of the water cycle within climate change studies. They are based on 40-yr ECMWF Re-Analysis (ERA-40) or ECMWF interim reanalysis (ERA-Interim) with temperatures (among other variables) adjusted such that their monthly means match the monthly temperature dataset from the Climatic Research Unit. To this end, daily minimum, maximum, and mean temperatures within one calendar month have been subjected to a correction involving monthly means of the respective month. As these corrections can be largely different for adjacent months, this procedure potentially leads to implausible differences in daily temperatures across the boundaries of calendar months. We analyze day-to-day temperature fluctuations within and across months and find that across-months differences are significantly larger, mostly in the tropics and frigid zones. Average across-months differences in daily mean temperature are typically between 10% and 40% larger than their corresponding within-months average temperature differences. However, regions with differences up to 200% can be found in tropical Africa. Particularly in regions where snowmelt is a relevant player for hydrology, a few degrees Celsius difference can be decisive for triggering this process. Daily maximum and minimum temperatures are affected in the same regions, but in a less severe way.

Description: Density distribution of the common infaunal bivalves, Macoma balthica and Cerastoderma edule, was studied along the Murman Coast of the Barents Sea during 2002–2010. In both species, abundance was generally higher in West Murman in contrast to East Murman. Highest density of Macoma balthica reaching 1535 ind. m−2 was observed in the Kola Inlet. Cerastoderma edule was less abundant; its density rarely exceeded 10 ind. m−2 in all but one site, where 282 ind. m−2 was registered. Reconstruction of abundance distribution across the European geographic range of Macoma balthica revealed that it does not match an ‘abundant-centre’ pattern, having features of ramped north. On the other hand, distribution of Cerastoderma edule abundance across the range generally follows an ‘abundant-centre’ pattern but southern edge populations show relatively higher abundances as compared with those at the north edge (the Barents Sea).

Description: No published information is available on the foraging ecology and choice of feeding habitat of New Zealand’s rarest breeding bird: the New Zealand Fairy Tern (NZFT) Sternula nereis davisae. To address this gap, we conducted an assessment of the largest remaining breeding population at Mangawhai Harbour, Northland, New Zealand, during the chick-rearing period of the 2010/2011 breeding season. We combined visual tracking of birds with prey surveys and stable isotope analyses, and we present the first quantitative assessment of NZFT foraging. We recorded 405 foraging dives that show NZFT foraging habitat includes the water edges, shallow channels, and pools on the tidal flats of mangrove-lined (Avicennia marina var. resinifera) parts of the estuary; tidal pools on mud- and sandflats in the mid-estuary and lower harbour; the shallow margins of the dredged main channel in the lower harbour; the oxbow lagoons on the sand spit; and coastal shallows. Our study identifies the mangrove-lined highly tidal and shallow mid-estuary and the lagoon on the sand spit as foraging hotspots for the Mangawhai breeding population of the NZFT. The prey survey employed a seine-net sampling method at identified NZFT foraging sites and yielded 4,367 prey-sized fish of 11 species, two of which had not previously been reported in Mangawhai Harbour, as well as numerous shrimps. The most abundant fish were gobies of the genus Favonigobius. Our stable isotope results highlight gobies as the most important prey for NZFT chick rearing, also indicating that flounder Rhombosolea sp. contribute to NZFT diet. We raise the possibility that shrimps may also constitute a substantial diet component for NZFT, potentially providing up to 21% of diet mass for adult birds. While our results provide a first basis to understanding the feeding ecology of NZFT during their breeding season in order to facilitate conservation planning, further research is required to address inter-annual variation and to identify key foraging grounds for this Critically Endangered bird at other breeding sites.

Description: El Niño–Southern Oscillation (ENSO) in the Pacific and the analogous Atlantic Niño mode are generated by processes involving coupled ocean–atmosphere interactions known as the Bjerknes feedback. It has been argued that the Atlantic Niño mode is more strongly damped than ENSO, which is presumed to be closer to neutrally stable. In this study the stability of ENSO and the Atlantic Niño mode is compared via an analysis of the Bjerknes stability index. This index is based on recharge oscillator theory and can be interpreted as the growth rate for coupled modes of ocean–atmosphere variability. Using observational data, an ocean reanalysis product, and output from an ocean general circulation model, the individual terms of the Bjerknes index are calculated for the first time for the Atlantic and then compared to results for the Pacific. Positive thermocline feedbacks in response to wind stress forcing favor anomaly growth in both basins, but they are twice as large in the Pacific compared to the Atlantic. Thermocline feedback is related to the fetch of the zonal winds, which is much greater in the equatorial Pacific than in the equatorial Atlantic due to larger basin size. Negative feedbacks are dominated by thermal damping of sea surface temperature anomalies in both basins. Overall, it is found that both ENSO and the Atlantic Niño mode are damped oscillators, but the Atlantic is more strongly damped than the Pacific primarily because of the weaker thermocline feedback.

Description: The feeding habits of the pelagic stingray ( Pteroplatytrygon violacea ) were studied using 84 stomachs of specimens caught in the northern Adriatic Sea in the period from April 2004 to October 2005. Percentage of empty stomachs found was overall very low, being a bit bigger in smaller specimens. The diet consisted of two main taxonomic groups such as teleost fish and cephalopods, but few specimens of crustaceans were recorded as well. The main food item was represented by anchovy, while cuttlefish and red band fish represented the alternative preys. Prey size was positively correlated with the size of predator. The proportion of anchovies in the diet grew with size of predator, while the one for red band fish decreased. The stingray was confirmed to be a top predator of pelagic fish species, although the presence of benthic prey shows that it feeds also at the bottom.

Description: The schooling behaviour of the oval squid Sepioteuthis lessoniana was observed over 4 summers at 3 observation sites in the coastal waters of Okinawa Island, Ryukyu Archipelago, Japan. During this field study, 3 static appearances (belt, ball and sheet shape) and 2 transitional appearances (high and low density) were noted, recorded and described. In addition to formations, a member of S. lessoniana schools also displayed particular and repeated behavioural patterns such as vanguard and intimidating display. The 3 observation sites were tropical coral reefs near the coastline at a depth of 1 to 15 m on an average. All participating observers snorkelled and were equipped with various underwater digital video and photographic cameras. The schools observed consisted of 8 to over 100 members with a wide range of body sizes. Despite these biological and locational differences, both static and transitional appearances were consistently observed with equally consistent individual behavioural patterns. There have been studies on related species, Sepioteuthis sepioidea, at the San Blas Islands along the Caribbean coast of eastern Panama, and the same species, S. lessoniana, at a different geographical location, Casuarina Beach on Lizard Island, Australia. The findings of this study are consistent with those reported previously, with some notable differences.

Description: Age structure and hatchling dates of the squid Illex argentinus collected by bottom-trawl fishery in southern Brazilian waters were assessed by the analysis of statolith growth increments. Catches occurred between 2001 and 2002, from 23° to 32°S at depths of 100–700 m. Squid from juvenile to post-spawning stages were collected year round, with age estimated from 98 to 320 days and mantle lengths ranging from 112 to 376 mm. Duration of life cycle events based on statolith growth zones revealed that squids can spend about 14% of their lifespan as paralarva (~30 days), 70% as juvenile (~130 days), leaving maturity and spawning condition to the terminal 10–20% (~30–60 days). The results suggest that, unlike estimates available for Patagonian populations, a general 0.5 year lifespan is predicted for I. argentinus off Brazil. The wide range of size-at-ages implied that catches of shortfin squid off southern Brazil probably include squid hatched throughout the year. Mature and spawning squid caught in summer months hatched in winter and spring, while winter catches revealed mature-spawning individuals hatched both in summer/autumn (~6 months of age) and winter/spring periods (~10–11 months of age). It has been argued that such groups may combine both squid resident of Brazilian outer shelf and slope (22°–34°S) with a six months' lifespan and migrating squid originated from the northern Patagonian shelf (~42°S) with 10–11 months' lifespan.

