Book Reviews

Subfossil remains of various groups of organisms preserved in peat and sediment archives are commonly used to infer past environmental changes using transfer functions based on species composition. However, the changes in community structure can also be explored using the functional trait approach. Investigation of functional traits in palaeoecological records can inform about the mechanisms through which abiotic variables such as temperature or moisture impact communities. Moreover, changes in functional traits provide information about changes in ecosystem functioning and can potentially lead to the reconstruction of past processes at the ecosystem scale. Here, we use five key functional traits of arcellinid testate amoebae (TAs), a group of protozoa that are key actors in the microbial foodwebs in peatlands. We apply this approach to the subfossil TA Holocene record of four geographically independent peatlands from Alaska, Switzerland, Poland and Russia. We found that species with larger shells were frequently eliminated from the communities most likely as a result of a switch towards drier conditions. However, when conditions were wetter, species with large shells and species with small shells could coexist because they differed in their trophic niche (i.e. preys). Our results show direct but site-specific links between TA trait data and the depth to water table and pH data inferred from TA species composition. This suggests that past environmental changes influenced both species composition and community function in these ecosystems. Overall, this study demonstrates that species- and trait-based approaches yield complementary information on past environmental changes. For instance, while taxonomic approaches reveal the changes in community composition over time, investigation of traits informs both on the causes and the consequences of these changes on ecosystem functioning.

A short analysis of all 111 atmospheric events conducted at the Semipalatinsk Test Site (STS) in 1949-1962 with regard to significant off-site exposure (more than 5 mSv of the effective dose during the first year after the explosion) has been made. The analytical method used to assess external exposure to the residents living in settlements near the STS is described. This method makes use of the archival data on the radiological conditions, including the measurements of exposure rate. Special attention was given to the residents of Dolon and Kanonerka villages exposed mainly as a result of the first test, detonated on August 29, 1949. For the residents of those settlements born in 1935, the dose estimates calculated according to the analytical method, are compared to those derived from the thermoluminescence measurements in bricks and electron paramagnetic resonance measurements in teeth. The methods described in this paper were used for external dose assessment for the cohort members at an initial stage of an ongoing epidemiological study conducted by the U.S. National Cancer Institute in the Republic of Kazakhstan. Recently revised methods and estimates of external exposure for that cohort are given in another paper (Simon et al.) in this conference.

Mired in the past — looking to the future: Geochemistry of peat and the analysis of past environmental changes

Nuclear and isotopic techniques are valuable tools in assessing the levels of environmental pollution by toxic elements and for studying how these contaminants affect human health. More than 90 counterparts from 55 countries around the world have participated in projects on these topics, supported by the International Atomic Energy Agency (IAEA), during last ten years. With the support of the IAEA, for example, an appropriate metrology for compositional characterization of size fractionated airborne particulate matter was developed, verified and implemented in more than 40 countries. This paper reviews the development and application of environmental metrology tools involving nuclear analytical and isotopic techniques, as seen from the particular perspective of IAEA programmes.

We investigated the evolutionary history of the striped field mouse to identify factors that initiated its past demographic changes and to shed light on the causes of its current genetic structure and trans-Eurasian distribution. We sequenced mitochondrial cyt b from 184 individuals, obtained from 35 sites in central Europe and eastern Mongolia. We compared genetic analyses with previously published historical distribution models and data on environmental and climatic changes. The past demographic changes displayed similar population trends in the case of recently expanded clades C1 and C3, with the glacial (MIS 3–4) expansion and postglacial bottleneck preceding the recent expansion initiated in the late Holocene and were related to environmental changes during the upper Pleistocene and Holocene. The past demographic trends of the eastern Asian clade C3 were correlated with changes in sea level and the formation of new land bridges formed by the exposed sea shelf during the glaciations. These data were supported by reconstructed historical distribution models. The results of our genetic analyses, supported by the reconstruction of the historical spatial distributions of the distinct clades, confirm that over time the local populations mixed as a consequence of environmental and climatic changes resulting from cyclical glaciation and the interglacial period during the Pleistocene.

