Deep water

Here, data on 50 265 Lophius piscatorius sampled between 1998 and 2006 on board commercial fishing vessels during observer trips and chartered surveys at Shetland, west of Scotland, and Rockall are analysed. In each area, length differed significantly with depth (p, 0.001), there was an increase in modal size with increasing depth down to 450 m, and large fish dominated hauls in deeper water. The sex ratio of all data combined was 0.88 females:1 male, but it varied by area, depth, and season, with males greatly out-numbering females in deep water west of Scotland during the first quarter of the year. The proportion at length that were female differed significantly with depth, and the highest proportions of mature fish were in deep water at Rockall and west of Scotland. L50 % maturities, for all data combined, were 102.4 cm for females and 58.3 cm for males.

Coastal erosion is and will be an increasing major environmental issue. We apply shape optimization techniques to the design of coastal structures such as breakwaters, groins and other innovative shapes. Actually, we compute the solution of a boundary value problem describing the water waves scattered by the structure and modify accordingly its shape, in order to minimize a pre-defined cost function taking into account the strength (energy) of the waterwaves. The optimization procedure relies on a new global semi-deterministic algorithm, able to pursue beyond local minima.

We test for and calibrate a proxy for ocean temperature based on the skeletal composition of the widely distributed, deepsea gorgonians in the family Isididae (bamboo corals), through use of three complementary methods: a short-term comparison of element/Ca ratios to a four-year temperature record, a long-term comparison with oceanographic records spanning forty years, and a geographic comparison of Isidids collected at sites ranging from the tropics to Antarctica. The assays consistently support a temperature-dependency for Mg/Ca ratios and suggest S/Ca is indirectly affected by temperature, but indicate little or no effect of temperature on P/Ca and Sr/Ca. The consensus relationship between Mg/Ca and temperature for Isidid calcite from the comparisons with the temperature time-series is T = À0.505 + 0.048 Mg/Ca, where T is in°C, Mg/Ca is in mmol/mol, and the applicable range is 3-6°C. The results of the geographic assay, though imprecise, suggest the applicable range extends to temperatures below freezing. The scatter of data points around the regression of temperature and Mg/ Ca is wide in all assays. This could reflect the effect of factors other than temperature on Mg/Ca ratios, but is also likely to reflect limitations of the field data, the effects of assumed constant growth rates in the corals and instrumental analytical error. The combined effects of micro-scale variability in growth rates and wide confidence intervals for each data point suggests that environmental reconstruction from Isidid internode calcite from sparse data or at time scales less than decades be done with caution. Comparisons within and among colonies do not indicate strong vital effects on ontogenetic variability in the corals, other than possibly close to the central pore of the coral. However, similar Mg/Ca ratios for Isidids from Antarctic and more temperate regions suggest adaptation to local conditions and hence a role for physiology at higher taxonomic levels, at least. Taxonomically higher level vital effects are also suggested by large differences between gorgonian families in their regressions between Mg/Ca and temperature, by Mg/Ca ratios that overlap over a wide temperature and habitat range, and for a nonlinear relationship between temperature and the slope of the Mg/Ca-temperature relationship across the order.

One of the critical information needs identified at the 2003 Deep-Sea Corals Workshop in Galway, Ireland, was to locate and chart deep-sea corals in order to develop reliable estimates of their distribution and abundance. While reports of deep-sea corals from the Gulf of Mexico date back to the 1860s, relatively little is known about their distribution or abundance. This paper attempts to provide a current assessment of the occurrence of Lophelia pertusa and Madrepora oculata in water depths greater than 200 m in the Gulf of Mexico by summarizing records from (1) published material, (2) the 2003 National Museum of Natural History Taxonomic Database, (3) findings obtained during the September-October 2003 NOAA-OE RV Ronald H. Brown cruise RB-03-07-leg-2 in the northern Gulf, and (4) from various unpublished sources.

For the first time it was possible to investigate a still poorly known region of the eastern Mediterranean Sea, the Libyan continental margin. An oceanographic cruise, performed during summer 2006, revealed an important and novel feature: a dense vein flowing along the continental slope. The paper describes the vein evolution with some insights on its dynamic and furnishes an estimate of its transport, which results to be comparable with the Adriatic Deep Water production rate. The cascading into a steep canyon which incises the continental shelf suggests that the vein may play an important role in ventilating the deep layers of the Ionian Sea.

