Nuclear Wastes in the Arctic Ocean. the Consequences of Past Dumping and Opportunities for Future Prevention

The view is expressed that the assessment of disposal of nuclear waste in the ocean (specifically the Arctic and Kara Seas) is critical to understanding Arctic pollution. Much needs to be done in deciding what we should do, even though many wastes are long-standing and persistent. in 1993, disclosures about Russian dumping of submarine nuclear reactors, nuclear fuel, and other radioactive wastes into the Arctic Ocean brought this region and its problems into the world spotlight and raised public concerns about the resulting health and environmental risks. As a result of this concern, the Congressional Office of Technology Assessment published a 1995 study, Nuclear Wastes in the Arctic (US Congress Office of Technology Assessment, 1995). This paper summarises and updates that study.     

Resource-associated divergence in the arctic marine amphipod<Emphasis Type="Italic"> Paramphithoe hystrix</Emphasis>

Host specialization has played an important role in the speciation of groups such as herbivorous insects and parasitic invertebrates. In this study, we provide evidence for its role in the diversification of the amphipod Paramphithoe hystrix Ross 1835 in Arctic marine waters. This species lives and feeds on the tissues of varied invertebrate hosts that are much larger than itself, including poriferans, hydrozoans and echinoderms, acting as a 'micropredator'. We examined the genetic structure of P. hystrix at sites in the Canadian Arctic where it is represented by a white form found on the light-coloured sea star Solaster endeca, a red form on the pink soft coral Gersemia rubriformis and by a spotted form with an unidentified host. These phenotypes occur in microallopatry, sometimes occupying alternate hosts just a few metres apart. Although their variation in host associates might have arisen from ingested host tissue, our results indicate that these morphs are genetically distinct. Mitochondrial (cytochrome c oxidase I) and nuclear (28S ribosomal RNA) gene sequences, as well as allozyme data all show strong genetic divergence between the three colour morphs, demonstrating their reproductive isolation. These results suggest that P. hystrix is a complex of at least three species, which may have arisen as a result of disruptive selection following host switches. Moreover, the depths of genetic divergence indicate that diversification of this complex was complete prior to the Pleistocene.Communicated by R.J. Thompson, St. John's     

The ties that bind: Inter-clonal cooperation may help a fragile coral dominate shallow high-energy reefs

In Belize, shallow fore-reef buttresses are dominated byAgaricia tenuifolia Dana. The ecological importance of this fragile coral in such a high-energy environment may be explained in part by an unusual cooperative interaction between adjacent clones ofA. tenuifolia. The shallow buttresses are often composed primarily of many clones ofA. tenuifolia growing in close proximity. Surveys conducted at Carrie Bow Cay, Belize, in 1986 and 1987 showed that intraspecific contacts between different clones are common and occur far more frequently than interspecific encounters with other sessile taxa. In contrast to many other corals, contacts between non-clonemates ofA. tenuifolia do not result in competitive interactions, tissue bleaching or death, or significantly altered patterns of colony growth. Instead, inter-clonal contact stimulates localized morphological changes in the skeletons of both corals directly beneath the contact interface, which tend to anchor the two corals against each other, making them more resistant to breakage and detachment. By mechanically stabilizing clusters of otherwise fragile corals, these cooperative interactions potentially enhance the long-term survivorship and hence the fitness of interactingA. tenuifolia clones.The views expressed here are those of the author and do not necessarily reflect those of the Office of Technology Assessment     

Temperature effects on accumulation and retention of radionuclides in the sea star,Asterias forbesi: implications for contaminated northern waters