Description: Intraspecific variation in characters such as arm sucker and gill lamellae counts in octopodids is yet to be thoroughly investigated, potentially hampering our ability to recognize species. In this study, data from 13 specimens of Muusoctopus hydrothermalis collected at four hydrothermal vents on the East Pacific Rise between 8°38′N and 12°48′N are considered. Although the northern and southern octopuses differ minimally in size, mean sucker count by arm in the northern group is 11.7 to 22.8% higher than it is in the southern group; in addition these octopuses typically have an additional gill lamella and bulkier funnel organs. The arms of each individual carry a different number of suckers. The difference is significant on nonadjacent arms, a pattern that merits examination in a broader taxonomic context. Why these differences exist among conspecifics remains unknown, the incidence of parasitic copepods is not different between the groups and the between-group variation in arm suckers seen here compares well with a previous report of variation among 18 specimens from the type locality. Increases in meristic characters (counts) in fish are attributed to lower temperatures during embryonic development following Jordan's rule. Northern and southern vents offer the octopuses a wide temperature range, but vent fluid chemistry differs. Northern vent fluids may be more toxic; if so, developing octopus embryos may survive only minimal vent fluid exposure and therefore develop at low temperatures. At the less toxic southern vents, eggs may survive greater exposure to vent fluids and thus develop at higher temperatures.

Description: The Cycladic blueschist belt, Greece, is mostly submerged below sea level and regional correlations are difficult to establish. Marbles are widespread within the belt and locally used as marker horizons to subdivide monotonous schist sequences. However, owing to the lack of distinctive petrographic characteristics, the marbles have not been used for island-to-island correlations. This study aims to investigate the potential of Sr-, C- and O-isotope compositions of marbles as a tool for unravelling the litho- and/or tectonostratigraphic relationships across the Cycladic islands, and as a proxy for the time of sediment formation. For this purpose, we have studied metamorphic carbonate rocks from the islands of Tinos, Andros, Syros, Sifnos and Naxos. Identical 87Sr/86Sr values for certain marble horizons occurring on Tinos, Andros and Sifnos are interpreted to document coeval regional carbonate precipitation. The 87Sr/86Sr values of the apparently least altered samples intersect the seawater curve multiple times within the most likely time interval of original carbonate precipitation (〈 240 Ma; as indicated by previously published ion probe U–Pb zircon data) and thus an unequivocal age assignment is not possible. Very broad temporal correlations are possible, but more subtle distinctions are not feasible. On Andros, the overlapping Sr-isotope values of marbles representing the lowest and highest parts of the metamorphic succession are in accordance with a model suggesting isoclinal folding or thrusting of a single horizon, or very fast sedimentation. In contrast, distinct 87Sr/86Sr values for samples from Tinos, representing different levels of the metamorphic succession, suggest that these rocks represent a temporal succession and not the tectonic repetition of a single horizon. Based on Sr-,O- and C-isotope characteristics alone the time equivalence ofmarbles occurring on different islands could not be documented unambiguously. However, by using various combinations of these parameters, some occurrences can be discriminated from the overall sample population. The new data further accentuate the general potential of coupled Sr-, C- and O-isotope characteristics for identification of archaeological provenance and complement existing datasets for Aegean marbles.

Description: The midwater scorpionfish Ectreposebastes imus (Scorpaeniformes: Setarchidae) is distributed in tropical and subtropical waters of the worldwide oceans, at depths of 150–800 m. It has previously been recorded from the Gulf of Guinea in the eastern Atlantic. The present work extends the northern limit for the distribution of E. imus in the Atlantic Ocean to the area of the Canary Islands.

Description: Morphologic analyses of a large collection of coleoid cephalopods from the Lebanese Upper Cretaceous yielded a much higher diversity than previously assumed and revealed numerous extraordinarily well-preserved, soft-part characters. An analysis of the Prototeuthidina, a gladius-bearing group with a slender torpedo-shaped body, revealed two species: Dorateuthis syriaca and Boreopeltis smithi n. sp. Previously unknown soft-part characters, such as the digestive tract, the gills, and the cephalic cartilage considerably improved our knowledge of D. syriaca. Since none of the investigated specimens show more than eight arms, similarities with modern squids are regarded as superficial. Boreopeltis smithi n. sp. is erected on the basis of its comparatively wide Paraplesioteuthis- like gladius. The latter species represents the first unambiguous record of this genus in Upper Cretaceous deposits. Phylogenetic analyses indicate that the prototeuthidid clade consists of two lineages. The plesioteuthidid lineage originates from early Jurassic Paraplesioteuthis and leads to Plesioteuthis and Dorateuthis. The other lineage is morphologically more conservative and leads to Boreopeltis.

Description: The scorpionfish Setarches guentheri (Scorpaeniformes: Setarchidae) usually dwells offshore, in soft bottom deep areas at depths of about 150 to 780 m and at bottom temperature range of 5.5°C–12.5°C. This species has the widest distribution of any known scorpaenid, although this is a rare bathydemersal scorpaenid. Setarches guentheri has a large distribution, occurring from the Indo-West Pacific (Tanzania to South Africa, India and Sri Lanka to the Bay of Bengal, Andaman Sea, north to Japan, Fiji and Hawaii, south to the Philippines, Indonesia and Western Australia), from the eastern Pacific (Chile) and from the Atlantic Ocean (in the western Atlantic, USA to Brazil, and in the eastern Atlantic). In the eastern Atlantic, it has been recorded from Morocco, Madeira and Cape Verde to South Africa and, in the Iberian Peninsula, there was only one previous record from the Algarve coast, Portugal. The present record constitutes a new extended northern limit for the distribution of S. guentheri in this area.

Description: Two species of the bobtail squid Heteroteuthis are reported from the Atlantic Ocean, H. dispar in the North Atlantic Ocean and H. dagamensis in the South Atlantic Ocean. In total 58 individuals were examined, 23 belonging to the species Heteroteuthis dispar and 35 belonging to the species H. dagamensis . All specimens were captured during the Walther Herwig Expeditions 1966, 1968, 1976 and 1982. A full description of both sexes of H. dispar and H. dagamensis is provided. These two species can only be distinguished by means of the male's enlarged suckers on arm pair III. Females are not useful for taxonomic identifications and are morphologically identical in both species. The results do not support the definition of subgenera in this genus. This is the first report for Heteroteuthis dagamensis in the South-West Atlantic Ocean.

Description: Calcareous tube polychaetes (family Serpulidae) are notorious biofoulers that are easily transported and introduced to allochthonous habitats. Here we report the recent introduction of Hydroides dianthus (Verrill, 1873) to eastern Japan as its first occurrence in East Asia, probably from European or American coasts. Specimens had been found on artificial hard substrata together with congeners H. ezoensis, H. exaltatus and H. fusicolus in Tokyo Bay, Japan in 2006. The origin, vector, source of introduction and possible impact of H. dianthus on Japanese coasts is discussed from a perspective based on worldwide Hydroides transport.

Description: This paper documents the arrival of Diplosoma listerianum into a habitat with no previously known history of the species. Once established, D. listerianum exploited rapid growth rates relative to the other fouling species present, to quickly become the dominant species in a local fouling assemblage. Most resident macrofoulers were out-competed for space and overgrown, although some resistance to overgrowth was demonstrated by the bryozoan Umbonula littoralis and the tunicate Ascidiella aspersa. In this instance, traits traditionally considered to be relevant for community resistance towards invasion, such as diversity, richness, dominant species identity and open space were not important in controlling the spread of D. listerianum

Description: A total of 104 Semirossia patagonica were collected all over the Patagonian shelf between the depths of 47 and 295 m. Mature female size varied from 10 to 35 mm ML, mature male size was 16–32 mm. Potential fecundity ranged between 527–766 eggs in pre-spawning females, ripe egg size was 3.4–5.0 mm. The oviduct capacity probably was no more than 30 eggs. The maximum number of spermatophores in males was 229. Males transfer 2–19 spermatophores to females during copulation. The ovulation pattern is asynchronous, individual spawning is continuous. Reproduction occurs all year round. Semirossia patagonica is a south-west Atlantic ecological sibling of north-east Atlantic bobtail squids Sepiola spp. and Sepietta spp.

