Search

Plankton are sensitive indicators of change and, at the base of marine food webs, they underpin important ecosystem services such as carbon sequestration and fisheries production. In the UK and the Northeast Atlantic region, change in plankton functional groups, or ‘lifeforms’, constructed based on biological traits, is the formally accepted policy indicator used to assess Good Environmental Status (GES) for pelagic habitats under the Marine Strategy Framework Directive (MSFD: 2008/56/EC). To identify changes in UK pelagic habitats, plankton lifeforms, were used from diverse UK data sets collected by different methods, including plankton sampling by nets, water bottles, integrating tube samplers, and the Continuous Plankton Recorder. A Plankton Index approach was used to identify change in plankton lifeforms. This is the first time that the pelagic plankton community has been assessed on a UK-wide scale and forms the foundation of the UK’s 2020 MSFD Assessment for pelagic habitat biodiversity and food webs. This approach revealed that some of the plankton lifeforms used in the assessment displayed spatially-variable changes during the past decade. Assessing plankton community change using a common indicator at the UK scale for the first time is a significant step towards evaluating GES for European seas. Determining GES for pelagic habitats, however, is a challenging process, with additional work required to interpret the assessment results and to identify causation of the changes observed.

Harmful algal blooms (HABs) are thought to be increasing in coastal waters worldwide. Anthropogenic nutrient enrichment has been proposed as a principal causative factor of this increase through elevated inorganic and/or organic nutrient concentrations and modified nutrient ratios. We assess: 1) the level of understanding of the link between the amount, form and ratio of anthropogenic nutrients and HABs; 2) the evidence for a link between anthropogenically generated HABs and negative impacts on human health; and 3) the economic implications of anthropogenic nutrient/HAB interactions. We demonstrate that an anthropogenic nutrient-HAB link is far from universal, and where it has been demonstrated, it is most frequently associated with high biomass rather than low biomass (biotoxin producing) HABs. While organic nutrients have been shown to support the growth of a range of HAB species, insufficient evidence exists to clearly establish if these nutrients specifically promote the growth of harmful species in preference to benign ones, or if/how they influence toxicity of harmful species. We conclude that the role of anthropogenic nutrients in promoting HABs is site-specific, with hydrodynamic processes often determining whether blooms occur. We also find a lack of evidence of widespread significant adverse health impacts from anthropogenic nutrient-generated HABs, although this may be partly due to a lack of human/animal health and HAB monitoring. Detailed economic evaluation and cost/benefit analysis of the impact of anthropogenically generated HABs, or nutrient reduction schemes to alleviate them, is also frequently lacking.

Although the terms 'health' and 'healthy' are often applied to marine ecosystems and communicate information about holistic condition (e.g. as required by the Ecosystem Approach), their meaning is unclear. Ecosystems have been understood in various ways, from non-interacting populations of species to complex integrated systems. Health has been seen as a metaphor, an indicator that aggregates over system components, or a non-localized emergent system property. After a review, we define good ecosystem health as: 'the condition of a system that is self-maintaining, vigorous, resilient to externally imposed pressures, and able to sustain services to humans. It contains healthy organisms and populations, and adequate functional diversity and functional response diversity. All expected trophic levels are present and well interconnected, and there is good spatial connectivity amongst subsystems.' We equate this condition with good ecological or environmental status, e.g. as referred to by recent EU Directives. Resilience is central to health, but difficult to measure directly. Ecosystems under anthropogenic pressure are at risk of losing resilience, and thus of suffering regime shifts and loss of services. For monitoring whole ecosystems, we propose an approach based on 'trajectories in ecosystem state space', illustrated with time-series from the northwestern North Sea. Change is visualized as Euclidian distance from an arbitrary reference state. Variability about a trend in distance is used as a proxy for inverse resilience. We identify the need for institutional support for long time-series to underpin this approach, and for research to establish state space co-ordinates for systems in good health. Changes in the northern North Sea, 1958-2008, plotted in a state space defined by the breeding success of kittiwakes, abundance of copepods Calanus spp., and simulated annual primary production.© Inter-Research 2013. www.int-res.com.

Dissolved organic nitrogen (DON) is recognised as an important N source for phytoplankton. However, its relative importance for phytoplankton nutrition and community composition has not been studied comprehensively. This study, conducted in a typical Scottish fjord, representative of near-pristine coastal environments, evaluates the utilisation of DON and dissolved inorganic nitrogen (DIN) by different microbial size fractions and the relationship of phytoplankton community composition with DON and other parameters. The study demonstrated that DON was important in supporting phytoplankton throughout the yearly production cycle. The higher-than-expected urea uptake rates and large fraction of the spring bloom production supported by DON suggested that organic N not only contributes to regenerated production and to the nutrition of the small phytoplankton fraction, but can also contribute substantially to new production of the larger phytoplankton in coastal waters. Multivariate statistical techniques revealed two phytoplankton assemblages with peaks in abundance at different times of the year: a spring group dominated by Skeletonema spp., Thalassiosira spp., and Pseudo-nitzschia spp. group delicatissima; and a summer/autumn group dominated by Chaetoceros spp., Scrippsiella spp., and Pseudo-nitzschia spp. group seriata. The multivariate pattern in community composition and abundance of these taxa was significantly correlated with the multivariate pattern of DON, urea, dissolved free amino acids, DIN, temperature, salinity, and daylength, with daylength and urea being particularly important, suggesting both physical and chemical controls on community composition.