Introduction In July 2023, the International Atomic Energy Agency (IAEA) issued a final report on its review of the ocean dumping plan for contaminated water from the Fukushima Daiich Nuclear Power Plant in Japan. According to the report, the IAEA did not verify the ocean dumping plan proposed by the Japanese government; instead, the IAEA reviewed whether the Japanese government’s explanation of its policy met the expression of international safety standards. Specifically, despite the Japanese government’s selection plan based on indirect circumstantial evidence, the IAEA did not provide its own perspective on the list of possible nuclides to be identified in the waste. Methods This is internally inconsistent with the IAEA’s own principle for selection, and contradicts its previous position of verifying the principle in advance. Moreover, it is worrying that the IAEA acknowledges the Japanese government’s approach to evaluating the post-dilution situation without considering the existing risks from the 2011 contamination. Results This approach views post-dilution dumping as a planned exposure and ignores possible increases in existing risks due to even minor additional events, such as sudden changes in the ecosystem. Discussion In addition, the uncertainties resulting from environmental changes, such as the climate crisis and variations in ocean currents and biota migration, have not been taken into account.These uncertainties and others, especially the non-target effects of prolonged, long-term exposure, should have been evaluated. Conclusion It is crucial to recognize that safety is a comprehensive concept and cannot be assessed by matching individual criteria one by one.

Radioactive waste and ocean dumping: The role of the IAEA

Application of radiotracers to studies of environmental pollution source and distribution is rather widespread. This is partly due to encouragement by the International Atomic Energy Agency (IAEA), which through its various symposia, e.g., on radiological techniques in pesticide research (IAEA, 1966a, 1970c) and also on other environmental pollutants (IAEA, 1975a, 1976), has disseminated knowledge on the subject. Perhaps the most extensive use has been in the study of pesticides (Dedek, 1967a,b, 1970, 1975; Casida, 1961; Dahm, 1957; Redemann and Meikle, 1958; Winteringham, 1960; Peterle, 1966; and documented in the bibliographies of Bingelli, 1963, 1965, 1967, 1969). Citing 110 references, DeWitt (1978) summarizes the application of isotopes in investigations of air, soil, and water pollution and concludes: Based on established isotope uses, on the projected increase in the pollution problem, and on the apparent social and economic pressure for pollution abatement, a significant demand for enriched isotopes appears to be developing for the assessment and control of air, water, and soil pollutants. Isotopic techniques will be used in combination with conventional methods of detection and measurement, such as gas chromatography, x-ray fluorescence, and atomic absorption. Recent advances in economical isotope separation methods, instrumentation, and methodology promise to place isotopic technology within the reach of most research and industrial institutions. Increased application of isotope techniques appears most likely to occur in areas where data are needed to characterize the movement, behavior, and fate of pollutants in the environment.

Nitrogen (N) is a central component of all organisms, making it a key element in the production of organic matter in lakes. However, excessive bioavailable N originating from waste water or fertilizer input can exacerbate eutrophication, reduce oxygen levels, and promote the growth of toxic algal blooms. Understanding the sources, sinks, and internal cycling of N in lacustrine environments, both today and in the past, is crucial for providing paleolimnological information that can be related to past environmental changes. Traditionally, past changes in the lacustrine N cycle have been reconstructed using bulk sedimentary N isotope (δ15N) analyses. While this approach is relatively inexpensive and fast, it is widely known that bulk sediment δ15N values can be biased by diagenetic alteration and external organic and inorganic (e.g., clay-bound) N input. Here, we introduce a proxy that is relatively new to limnogeology, overcomes these issues, and has successfully been applied in paleoceanographic reconstructions for over two decades: diatom-bound nitrogen isotope ratios. The siliceous shells (called frustules) of diatoms contain small amounts of organic matter, whose nitrogen isotope composition is thought to be protected from diagenetic alteration and bacterial degradation. Previous studies have shown that the diatom-bound N isotopic composition correlates with the N isotopic composition of nitrate in the surface waters, which the diatoms assimilated during growth. Since the N isotopic composition of surface-water nitrate directly depends on N inputs/outputs (i.e., size of N fluxes and their respective δ15N), as well as internal N cycling processes, which all have a distinct impact on the N isotopic signature, diatom-bound δ15N can be used to infer past changes in the lacustrine N cycle.Here, we present the first lacustrine application of the diatom-bound N isotope paleo-proxy, reconstructing nutrient cycling and paleoenvironmental conditions over the past centuries in Swiss lakes. In Lake Lugano (Switzerland), for example, we demonstrated that denitrification and N2 fixation were tightly coupled during the peak eutrophication period, and that changing redox conditions in the sediment influenced the extent of N-isotopic alteration of the bulk sediment (Studer et al., 2024). Furthermore, we will present our team's recent efforts to further ground-truth the diatom-bound N isotope proxy, including (i) data from natural lacustrine environments that provide insights into the acquisition of the diatom-bound N isotope signature during diatom growth, and (ii) data from degradation experiments under controlled laboratory conditions that address the resilience of the diatom-bound N isotope signature against early diagenetic alteration. ReferencesStuder, A.S., Wörmer, L., Vogel, H., Dubois, N., Hinrichs, K.-U., Bartosiewicz, M., Lepori, F., Lehmann, M.F. 2024. First lacustrine application of the diatom-bound nitrogen isotope paleo-proxy reveals coupling of denitrification and N2 fixation in a hyper-eutrophic lake. Limnology and Oceanography, 69, 1797-1809. https://doi.org/10.1002/lno.12627