Radioactive waste disposal and nuclear testing concentrated in high latitudes in the northern hemisphere have resulted in the accumulation of radionuclides in Arctic marine ecosystems, but little is known of the consequences for marine biota in these waters. Under controlled laboratory conditions in May through September 1994, we examined the bioaccumulation in sea stars, Asterias forbesi (Desor), or the radionuclides ²⁴¹Am, ⁵⁷Co and ¹³⁷Cs, all of which are important components of disposed radioactive wastes. Experiments at 2 and 12°C determined the relative importance of food (the bivalve, Macoma balthica) and water as sources of radionuclides and assessed the influence of temperature on radionuclide influx and efflux rates. The lower temperature greatly increased the retention of radionuclides ingested with food; for instance, the biological half-life (tb _1/2) of ²⁴¹Am in the sea stars was 31 d at 12°C, but was virtually infinite at 2°C. Retention of ingested ⁵⁷Co was also increased at 2°C (tb _1/2=41 d). ¹³⁷Cs was not accumulated from food. Low temperature significantly reduced net influx rates of ¹³⁷Cs from water, but did not affect net uptake of ²⁴¹Am or ⁵⁷Co. Temperature had little effect on the retention of all three isotopes obtained from the dissolved phase. These experiments suggest that extrapolation of results of previous radioecological studies, conducted at warmer temperatures, to polar or temperate winter environments may be problematic, and that nuclear waste isotopes obtained through trophic transfer may be retained far more efficiently in high latitude marine biota than by fauna from warmer ecosystems.     

Effect of poultry,cattle, sheep manures and sewage sludge on N mineralisation

The effects of various organic wastes on nitrogen mineralisation in soil were investigated. For this purpose, poultry (pl), cattle (ct), sheep (sh) manures and sewage sludge were used as organic wastes. This study was conducted as a laboratory incubation experiment with a calcareous soil. Organic wastes (3%) were added to pots of soil and incubated at 28°C for 16 weeks under non-leaching conditions. The cumulative mineralised N was then fitted to a single exponential model. Maximum nitrogen mineralisation was determined in the second week of incubation in soil treated with poultry manure. Overall, the results showed that the amount of mineral nitrogen in soil treated with different organic wastes was controlled by the type of manure. The results indicated that among the organic wastes, sewage sludge induced the highest quantities of net N mineralisation. Generally, organic wastes increased the amount of N mineralisation in the studied soil and the values of N₀ and k in treated soil varied depending on the type of organic waste. The highest N₀ and k values were found in poultry-treated soil.     

Flexible incubation rhythm in northern fulmars: a comparison between oceanographic zones

Variation in the timing and abundance of marine food resources is known to affect the breeding behaviour of many seabirds, constraining our understanding of the extent to which these behaviours vary in different parts of a species’ range. We studied incubation shifts of northern fulmars (Fulmarus glacialis) breeding at two colonies in Arctic Canada (High Arctic oceanographic zone) and one colony in the UK (Boreal oceanographic zone) between 2001 and 2005. Fulmars in Arctic Canada had longer incubation shifts than previously reported at more southern colonies, presumably because marine productivity is lower early in the breeding season in the Arctic. Shift durations were particularly long at one colony in years with abnormally late, extensive sea-ice cover, although at the other Arctic colony, where sea-ice cover is predictably late every year, the duration of shifts was shorter than expected. At the Boreal colony, incubation shifts were much longer than expected, similar to Arctic colonies, and likely attributable to poor marine food supplies in the North Sea in recent years. Collectively, our data suggest that fulmars can adjust their incubation rhythm to compensate for poor marine feeding conditions, although this may incur a cost to body condition or reproductive success.     

Die Organisation der Früherkennung von Umweltproblemen im Rahmen der wissenschaftlichen Beratung der Umweltpolitik

This study is based on the theses that

1. early diagnosis is indispensable for the management of environmental problems in the context of precautionary policy, which have the character of a “creeping disaster” and that
2. the public must play the active role that is adequate within a democratic society.

In the context of the study, three existing advisory committees for environmental policy as well as two concepts which have not been put into effect are investigated. In the second part of the study the concepts and the working method of the three existing advisory committees are portrayed: the Council of Experts for Environmental Questions (SRU), the German Advisory Council on Global Change (WBGU), and the Office of Technology Assessment of the Federal Parliament (TAB). In part I, the concept of the Picht commission from 1972, which has never been implemented in this form was introduced. Part III deals with the critique of these committees and with an alternative concept of early diagnosis which has not yet been put into effect. In part IV, the work of the oldest of the committees, the SRU, is examined with respect to the three most important environmental problems of the last 15 years.     