The peculiar mixing processes at the pycnocline and deep regions of the Black Sea are reviewed. In addition to the wind stirring and convective mixing, active in the upper pycnocline, the other important mechanism that results in limited ventilation of the anoxic waters of the Black Sea is the Mediterranean dense water inflow from the Bosphorus, modified by the entrainment of surface and intermediate waters, introduced into the interior through double-diffusive intrusions. This inflow, aided by the surface Ekman flux divergence, boundary processes and internal wave breaking, is the main mechanism for the mixing and renewal of the sub-pycnocline waters in the Black Sea interior. A review of these mixing processes is complemented by results from isotope measurements with improved accuracy and reduced noise compared to earlier experiments. Measurements of the stable isotopes oxygen-18 ( 18 O) and deuterium ( 2 H) confirm the origin of the water masses in the Black Sea and in the Turkish Straits, including the sea of Marmara, to be a continuous mixture with variable fractions of salty Mediterranean waters with inflowing fresh waters. Tritium ( 3 H) measurements confirm very little penetration of the transient signal to the sub-pycnocline and deep waters of the Black Sea, in comparison to the better ventilated Mediterranean waters filling the lower layer of the Marmara Sea. The comparison of stable and transient tracer isotopes shows the effects of fresh waters originating from the north-western shelf, and the difference between the renewal mechanisms of the Marmara and Black seas, as well as those between the upper and lower pycnocline of the Black Sea.

In this paper we give a discussion of the number of"effective modes" of the two-and three-dimensional nonlinear Schr~Sdinger equation. First, we give a simple analytic explanation of the numerical results of Martin and Yuen on the long-time evolution of spatially periodic solutions of the two-dimensional nonlinear Schrrdinger equation for a weakly nonlinear, deep-water, modulated gravity wavetrain. We show that this nonlinear system can be described as effectively possessing an arbitrarily high number of degrees of freedom so that the overall motion can at best be only quasi-recurrent. Then, we explore the connection between the number of "effective modes" and the collapsing tendency of solutions of the spherically-symmetric nonlinear Schrrdinger equation. In the three-dimensional cubic nonlinear case where the solutions are known to exhibit collapsing tendency, we find that the number of"effective modes" increases with the increase in the wave-amplitude (this is in contrast to the one-dimensional case ). We give quantitative estimates of the limitations of the cubic nonlinear model, nonetheless, in describing the Langmuir collapse process. In the three-dimensional full exponential nonlinear case where the solutions are known to exhibit no collapsing tendency and evolve into localized stationary structures, we find a clear reduction in the number of"effective modes". Indeed, the number is independent of the magnitude of the wave amplitude! These results appear to indicate that the number of "effective modes" can also serve as a measure of the collapsing tendency of the solutions of the spherically-symmetric nonlinear Schrrdinger equation.

The Iceland-Scotland Overflow Water (ISOW) is one of the two main dense overflows entering the subpolar North Atlantic across the Greenland-Scotland Ridge. The downstream modification of ISOW as it spreads west and transforms into the Northeast Atlantic Deep Water (NEADW) has not been fully described in either space or time. The figure addresses both issues by showing the salinity of the ISOW/NEADW (salinity maximum) core from the Iceland Basin to the Labrador Sea for two extreme time periods: warm and saline 1964-1972 (Panel A) and cold and fresh 1995 -1997. The complexity of the watermass interactions that modify the spreading plume en route is clear from this figure. NEADW rapidly increases in thickness (not shown) and freshens by $0.03 as its spreading plume rounds the snout of the Reykjanes Ridge to enter the Irminger Sea. This provides a clear indication of an increase in the entrainment and influence of the Labrador Sea Water (LSW) west of the Ridge. The decline in the NEADW salinity (by $0.02) continues along the western boundary where a thinning NEADW plume passes south between the low-salinity LSW and Denmark Strait Overflow Water (DSOW); the freshening influence of DSOW is now adding to that of LSW. Some renewed salinification of NEADW evidently takes place in the Newfoundland Basin. This can be attributed to a fraction of saltier NEADW traveling directly from the Reykjanes Ridge to the Newfoundland Basin without entering the Labrador Sea, and then mixing with the fresher NEADW plume arriving from the Labrador Sea. This mixing process is facilitated by the Newfoundland Basin anticyclonic gyre, known as the Mann Eddy. The Mann Eddy spins both NEADW and DSOW (which resides below NEADW), forming a local recirculation of these waters in the Basin.

During 1997, quarterly exploratory cruises of the R/V``Archipelago'' were carried out in order to study the deep water crab Chaceon af®nis [Res. Camp. Sci. Mo Ânaco Fasc. VII (1894) 1], South of Pico island (Azores) and at the Menez Gwen hydrothermal vent area (SW of the Azores, within the Azorean Economic Exclusive Zone). The crabs were caught with bottom traps according to a speci®ed survey design. Different areas between 300 and 1200 m depth were surveyed. Information from previous collections was also compiled and analysed. A total of 1153 crabs (726 males and 427 females) were caught at depths ranging from 600 to 1100 m on rocky and/or muddy bottoms. Size ranged from 39 to 177 mm carapace length (CL), the males being larger than females. Males were relatively more abundant at depths <800 m and females relatively more abundant at depths >800 m. The greatest abundance occurred at depths from 700 to 800 m. Ovigerous females, which were consistently >70 mm CL, were found only from October to March. An annual reproductive cycle is suggested. Size at ®rst maturity for the females, was estimated to be within the size range of 83±97 mm CL. Other ecological and biological information such as distribution, morphometric aspects related to reproduction, occurrence of parasites and epibionts, are discussed, as well as by-catch species.