Description: Recent scientific and commercial deepwater trawls provide evidence that the loliginid squid, Loligo gahi occurs much deeper than previously believed. Three immature and maturing squids were caught in two hauls between 528 and 626 m depth, exceeding the previous maximum recorded depth of 400 m. An L. gahi egg mass was found on the bottom attached to polychaete tube sampled from depths of 68–71 m. It represents a new spawning habitat, because before the species was known to spawn only in inshore kelp forests, well off the bottom, at depths 〈20 m.

Description: The jumbo or Humboldt squid, Dosidicus gigas, is an important fisheries resource and a significant participant in regional ecologies as both predator and prey. It is the largest species in the oceanic squid family Ommastrephidae and has the largest known potential fecundity of any cephalopod, yet little is understood about its reproductive biology. We report the first discovery of a naturally deposited egg mass of Dosidicus gigas, as well as the first spawning of eggs in captivity. The egg mass was found in warm water (25–27°C) at a depth of 16 m and was far larger than the egg masses of any squid species previously reported. Eggs were embedded in a watery, gelatinous matrix and were individually surrounded by a unique envelope external to the chorion. This envelope was present in both wild and captive-spawned egg masses, but it was not present in artificially fertilized eggs. The wild egg mass appeared to be resistant to microbial infection, unlike the incomplete and damaged egg masses spawned in captivity, suggesting that the intact egg mass protects the eggs within. Chorion expansion was also more extensive in the wild egg mass. Hatchling behaviours included proboscis extension, chromatophore activity, and a range of swimming speeds that may allow them to exercise some control over their distribution in the wild.

Description: Ocean island volcanoes frequently develop local rift zones associated with flank movement and flank collapses. The ocean island El Hierro grew by coalescence and collapse of three volcanic edifices, which are an elongated topographic ridge (the Southern Ridge) and two semi-circular volcanic cones (Ti˜nor volcano, El Golfo volcano). During edifice growth and volcano coalescence, eruption fissures nucleated into rift zones that developed a complex triangle pattern. In scaled analogue experimentswe could successfully reproduce the geometry of rift zones and unstable flanks as observed on El Hierro. The experimental results suggest that the rift configuration on El Hierro is the result of gravitational volcano spreading over deformable basal substrata, rather than of deep-seated magma updoming as thought previously. This paper elucidates the importance of the basal substratum and gravitational spreading, and the relationship to rifting and flank instability on El Hierro Island, and may help in understanding similar volcano architectures elsewhere.

Description: Sea ice deforms under convergent and Shear motion, causing rafting and ridging. This results in thicker ice than could be formed by thermodynamic growth only. Three different approaches to Simulating the formation of pressure ridges in a dynamic–thermodynamic continuum model are considered. They are compared with and evaluated by airborne laser profiles of the Sea-ice Surface roughness. The respective characteristic of each of the three ridging Schemes is (1) a prognostic equation for deformation energy from which ridge parameters are derived; (2) a redistribution function, Shifting ice between two categories, level and ridged, combined with a Monte Carlo Simulation for ridge parameters; and (3) prognostic equations for ridge density and height, resulting in the formation of ridged-ice volume. The model results Show that the ridge density is typically related to the State of ice motion, whereas the mean Sail height is related to the parent ice thickness. In general, all of the three models produce realistic distributions of ridges. Finally, the Second ridging Scheme is regarded as the most appropriate for climate modelling, while the third Scheme has advantages in Short-term Sea-ice forecasting.

Description: The vertical distribution of the hydromedusa Aequorea forskalea was investigated using observations from the research submersible 'Jago' collected during 36 dives off the west coast of southern Africa during November 1997 and April 1999. The mean population depth of Aequorea? forskalea deepened with increasing sea surface temperature. We suggest that this behaviour enables individuals to avoid offshore advection, to minimize spatial overlap with other large medusae and to maintain their position over the middle of the shelf.

Description: Fossilized argonaut egg cases have been recovered from marine siltstones of the late Miocene exposed around margins of the Los Angeles Basin, California. Low radial ribs on the thin, keelless, planispirally coiled egg cases suggest referring them to Mizuhobaris lepta new species. Occurrence of these egg cases in fine-grained Monterey Formation sediments with mesopelagic fish fossils, nannofossils, and Foraminifera indicate deposition in middle-to-upper bathyal depths. Argonaut egg cases have been described from Tertiary strata in Japan, New Zealand, Sumatra, and Europe, but this is the first report of fossilized argonaut egg cases from the Western Hemisphere. Secretion of egg cases by argonauts probably developed during the Paleogene as a solution to problems of spawning encountered by octopi as they acquired an epipelagic, open-ocean habitat. Shape and sculpture of the egg cases represent responses to hydrodynamics rather than an inheritance from or copying of ectocochliate cephalopods. The cases may provide the eggs with protection from ultraviolet radiation present in the argonauts' near-surface habitat.

Description: Single grains of detrital white mica from two different synorogenic sediments in the Southern Urals were analysed using the in situ ultraviolet laser ablation Ar–Ar dating technique to discriminate between age signatures associated with a high-pressure signal (phengites) from those related to muscovite only. Two disparately aged sandstone formations of Neoproterozoic (Upper Vendian) and Upper Devonian (Famennian) age were formed by the erosion of high-relief source areas with contemporaneously exhumed high-pressure rocks. A bimodal distribution of ages and chemical compositions can be detected in the two detrital populations. There is no age overlap between the two populations, reflecting completely different source areas containing high-pressure rocks of different ages.Within the Upper Vendian sandstones, detrital white mica from a 571–609 Ma age group is phengitic in composition (Si 3.3–3.41 per formula unit), while an older 645–732 Ma age group is comprised of muscovite composition grains only. The first group is compatible with the time of late exhumation and emplacement of a source area containing high-pressure rocks, the Neoproterozoic Beloretzk terrane. The older age range is compatible with a long history of cooling and the allochthonous nature of this terrane. Detrital white mica from the Famennian sandstones(Zilair Formation) comprises one age group (342–421 Ma) containing phengite (Si 3.21–3.39 per formula unit) and muscovite, and a second group (446–496 Ma) containing muscovite only. While the derivation of the second group cannot be correlated with any as yet known regional data, the first age group indicates the earliest arrival of high-pressure rocks at the surface along the suture zone after Late Devonian arc–continent collision.

Description: Age and growth of Todarodes sagittatus were estimated based on statolith analysis from individuals (N=352; 81–418 mm mantle length) caught by bottom trawlers during a year of sampling in the western Mediterranean. The daily nature of statolith increments was indirectly validated comparing the mean age of consecutive monthly modes (identified on the monthly length–frequency distributions) with the corresponding increase of 30 days. In agreement with other ommastrephids, results confirmed the following points: (1) lifespan lasts nearly a year; (2) growth rates decrease with age; (3) when adult, females have higher growth rates than males; and (4) females mature about a month later than males. Significant correlation was found between hatching (which occurred throughout the year but with a peak in November) and temperature at 50 m depth (where it is thought that hatchlings inhabit). Age and growth results were compared with those obtained in a similar work carried out in north-west Africa (Arkhipkin et al., 1999). Comparisons suggested that due to higher growth rates in juveniles, southern populations reach maturity and consequently decrease somatic growth at younger ages and smaller sizes than northern squid, which attain larger sizes as a result of maintaining fast growth and delaying maturation. Greater growth rates in juveniles from west Sahara could be explained by higher temperatures in this area than in the Mediterranean.