Molecular level toxicological evaluation of a dental composite implanted in albino rats

Dental composite (DC) resins are synthetic resins which are used as restorative material or adhesives in dentistry. Monomers and other components released into the oral environment from the DC material even after polymerization might affect the surrounding tissues and even the whole body gradually. Biocompatibility of DC has to be stringently evaluated since the fillings are in close contact with mucosa, tooth, and pulp. Common difficulties with various current dental materials include allergies, chemical leakage from the material, and pulpal irritation which are due to the byproducts of chemical reactions during different stages of material hardening. Dental Products Laboratory of Sree Chitra Tirunal Institute for Medical Sciences and Technology developed a new BIS-GMA-based DC. In this study the oxidative stress induced by this DC material in vivo was tested for a period of 1, 4, 8, 26, or 52 weeks in albino rats. Dental materials were implanted intramuscularly into the gluteus muscle and oxidative biomarkers such as lipid peroxidation, 8-oxo-deoxyguanosine (8-OHdG) concentration, and total glutathione content analyzed. Data showed no significant changes in antioxidant defense system and 8-OHdG levels in nuclear DNA of the tissue. Serum biochemical results confirmed that animals were in normal functioning physiological state.     

Mitochondrial cytochrome b variation in sleeper sharks (Squaliformes: Somniosidae)

Sleeper sharks are a poorly studied group of deep-sea sharks. The subgenus, Somniosus, contains three morphologically similar species: S. microcephalus found in the Arctic and North Atlantic; S. pacificus in the North Pacific; and S. antarcticus in the Southern Ocean. These sharks have been reported mainly in temperate to polar waters and occasionally in subtropical locations. They have not been recorded in tropical waters. This study investigates the relationships among the accepted species of Somniosus through analysis of mitochondrial cytochrome b sequence variation. Seventy-five samples were examined from four sampling locations in the North Pacific, Southern Ocean and North Atlantic. Twenty-one haplotypes were found. A minimum spanning parsimony network separated these haplotypes into two divergent clades, an S. microcephalus and an S. pacificus/antarcticus clade, strongly supporting the distinction of S. microcephalus as a separate species from the Pacific sleeper shark species. Analysis of genetic structure within the S. pacificus/antarcticus clade (analysis of molecular variance, allele frequency comparisons, and a nested clade analysis) showed limited or no differences amongst three populations. Further examination of genetic variation at more variable mtDNA and nuclear markers is needed to examine the species status of S. pacificus and S. antarcticus.     

Histology of Sculpin spp. in east Greenland. I. Histological measures

There is inadequate morphological nomenclature and definition of organ pathology when using wild fish in biomonitoring of environmental pollution. The aim of this investigation was to provide a guide that assesses histology of Shorthorn (Myoxocephalus scorpius) and Fourhorn (Myoxocephalus quadricornis) sculpins obtained from a study using these two fish species as bioindicator organisms to evaluate environmental impact attributed to a dumpsite located in East Greenland. Specific histopathological lesions were quantified on the basis of Bernet et al. and all lesions were photomicrographed, evaluated, and placed into specific categories of five reaction patterns. These were circulatory disturbances, regressive changes, progressive alterations, inflammation, and tumors based on anatomical location, type, and severity. This method is postulated to enable an objective assessment of the histological integrity of fish gills and liver; thus, making it possible to compare sculpin pathology and reaction patterns at different locations. Data suggest that this updated histological guide might be used for identification and quantification of histological lesions when applying sculpins in biomonitoring programs in Greenland and other Arctic regions.     