The purpose of this study was to examine whether trained competitive runners could maintain on-land running performance and kinematics, using 8 wk of deep water run supplement training (30%) instead of just on-land training. Eight trained male runners (V0 2MAX : 53,3 ± 4.1 ml. Kg,1. min,1) were assigned to one of the two groups, on-land run just (R) or water run supplement (WR). Following 8 wk of workouts, no significant intragroup or intergroup differences were observed for treadmill V0 2MAX , running economy, horizontal velocity, stride length, stride rate, time of support, time of flight and segmental body positions. It was concluded that deep water running may serve as an effective training supplement to land-based running for the maintenance of aerobic performance and running kinematics for up 8 wk in trained middle-distance runners.

Laser Doppler anemometry (LDA) was used to measure the instantaneous downstream and vertical velocities in a series of simple and reflected saline density currents in a lock-exchange flume tank. All the currents were turbulent and subcritical. Mean downstream fluid velocities were in excess of the head velocity by up to 30%, and instantaneous velocities were greater by up to 50%. Turbulence intensities were highest within the head, and generally greatest in the middle part of the current, but did not correspond with the level of highest mean velocities. The maximum Reynolds stress also occurred within the head; large negative values were associated with shear along the upper boundary of the current. Peaks of turbulence, Reynolds stress and shear velocity occurred in association with the arrival of reflections. In large-scale turbidity currents, suc!a reflections would be capable of re-entraining and resuspending sediment deposited by the forward current. Some reflections take the form of solitary waves within a residual flow with a velocity vector in the opposite direction. In nature, these could produce symmetrical ripples in environments below storm-wave base.

Aspects of the morphology of 3 related Neogene species of Bolivinita are described and some features are related to the structural design of the shells. Possible hydromechanical consequences of the architectural differences between B. quadrilatera (rectangular spiral profile) and B. compressa (flattened, alate, spiral profile) are inferred but, qualitatively, no outstanding advantages of the descendant alate form (B. compressas are apparent. Both taxa occupied deep water biotopes. Biometric data on spiral shape of the species (topotypic or near topotypic material) does not support previous views that B. pobana was the immediate ancestor of B. com pressa. Toothplate construction in the group involves partial closure of the antecedent aperture. The location and shape of the tooth plate indicate that it would impede rather than Iaci litate the passage of cytoplasm.

Seismic-facies analysis of a seismically-anomalous sequence of mid-Cretaceous (Cenomanian-Turonian) basin fill in Lease Block 34/8, Viking Graben, Norwegian North Sea, reveals a possible slide block (?) composed of Jurassic-age Brent Group strata that apparently detached from the adjacent structural high (34/8 structure) and slid downslope onto Lower Cretaceous sediments in the Vikinq Graben floor. In addition, this mid-Cretaceous sequence contains two broad submarine channels that trend southward into the graben from the southern tip of the slide block (?) and the adjacent structural high. The channels appear to be erosional features formed by turbidity currents and mass-wasting processes. The Brent slide block (?) may represent an additional hydrocarbon prospect within the Lease Block 34/8.

An examination of the extensive hydrographic data sets collected by C.S.S. Hudson and F.S. Meteor in the Norwegian and Greenland Seas during February-June 1982 reveals property distributions and circulation patterns broadly similar to those seen in earlier data sets. These data sets, however, reveal the even stronger role played by topography, with evidence of separate circulation patterns and separate water masses in each of the deep basins. The high precision temperature, salinity and oxygen data obtained reveals significant differences in the deep and bottom waters found in the various basins of the Norwegian and Greenland Seas.

Chemical and key microbiological processes (assimilation of carbon dioxide, oxidation and fofß1ation of methane, and sulfate reduction) occurring at the aerobic-an aerobic interface in the deep-water zone of the Black Sea were investigated. Measurements were taken at depths from 90 to 300 m at intervals of 5-10 m. The integral rate of the dark assimilation of carbon dioxide varied from 120 to 207 mgC/(m2 dar) with a maximum at the boundary of cyclonic currents. The organic matter (OM) formed flom methane comprised less than 5% of the OM form~d from carbon dioxide. A comparison between the rates of methane oxidation and methane production suggeststhat methane that is oxidiied at depths from 100 to 300 m was fofß1ed in deeper water horizons. The maximum rate of sulfate reduction (1230 mg S/(m2 day)) was observed in the western halistatic region. and the minimum rate (490 mg S/(m2 day). in the eastern halistatic region. The average rate of h~drogen sulfide production measured at tbree deep-sea stations amounted to 755 mg S/(m2day), or 276 g S/(m year).

We present the derivation of an analytical model for the selfshading error of an oceanographic upwelling radiometer. The radiometer is assumed to be cylindrical and can either be a profiling instrument or include a wider cylindrical buoy for floating at the sea surface. The model treats both optically shallow and optically deep water conditions and can be applied any distance off the seafloor. We evaluate the model by comparing its results to those from Monte Carlo simulations. The analytical model performs well over a large range of environmental conditions and provides a significant improvement to previous analytical models. The model is intended for investigators who need to apply self-shading corrections to radiometer data but who do not have the ability to compute shading corrections with Monte Carlo simulations. The model also can provide guidance for instrument design and cruise planning.