There is a perception that anthropogenically-driven changes in nutrient supply to coastal waters influences the abundance, frequency and toxicity of harmful algal blooms (HABs) through a change in the form or ratio of nutrient that limits phytoplankton growth. If nutrient concentrations are not limiting for growth, then ratios do not influence floristic composition. At non-limiting concentrations, evidence that alteration of nitrogen: phosphorus (N:P) ratios has stimulated HABs is limited, and primarily based on hypothesised relationships in relatively few locations (in particular: Tolo Harbour Hong Kong and Dutch Coastal Waters). In all cases, an unequivocal causal link between an increase in HABs (frequency, magnitude or duration) and change in N or P as the limiting nutrient is difficult to establish. The silicon (Si) limitation hypothesis is generally supported by experimental evidence and field data on the nuisance flagellate Phaeocystis. We found little evidence that high N:Si ratios preferentially promote harmful dinoflagellates over benign species. Laboratory studies demonstrate that nutrient ratios can influence toxin production, but genus and species specific differences and environmental control make extrapolation of these data to the field difficult. Studies of the role of dissolved and particulate organic nutrients in the growth of HAB species, while limited, demonstrate the potential for organic nutrients (especially organic N) to support the growth of a range of HAB species. There is a clear need for better understanding of the role of mixotrophy in the formation of HABs and for studies of HAB and non-HAB species in competition for environmentally realistic concentrations of organic nutrients.

Recent European Court rulings in the context of eutrophication viewed proliferation of a particular species of algae as a disturbance to the balance of aquatic ecosystems and the proliferation of one or more species as a cause of a reduction in other species. We discuss the scientific basis for this opinion in relation to the growth of marine primary producers and current debates about ecosystem stability. Opposing views in this debate are those of (a) the ‘balance of nature’ paradigm, in which communities of organisms tend towards a stable climax composition, and (b) communities as dynamic systems that may be governed by ‘basins of attraction’ in state space. We use data from the Irish Sea and Narragansett Bay, together with a review of the literature, to show that: the dynamics of temperate marine phytoplankton, with seasonal successions, corresponds more to (b) than to (a); the temporary dominance of any one species of micro-alga or cyanobacterium is part of the natural dynamics of phytoplankton communities and does not permanently impact on other species. Understanding the phytoplankton as a dynamic system suggests its status should not be assessed against a 'climax' model and that eutrophication should be diagnosed from fundamental (nutrient-induced) perturbations of ecosystem state and function rather than from changes in fixed assemblages of species and thresholds of abundance.

We present the scientific case for inclusion of penetrators into the Europan surface, and the candidate instruments which could significantly enhance the scientific return of the joint ESA/NASA Europa-Jupiter System Mission (EJSM). Moreover, a surface element would provide an exciting and inspirational mission highlight which would encourage public and political support for the mission. Whilst many of the EJSM science goals can be achieved from the proposed orbital platform, only surface elements can provide key exploration capabilities including direct chemical sampling and associated astrobiological material detection, and sensitive habitability determination. A targeted landing site of upwelled material could provide access to potential biological material originating from deep beneath the ice. Penetrators can also enable more capable geophysical investigations of Europa (and Ganymede) interior body structures, mineralogy, mechanical, magnetic, electrical and thermal properties. They would provide ground truth, not just for the orbital observations of Europa, but could also improve confidence of interpretation of observations of the other Jovian moons. Additionally, penetrators on both Europa and Ganymede, would allow valuable comparison of these worlds, and gather significant information relevant to future landed missions. The advocated low mass penetrators also offer a comparatively low cost method of achieving these important science goals. A payload of two penetrators is proposed to provide redundancy, and improve scientific return, including enhanced networked seismometer performance and diversity of sampled regions. We also describe the associated candidate instruments, penetrator system architecture, and technical challenges for such penetrators, and include their current status and future development plans.

The dinoflagellate Noctiluca scintillans is one of the most important and abundant red tide organisms and it is distributed world-wide. It occurs in two forms. Red Noctiluca is heterotrophic and fills the role of one of the microzooplankton grazers in the foodweb. In contrast, green Noctiluca contains a photosynthetic symbiont Pedinomonas noctilucae (a prasinophyte), but it also feeds on other plankton when the food supply is abundant. In this review, we document the global distribution of these two forms and include the first maps of their global distribution. Red Noctiluca occurs widely in the temperate to sub-tropical coastal regions of the world. It occurs over a wide temperature range of about 10°C to 25°C and at higher salinities (generally not in estuaries). It is particularly abundant in high productivity areas such as upwelling or eutrophic areas where diatoms dominate since they are its preferred food source. Green Noctiluca is much more restricted to a temperature range of 25°C–30°C and mainly occurs in tropical waters of Southeast Asia, Bay of Bengal (east coast of India), in the eastern, western and northern Arabian Sea, the Red Sea, and recently it has become very abundant in the Gulf of Oman. Red and green Noctiluca do overlap in their distribution in the eastern, northern and western Arabian Sea with a seasonal shift from green Noctiluca in the cooler winter convective mixing, higher productivity season, to red Noctiluca in the more oligotrophic warmer summer season.