Description: Markedly different cooling histories for the hanging- and footwall of theVari detachment on Syros and Tinos islands, Greece, are revealed by zircon and apatite fission-track data. The Vari/Akrotiri unit in the hangingwall cooled slowly at rates of 5–15 ◦CMyr−1 since Late Cretaceous times. Samples from the Cycladic blueschist unit in the footwall of the detachment on Tinos Island have a mean zircon fission-track age of 10.0±1.0 Ma, which together with a published mean apatite fission-track age of 9.4±0.5 Ma indicates rapid cooling at rates of at least ∼60 ◦CMyr−1. We derive a minimum slip rate of ∼6.5 kmMyr−1 and a displacement of 〉∼20 km and propose that the development of the detachment in the thermally softened magmatic arc aided fast displacement. Intra-arc extension accomplished the final ∼6–9 km of exhumation of the Cycladic blueschists from ∼60 km depth. The fast-slipping intra-arc detachments did not cause much exhumation, but were important for regionalscale extension and the formation of the Aegean Sea.

Description: The effect of boundary conditions on the ‘critical dynamics’ at the onset of Taylor vortices is investigated in a combined numerical and experimental study. Numerical calculations of Navier–Stokes equations with ‘stress-free’ boundary conditions show that the Landau amplitude equation provides a good model of the transient dynamics. However, this rapidly breaks down when the ‘no-slip’ condition is approached. Apparent ‘critical’ behaviour observed in experiments is shown to have a surprising dependence on the length of the system.

Description: Specimens of the onychoteuthid squid Moroteuthis ingens were collected from four sites in the Southern Ocean: Macquarie Island, the Falkland Islands, the Chatham Rise (New Zealand) and the Campbell Plateau (New Zealand). Spatial variations in diet among these areas were investigated using stomach contents and lipid and fatty acid profiles. Myctophid fish were prominent prey items at all sites, and the diet at New Zealand sites contained temperate myctophid species that were not identified at other sites. The diet at the Falkland Islands differed considerably from other sites due to the large proportion of cephalopod prey that had been consumed by M. ingens . This is likely to be due to the absence of key myctophids, such as Electrona carlsbergi , and the abundance of smaller squid such as Loligo gahi and juvenile M. ingens over the Patagonian Shelf. Stomach contents data could not be used effectively to determine dietary differences between the Chatham Rise and Campbell Plateau, largely due to differences in sample sizes between these sites. Lipid class and fatty acid profiles of the digestive gland indicated that the diet of M. ingens differed significantly between the Chatham Rise and Campbell Plateau, despite the relative proximity of these sites. We conclude from total lipid content that this was due to a reduction in food availability to M. ingens at the Campbell Plateau. The highly productive waters of the Subtropical Front pass over the Chatham Rise, whereas the Campbell Plateau is situated in less productive sub-Antarctic water. Differences in oceanographic conditions are likely to have driven dietary variations between these two sites.

Description: The syntypes of the endemic Southern Ocean octopodid Pareledone polymorpha (Robson, 1930) were re-examined and measurements, counts and indices are presented. The two forms described by Robson, namely oblonga and affinis , are determined to have no taxonomic validity. The species polymorpha shows morphological similarities with Pareledone adelieana (Berry, 1917) but differs in relative arm lengths, sucker counts, external colouration and size at maturity. Both species are transferred to the new genus Adelieledone , which is separated from the genus Pareledone s.s. by the transverse ridges in the ligula groove of the hectocotylus, the sharp tip of the lower beak, the enlarged posterior salivary glands, the absence of stylets and by skin sculpture, especially by the presence of two longitudinal integumentary ridges on the dorsal mantle. A new species, Adelieledone piatkowski , is described from the Antarctic Peninsula. Beak morphology can discriminate the genera in predator studies.

Description: This paper examines the relationship between simulation and experiment. Many discussions of simulation, and indeed the term “numerical experiments,” invoke a strong metaphor of experimentation. On the other hand, many simulations begin as attempts to apply scientific theories. This has lead many to characterize simulation as lying between theory and experiment. The aim of the paper is to try to reconcile these two points of view—to understand what methodological and epistemological features simulation has in common with experimentation, while at the same time keeping a keen eye on simulation's ancestry as a form of scientific theorizing. In so doing, it seeks to apply some of the insights of recent work on the philosophy of experiment to an aspect of theorizing that is of growing philosophical interest: the construction of local models.

Description: Possible effects of ‘El Niño’ Southern Oscillation (ENSO) components ‘El Niño’ and ‘La Niña’ on populations of southern elephant seals, Mirounga leonina, were analysed. Changes in the cephalopod diet composition of moulting females at King George Island, Antarctic Peninsula were considered. The diet of female elephant seals sampled in 1991–1992 and 1992–1993 (El Niño years) were compared with those taken in 1995–1996 (La Niña year) at the same site and employing the same methodology. The squid Psychroteuthis glacialis constituted the main cephalopod prey of the seals. A reduction in the ‘Index of Biomass Ingested’ by female elephant seals (IBIF) of this prey species was observed in ‘El Niño’ years (1992, 1993) compared with the ‘La Niña’ year (1996). This reduction in biomass applied to all squid species in the seals' prey with the exception of Galiteuthis glacialis, which occurred in low numbers, but was more abundant during El Niño years than in the La Niña year.

Description: Lipid content, lipid class and fatty acid composition of four Southern Ocean cephalopod species – the myopsid Sepioteuthis australis and three oegopsids, Gonatus antarcticus , Moroteuthis robsoni and Todarodes spp. – were analysed. The lipid content of the digestive gland was consistently greater than that of the mantle, and was an order of magnitude greater in oegopsid species. The lipid class and fatty acid composition of the mantle and digestive gland also differed markedly in each species. Digestive gland lipid is likely to be of dietary origin, and large amounts of lipid in the digestive gland of oegopsids may accumulate over time. Thus the digestive gland is a rich source of fatty acid dietary tracers and may provide a history of dietary intake. However, the absolute amount of dietary lipid in the digestive gland of oegopsid species exceeds the absolute lipid content of mantle tissue. Therefore the overall lipid “signature” of an oegopsid may more closely resemble its prey species rather than its mantle tissue. When lipid techniques are used in dietary analysis of teuthophagous predators, squid may not be represented by a unique signature in analyses and their importance in the diets of predators may be underestimated.

Description: Uplift of the Rhenish Massif can be demonstrated by means of the stream-made river terrace system that accompanies the Rhine river and its tributaries along their way through or within this part of the Variscan fold and thrust belt. The height difference between a former valley floor, especially that of the Younger ‘Hauptterrasse’ (Main Terrace), and the recent one allows to quantify the uplift by the amount of downcutting erosion. The uplift velocity increased just after the BRUNHES / MATUYAMA boundary, i.e. about 0.8 Ma B.R Since that time, a domal uplift of more than 250 m is documented in the eastern Hunsriick and in the south-eastern Eifel. The area of this maximum height anomaly is situated just between the East-and West-Eifel Quaternary volcanic districts. Thus, causal connections are supposed. The domai uplift is affected by normal faulting partly inherited since Tertiary rifting.

Description: Squid of the genus Alloteuthis from the Aegean Sea and eastern Mediterranean were identified as A. media. It is not possible to distinguish A. media from A. subulata by relative fin length. Both ‘species’ are probably intraspecific forms. Egg size varied from 1·5 to 2·3 mm. Oocyte maturation in the ovary occurs in batches. The potential fecundity is some 1000–4000 eggs, most of these being released during continuous spawning accompanied by female growth.