... C. Mark Moore 1, 2 , Matthew M. Mills 3 , Eric P. Achterberg 2 , Richard J. Geider 1 , Julie LaRoche 4 , Mike I. Lucas 5 , Elaine L. McDonagh 2 , Xi Pan 2 , Alex J. Poulton 2 , Micha JA Rijkenberg 2 ... Figure 1: Cruise tracks and maps of annual mean excess nutrient distributions. ...

We examined the behavioural ecology of mothers and calves during the first year of life to identify variables predicting calf mortality among bottlenose dolphins. Specifically, we investigated whether the primary cause of calf mortality was poor calf condition or shark predation. Seventy-five per cent of calves that died (N Z 12) showed visible signs of poor health compared with 4.7% of the survivors (N Z 21). Calves that spent more time swimming in infant position (in contact under the mother) in the first year of life were more likely to die by 3 years of age than calves that spent less time swimming in infant position. No other behavioural or ecological measures tested were associated with calf mortality. We suggest that the mother and/or calf may compensate for poor calf health by increasing the time spent in contact with the mother. In contrast, frequent mother-calf separation and high rates of calf socializing and foraging are proposed to be indicators of vigour. Although most of our results do not support the predation hypothesis, mothers altered one behaviour in relation to predation risk. Mothers rested less in deep water during the warm months, where and when predation risk was high, than during the cool months, when predation risk was low, suggesting that predation risk influenced maternal vigilance. However, calf mortality was not higher in warm months than in cool months. Our results suggest that poor calf condition, not predation, is the primary cause of calf mortality.

Seagrasses, marine flowering plants, are widely distributed along temperate and tropical coastlines of the world. Seagrasses have key ecological roles in coastal ecosystems and can form extensive meadows supporting high biodiversity. The global species diversity of seagrasses is low (< 60 species), but species can have ranges that extend for thousands of kilometers of coastline. Seagrass bioregions are defined here, based on species assemblages, species distributional ranges, and tropical and temperate influences. Six global bioregions are presented: four temperate and two tropical. The temperate bioregions include the Temperate North Atlantic, the Temperate North Pacific, the Mediterranean, and the Temperate Southern Oceans. The Temperate North Atlantic has low seagrass diversity, the major species being Zostera marina, typically occurring in estuaries and lagoons. The Temperate North Pacific has high seagrass diversity with Zostera spp. in estuaries and lagoons as well as Phyllospadix spp. in the surf zone. The Mediterranean region has clear water with vast meadows of moderate diversity of both temperate and tropical seagrasses, dominated by deep-growing Posidonia oceanica. The Temperate Southern Oceans bioregion includes the temperate southern coastlines of Australia, Africa and South America. Extensive meadows of low-to-high diversity temperate seagrasses are found in this bioregion, dominated by various species of Posidonia and Zostera. The tropical bioregions are the Tropical Atlantic and the Tropical Indo-Pacific, both supporting mega-herbivore grazers, including sea turtles and sirenia. The Tropical Atlantic bioregion has clear water with a high diversity of seagrasses on reefs and shallow banks, dominated by Thalassia testudinum. The vast Tropical Indo-Pacific has the highest seagrass diversity in the world, with as many as 14 species growing together on reef flats although seagrasses also occur in very deep waters. The global distribution of seagrass genera is remarkably consistent north and south of the equator; the northern and southern hemispheres share ten seagrass genera and only have one unique genus each. Some genera are much more speciose than others, with the genus Halophila having the most seagrass species. There are roughly the same number of temperate and tropical seagrass genera as well as species. The most widely distributed seagrass is Ruppia maritima, which occurs in tropical and temperate zones in a wide variety of habitats. Seagrass bioregions at the scale of ocean basins are identified based on species distributions which are supported by genetic patterns of diversity. Seagrass bioregions provide a useful framework for interpreting ecological, physiological and genetic results collected in specific locations or from particular species.

Satellite-based information on significant waves is increasingly being made available to ocean scientists and engineers at low costs. While such measurements have a number of useful applications the manner with which the satellites sense the waves limits their applications to nearshore locations. This paper discusses an approach based on the radial basis function (RBF) type of artificial neural networks to map remote-sensed deep-water waves with the coastal waves. Significant wave heights at a number of locations over a track parallel to the coastline are used to estimate the significant wave heights at a nearshore site. The success of the method adopted was confirmed from the satisfactory error measures it produced during the testing carried out following the network training. It was also found that the satellite data need a 'local tuning' as done in the RBF before their further use in network computations. This work also highlighted importance of innovative approaches to calibrate a network on the basis of a given data set.