著者人数：156名, Accepted: 2008-05-27, 資料番号: SA1000998000

Tett, P., Carreira, C., Mills, D. K., van Leeuwen, S., Foden, J., Bresnan, E., and Gowen, R. J. 2008. Use of a Phytoplankton Community Index to assess the health of coastal waters. – ICES Journal of Marine Science, 65: 1475–1482. Monitoring of marine-ecosystem status and health requires indicators of community structure and function. As a structural indicator, we propose a Phytoplankton Community Index (PCI) based on the abundance of “life-forms” such as “pelagic diatoms” or “medium-sized autotrophic dinoflagellates”. To calculate the PCI, data showing seasonal variation in these abundances are plotted in “life-form space” of two or more dimensions. Data from a “type-specific reference condition” are then enclosed within a reference envelope. Comparison data are plotted into the same coordinate system, and the PCI is the proportion (between 0 and 1) of these new data that fall within the reference envelope. Results from initial applications of this method are shown for UK coastal waters in the northern North Sea (near Stonehaven), a Scottish fjord (Loch Creran), and the eastern Irish Sea (including Liverpool Bay). The Stonehaven data (1997–2005) were used to compare values obtained from weekly sampling with those from monthly sampling. A spatial comparison between more- and less-nutrient-enriched waters in the eastern Irish Sea (1991–2003) showed little difference in phytoplankton community structure. Loch Creran has experienced a large change in the “balance of organisms”, and hence a reduction in the PCI, between 1979–1981 and 2006/2007, associated with a decrease in chlorophyll but no apparent change in nutrients. These results are discussed in relation to the intended uses of the PCI as an index of biological quality for the Water Framework Directive (WFD) and an index of ecosystem health in the context of eutrophication. Although the method only measures change, it can also be used as an indicator of biological quality if the reference conditions are those defined for a WFD waterbody, and as an indicator of health if appropriately calibrated. Suggestions are made for further development.

Measurements of sub-surface light attenuation (Kd), Secchi depth and suspended particulate material (SPM) were made at 382 locations in transitional, coastal and offshore waters around the United Kingdom (hereafter UK) between August 2004 and December 2005. Data were analysed statistically in relation to a marine water typology characterised by differences in tidal range, mixing and salinity. There was a strong statistically significant linear relationship between SPM and Kd for the full data set. We show that slightly better results are obtained by fitting separate models to data from transitional waters and coastal and offshore waters combined. These linear models were used to predict Kd from SPM. Using a statistic (D) to quantify the error of prediction of Kd from SPM, we found an overall prediction error rate of 23.1%. Statistically significant linear relationships were also evident between the log of Secchi depth and the log of Kd in waters around the UK. Again, statistically significant improvements were obtained by fitting separate models to estuarine and combined coastal/offshore data – however, the prediction error was improved only marginally, from 31.6% to 29.7%. Prediction was poor in transitional waters (D = 39.5%) but relatively good in coastal/offshore waters (D = 26.9%). SPM data were extracted from long term monitoring data sites held by the UK Environment Agency. The appropriate linear models (estuarine or combined coastal/offshore) were applied to the SPM data to obtain representative Kd values from estuarine, coastal and offshore sites. Estuarine waters typically had higher concentrations of SPM (8.2–73.8 mg l−1) compared to coastal waters (3.0–24.1 mg l−1) and offshore waters (9.3 mg l−1). The higher SPM values in estuarine waters corresponded to higher values of Kd (0.8–5.6 m−1). Water types that were identified by large tidal ranges and exposure typically had the highest Kd ranges in both estuarine and coastal waters. In terms of susceptibility to eutrophication, large macrotidal, well mixed estuarine waters, such as the Thames embayment and the Humber estuary were identified at least risk from eutrophic conditions due to light-limiting conditions of the water type.

While the surface missions to the Moon of the 1970s achieved a great deal, scientifically much was also left unresolved. The recent plethora of lunar missions (flown or proposed) reflects a resurgence in interest in the Moon, not only in its own right, but also as a record of the \ud early solar system including the formation of the Earth. Results from recent orbiter missions have shown evidence of ice or at least hydrogen within shadowed craters at the lunar poles.

The question of whether the Irish Sea is eutrophic is addressed by reviewing the evidence for anthropogenic nutrient enrichment, elevated phytoplankton production and biomass and undesirable disturbance in the context of the EU and OSPAR definitions of eutrophication. Winter concentrations of dissolved available inorganic phosphate (DAIP), nitrogen (DAIN as nitrate and nitrite) and silicate (Si) in coastal waters and concentrations of DAIP and Si in offshore waters of the Irish Sea are elevated relative to winter Celtic Sea shelf break concentrations (0.5 μM DAIP, 7.7 μM DAIN and 2.7 μM Si). Significant, negative nutrient salinity relationships and analysis of the Isle of Man nutrient time-series indicate that the elevated Irish Sea levels of DAIP and DAIN are the result of anthropogenic enrichment with highest concentrations (≈2.0 μM DAIP, 30 μM DAIN and 17 μM Si) measured in near shore eastern Irish Sea waters. Summer levels of phytoplankton chlorophyll (Chl) range from

Special issue: Oceans and Human Health.-- 31 pages, 3 figures, 2 box, Microalgal blooms are a natural part of the seasonal cycle of photosynthetic organisms in marine ecosystems. They are key components of the structure and dynamics of the oceans and thus sustain the benefits that humans obtain from these aquatic environments. However, some microalgal blooms can cause harm to humans and other organisms. These harmful algal blooms (HABs) have direct impacts on human health and negative influences on human wellbeing, mainly through their consequences to coastal ecosystem services (fisheries, tourism and recreation) and other marine organisms and environments. HABs are natural phenomena, but these events can be favoured by anthropogenic pressures in coastal areas. Global warming and associated changes in the oceans could affect HAB occurrences and toxicity as well, although forecasting the possible trends is still speculative and requires intensive multidisciplinary research. At the beginning of the 21st century, with expanding human populations, particularly in coastal and developing countries, mitigating HABs impacts on human health and wellbeing is becoming a more pressing public health need. The available tools to address this global challenge include maintaining intensive, multidisciplinary and collaborative scientific research, and strengthening the coordination with stakeholders, policymakers and the general public. Here we provide an overview of different aspects of the HABs phenomena, an important element of the intrinsic links between oceans and human health and wellbeing, The research was funded in part by the UK Medical Research Council (MRC) and UK Natural Environment Research Council (NERC) for the MEDMI Project; the National Institute for Health Research Health Protection Research Unit (NIHR HPRU) in Environmental Change and Health at the London School of Hygiene and Tropical Medicine in partnership with Public Health England (PHE), and in collaboration with the University of Exeter, University College London and the Met Office; and the European Regional Development Fund Programme and European Social Fund Convergence Programme for Cornwall and the Isles of Scilly (University of Exeter Medical School). EB was supported by the CTM2014-53818-R project, from the Spanish Government (MINECO). KDA was in receipt of funding from the BBSRC-NERC research programme for multidisciplinary studies in sustainable aquaculture: health, disease and the environment. P. Hess was supported by Ifremer (RISALTOX) and the Regional Council of the Pays de la Loire (COSELMAR). Porter Hoagland was supported by the US National Science Foundation under NSF/CNH grant no. 1009106