Accomplishments of the NATO/CCMS pilot study on international information exchange on dioxins and related compounds∗

A project promoting the international exchange of information on chlorinated dibenzo‐p‐dioxins and dibenzofurans (CDDs and CDFs) was conducted under the auspices of the Committee on the Challenges of Modern Society (CCMS) of the North Atlantic Treaty Organization (NATO). Initiated in 1985, the Pilot Study on International Information Exchange on Dioxins and Related Compounds was a three‐year effort to improve the state of the art of dioxin research, regulation, and technology by encouraging collaboration among interested countries and organizations. Participating nations included Canada, Denmark, the Federal Republic of Germany, Italy, the Netherlands, Norway, the United Kingdom, and the United States. Numerous activities were accomplished to promote information exchange so that better informed decisions can be made concerning future research activities and resource allocations. Three major areas were addressed: Exposure and Hazard Assessment, Technology Assessment, and Management of Accidents. A total of 15 CCMS reports were published which summarize the achievements of the Pilot Study.     

Benthic ecology of the high arctic deep sea

An analysis is made of 75 quantitative benthic samples collected by Mini-LUBS, and 28 qualitative benthic samples collected with the small biological trawl, from Fletcher's Ice Island, T-3, while it was drifting over the Alpha Cordillera region of the High Arctic Ocean during October, 1969 through February, 1970 and in March, 1972. The depth range was 1000 to 2500 m. Benthic foraminiferans account for about 53%, bivalves for 27%, sponges for 7%, and polychaetes for 5% of the total biomass. Other groups make up the remaining 8%. The weight ratio of macro- to meiofauna is 1:1. Numerically, excluding Foraminifera, polychaetes comprise 42%, nematodes 16%, sponges 11%, and bivalves 8% of the total fauna. The remaining 23% is composed of 13 other taxa. Biomass in the Amerasian Basin at depths of 1000 to 2000 m is extremely low (0.04 g/m); it is comparable to depths of 5000 to 6000 m in the oligotrophic red-clay area of the mid-Pacific Ocean, and is 40 times less than biomass at comparable depths from Antarctica and off Peru. Diversity, as calculated by the Shannon-Weaver method, is low, suggesting that the Arctic ecosystem is young, as reported in earlier studies (Dunbar, 1968; Menzies et al., 1973). Although the H' values are low, no biocoenoses of oligomixity in the deep Arctic are revealed, contrary to previous statements and beliefs. There may be fewer major benthic groups in the Arctic Ocean than in other parts of the world oceans. Following the conventional terminology of Petersen (1913) and Thorson (1957), we have called the High Arctic biocoenoses of the Alpha Cordillera region a Thenea abyssorum-Spirorbis granulatus community.     

Growth and sexual maturity of the northern propellerclam (<Emphasis Type="Italic">Cyrtodaria siliqua</Emphasis>) in Eastern Canada,with bomb radiocarbon age validation

The northern propellerclam Cyrtodaria siliqua is a common bycatch in the Arctic surfclam, Mactromeris polynyma fishery on Banquereau Bank in Eastern Canada. Samples of the propellerclam from this exploited fishery were used to determine the life history characteristics of the population. The age structure of the population is dominated by old animals to ages exceeding 100 years. We validated the age estimates for the propellerclam through analysis of bomb-produced radiocarbon in the shell growth increments deposited before, during and after the atmospheric atomic bomb testing periods of the 1950s and 1960s. Radiocarbon from shells with presumed birth dates between the late 1950s and 1970s clearly reflected the sharp increase in oceanic radiocarbon attributable to previous nuclear testing, indicating that age estimates based on shell increment counts are accurate. Estimates of von Bertalanffy growth parameters revealed that the growth rate of the population was relatively rapid for the first 20 years of life, slowing down to very low growth rates thereafter. Sexual maturity was estimated as being reached at 28.6 mm in length and 4.7 years in age. Size–weight morphometric relationships were also calculated.     