Description: Todarodes sagittatus (N=1131) were opportunistically sampled from commercial and research trawling in Irish and Scottish waters between 1993 and 1998. The results suggest that the species is common in deep waters (〉200 m) to the west of Ireland and Scotland, particularly in late summer and autumn. The size of squid caught was related to depth, with larger squid caught deeper, and is indicative of an ontogenetic, bathymetric migration. Females were more common (sex ratio 1·00:0·46), and attained a larger maximum size (520 mm mantle length (ML)) than males (426 mm ML). Mature females (360–520 mm ML) were caught in deep water (〉500 m), between March and November, with a large catch of mature females taken off the west coast of Ireland in August 1996. Mature males (300–426 mm) were found from August to November. Potential fecundity was estimated to range from 205,000–523,500 eggs female −1 . Putative daily increments in statoliths indicated a life cycle of slightly over a year, with rapid growth of approximately 1·8 mm d −1 during subadult and adult life. Fish were the most important prey of T. sagittatus and 17 fish prey taxa were identified, of which pelagic species were the most important.

Description: Four Benthoctopus species are recognized in the waters of the Falkland Islands: B. eureka , B. magellanicus, Benthoctopus sp. A , and Benthoctopus sp. B . Initial oocyte reserve of B. eureka is 250–535 eggs, the actual fecundity is 75–234 eggs while the rest of the oocytes degenerate at maturation. Larger females have higher fecundity. Gonad maturation of Benthoctopus sp. A and Benthoctopus sp. B follows a similar pattern. The Benthoctopus egg masses contained 170–190 eggs. The hatchlings possess arms that are much longer than mantle length with a large number of suckers, and do not have discernible chromatophores.

Description: A large, mature, female cirrate octopod, Cirroteuthis magna , was caught in a research trawl at 3200-m depth on the Cape Verde Terrace off the west African coast in November 1999. It is only the fourth recorded specimen of this species and the largest specimen (1,700 mm TL; 330 mm ML) of cirrate octopod ever caught. Detailed measurements were taken of the fresh and preserved specimen and indicated considerable shrinkage (17–32%) during formalin preservation. Careful dissection revealed large mature eggs (12·5–14 mm long) in the proximal oviduct, and a wide range of egg sizes and development stages in the ovary. The taxonomy and ecology of the species is briefly discussed.

Description: Two taxa of commercially exploited cuttlefish, Sepia officinalis and S. hierredda , are compared for the first time on the bases of quantitative morphology and allozyme polymorphisms. Morphometric measurements and meristic counts of selected soft and hard (cuttlebone) body characters, with allozyme electrophoretic analysis are used. Samples were obtained from north-west Iberian Peninsula and Senegalese waters (West Africa). Significant differences in mantle width, arm and hectocotylus length, numbers of rows of reduced suckers on the hectocotylus and in most cuttlebone measurements were found. Canonical discriminant functions of cuttlebone measurements for males and females were calculated. Allozyme electrophoresis for 33 presumptive loci showed low levels of genetic variability and 13 diagnostic loci between the two Sepia taxa. The genetic identities ( I ) in pairwise comparisons of populations of both taxa were I =0·582–0·596, which are typical values for congeneric species. These congruent morphological and genetic results strongly suggest that S. officinalis and S. hierredda are different species.

Description: Biological data are presented on two specimens of Taningia danae , an adult female caught by a trawler in Galician waters (north-west Spain) and a juvenile caught in a deep-water research trawl in Scottish waters (UK). The species has not previously been recorded in either area, although its presence has been inferred from beaks found in sperm whale stomach contents.

Description: Published information on the diet of Cuvier's beaked whales Ziphius cavirostris (Odontoceti: Ziphiidae) is reviewed and new information on the stomach contents of three animals: two stranded in Galicia (north-west Spain) in February 1990 at A Lanzada, and in February 1995 at Portonovo; and the third stranded in February 1999 in North Uist (Scotland), is presented. The whale stranded in 1990 was a male; the other two were adult females. All animals were 〉5 m long. The limited published information on the diet of this species indicates that it feeds primarily on oceanic cephalopods although some authors also found remains of oceanic fish and crustaceans. Food remains from the three new samples consisted entirely of cephalopod beaks. The Scottish sample set is the largest recorded to date for this species. The prey identified consisted of oceanic cephalopods, mainly squid (Cephalopoda: Teuthoidea). The most frequently occurring species were the squid Teuthowenia megalops , Mastigoteuthis schmidti and Taonius pavo (for the Galician whale stranded in 1990), Teuthowenia megalops and Histioteuthis reversa (for the second Galician whale) and T. megalops , Gonatus sp. and Taonius pavo (for the Scottish whale). Other prey included the squid Histioteuthis bonnellii , Histioteuthis arcturi and Todarodes sagittatus as well as Vampiroteuthis infernalis (Cephalopoda: Vampyromorpha), Stauroteuthis syrtensis and Japetella diaphana (Cephalopoda: Octopoda). The squid eaten (estimated from the measurement of the lower beaks) included juvenile and mature individuals of the most important species ( Teuthowenia megalops , Gonatus sp.). The range of species found in the diet of Z. cavirostris is greater than that reported for sperm whales and bottlenosed whales in the north-east Atlantic.

Description: The relationship between sperm reservoir and total spermatophore length among 168 spermatophores from 44 species in 11 genera has been considered. Bivariate plots show that four Atlantic species of the genus Eledone produce spermatophores with relatively large sperm reservoirs that differ from all others. Measurements of the remaining spermatophores are so tightly correlated that a single equation explains over 96% of the variation. Functional constraints on gross spermatophore morphology may be so strong that males cannot manipulate sperm reservoir size independently of spermatophore size to maximize the sperm delivered at a single copulation. Alternate means to assure male paternity may have evolved in the group as a result. Despite the overall uniformity of the relationship among all species other than those of Eledone in the Atlantic, these measurements distinguish the overtly similar species Octopus bimaculatus – Octopus bimaculoides and separate Benthoctopus januarii from all others.

Description: This study provides a description of the Mediterranean monk seal ( Monachus monachus ) diet from the Aegean Sea coast of Turkey. A total of 23 prey items belonging to five species were identified from the two stomachs examined. Cephalopods constitute the dominant prey group by weight (94·01%). Sarcotragus sp. (Porifera) and Posidonia oceanica (Magnoliophyta) are assumed to be incidental prey. Of the cephalopods identified, Eledone moschata and Bathypolypus sponsalis were encountered for the first time in a monk seal stomach.

Description: Possible effects of “El Niño” Southern Oscillation (ENSO) components “El Niño”and “La Niña“ on populations of southern elephant seals, Mirounga leonina L., are considered in this study. Information on pup weaning mass, collected at King George Island, South Shetland Islands, over a ten-year period (1985–94) was analysed with respect to the occurrence of ENSO and recent research in feeding ecology of this population in the Bellinghausen Sea. Weaning mass of elephant seals was found to be higher during “La Niña” and a lower during “El Niño”. Differences in weaning mass between sexes varied in different proportions during El Niño and La Niña. The teleconnection between tropical Pacific anomalies and the Bellinghausen Sea deserves further research, and our results suggest a way to study this phenomenon using data of elephant seal pups weaning mass as indicators of changes in food availability.

Description: A female Octopus macropus , the first ever observed spawning, attached eggs (4·0×1·2 mm, with a chorion stalk 4 mm in length) individually or in clusters to a hard substrate, and brooded them till hatching. Hatchlings measured 4·0 mm in dorsal mantle length, 5·5 mm in total length and were planktonic; their short arms had seven suckers each, the outer demi-branch of each gill had ten lamellae. The chromatophore pattern confirmed an earlier identification of young individuals from the plankton (Naef, 1923).

Description: A new species of terebellid polychaete, Lanice arakani sp. nov., is described from two specimens collected in deep water at seamounts of the west Pacific by the submersible `JAGO', and comparisons are made with the established species of the genus. Special reference is given to the morphology of the worm's sediment tube and in situ observations.

Description: Population structure of the short-finned squid Illex illecebrosus (Ommastrephidae) was studied on the Nova Scotian shelf between July–September 1984. It was characterized by a prevalence of winter-hatched squid in summer–early autumn, their short (three months of the summer) occurrence on the shelf, and a predominance of females in sex ratios during the feeding period. Ages of squid were estimated by statolith increment counts and ranged from 128 to 201 d. Growth in length was described by linear model with daily growth rates of 0.99 mm/d −1 . Adding the length-at-age data from juveniles caught in 1979 to the 1984 data set enabled to construct an ontogenetic growth curve for the winter-hatched squid which was best approximated by the Gompertz growth function.