Introduction. Nematodes are significant pests of bananas and plantains world- wide. Different levels of susceptibility to these pests have been reported. Studies were carried out to investigate differences in root systems and development of Musa clones with different levels of susceptibility and their possible role in the host-parasite relationship. Materials and methods. Five Musa clones, of which four were susceptible and one resistant to the nematode Radopholus similis, were grown in a plot naturally infested by this nematode. Root samples were collected 6 months after planting and measurements were made on the significance of tissue areas in root cross-sections, and the significance of root mass, root development and nematode populations with depth. Results. No significant difference was observed between cultivars in their general structural organisation or the relative significance of the tissue component of the root cross-section. A significantly lower number of air lacunae was found in the resistant acces- sion in comparison with the susceptible ones. All the accessions except Christine (ABB) were comparable in their root development in the soil profile with more than 70% of the total root mass produced above 40 cm. The greatest nematode population and damage on roots were found at depths between (20 and 40) cm. Conclusions. This is the first report on differences in air spaces between Musa cultivars, and their role in the Musa-nematode relationship needs further investigation. Musa / Cameroon / plant nematodes / host resistance to pests / roots / plant morphology / growth

Nutrient data from five winter cruises since 1994 and the 40-year time series from the CYPRIS station in the Irish Sea are used to assess the controls of winter concentrations in the Celtic and Irish Seas and the Malin Shelf region of the north-west European shelf. At the Malin Shelf break, boundaries between ocean water, the shelf edge current and shelf waters were well defined by changes in salinity, temperature and concentrations of nutrients (nitrate + nitrite (N), phosphate (P) and silicate (Si)). Concentrations fell from oceanic values of 11.0 [mu]M N, 0.68 [mu]M P and 4.75 [mu]M Si to 7.4 [mu]M N, 0.53 [mu]M P and 3.3 [mu]M Si in open shelf sea waters. Across the Celtic Sea shelf break boundaries are less well defined. Areas of water with concentrations of nutrients below those off-shelf are detected in certain areas. Denitrification is a ubiquitous process on the shelf. The accumulated loss of nitrate relative to phosphate increases moving from the shelf break into the Irish Sea. Comparisons of estimated rates of denitrification with measured N:P ratios suggest waters on the Malin Shelf have an age of 400 days relative to ocean water crossing the shelf break. Across the Celtic Sea the transit time for water from the Atlantic Ocean into the central Irish Sea is six years, consistent with the complexity of water types and frontal structures. Concentrations at CYPRIS are consistent with the degree of nitrate loss from the water on route to the central Irish Sea. Relatively high concentrations of silicate measured at CYPRIS station indicate this location is more influenced by waters with an origin south of 53.5[deg]N than from the eastern Irish Sea

Square root data compression is particularly suited to compression of scientific data where there shall be no reconstruction data artifacts, and reconstruction errors are required to be less than specified Poisson statistical noise levels. Its fixed compression ratio also makes it particularly suitable for real-time engineering implementation where telemetry rates and computer memory capacities are constrained. The compression scheme is described together with formulas that determine optimized control parameters to allow any input and compressed dynamic ranges to be accommodated, including joining to uncompressed data regions where zero data errors are desired to protect low count information. Further formulas are presented that allow optimized reconstruction values and maximum reconstruction error limits to be determined. Finally, some examples are presented that demonstrate its particular suitability for scientific applications.

Sediment characteristics, sediment respiration (oxygen uptake and sulphate reduction) and sediment–water nutrient exchange, in conjunction with water column structure and phytoplankton biomass were measured at five stations across the western Irish Sea front in August 2000. The transition from thermally stratified (surface to bottom temperature difference of 2.3 °C) to isothermal water (14.3 °C) occurred over a distance of 13 km. The influence of the front on phytoplankton biomass was limited to a small region of elevated near surface chlorophyll (2.23 mg m −3 ; 50% > biomass in mixed waters). The front clearly marked the boundary between depositional sediments (silt/clays) with elevated sediment pigment levels (≈60 mg m −2 ) on the western side, to pigment impoverished ( −2 ) sand, through to coarse sand and shell fragments on the eastern side. Maximal rates of sedimentary respiration on the western stratified side of the front e.g. oxygen uptake S2 (852 μmol O 2 m −2 h −1 ) and sulphate reduction at S1 (149 μmol SO 4 2− m −2 h −1 ), coupled to significant efflux of nitrate and silicate at the western stations indicate closer benthic–pelagic coupling in the western Irish Sea. Whether this simply reflects the input of phytodetritus from the overlying water column or entrapment and settlement of pelagic production from other regions of the Irish Sea cannot yet be resolved.