Structural confirmation of the sea ice biomarker IP25 found in Arctic marine sediments

IP₂₅ is a highly branched isoprenoid and an organic geochemical biomarker that is produced by some Arctic sea ice diatoms. IP₂₅ has previously been used in Arctic palaeo sea ice reconstruction studies and as a tracer for studying Arctic food webs. Here, the molecular structure of IP₂₅ has been confirmed by ¹H and ¹³C NMR spectroscopy following large-scale extraction from marine sediments obtained from the Canadian Arctic and purification using a combination of open-column and HPLC chromatographic methods. The structure of IP₂₅ was consistent between the three different sampling locations and was identical to that found previously for this biomarker following synthesis from a closely related highly branched isoprenoid diene. Since this study represents the first structural characterisation of IP₂₅ in sediments, future analysis of sedimentary IP₂₅ for palaeo Arctic sea ice reconstructions can be carried out with much greater confidence.     

Multiple trans-Arctic passages in the red alga Phycodrys rubens: evidence from nuclear rDNA ITS sequences

In order to investigate how episodes of geological and climatic change have influenced the distribution and evolutionary diversification of Arctic to cold temperate-North Atlantic seaweed species, intraspecific genetic variation was analyzed among isolates of the sublittoral, benthic red alga Phycodrys rubens (collected between June 1992 and January 1994). Rooted phylogenetic analyses of nuclear ribosomal DNA internal transcribed spacer (ITS) sequences and the plastid encoded Rubisco spacer sequences suggest that P. rubens invaded the North Atlantic from the Pacific shortly after the opening of the Bering Strait (3 to 3.5 million years ago), colonizing both the western and eastern Atlantic coasts. Based on these data we further hypothesize that P. rubens survived along the European coasts during the more recent Pleistocene glaciations, while becoming locally extinct along the North American Atlantic coasts. Following retraction of the last ice sheet, the western Atlantic coast was colonized a second time from the Pacific. The presence of two distinct genetic types (based on ITS and Rubisco sequences) along the European coasts is postulated to be a result of isolation and subsequent differentiation. This is likely because ice-free areas are known to have existed in northern Scotland and Norway during the last glaciation. The presence of an East Atlantic genetic type along the West Atlantic coast is believed to be a recent introduction (caused by human activity) of P. rubens to Newfoundland.     

Monitoring of soil biochemical quality parameters under greenhouse spinach cultivation through animal waste recycling

Under the intensive agricultural system, direct application of animal slurries to soils can provide a sustainable disposal of these wastes by inducing positive changes in soil quality and fertility. However, how animal wastes quantitatively affect the key nutrients (C, N, P and S) transforming soil enzymes is not clearly known. A greenhouse spinach cultivation study demonstrated that pig slurry, either in raw (RS) or processed (aerobically aged) (PS) form, significantly (p?β-glucosidase (23–39%), urease (59–103%), nitrate reductase (73–103%) and dehydrogenase (27–72%)) and microbial growth in soil as compared to the unamended control. However, it did not significantly (p?>?.05) alter the aryl sulphatase enzyme activity. Slurry applications also significantly improved the macro (N, P and K) and micronutrients (Cu, Mn, Zn and Fe) uptake by spinach plant and hence the yield (2.9–3.38 times higher than control). Similarly, compared to chemical fertilisers the application of pig slurries improved soil biological and biochemical parameters as well as plant nutrients uptake. This study demonstrated the closing of global energy and nutrient cycles through land application of animal wastes without compromising the crop yield.     

Disposal of Mine Wastes Containing Pb and Zn Near the Ocean: An Assessment of Associated Environmental Implications in the Arctic

The past two decades have witnessed an increase in the exploration for, and development of, mineral resources at Arctic latitudes. Such effort has resulted in the commencement of production at a number of different localities in close proximity to the ocean. Since proximity to a source of transportation for the conveyance of concentrates to the market is a primary requirement governing the economic decisions for the mine to proceed, it is logical that ore deposits near a coastline are primary targets for development.