Description: Length composition, maturation and growth of the ommastrephid squid Todaropsis eblanae were studied using length–frequency distributions (LFDs) and statoliths of squid caught off the north-west African coast. Length–frequency distributions were quite similar in all seasons studied, indicating all year round spawning. However, both high proportions of mature squid in the winter and the hatching peak of squid from our sample in spring suggested the winter–spring peak of spawning. Immature and maturing squid had rather high growth rates, attaining 140—150 mm of dorsal mantle length (ML) by the age of 160—170 d. Todaropsis eblanae is likely to have an annual life cycle on the north-west African shelf.

Description: A new octopod species, Graneledone gonzalezi sp. nov., is described from 19 specimens collected off the northern Îles Kerguelen. This is a bathyal octopus which is characterized by: the absence of supra-ocular papillae, short arms, a long ligula without copulatory ridges, a narrow head, six filaments per outer demibranch and radula exhibiting no archaic traits, medium size oocytes and a low number of very long spermatophores. Graneledone gonzalezi is compared with its other congeneric species and found most closely resemble G. antarctica . The geographic and bathymetric distribution of G. gonzalezi is also discussed.

Description: The stranding of a female specimen of the genus Architeuthis , a species not previously recorded in the Mediterranean Sea, is reported from the southern Spanish coast (Alboran Sea, western Mediterranean). The geographical distribution of the species is discussed.

Description: Stomach contents of Todarodes sagittatus caught by trawlers working from 100 to 800 m depth in the Balearic Sea (western Mediterranean) were studied. From the 348 stomachs examined (153 males and 195 females) 33.62% were empty (39.21% in males and 29.74% in females). The diet of the squid was composed of 58 different prey items belonging to four major groups: Osteichthya, Crustacea, Cephalopoda and Chondrichthya. Osteichthyes, crustaceans and cephalopods were the most common prey, with a frequency of occurrence value of 84.85, 48.92 and 29.87% respectively. A change in the diet as the squid grows was observed, since juveniles feed basically on fishes while adults prey more actively on crustaceans. Analysis of the diet by size-classes reflected an ontogenetic migration to deeper waters since, parallel to the increase of size, a raise in the percentage of prey species inhabiting deeper waters was detected. Cannibalism was quite frequent, since T. sagittatus was the second most common cephalopod prey. Females had higher fullness-weight index and lower emptiness index than males, which reflects their major energetic demand for egg production.

Description: The population structure of the European flying squid Todarodes sagittatus was studied using data of about 5000 squid caught in waters off the western Sahara between 1969 and 1997. The bulk of the population consisted of winter-spawned squid, which occurred as juveniles of 80–120 mm mantle length (ML) over the slope in spring, and as immature squid of 160–180 mm ML both on the shelf and slope in summer. In autumn, the squid attained 220–280 mm ML, matured, and shifted to the slope, where the spawning was supposed to occur in winter. Age and growth of T. sagittatus was studied using statolith ageing techniques. Assuming daily production of putative growth increments within statoliths, as well as sizes and proportions of immature and maturing females, the lifespan of the west Saharan populations of T. sagittatus lasts ∼1 y. Todarodes sagittatus is a fast growing squid at juvenile and immature ontogenetic phases. Early maturation (at ages 220–230 d in males and 250–260 d in females, respectively) and subsequent decrease of somatic growth rates caused rather small modal sizes of mature squid (250–300 mm ML) compared with those of their northern counterparts (350–420 mm ML). Both hatching dates and seasonality in occurrence of mature females shows that in waters off the western Sahara T. sagittatus spawns throughout the year with a well-pronounced winter peak.

Description: Size of ripe eggs and potential fecundity are described in the squid of the subfamilies Todaropsinae and Todarodinae (Oegopsida: Ommastrephidae)— Todaropsis eblanae from West Africa, Todarodes angolensis from Namibia, Todarodes sagittatus from north-west Africa and the Mediterranean Sea, Todarodes sp. from the south-east Pacific, Nototodarus hawaiiensis from the south-east Pacific and West Indian Ocean and Martialia hyadesi from the south-west Atlantic. Females of both subfamilies are characterized by a wide range of ripe egg size (0.7–2.4 mm) and low and medium values of potential fecundity (20,000–2,500,000).

Description: A total of 57 comparative hauls using a rectangular midwater trawl with a fishing mouth area of 50 m2 (RMT 50) were carried out along the sides of an imaginary triangle south of Madeira in 1986. A total of 1258 cephalopods were caught, giving a mean of 22 per haul with a range from 0 to 67. The nets were used with a diver's light on the top bar which was either switched off or was operated with a 20, 70 or 150 W bulb, powered by a car battery. A significantly greater number of individuals per haul was caught with lights on than without lights, increasing from a mean of 13·5–25·1, a factor of 1·8. Similarly, the number of species caught was increased from a mean of 7 to 10·4, a factor of 1·5 and the volume of cephalopods was increased from a mean of 41·1–162·3ml, a factor of 3·9. Similar comparisons made for catches during day or night separately and on the three courses separately also showed marked increases with the lights. Samples show that increase in power of the lights increased the total number of cephalopod individuals caught. In the 12 species with more than ten individuals, in 33 of the 36 comparisons (of number of individuals, species and volumes) there is an increase with the light. The most influenced species was Taonius pavo which increased in numbers by a mean factor of 3·9 times with 20W, 4·0 times with 70W and 6·1 times with 150W when compared with the numbers caught with no light.

Description: Octopuses ( Eledone cirrhosa (Octopoda: Cephalopoda)) held in an aquarium were subjected to varying conditions of feeding and starvation to evaluate putative indices of feeding and growth. Specific growth rate (%d −1 ) was linearly related to feeding rate (% of the body mass d −1 ) in animals with a mean body mass of 250 g at 15°C. Maximum growth rates varied between 〉 2% d −1 (body weights 〈 300 g) to 〈 1% d −1 (body weights ≤ 900 g) but specific growth rates were not related to body weight. Growth rates became negative (weight loss) after one week without food. The digestive gland index (DGI) was significantly correlated with short and long-term feeding and specific growth rates, and with body weight. Muscle RNA concentration was linearly correlated with growth rate during the previous 1–3 weeks but not with feeding rate. RNA:protein ratios were not different between mid-arm and mantle sample sites but arm tip values were significantly higher. RNA:protein ratio was related to body weight only in feeding animals. It is concluded that DGI is an index of feeding rate and that RNA:protein ratio can be used as an index of recent (~ 4 weeks) growth rate.

Description: Growth in Loliolus noctiluca (Myopsida: Loliginidae) in Western Port, Victoria, Australia was studied from statolith growth increments. Tetracycline staining experiments verified previous work on tropical forms of this species that showed growth increments to be deposited daily. A logistic growth function described the relationship between length and increment number. There appear to be major differences in the form of growth, longevity and life history pattern between tropical and temperate forms of this species. These are probably attributable to differences in environmental conditions.