Molecular biomarkers (C 37 alkenones, n-nonacosane and n-hexacosanol) and TOC are used together with benthic N 18 O and N 13 C data to document the hydrographic response of the western Mediterranean Sea to rapid climatic variability. These proxies are recorded in core MD 95-2043 (Alboran Sea) affording the study of the DansgaardÔ eschger (D^O) and Heinrich (HE) variability during the last glacial period. The results suggest that rapid changes in the western Mediterranean thermohaline circulation occurred in parallel to sea surface temperature oscillations. Enhanced deep water ventilation occurred during cold intervals (HE and D^O Stadials) probably driven by a strengthening of north-westerly wind over the north-western Mediterranean Sea. In contrast, decreased intensity of the thermohaline circulation is detected during warm intervals (D^O Interstadials) which led to low oxygenated deep water masses and better preservation of the organic matter in the sediment. ß

A multi-criteria approach was applied for the disposal into the sea of w1100 000 m 3 of sediment, dredged from a coastal area in the northeastern part of the Thermaikos Gulf. This sediment (classified as muddy) is distributed vertically into two distinct Layers (A and B) with the thickness of the surficial sedimentary unit ranging from 7 to 54 cm. Its geochemistry reveals increased Cr and Ni concentrations, which may be attributed to natural enrichment through the erosion of the adjacent igneous and metamorphic rocks. In addition, a low to moderate contamination from urban-originated heavy metals, like Cu, Pb and Zn as well as from aliphatic and polycyclic hydrocarbons was identified for the upper Layer A. However, the limited proportion (5.5%) of the polluted Layer A in the total volume of the dredged material could not affect the good quality (assessed by the Sediment Quality Guidelines) of the bulk sediment. The identification of the optimum marine dumping site was based on (a) the physicochemical similarity (detected by the application of a cluster analysis) of the dredged material with the surficial deposits of potential dumping sites in the Outer Thermaikos Gulf, and (b) the consideration, based on previous studies, of various criteria related to the disposal area such as deep-water circulation, influence on living resources, impact on economical (aquaculture, fishing, navigation), recreational (fishing) and military activities.

Five years (1998, 2000-2003) of summer records of temperature, nutrients and dissolved oxygen concentrations in the upper 400 m of the water column of the northern Gulf of Aqaba were employed to produce a simple statistical model of the relationship between temperature versus nitrate, phosphate, silicate and dissolved oxygen concentrations. Temperature profiles in the upper 400 m during summer revealed a clear thermocline in the upper 200 m. This was reflected in nutrient and oxygen concentrations as nitrate, phosphate, and silicate increased from the surface to deep water while dissolved oxygen decreased. The best fit relationship between temperature versus nitrate and phosphate was inverse linear and the best fit correlation between temperature versus silicate and dissolved oxygen was fractional. The observed nutrient concentrations were shaped by a combination of the hydrodynamics and biological factors. Deep winter mixing and high nutrient concentrations dominate during winter. Shortly after the water stratifies in spring, the nutrients are drawn down by phytoplankton during the spring bloom and remain low throughout the rest of the year. The regression equations presented here will be useful in estimating nutrient concentrations from temperature records as long as the annual natural cycle is the main driver of nutrient concentrations and

He is injected in the deep ocean at plate boundaries in relation with hydrothermal activity. Its oceanic distribution, which is at a steady-state, shows appreciable vertical and horizontal gradients. Hence, 3 He conservation equations may be inverted to determine the flow field and mixing coefficients within the ocean. Here, we use this technique to investigate the deep circulation of the Red Sea, whose deep thermohaline circulation is comparable to that of a miniature world ocean. 3 He data, which are a combination of the Geosecs, Meseda and Merou cruises, are inverted using a linear inverse box model. The present study allows us to draw the details of the internal circulation. The latter is characterized by (i) a descending branch in the northernmost part of the basin, which corresponds to the sinking and subsequent north-south movement of dense surface waters and of additional water entrained by the sinking plume, (ii) by an internal counterclockwise recirculating loop with a northward return flow at intermediate depth. In the literature, the rate and modes of renewal of the Red Sea deep waters are poorly constrained, with bulk residence time estimates ranging from a few decades to a few centuries. In our model, the deep water renewal rate is directly dependent on the magnitude of the 3 He sources. The global 3 He flux is estimated using two independent approaches. The first method is based on the calculation of the mean 3 He transfer flux at the air-sea interface. The second approach relies on recent estimates of the global terrestrial 3 He flux. Both methods agree within their respective uncertainties. The circulation scheme defined by the inversion is further constrained by simulating the bomb 14 C distribution. Both isotopes, one steady-state tracer (3 He) and one transient tracer (14 C), lead to reasonable agreement. The renewal time corresponding to the sinking of newly formed deep water in the northern part of the basin is 60 years. However, the global ventilation rate, deduced from the simulation of the decay rate of a numerical tracer, is much faster (26 years). This result shows, as already pointed out by others, that deep water formation is not the only process by which the deep Red Sea is ventilated. Although this mechanism is important in our model, the basin wide deep circulation coupled with efficient vertical exchange between the deep basin and the upper layers appear to be an even more powerful mode of ventilation.