In spite of significant progress in the development and calibration of new proxies, major challenges still limit our ability to use these indicators to fully understand past environmental changes. Over the past two decades, both field and laboratory experiments have shed light on the importance of trace metals in controlling –through limitation or toxicity - the growth and composition of phytoplankton communities. Nonetheless, there is still a lack of reliable tools to evaluate trace metals–phytoplankton interactions during past environmental and climatic perturbations. In this work, we evaluated the use of the Zn content of silicate shells (frustules) of fossil diatoms to track past changes in Zn bioavailable concentrations of surface waters. This essential element is delivered to both continental and ocean waters via natural and/or anthropogenic inputs. Our approach combined laboratory and field experiments.

Although quite common in terrestrial environments, population differentiation across contiguous geographical areas due to vicariance processes or geographical barriers are far less frequent in the marine environment. Movements in pelagic species such as cetaceans are potentially unrestricted over vast distances. This raises the question of how populations become genetically differentiated, what factors drive individual dispersal, and how speciation occurs in marine pelagic species. The present thesis aimed to investigate how these processes occur at two different evolutionary scales: within (micro-evolution) and between (macro-evolution) species. Combining phylogenetic, phylogeographic, and population genetic approaches complemented with ecological modelling, this thesis investigates the evolution of a group of small cetaceans: the porpoise family (Phocoenidae). The study of the phylogenetic relationships between porpoises as well as their biogeography showed that the seven extant porpoise species radiated during the last 5 million years in response to past environmental changes. At the more recent evolutionary scale within the harbor and finless porpoise species, I investigated the processes partitioning the genetic variation among populations, ecotypes, or subspecies. Analysis of empirical and simulated genetic data shed light on past changes in population size and connectivity, while suitable habitat modelling provided insights into the environmental context in which these demographic events happened. Results revealed that all within species subdivisions arose during the last million years and were strongly influenced by the environmental changes occurring during the Last Glacial Maximum (~26-19 kilo years). The results of this thesis provide a framework for the management and conservation of porpoises.

<p>With the Arctic currently warming at a rate at least twice that of the global average, the coupled Arctic ecosystem is losing ice. This includes significant land-ice loss from the Greenland Ice Sheet and Arctic ice caps and glaciers, reduction in extent and thickness of Arctic sea ice, and thawing permafrost. This scale of environmental change significantly affects Arctic people, wildlife, infrastructure, transportation, and access. Societal response to these changes relies on advances in and application of research spanning multiple scientific disciplines, with policy-making done in partnership with Indigenous people, governments, private agencies, multinational corporations, and other interested groups. Everyone will interface with outcomes due to a changing climate and the challenge is mounting for the next generation of leaders. The cross-disciplinary nature of the challenge of Arctic ice loss and climate change must be met by cross-disciplinary undergraduate education. While higher education aims for disciplinary training in natural sciences and social sciences, there is an increasing responsibility to integrate topics and immerse students in real-world issues. And, in our experience the undergraduates we teach are eager for courses that can do this well.</p><p>What is immersive undergraduate education? We consider this as either immersing students in a focused topic in the classroom, immersing students in a place (especially while abroad), or combining the two through targeted lectures, informed discussions, travel, and writing. With regard to the Arctic, it is necessary to bring scientific understanding to learning activities otherwise focused on societal impacts, policy making, and knowledge exchange through public writing.</p><p>We share from our practical experience teaching Arctic-focused courses to classes each with 10-30 students with majors from across the University of Washington (UW) campus (total undergraduate student body of 32,000). Three recent activities that integrate the state of science with impacts on society in undergraduate courses include: 1) a four-week study abroad course to Greenland and Denmark focusing on changes in the Greenland Ice Sheet and sea-level rise, 2) a 10-week Task Force course in Arctic Sea Ice and International Policy in partnership with the UW International Policy Institute at the Henry M. Jackson School of International Studies that includes one-week in Ottawa where students develop a mock Arctic sea ice policy for Canada consistent with Inuit priorities, and 3) a 10-week seminar in public writing where students write mock newspaper articles, book reviews, and policy summaries about ice in a changing climate. These courses were designed to include a similar subset of earth science, atmospheric science, and oceanography, but the distinct structure and application of the science in these three separate courses led to distinct learning outcomes. In addition, we present how the academic minor in Arctic Studies at the University of Washington has allowed students to design their own integrated understanding of Indigenous and nation-state Arctic geopolitics, Arctic environmental change, and policy by taking a selection of courses and engaging in research and report writing.</p>