International audience; The basin of Thau in southern France is a shallow, weakly flushed lagoon which is an important location for oyster cultivation. Phytoplankton analyses were carried out in 1975–1976 and then (almost) continuously since 1987. We report an investigation of ‘the balance of organisms’ in phytoplankton in relation to reductions in phosphorus loading, using two new tools based on phytoplankton lifeforms: the Plankton Index for Phytoplankton (PIp); Euclidean distance in state-space. Our results show the utility of the tools for analysing changes in the ‘balance of organisms’ at the level of functional groups (in our study diatoms and dinoflagellates), but also illustrate the difficulties in demonstrating the reversal of human impacts resulting from eutrophication.The comparison between 1987–89 and 1976 showed the expected ‘de-eutrophication’ due to the reduction in dissolved inorganic phosphate (DIP), with a decrease in dinoflagellate abundance. Since 1989, year-to-year variation in annual mean concentrations of DIP may have contributed to inter-annual variability in the balance of the two lifeforms, but the data suggest that the system has remained in a dynamically stable regime because: (1) there was no long-term trend in Euclidean distance from the reference; and (2) there was no increase in inter-annual variability about the time-series mean Euclidean distance suggesting there has been no decrease in resilience which might signal a regime change.Integrated management of human activities will be required to manage (and reduce) total P in the system. Monitoring phytoplankton and nutrients concentrations to determine how primary production and the balance of species respond to further changes in the nutrient status of the lagoon should be an integral part of any management programme.

Single point time-series data collected in the Irish Sea since 1954 by Allen et al. (1998) have been re-evaluated using more recent data and areal winter surveys of the Celtic and Irish Seas. Survey data illustrate the heterogeneity of nutrient distributions with N (≈28 M) and P (2·0 M) enrichment of the eastern Irish Sea relative to the western Irish Sea (7–8 M N and 0·7 M P). Salinity nutrient relationships demonstrate distinct regional differences throughout the two seas. Trends in the Isle of Man time-series are unlikely to have resulted from changes in analytical procedures and personnel. Concerns over data quality cannot be resolved and there are no independent data to validate the time-series. Including more recent data shows P has declined since the late 1980s and N concentrations have remained stable since the mid 1970s. The absence of a Si trend is consistent with limited anthropogenic influence on riverine Si concentrations. Trends in N and P are consistent with changes in riverine concentrations of these two nutrients and the biogeochemical processes controlling their cycling in shelf waters. Denitrification is the most likely reason for offshore Irish Sea concentrations of N being lower than expected.

Fluvial and sewage loading of N and P to Liverpool Bay (England) elevated winter con- centrations of dissolved inorganic N (29.2 µM) and P (1.7 µM) and molar ratios of N:P (17.0) and N:Si (6.0) compared to Irish coastal waters (9.5 µM N, 0.8 µM P; N:P 12.0 N:Si 1.9). At the enriched site in Liverpool Bay, enhanced spring production (up to 3165.8 mg C m -2 d -1 ) summer production (471.8 to 971.5 mg C m -2 d -1 ) and biomass (4.1 to 13.6 mg chorophyll m -3 ) was dominated by diatoms. Annual production at this site was estimated as 182 g C m -2 compared to 97 g C m -2 at the Irish coastal sta- tion. Enrichment and shifts in nutrient ratios did not favour flagellate growth compared to growth of diatoms in Liverpool Bay. Low amounts of sediment phytopigments (9.2 to 26 mg m -2 ), low concen- trations of pore water Si (mean, 9.8 µM), and a negligible summer benthic efflux of Si (1.0 µmol m -2 h -1 ) suggested little phytodetrital input to sediments in Liverpool Bay and that summer diatom pro- duction required an allochthonous supply of Si. At the Irish coastal station, coupling between benthic and water-column processes ensured that benthic efflux of Si was sufficient to support the bulk of summer diatom production. Water-column recycling of N was an order of magnitude greater than sediment recycling of N at both coastal sites.

The impact of the spring bloom on benthic remineralisation rates was studied in offshore waters of the western Irish Sea during 1998. Initiation of the spring bloom coincided with the onset of thermal stratification at the end of April. Peak chlorophyll biomass (6.48 mg chl m -3 ) and algal standing stock (145.0 mg chl m -2 ) were measured on May 11, and the bloom lasted approximately 1 mo. Sediment oxygen uptake increased to 1658 μmol m -2 h -1 for a short period in early May, which was followed by increased denitrification (up to 48 μmol N m -2 h -1 ) in late May and early July. Subsequently sulphate reduction increased (up to 83 μmol SO 4 2- m -2 h -1 ) in early July. Efflux of nitrate remained low but constant (10 μmol m -2 h -1 ) throughout the study, accounting for 27 % of ammonified organic N, with the remaining 63% being denitrified. Sediment depth profiles of chlorophyll and phaeopigment showed deep (>30 cm) mixing of phytodetritus into the sediment in early July, which may explain the high rates of sulphate reduction measured at this time. Evidence of a large phytodetrital flux to the benthos during spring 1998 was limited. Deepening of chlorophyll isopleths suggested sinking of algae in early May, although sediment pigment concentrations indicated a continual but low input. Benthic oxygen consumption represented 46 % of total spring phytoplankton production or 61% of new production and approximately balanced the calculated flux of detrital carbon (C) to the benthos. The impact of detrital C (assumed to be largely phytodetritus immediately after the spring bloom) on the benthos was short lived, being rapidly remineralised, and in turn little spring production would have been available for secondary production, e.g. Nephrops norvegica. In such years, benthic production, particularly that of N. norvegica, must be supported by phytoplankton production which takes place after the bloom or by detrital C which is advected into the area following the breakdown of the gyre.

Concentrations of nitrate and nitrite (N), phosphorus (P) and silica (Si) were measured at a grid of stations in the north-west Irish Sea throughout 1992. The data were treated synoptically by mapping and graphical analysis to integrate data from 28 different stations. In spring, there was concurrent depletion of N, Si and P in the molar ratio 9·5:6·4:1, indicating that N was depleted before P and Si. Areal integrals were calculated for N and P at each station, which ranged in depth between 15 and 150 m. Over the summer, P integrals reducedpro ratawith depth up to 60 m, but in stations deeper than 60 m, there was no further reduction in P. In contrast, the areal N integral decreased in proportion to depth even in the deepest stations. It is suggested that loss of N in the deepwater stations may be due to denitrification in the bottom water. Over the winter, N, P and Si concentrations returned to the winter maximum in more or less constant proportions. Mechanisms for the control of the nitrate concentration are discussed. A desk budget suggests thatin situregeneration of nitrate is the dominant process.