Plate tectonic reconstructions for the Cretaceous have assumed that the major continental blocks-Eurasia, the Late Cretaceous the Atlantic-Indian Ocean complex was a long, narrow, sinuous ocean basin extending off the Tethys and around Africa.

The distribution of seismic units in deposits of the basins near the Antarctic-Scotia plate boundary is described based on the analysis of multichannel seismic reflection profiles. Five main seismic units are identified. The units are bounded by high-amplitude continuous reflectors, named a to d from top to bottom. The two older units are of different age and seismic facies in each basin and were generally deposited during active rifting and seafloor spreading.

Recent studies have confirmed the relationship between iron supply and phytoplankton growth rates in all three high-nitrate low-chlorophyll (HNLC) oceanic provinces. However, there is little evidence, so far, of the role of iron in altering the efficiency of the biological pump via increased downward export of particulate organic carbon (POC). The NE subarctic Pacific is unique among HNLC regions in that long time series pelagic observations and deep-moored sediment trap records exist which may provide the best opportunity thus far to test aspects of the iron hypothesis. Episodic elevated levels of chlorophyll a ( > 2.0 [tg L -l) were observed 6 times between 1964 and 1976 at the former site of Ocean Station Papa (OSP). In addition, between 1984 and 1990 on at least three occasions, concurrent pulses of POC and biogenic silica were recorded in deep-moored traps at OSP. Possible explanations for these events, such as lateral advection of more productive waters, iron-mediated blooms, or grazing by salp swarms are discussed and tested using an existing downward POC flux model. Owing to the episodic nature of such events, no available data are sufficiently comprehensive to unequivocally rule out any of these explanations. Nevertheless, from the data available, the occurrence of pelagic or deep water pulses, approximately once every 3 years, are most consistent with iron-mediated diatom blooms, and of the sinking of POC and biogenic silica (from such a bloom) to depth, respectively. A comparison of the timing of these iron-mediated pulses with that of the transport probabilities of atmospheric dust supply from Asia and Alaska provides an opportunity to assess the likelihood of a coupling between the atmosphere and the ocean.

We review current knowledge and understanding of the biology and ecology of the calanoid copepod Calanus helgolandicus in European waters, as well as provide a collaborative synthesis of data from 18 laboratories and 26 sampling stations in areas distributed from the northern North Sea to the Aegean and Levantine Seas. This network of zooplankton time-series stations has enabled us to collect and synthesise seasonal and multi-annual data on abundance, body size, fecundity, hatching success and vertical distribution of C. helgolandicus. An aim was to enable comparison with its congener Calanus finmarchicus, which has been studied intensively as a key component of European and north east Atlantic marine ecosystems. C. finmarchicus is known to over-winter at depth, whereas the life-cycle of C. helgolandicus is less well understood. Overwintering populations of C. helgolandicus have been observed off the Atlantic coast between 400 and 800 m, while in the Mediterranean there is evidence of significant deep-water populations at depths as great as 4200 m. The biogeographical distribution of C. helgolandicus in European coastal waters covers a wide range of habitats, from open ocean to coastal environments, and its contribution to mesozooplankton biomass ranges from 6% to 93%. Highest abundances were recorded in the Adriatic and off the west coast of Spain. C. helgolandicus is generally found in 9-20°C water, with maximum abundances from 13-17°C. In contrast, C. finmarchicus is found in cooler water between 0 and 15°C, with peak abundances from 0 to 9°C. As water has warmed in the North Atlantic over recent decades, the range of C. helgolandicus and its abundance on the fringes of its expanding range have increased. This review will facilitate development of population models of C. helgolandicus. This will not only help answer remaining questions but will improve our ability to forecast future changes, in response to a warming climate, in the abundance and distribution of this important species.

The lower part of the Carboniferous Shannon Basin of Western Ireland contains a deep-water succession which exceeds 1200 m in thickness that comprises five lithologically different units deposited within a confined, relatively narrow basin: (i) a calciclastic debris-flow and turbidite unit formed by resedimentation from nearby carbonate platforms, (ii) a siliciclastic black shale succession with former source potential which onlaps basin margins (Clare Shales), (iii) a sandstone-dominated turbidite formation, controlled by ponded accommodation and deposited axially in the basin (Ross Formation), (iv) a mudstone-rich turbidite-bearing succession, which onlaps basin margins (lower Gull Island Formation), and (v) a mudstone-dominated prograding slope succession (upper Gull Island Formation and lower Tullig Cyclothem), which grades transitionally upwards into deltaic deposits. The top unit records progradation at a time when basin differential subsidence had diminished significantly and local basin topography did not control deposition. The two upper mudstone-dominated units are different in terms of both sandstone content and their genetic significance within the overall basin-fill, and their potential relevance as reservoir analogues. The lower part of the Gull Island Formation contains three principal facies associations: (a) shallow turbidite channels and sheets representing channel margin and levee deposits, (b) mud-rich slumps, and (c) less than 1 m thick, rare, hemipelagic shales. More than 75% is deformed by soft-sediment deformation, but only to a smaller degree affecting sandstone units. The turbidites record transport to the ENE, along the axis of the basin, while the slumps were derived from an unstable northern slope and transported transversely into the basin towards the southeast. The distribution of turbidite sandstone and slumps is inversely proportional. Sandstones decrease in importance away from the basin axis as slumps increase in number and thickness. The lower part of the Gull Island Formation is interpreted to record progressive fill of a deep basin controlled by local, healed slope accommodation with onlap/sidelap of the basin margins. The instability resulted from a combination of fault-controlled differential subsidence between basin margin and basin axis, and high rates of sedimentation. The upper part of the Gull Island Formation is entirely dominated by mudstones, which grade upwards into siltstones. It contains rare, up to 15 m thick, isolated channels filled by turbidites, showing transport towards the east. The upper part records easterly progradation of a deepwater slope genetically tied to overlying deltaic deposits, and controlled by regional accommodation. The contrasts between the lower and upper parts of the Gull Island Formation show that onlapping/sidelapping turbidite successions have reservoir potential near basin axes, but that prograding deep-water slopes are less likely to have reservoir potential of significance. A suggested regional downlap surface between the two parts is a significant break and marker in terms of reservoir potential.