Description: Two large (dorsal mantle length 42.5 and 47.5 cm), mated spent females of circum‐Antarctic bathypelagic cranchiid squid Galiteuthis glacialis were caught early in March 1992 at the surface of the ice hole in the western Weddell Sea over depths 1915‐1920 m by the team of the U.S.A.‐Russian Ice Station Weddell‐I. The structure of the reproductive system of adult females is described for the first time in detail. Both were gelatinous, devoid of tentacles, with empty or almost empty stomachs. The empty spermatangia (sperm reservoirs of spermatophores) 30‐35 mm in length were distributed in the mantle tissues parallel to the mantle surface and to each other in the dorso‐anterior part of the mantle: 13 in one female, parallel to the body axis, and 20 in the other, parallel (13) or perpendicular (7) to the body axis. In the latter case, they represented probably two mating events. The spermatangia lay nearer to the inner than the outer mantle side and opened by a round window on the inner side; the skin with chromatophores above them remained intact. The spermatozoa had one flagellum and rod‐like heads, length 5.0‐5.3 μm, width 1.2‐1.5 μm. The most characteristic features are: a very simple type of blood vessel branching making each micro‐gonad currant‐like, not grape‐like; a very compact disposition of oviducal, nidamental glands and gill, forming a united complex located on both sides of the mantle cavity; and an ovary connected by mesentery along all its length with the continuation of the stomach from the caecum to the end of the gastrogenital ligament. Only immature degenerating trophoplasmatic oocytes, length 0.9‐1.4, av. 1.0‐1.2 mm, were contained in ovaries; only one mature egg (length 3.3 mm, width 2.4‐2.5 mm) was found in each female. The absence of oocytes 〈0.9 mm and 1.5‐3.2 mm indicates that the maturation of oocytes proceeds rather synchronously, one large portion of eggs (some tens of thousands) matures in a short time while others degenerate. The residual fecundity is assessed to be approximately 20,000 eggs. It is hypothesized that mating occurs shortly before spawning and that mature males do not undergo gelatinous degeneration and do not lose tentacles. Spermatophores are placed on the inner side of the female's mantle with the aid of the male's tentacles and/or arms (less probably by the penis), but the exact mode of implantation is unclear. Spawning probably occurs at depths of adult habitat (approx. 500–2500m), may be multiportional but short; the exhausted female loses neutral buoyancy, rises to the surface and dies. Rising to the surface after spawning is a common feature of females of many meso‐ and bathypelagic squids undergoing gelatinous degeneration during maturation (Onychoteuthidae, Gonatidae, Histio‐teuthidae, Cranchiidae, etc.) and may explain the common occurrence of large deep‐water squids in the stomachs of seabirds, including those incapable of diving, and marine mammals.

Description: A total of 57 comparative hauls using a rectangular midwater trawl with a fishing mouth area of 50 m 2 (RMT 50) were carried out along the sides of an imaginary triangle south of Madeira in 1986. A total of 1258 cephalopods were caught, giving a mean of 22 per haul with a range from 0 to 67. The nets were used with a diver's light on the top bar which was either switched off or was operated with a 20, 70 or 150 W bulb, powered by a car battery. A significantly greater number of individuals per haul was caught with lights on than without lights, increasing from a mean of 13·5–25·1, a factor of 1·8. Similarly, the number of species caught was increased from a mean of 7 to 10·4, a factor of 1·5 and the volume of cephalopods was increased from a mean of 41·1–162·3ml, a factor of 3·9. Similar comparisons made for catches during day or night separately and on the three courses separately also showed marked increases with the lights. Samples show that increase in power of the lights increased the total number of cephalopod individuals caught. In the 12 species with more than ten individuals, in 33 of the 36 comparisons (of number of individuals, species and volumes) there is an increase with the light. The most influenced species was Taonius pavo which increased in numbers by a mean factor of 3·9 times with 20W, 4·0 times with 70W and 6·1 times with 150W when compared with the numbers caught with no light.

Description: A specimen of Chaunoteuthis mollis (Cephalopoda: Onychoteuthidae), a mature mated female, from the Straits of Messina was examined. Measurements and indices were compared with those of Onychoteuthis banksii reported by previous authors. The differences found were attributed to the degeneration of the C. mollis specimen, due to sexual maturation. Two subocular (one under each eye) and two visceral photophores, similar to those of O. banksii , were present in the C. mollis specimen. The size of the posterior visceral photophore of C. mollis fit the regression line correlating posterior photophore diameter to mantle length in O. banksii. These results corroborate the hypothesis, put forward by other authors, that C. mollis represents the mature female of O. banksii.

Description: Three specimens of the giant squid Architeuthis were by-caught in demersal trawls to the west of Ireland, between April and June 1995. All three specimens were mature males, of mantle length 975–1084 mm. Although some intraspecific variation in fin, beak and gill were noticed, all three specimens were tentatively assigned to the species A. dux. The three specimens had food remains in their stomachs and food items identified included Micromesistius poutassou, Trachurus trachurus, Nephrops norvegicus and Eledone cirrhosa . Age estimates were made by counting putative daily growth increments in ground statoliths, and ranged from 294–122 d, giving percentage daily growth rates of 2·96–4·25% indicating a short life cycle and extremely rapid growth.

Description: Deep-water trawling for fish species on the shelf slope off Scotland results in a by-catch of rare cephalopod species. The cirrate octopus Opisthoteuthis grimaldii is normally present below 800 m; at least one other species of cirrate and five species of incirrate octopus are found; significant extensions of range and depth are recorded. An incidental catch of the ommastrephid squid, Todarodes sagittatus , included a fully mature specimen and is indicative of its probable breeding locations. The results highlight the many taxonomic and systematic uncertainties surrounding the rarer cephalopod forms, and emphasize the utility of the fishing by-catch.

Description: Cephalopod prey of several cetacean species from Hawaiian waters were identified and quantified from the beaks in stomachs of stranded individuals. The different species of cetaceans all appear to target different species and sizes of cephalopods. Beaks from two sperm whales ( Physeter catodon ) included a total of 312 upper and 292 lower beaks (mandibles) of cephalopods. All of the cephalopods represented by lower beaks were oceanic squid belonging to 20 or more species in 14 families. The major constituents of the whale diet were Histioteuthis hoylei (45% by number and 10·9% by dry weight), Ommastrephes bartrami (7·6% by number, 30·6% by weight) and Architeuthis sp. (only 0·7% by number, but 26·5% by weight). In a Risso's dolphin ( Grampus griseus ) stomach, 1051 upper beaks and 1349 lower beaks were present. Eighteen or more genera of cephalopods in 15 families were present. The major constituents of the Grampus diet were Enoploteuthis spp. (36·1% by number and 30·1% by dry weight) and Abraliopsis spp. (23·6% by number, but only 4·9% by weight) and O. bartrami (1·3% and 32·1% respectively). The melon-headed whale ( Peponocephala electra ) eats fish as well as cephalopods which are represented by only six lower beaks belonging to five genera, Enoploteuthis, Teuthowenia, Abraliopsis, Abralia sp. and Bathyteuthis abyssicola . The beaked whale (unidentified) contained two lower beaks which were O. bartrami. Stenella attenuata also eats fish and the sample contained lower beaks, one of Enoploteuthis sp. and seven of an Abraliopsis sp.

Description: Observations on samples from Spanish trawlers between September and November of 1995 revealed the presence of mated females of Loligo gahi (Cephalopoda: Loliginidae) from 164–285 m depth, in the Western area of the Falkland Islands Conservation Zone. 93.8% of the mature females, and 31.0% of the maturing ones, were mated. Deposition of spermatophores always took place in the oral membrane between the connectives of arms IV. The relationships between sexual maturation and copulation have been analysed, and the hypothesis of mating acting as a ‘trigger’ of the final sexual maturation in Loligo gahi females is proposed and discussed.

Description: This paper gives morphometric variations and dorsal mantle length–total weight (DML-TW) relationships for Illex coindetii in the eastern Central Atlantic area. Positive allometry was observed in males and negative in females of the species. The most variable body measurements between males and females were width and perimeter of the head. In the study area, divergence of morphometric measurement starts at 95 mm. The point of divergence, however, varies with latitude; fluctuating from 104 mm in the north (Morocco and Sahara) to 76 mm in the central area (Mauritania and north of Senegal) and 73 mm in the south (Gulf of Guinea). The relationships between DML and TW showed that sexual dimorphism due to differential growth between males and females starts to occur at 56 mm ML. The starting point of sexual dimorphism (56 mm) varies according to the zone; the higher the latitude, the later it occurs. Thus, sexual dimorphism occurs at 49 mm in the south (Gulf of Guinea), at 54 mm in the central area (Mauritania and north of Senegal) and at 74 mm in the north (Morocco and Sahara). Females grow larger than males, but males were heavier at any given length. As latitude decreased, a slow down in the increase in weight-at-length was observed in both sexes.