Satellite and rocket borne experiments impose unique requirements on the systems that control them. High input data rates from sensors have to be coupled to a limited spacecraft telemetry resource. A suite of algorithms designed to ensure the most effective possible use of the telemetry allocation for an instrument studying space plasma electrons are described. These have been implemented in the data processing unit of the Plasma Electron and Current Experiment (PEACE) that will fly onboard the four Cluster spacecraft. Due to the high processing load and large throughput of data, two T222 17 MHz transputers were used as the onboard processors and the algorithms coded using the Occam programming language. To achieve the necessary reduction in the size of the dataset three different approaches have been used. Onboard moment calculations are performed. These provide a general characterisation of the measured electron distribution at the rate of once per spin of the spacecraft. For more detailed studies, sections and cuts of the raw sensor data can be selected. These distributions are designed to be compressed and telemetered at spin resolution. Some of these datasets can be aligned to the magnetic field direction. Finally much larger distributions of sensor counts can, for one spin, be stored and fed into the telemetry stream whenever there is room.

Simple models which predict the dispersion and input of organic waste from cage fish farms can be used as management tools for the siting of farms and assessing the potential for enrichment of the benthic ecosystem. A modification of the sediment model originally described by Gowen et al. (1988) is presented. The modifications include: variation in bottom topography; changes in current speed with depth; correction of horizontal current flow in response to changing depth. Data from a fish farm in Chile are used to compare simulations of dispersion and sediment loading from the original and modified models.

Emplacement of four or more kinetic penetrators geographically distributed over the lunar surface can enable a broad range of scientific exploration objectives of high priority and provide significant synergy with planned orbital missions. Whilst past landed missions achieved a great deal, they have not included a far-side lander, or investigation of the lunar interior apart from a very small area on the near side. Though the LCROSS mission detected water from a permanently shadowed polar crater, there remains in-situ confirmation, knowledge of concentration levels, and detailed identification of potential organic chemistry of astrobiology interest. The planned investigations will also address issues relating to the origin and evolution of the Earth–Moon system and other Solar System planetary bodies. Manned missions would be enhanced with use of water as a potential in-situ resource; knowledge of potential risks from damaging surface Moonquakes, and exploitation of lunar regolith for radiation shielding. LunarNet is an evolution of the 2007 LunarEX proposal to ESA (European Space Agency) which draws on recent significant advances in mission definition and feasibility. In particular, the successful Pendine full-scale impact trials have proved impact survivability for many of the key technology items, and a penetrator system study has greatly improved the definition of descent systems, detailed penetrator designs, and required resources. LunarNet is hereby proposed as an exciting stand-alone mission, though is also well suited in whole or in-part to contribute to the jigsaw of upcoming lunar missions, including that of a significant element to the ILN (International Lunar Network).

Some forms of aquaculture cause significant impact on the natural environment and hence there is considered to be a need to control aquaculture developments. One approach would be to predict the impact prior to development and relate the predictions to predetermined standards. Predicting the otential for eutrophication requires the quantification of the amount of soluble waste being released from fish farms; use of numerical models to predict eutrophication in terms of enhanced phytoplankton biomass; establishment of environmental quality objectives and standards. This paper discusses the second and third requirements. Predictive models ranging from empirical relationships between variables to complex ecosystem models have been developed for managing eutrophication of lakes and coastal waters. The use of different types of model are discussed in the context of aquaculture development and it is concluded that empirical models should be used by regulatory authorities as a screening tool to provide a quantitative prediction of the potential for eutrophication. The establishment of environmental quality objectives and standards should be an integral part of any framework plan for aquaculture development. It is suggested that chlorophyll, rather than dissolved nutrients is a more appropriate variable to use as a standard for eutrophication associated with the growth of phytoplanton. It is concluded that there is a requirement for scientifically based values of standards to be set for coastal waters

Phytoplankton are free-floating plants found in marine and freshwaters that through their photosynthetic growth form the base of the aquatic food chain. A small subset of the phytoplankton may be harmful to human health or to human use of the ecosystem. The species that cause harm are now widely referred to as ‘Harmful Algae’ with the term ‘Harmful Algal Bloom’ (HAB) commonly being used to describe their occurrence and effects. In terms of human health, the most important consequence is the production, by some species, of biotoxins. Typically, biotoxin-producing phytoplankton species exist at relatively low densities (c. few hundred or thousand of cells per litre) with the toxins becoming concentrated in the flesh of organisms (particularly bivalve molluscs) that filter feed on phytoplankton. In most cases, there are no adverse effects to these primary consumers, but this concentrating mechanism creates a risk to health if the shellfish are consumed by humans. In this review, we provide an overview of the mechanisms through which marine phytoplankton may cause harm to humans in terms of heath, and the negative effects on the use of ecosystem services. Subsequently, we consider HAB issues in the area we are most familiar with: UK coastal waters. Finally, the methodologies used to safeguard human health from HAB-generated syndromes are discussed.

About the book: This invaluable volume set of Advances in Geosciences continues the excellent tradition of the Asia-Oceania scientific community in providing the most up-to-date research results on a wide range of geosciences and environmental science. The information is vital to the understanding of the effects of climate change, extreme weathers on the most populated regions and fastest moving economies in the world. Besides, these volumes also highlight original papers from many prestigious research institutions which are doing cutting edge study in atmospheric physics, hydrological science and water resource, ocean science and coastal study, planetary exploration and solar system science, seismology, tsunamis, upper atmospheric physics and space science.