A statical model of random wave is developed using Stokes wave theory of water wave dynamics. A new nonlinear probability distribution function of wave height is presented. The results indicate that wave steepness not only could be a parameter of the distribution function of wave height but also could reflect the degree of wave height distribution deviation from the Rayleigh distribution. The new wave height distribution overcomes the problem of Rayleigh distribution that the prediction of big wave is overestimated and the general wave is underestimated. The prediction of small probability wave height value of new distribution is also smaller than that of Rayleigh distribution. Wave height data taken from East China Normal University are used to verify the new distribution. The results indicate that the new distribution fits the measurements much better than the Rayleigh distribution.

Populations dominated by Cystoseira zosteroides, an endemic and threatened Mediterranean seaweed, colonize deep-water rocky habitats down to more than 50 m depth. Assemblages dominated by this species display high algal and invertebrate species richness. Algal biomass averages 1134 g dw m À2 . Erect and turf algae account for only 25% of total algal dry weight, while encrusting corallines are responsible for the remaining 75%. Sponges, bryozoans and ascidians constitute the dominant sessile macrofauna. Cystoseira zosteroides is the dominant erect algae, with a mean biomass of 60.6 g dw m À2 , and densities ranging from 4 to 7 plants m À2 . The alien turf alga Womersleyella setacea has a biomass of 104.2 g dw m À2 and covers most of the understory substrate. The size-frequency distribution of C. zosteroides populations shows differences over time. Mean annual growth of the main axis is around 0.5 cm and mean annual mortality rate is lower than 2%. Recruitment was almost nil during the studied period of time (10 years). Processes structuring these deep-water Cystoseira stands must be driven by episodic disturbances, afterdisturbance recruitment pulses, and long periods of steady growth that last at least 10 years. However, it is also possible that recruitment is irreversibly inhibited by the alien alga W. setacea in which case these old-growth stands are faced with extinction. The highly diversified assemblages and the low growth and low mortality rates of C. zosteroides indicate high vulnerability to natural and anthropogenic disturbances, and call for effective measures to ensure their conservation.

Cassava or manioc (Manihot esculenta Crantz), a perennial shrub of the New World, currently is the sixth world food crop for more than 500 million people in tropical and sub-tropical Africa, Asia and Latin America. It is cultivated mainly by resource-limited small farmers for its starchy roots, which are used as human food either fresh when low in cyanogens or in many processed forms and products, mostly starch, flour, and for animal feed. Because of its inherent tolerance to stressful environments, where other food crops would fail, it is often considered a food-security source against famine, requiring minimal care. Under optimal environmental conditions, it compares favorably in production of energy with most other major staple food crops due to its high yield potential. Recent research at the Centro Internacional de Agricultura Tropical (CIAT) in Colombia has demonstrated the ability of cassava to assimilate carbon at very high rates under high levels of humidity, temperature and solar radiation, which correlates with productivity across all environments whether dry or humid. When grown on very poor soils under prolonged drought for more than 6 months, the crop reduce both its leaf canopy and transpiration water loss, but its attached leaves remain photosynthetically active, though at greatly reduced rates. The main physiological mechanism underlying such a remarkable tolerance to drought was rapid stomatal closure under both atmospheric and edaphic water stress, protecting the leaf against dehydration while the plant depletes available soil water slowly during long dry periods. This drought tolerance mechanism leads to high crop water use efficiency values. Although the cassava fine root system is sparse, compared to other crops, it can penetrate below 2 m soil, thus enabling the crop to exploit deep water if available. Leaves of cassava and wild Manihot possess elevated activities of the C4 enzyme PEP carboxylase but lack the leaf Kranz anatomy typical of C4 species, pointing to the need for further research on cultivated and wild Manihot to further improve its photosynthetic potential and yield, particularly under stressful environments. Moreover, a wide range in values of K m (CO2) for the C3 photosynthetic enzyme Rubisco was found among cassava cultivars indicating the possibility of selection for higher affinity to CO2, and consequently higher leaf photosynthesis. Several plant traits that may be of value in crop breeding and improvement have been identified, such as an extensive fine root system, long leaf life, strong root sink and high leaf photosynthesis. Selection of parental materials for tolerance to drought and infertile soils under representative field conditions have resulted in developing improved cultivars that have high yields in favorable environments while producing reasonable and stable yields under stress.