Description: In this study, the impact of oceanic data assimilation on ENSO simulations and predictions is investigated. The authors’ main objective is to compare the impact of the assimilation of sea level observations and three-dimensional temperature measurements relative to each other. Three experiments were performed. In a control run the ocean model was forced with observed winds only, and in two assimilation runs three-dimensional temperatures and sea levels were assimilated one by one. The root-mean-square differences between the model solution and observations were computed and heat content anomalies of the upper 275 m compared to each other. Three ensembles of ENSO forecasts were performed additionally to investigate the impact of data assimilation on ENSO predictions. In a control ensemble a hybrid coupled ocean–atmosphere model was initialized with observed winds only, while either three-dimensional temperatures or sea level data were assimilated during the initialization phase in two additional forecast ensembles. The predicted sea surface temperature anomalies were averaged over the eastern equatorial Pacific and compared to observations. Two different objective skill measures were computed to evaluate the impact of data assimilation on ENSO forecasts. The authors’ experiments indicate that sea level observations contain useful information and that this information can be inserted successfully into an oceanic general circulation model. It is inferred from the forecast ensembles that the benefit of sea level and temperature assimilation is comparable. However, the positive impact of sea level assimilation could be shown more clearly when the forecasted temperature differences rather than the temperature anomalies themselves were compared with observations.

Description: Changes in the molecular structure of a highly ordered kaolinite, intercalated with urea and potassium acetate, have been studied using Raman microscopy. A new Raman band, attributed to the inner surface hydroxyl groups strongly hydrogen bound to the acetate, is observed at 3605 cm (super -1) for the potassium acetate intercalate with the consequential loss of intensity in the bands at 3652, 3670, 3684 and 3693 cm (super -1) . Remarkable changes in intensity of the Raman spectral bands of the low-frequency region of the kaolinite occurred upon intercalation. In particular, the 144 and 935 cm (super -1) bands increased by an order of magnitude and were found to be polarized. These spectroscopic changes provide evidence for the inner surface hydroxyl group-acetate bond being at an angle approaching 90 degrees to the 001 face. Decreases in intensity of the bands at 243, 271 and 336 cm (super -1) were observed. The urea intercalate shows additional Raman bands at 3387, 3408 and 3500 cm-1 which are attributed to N-H vibrations after formation of the urea-kaolinite complex. Changes in the spectra of the inserting molecules were also observed.

Description: Recent attention to members of the sepiolid squid genus Euprymna and symbiotic associations with luminescent bacteria ( Vibrio fischeri strains) has prompted a review of this poorly-resolved group of squids. Twelve nominal species have been placed in this genus of which the majority are ill-defined, known only from their original descriptions and separated on the basis of inadequate characters. As a first step in resolving this group, a temperate Australian species, the Southern dumpling squid, Euprymna tasmanica , is here redescribed in detail. As the genus Euprymna currently stands, most members are only distinguished on the number and position of enlarged suckers in mature males. No diagnostic characters are available to identify females. All nominal species placed in this genus are reviewed and a key to proposed valid species is presented. Six species are considered here to be valid: Euprymna berryi, E. hoylei, E. morsei, E. scolopes, E. tasmanica and an undescribed species treated here as Euprymna sp. 1. Euprymna similis is a synonym of E. morsei of Japan. Due to inadequate original descriptions, and lost or poor type material, two species are considered here to be nomen dubia ( E. schneehageni and E. pusilla ), while the taxonomic status of four additional species remain unresolved ( E. albatrossae, E. bursa, E. phenax and E. stenodactyla ).

Description: Records of unusual cephalopods, taken as by-catch in Irish and Scottish waters in the years 1985–1995, are presented. Of most interest are three specimens of giant squid (Architeuthis) that were caught in bottom trawls off the west of Ireland between April and June 1995, all were mature males of mantle length ∼1000 mm. Other records include a large mature female Histioteuthis bonnellii from the west of Ireland and three specimens of the gelatinous incirrate octopus, Haliphron atlanticus.

Description: The statolith microstructure was studied in 142 females (mantle length, ML, ranging from 77–402 mm) and 119 males (72–328 mm ML) of Martialia hyadesi caught on the Patagonian and Falkland shelves and at the Antarctic Polar Frontal Zone between 1989–94. The statolith microstructure dark zone in this species, contains narrower and more numerous growth increments than the dark zones of other ommastrephid squids. Assuming daily production of putative growth increments within statoliths males live up to 12 months, and females live up to 13 months. It is likely that the life cycle lasts c. 1 yr, but immature squids with ages 〉330–340 d suggest that a part of M. hyadesi populations could have life span 〉1 yr. Growth in length was best described by the Gompertz function, whereas growth in weight was best described by the logistic function. M. hyadesi is characterized by slow juvenile growth (〈100 mm ML), fast growth of immature squids and a sharp decrease in growth rates during maturation. M. hyadesi mature later (at ages 〉270 d) than other temperate ommastrephids, but maturation is rather rapid (2–3 months). In the south-west Atlantic, M. hyadesi hatch throughout the year.

Description: In this paper the performance of the global coupled general circulation model (CGCM) ECHO-2, which was integrated for 10 years without the application of flux correction, is described. Although the integration is rather short, strong and weak points of this CGCM can be clearly identified, especially in view of the model's performance of the annual cycle in the tropical Pacific. The latter is simulated with more success relative to the earlier version, ECHO-I. A better representation of the low-level stratus clouds in the atmosphere model associated with a reduction in the shortwave radiative flux at the air-sea interface improved the coupled model's performance in the southeastern tropical oceans, with a strongly reduced warm bias in these regions. Modifications in the atmospheric convection scheme also eliminated the AGCM's tendency to simulate a double ITCZ, and this behavior is maintained in the CGCM simulation. Finally, a new numerical scheme for active tracer advection in the ocean model strongly reduced the numerical mixing, which seems to enhance considerably the level of interannual variability in the equatorial Pacific. One weak point is an overall cold bias in the Tropics and midlatitudes, which typically amounts to 1°C in open ocean regions. Another weak point is the still too strong equatorial cold tongue, which penetrates too far into the western equatorial Pacific. Although this model deficiency is not as pronounced as in ECHO-1, the too strong cold tongue reduces the level of interannual rainfall variability in the western and central equatorial Pacific. Finally, the interannual fluctuations in equatorial Pacific sea surface temperatures (SSTs) are too equatorially trapped, a problem that is also found in ocean-only simulations. Overall, however, the authors believe that the ECHO-2 CGCM has been considerably improved relative to ECHO-1.

Description: The natural feeding of the two most abundant ommastrephid squid (Cephalopoda: Ommastrephidae) in Galician waters was studied and compared. A sample of 334 stomach contents of Todaropsis eblanae (34–222 mm ML) and 267 stomach contents of Illex coindetii (50–379 mm ML) caught by commercial trawlers was examined. A total of 21 (T. eblanae) and 23 (I. coindetii) different prey items, belonging to three zoological groups (Teleostei, Crustacea and Cephalopoda), were taken by these cephalopods. However, 43% of the T. eblanae diet comprised only one fish species, Micromesistius poutassou. The diet of these squid species was significantly influenced by the geographical area (both species), size (T. eblanae) and maturation (I. coindetii). Feeding rate of both species decreased with size, but the percentage of stomachs with food remains increased in maturing and mature females. Weight of prey captured was dependent on available prey sizes and, in small individuals, maximum prey weight was very close to the squid weight. Both squid species are mainly neritic nekto-benthic predators, but I. coindetii seems to have a broader and more pelagic diet.