The Europa-Jupiter System Mission (EJSM) is a joint ESA/NASA mission under study, within which there will be orbital platforms targeted to both Europa (JEO) and Ganymede (JGO) [1]. We describe here a ?Thermogravimetry/biosensor system designed to measure volatile (water/organics) compounds and detect possible biosignatures from Europa and Ganymede surface or subsurface. The instrument is studied in the framework of the Penetrator Surface Elements proposed to EJSM.

The distribution of plankton in relation to physical oceanographic features on the southern Malin Shelf and in the North Channel of the Irish Sea was investigated during August 1996. The near surface 13.5 degrees C isotherm and 35.20 isohaline marked the location of the Islay and Irish coastal fronts, respectively. An additional salinity front was observed to the south-east of Islay. A mergence of the Irish coastal front and the salinity component of the Islay front suggested that, at certain times, a frontal boundary separating coastal and oceanic water may extend from south-west Ireland north along the western Scottish Shelf. The presence of highly saline (>35.35) water on the outer shelf indicated the intrusion of Atlantic water. The frontal boundaries influenced the distribution of plankton on the southern Malin Shelf and in the North Channel. The outer shelf region was characterized by the presence of Chaetoceros atlanticus, Gonyaulax polygramma, Oxytoxum scolopax, Doliolum gegenbauri, Sagitta tasmanica, and S. maxima. Halosphaera minor and Limacina retroversa were distributed between the shelf edge and the Irish coastal and Islay fronts. Gyrodinium aureolum dominated the phytoplankton of the Islay front but in contrast, Ceratium longipes was restricted to the east of the Islay Front. The distinct spatial separation of species suggested that there was no exchange of southern Malin Shelf and North Channel water at the time of the study.

An electron analyser to measure the three-dimensional velocity distribution of electrons in the energy range from 0.59 eV to 26.4 keV on the four spacecraft of the Cluster mission is described. The instrument consists of two sensors with hemispherical electrostatic energy analysers with a position-sensitive microchannel plate detectors placed to view radially on opposite sides of the spacecraft. The intrinsic energy resolutions of the two sensors are 12.7% and 16.5% full width at half maximum. Their angular resolutions are 2.8° and 5.3° respectively in an azimuthal direction and 15° in a polar direction. The two sensors will normally measure in different overlapping energy ranges and will scan the distribution in half a spacecraft rotation or 2 s in the overlapped range. While this is the fastest time resolution for complete distributions, partial distributions can be recorded in as little as 62.5 ms and angular distributions at a fixed energy in 7.8 ms. The dynamic range of the instrument is sufficient to provide accurate measurements of the main known populations from the tail lobe to the plasmasheet and the solar wind. While the basic structure of the instrument is conventional, special attention has been paid in the design to improving the precision of the instrument so that a relative accuracy of the order of 1 % could be attained in flight in order to measure the gradients between the four spacecraft accurately; to decreasing the minimum energy covered by this technique from 10 eV down to 1 eV; and to providing good three dimensional distributions.

A chromatographic/fluorcmetric method was used to measure changes in the proportions of four planktonic dihydroporphyrin pigments during the spring bloom of 1979 in two f jordic sea-lochs, Creran and Etive, on the west coast of Scotland. Very little pheophytin a was detected during the bloom. Chlorophyll a, and to a lesser extent chlorophyllide a, were the two main pigments found during the bloom. During senescence the main pigment breakdown route appeared to be via chlorophyllide a to pheophorbide a. These results suggest that standard methods for measurement of ‘chlorophyll’ which do not distinguish between chlorophyll a and chlorophyllide a might significantly over-estimate the photosynthetic potential of phytoplankton.

SynopsisLochs Fyne and Striven are deep-silled fjords opening into the northern Firth of Clyde. They receive relatively little freshwater from local runoff, have a relatively low rate of tidal exchange, and undergo periods of deep water stagnation. Both contain fish farms which have lost stock because of phytoplankton blooms. Loch Striven was investigated in detail in 1980. Observations are also reported for 1979 and 1981, and for Loch Fyne from 1980–1982. Most stratification in Striven is due to salinity layering, but most of the freshwater in the loch probably originates in the Clyde Estuary and is associated with high concentrations of nitrate. Typical phytoplankton biomasses in Striven are the same as those in the western seaboard Loch Creran, but maxima exceed those in Creran. In addition to a red tide of Gyrodinium aureolum in September, 1980, three periods of high biomass seem to be a regular feature of the phytoplankton calendar in Striven. The spring increase takes place in March or early April, is dominated by the diatom Skeletonema costalum, and probably depends on the stabilizing effects of reduced near-surface salinities. A summer flourishing of Leptocylindrus danicus and dinoflagellates is also associated with near-surface salinity layering. A late spring bloom of diatoms, dinoflagellates and small flagellates, some ichthyotoxic, appears to be related to the occurrence of thermohaline stratification and near-surface nutrient depletion; on some occasions lochhead upwelling may also have been involved. Insofar as data are available, the ecology of phytoplankton in Loch Fyne appears similar to that in Loch Striven.

The hydrography and phytoplankton ecology of Loch Ardbhair, a small sea-loch on the northwestern coast of Scotland, was studied between January 1981 and July 1982. Tidal exchange was the dominant hydrographie feature of the loch and the exchange time was estimated to be between 1 and 2 days. In 1981 seasonal changes in phytoplankton biomass and species succession were similar to other sea-lochs, although the spring peak, and summer levels of, phytoplankton biomass (3.0 and 1.0 mg chlorophyll · m−3 respectively) were lower than might have been predicted from winter levels of nitrate. Chlorophyll levels in Ardbhair were much higher in July 1982 (up to 3.5 mg · m−3) compared to July 1981 (0.7 mg · m−3) and the phytoplankton was dominated by dinoflagellates rather than microflagellates and diatoms. It is suggested that rapid exchange limits in situ growth of phytoplankton in Ardbhair and that phytoplankton biomass and species composition in Ardbhair closely resembles that of Eddrachillis Bay with which the loch exchanges. The importance of these results concerning the risk, to loch-based fish farms, from ichthyotoxic blooms is discussed.