In order to assess the potential for enhanced agrochemical contamination of shallow groundwaters, a field study was established on the Upper Chalk in Hampshire, UK. Two instrumented sites, 380m apart, were established on a hillslope; one on the interfluve with a deep water table (∼18m depth), the other on the dry valley bottom where the groundwater was close to the

Global catches of marine fishery resources declined during the last decades; however, there has been a trend of increasing exploitation of deepwater resources that are especially vulnerable to depletion. Such a tendency was noticeable in Pacific Latin America, too. In Costa Rica, the vast majority of the commercial fishing activities are concentrated on the Pacific coast. The target species for the deepwater fishery in Costa Rica are the two pandalids Heterocarpus affinis and H. vicarius as well as Solenocera agassizii, the latter one being the most important in terms of annual landings. Here we compile the information available from Costa Rica about each of the three target species. Furthermore, we describe research activities related to the Costa Rican deepwater resources and present available data about by-catch and discards in this fishery. Finally, the current situation of the administration and management of these resources in Costa Rica is described. Strengthening collaboration between governmental agencies, the fishery sector, non-governmental organizations, and the academic sector is recommended to avoid an uncontrolled overfishing of these valuable deepwater resources along the Pacific coast of Costa Rica.

Analysis of the monitoring data on the radionuclides specific activity in water of the Cooling Pond of Chornobyl NPP revealed the regular seasonal cycling of the 137 Cs concentration but did not reveal this for 90 Sr. It is strongly supposed that this phenomenon is caused by the microbialcontrolled seasonal dependant flux of 137 Cs from the bottom sediments to the water. Analysis of the 137 Cs profiles in deep water sediment (silt) provides additional forcible argument in favour of this supposition.

The paleotectonic and volcanic features of the Jurassic-Cretaceous carbonate successions, outcropping in central-western Sicily, allow us to restore the tectono-sedimentary evolution of a sector of the African continental margin. These successions consist of shallow-to-deep-water Mesozoic deposits that have formed in the carbonate platform-to-pelagic plateau depositional setting of the so-called Trapanese paleogeographic domain. Fieldwork, including structural analyses, has indicated the occurrence of lateral facies changes, resedimented materials, volcanic products (pillow lavas and tuffitic deposits), unconformity surfaces and paleofaults of different trends and age. These data, combined with facies and a physical-stratigraphic analysis, allow one to distinguish between the different tectono-stratigraphic settings. A structural low, filled with thick pillow lavas and reworked deposits, appears bordered by two main structural highs: an articulate carbonate-pelagic platform with a stepped fault margin, and the flank of a structural high, where the volcanoclastic deposits are interlayered with reworked reef materials, suggest the occurrence of a submarine volcano, that evolved into an atoll-type carbonate shelf setting. Tectonic and magmatic events punctuated the sedimentary evolution during the Early Jurassic, Middle-Late Jurassic, Early and Late Cretaceous. The horst and graben structures connected by steeped margins and the occurrence of distinctive types of volcanic products suggest that the study areas could represent a sector of the Jurassic-Cretaceous southern Tethyan passive continental margin, situated at the edge of the continental platform bordering those basinal areas where rifting and possible spreading processes were active during the Mesozoic.

Hatchling marine turtles emerge at night from underground nests, enter the ocean, and swim offshore. Here, we measured the intensity (hours swimming) and the temporal patterning (diurnal vs. nocturnal expression) of activity shown by Malaysian (Sulu Sea) hawksbill (Eretmochelys imbricata) and green turtle (Chelonia mydas) hatchlings tethered inside pools for six days, postemergence. The results were compared to the activity shown during the same period of development by sea turtles in Florida. The two species from Malaysia showed significant differences in activity both from one another and from the Florida (leatherback, Dermochelys coriacea; loggerhead, Caretta caretta; and green turtle) species. Hawksbills were less active than the hatchlings from Florida, swimming on average , 6 h/d. Hawksbills did not show a frenzy period of hyperactive swimming, typical of the first day of offshore migration by the hatchlings from Florida. Green turtles swam on average about 17 h each day during a two-day frenzy period that was one day longer than the frenzy period shown by green turtles from Florida; thereafter, activity showed a significant decline. These results suggest the two species use different strategies to avoid predators near shore. Hawksbills may hide in flotsam or remain inactive to minimize detection; whereas, green turtles may reduce their exposure time by rapid locomotion through shallow water. We conclude that the frenzy period shown by hatchlings during offshore migration is a variable trait both among marine turtle species and between green turtle populations nesting on Western Atlantic and Sulu Sea beaches.