Closely tied to coastal mining developments is the need to dispose of tailings and waste rock in the most economical manner. Prior to the advent of heightened public awareness and environmental concern, and the enactment of pollution legislation, disposal practices were largely based upon convenience. Currently, however, proposed disposal and operating practices receive closer scrutiny, with a view to providing adequate protection for aquatic resources and habitat. This paper summarizes some of the features of three Arctic mines, wastes from which enter the marine environment, and compares the disposal practices used at each to measures of environmental change as indicated by metal concentrations in various media.     

Assessment of the impacts of municipal solid waste dumps on soils and plants

The study aimed at evaluating the impacts of open municipal solid wastes dumps on soil and vegetation near the main roads linking major cities in Nigeria. We hypothesised that the metals from the wastes exerted substantial impacts at the dump sites which affect the soil and plants. Data were analysed from five dump sites and five control sites. The result revealed that the effects of the heavy metals (HM) were significant and higher at the dump sites where their concentrations were far above the EU, and Canadian environmental quality permissible limits for agricultural soils and vegetation. In contrast with dump sites, a significant relationship (R²?=?0.70; p??Cr?>?Pb at both dump sites and control sites. Further study on the effects of more HM on soil and plant is recommended in the area. Recycling and bio-phytoremediation processes should also be introduced.     

Bioremediation of toxic metals mercury and cesium using three types of biosorbent: bacterial exopolymer,gall nut,and oak fruit particles

Cesium and mercury are two mono-valent elements which can be found in toxic industrial, medical, and nuclear wastes. Their presence in the environment has deleterious effects on the ecosystem, living organisms including humans. Due to the chemical nature of these metals, bioremediation by conventional methods is more difficult to achieve compared to other metals. In this study, we used three biosorbents (oak powder, gall nut, and bacterial exopolymer) for the bioremediation of Hg and Cs. Bio-polymer was produced in the GMS mineral broth. Synthetic wastes of Hg(NO₃)₂ and isotope Cs-133 as the single-metal solutions were used. The biorefining process was carried out in glass columns, made of Pyrex, with dimensions 20?×?7/2?cm² with a V-shaped bottom. The samples were analyzed using atomic absorption. The experimental results showed that eliminated metal percent by oak powder, gall nut, and bacterial exopolymer were, respectively, of 94.8%, 96%, and 13.8% for Hg and 7.8%, 4.4%, and 69.4% for Cs. The tests revealed that Ca⁺⁺, when used as flocculant, played a key role in both biosorption and bio-precipitation rates. Consequently, it was concluded that the investigated biosorbents could be use as an integrated biosorption system for the refinement of mixed wastes.     

<Emphasis Type="Italic">Sympagohydra tuuli</Emphasis> (Cnidaria,Hydrozoa): first report from sea ice of the central Arctic Ocean and insights into histology,reproduction and locomotion

Various cnidarians have adapted their life style to interstitial habitats of marine sediments. Recently, for the first time a hydroid was reported from the interstitial brine channel system of Arctic fast ice. Due to its derived features, the new genus and species Sympagohydra tuuli was introduced. Here we describe findings of S. tuuli in sea ice at several sites within the central Arctic Ocean. In our view the results of this study do not allow assignment of Sympagohydra to any known family and we, therefore, suggest the introduction of a new family Sympagohydridae which is placed within the hydrozoan subclass Hydroidolina, order Anthomedusae, suborder Capitata. A first detailed histological analysis of S. tuuli is presented. In vivo analysis of locomotion and reproduction revealed a remarkable convergent evolution in S. tuuli and distant meiobenthic relatives. Shared traits are a flagellated epidermis enabling the animals to glide within small interstices by means of flagellar beating as well as an internalised embryogenesis. In S. tuuli gametogenesis occurs in the absence of gonophores inbetween gastro- and epidermis clearly separated from the epidermis. Budding was observed as the vegetative mode of reproduction. Documentation of feeding behaviour identified copepod nauplii and rotifers as prey items and demonstrates a high trophical position of the hydroids within the sympagic food web. Occurrence of reproducing individuals and pronounced tolerances towards changing temperatures and salinities indicate S. tuuli as a truly sympagic species. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.