14 souches de Nannochloris. Les besoins nutritifs, la forme et les dimensions sont d'importants moyens de discrimination de ces organismes dans la nature

This instrument measures the three-dimensional (3-D) distribution function of positive ions at the UKS. Novel electrostatic analyzers using 2600 turning angle cover all viewing angles as the spacecraft rotates. The instrument has sufficient resolution to measure the solar wind as well as giving full 3-D coverage within a spin period. The operation of the experiment and organization of the data are synchronized to the spacecraft spin. A sample of the real-time data showing magnetospheric boundary crossings is presented.

The distributions of water column stratification, phytoplankton and nutrients were investigated in the Sound of Jura, Scotland, during July 1982 and June–July 1983. The amount of stratification was mainly related to variation in tidal currents and bathymetry along the length of the Sound. Frontal zones separated the well-mixed northern Sound, and lateral regions, from thermally stratified water in the middle of the Sound. In the south transitionally stratified water extended into the North Channel of the Irish Sea. The phytoplankton in well-mixed regions was dominated by diatoms, whereas naked dinoflagellates and microflagellates were important in stratified regions. The distribution of phytoplankton biomass, indicated by chlorophyll concentration averaged over the water column, is explained by the effects of vertical mixing on the average illumination experienced by phytoplankton and by the supply of nutrients to the euphotic zone. Highest mean water column chlorophyll was found near Islay, perhaps due to special local input of nutrients into the euphotic zone there. Biomass was also high in the southern region of transitional stratification. The northern and lateral fronts were not clearly associated with high phytoplankton biomass, perhaps because of the small size of the features in relation to the advective field. Phytoplankton biomass was generally low in well-mixed waters, and at the surface in well-stratified regions. It is suggested that transitional stratification may enhance productivity in the southern region to two to three times that in the well stratified and mixed regions of the Sound. The variations in stratification along the Sound may have important implications for primary productivity in the lochs that exchange with it.

In this article we examine the factors which affect the determination of the plasma bulk parameters in space, with particular emphasis on the density determination. We make this assessment with reference to a particular instrument, the AMPTE‐UKS ion instrument, in order to be specific, but the issues raised here are likely to be encountered in the use of any space plasma instrument containing electrostatic energy analyzers or microchannel plate detectors. We have established a mathematical formalism for determining these parameters by relating the measured counts to the distribution function in terms of the geometric factor. The geometric factor is determined in the calibration of the instrument which is described in some detail. Among the factors we have considered are our calibration techniques, MCP efficiency, detector energy, and angular resolution, as well as the approximations used in our mathematical formalism. To establish confidence in our determination, we used a computer simulation to look for ...

Relatively little is known about dissolved organic nitrogen (DON) in the marine environment because research has historically focused on dissolved inorganic nitrogen (DIN). In this study we combine measurements of dissolved organic matter (DOM), DIN, particulate organic nitrogen (PON), dissolved inorganic phosphorus (DIP) and silicon (DIS), with temperature and salinity data from the western shelf region of the UK and Ireland, and with inorganic and organic nitrogen (N) data from the western Irish Sea to develop an understanding of N dynamics in the Irish Sea and adjacent shelf waters, and investigate the role of DON in the nitrogen budget of the seasonally stratifying western Irish Sea. In January 2013, the sampling area was divided by density fronts into 4 regions of distinct oceanography and homogeneous chemistry. DON concentrations accounted for 25.3 ± 1.8% of total dissolved N (TDN) across all regions. DOM concentrations generally decreased from the freshwater influenced water of Liverpool Bay to the oceanic waters of the Celtic Sea and Malin Shelf. Urea and dissolved free amino acids (DFAA) together made up 27.3 ± 3.1% of DON. Estimated concentrations in the rivers discharging into Liverpool Bay were 8.0 and 2.1 μmol N L −1 respectively: at the high end of reported riverine concentrations. Oceanic nutrient inputs to the Irish Sea only have a small influence on N concentrations. Riverine N inputs to the Irish Sea are substantial but are likely removed by natural N cycling processes. In the western Irish Sea, DON and PON concentrations reached maxima and minima in midsummer and early spring respectively. DIN followed the opposite trend. DON accounted for 38% of the yearly internal N cycling and we estimated that as much as 1.4 ± 1.2 μmol N L −1 of labile DON was available as an N source at the start of the spring bloom. Our study supports the view that DON plays an important role in N cycling in temperate shelf and coastal seas and should be included more often in biogeochemical measurements if we are to have a complete understanding of N dynamics in a changing world.

A simple method to estimate cardiac size from single frontal plane chest roentgenograms has been described. Pre- and postflight chest X-rays from Apollo 17, and Skylab 2 and 3 have been analyzed for changes in the cardiac silhouette size. The data obtained from the computed cardiothoracic areal ratios compared well with the clinical cardiothoracic diametral ratios (r = .86). Though an overall postflight decrease in cardiac size is evident, the mean difference was not statistically significant (n = 8). The individual decreases in the cardiac silhouette size postflight are thought to be due to decrements in intracardiac chamber volumes rather than in myocardial muscle mass.

Enlarged labia minora can be bothersome for functional, aesthetic, and social reasons. Reassurance that variation in size is normal is often all that is needed. However, there are women with legitimate complaints that make surgical reduction acceptable and necessary. Surgical intervention should not be ignored because of other debilitating medical problems. One such unusual case is presented here.