Human-induced climate alteration is impacting ecosystem functioning and services. Ocean acidification and deoxygenation, mass extinction, rising sea level and extreme meteorological events are related to the rise of atmospheric CO2 and the consequent increase in temperature. The rate of environmental change is extremely fast, hampering the biota to adapt to the ongoing new conditions, therefore increasing the potential impact on the ecosystem. The geological record is a powerful tool to investigate past trends in order to better understand the current climate change. The ability of geosciences to reconstruct the whole “evolutionary history” of past extreme events, from their onset to their conclusion and the consequent recovery of the ecosystem is something that must be exploited to increase awareness. As an example, the environmental reconstruction of the main events related to abrupt (natural) emissions of CO2 during Earth history underlines that the current climate change is outstanding in terms of rate of environmental change and impact on ecosystems. Understanding and disclosing these findings is crucial in order to increase the population’s awareness of the current ecosystem threat and therefore, contributing to mitigate the impact. This because, trivially, “people cannot care about something that they do not know”. Anthropogenic pressure mostly derives from governance regime; this can be changed if population consciousness boosts governance actions for climate change mitigation. In this perspective, the geoscience, with its potential to explore and constrain past environmental changes, necessitate to be more considered in the educational career both at school and in the mass media worldwide. Clear examples of how, and how much, the awareness of the population regarding the current climate change plays a fundamental role in stimulating sustainable governance actions derive from the “Youth for climate” movement. Here we propose easily performable, inclusive and proactive educational tools for mitigation strategies to face possible future impacts deriving from the climate evolution, as pointed out in the United Nations 2030 Agenda (Sustainable Development Goal 13: Climate Action). We mainly focus our activities on marine sediments, in order to draw the attention to this widely unknown environment and to show how climate change affects the oceans; this also supports the UN Ocean Decade. In order to assess the knowledge and perception on climate change and ocean life evolution, we will present some data collected among the secondary school students reached by a public engagement project devoted to the dissemination of these subjects.

The most widely accepted international guidelines for protection of the public from ionizing radiation and in circumstances related to intervention strategies to reduce exposures to preexisting conditions, such as those on Rongelap Island, come from the International Commission on Radiological Protection, the National Council on Radiation Protection and the International Atomic Energy Agency. By all internationally agreed scientific criteria, present radiological conditions on Rongelap Island are considered safe for permanent resettlement. Safe implies that no additional cancer deaths are expected among those living on Rongelap Island beyond the number that would occur in a community of the same population size, similar ages and mix of males and females, who do not experience exposure to residual fallout by living on the island. It is expected that the average dose received by Rongelap Island residents will fall well below the dose adopted by the Republic of the Marshall Islands Nuclear Claims Tribunal considered a ''safe'' or acceptable health risk. These conclusions are supported by environmental measurements and assessments performed by the Lawrence Livermore National Laboratory (LLNL) including the results of radiological surveillance of resettlement workers living on Rongelap Island for various lengths of time from 1999 through 2002, and independent studies conducted by Japanese scientists. Atmospheric testing of nuclear weapons was responsible for the widespread dispersion of radioactive fallout around the globe. Rongelap Island received higher levels of fallout from local or close-in fallout deposition from nuclear testing on Bikini Atoll. The main pathway for exposure to radiation from the bomb testing is ''internally'' through ingestion of radioactive cesium (cesium-137) taken up from the soil into locally grown foodstuffs. Resettlement workers living on Rongelap Island who ate local foods have volunteered to have the cesium-137 content of their bodies measured. The measuring device is called a whole body counter. A person relaxes in a chair for a few minutes while counts are taken using a detector a few inches away from the body. The whole body counting program on Rongelap Island was established under a cooperative agreement between the Rongelap Atoll Local Government (RALG), the Republic of the Marshall Islands and the U.S. Department of Energy (DOE). Local technicians from Rongelap continue to operate the facility under supervision of scientists from LLNL. Whole body counting data collected on resettlement workers during the initial phases of resettlement can tell us what exposure level a permanently resettled population could reasonably expect. The average internal dose to resettlement workers from cesium-137 is less than 1 mrem (0.01 mSv) per year. The highest individual dose observed over the last 3-years was less than 4 mrem (0.04 mSv) per year. The RALG-DOE resettlement support plan also calls for spreading potassium fertilizer across the agricultural areas to prevent the uptake of cesium-137 into plants. Fertilization will reduce the dietary intake of cesium-137 and reduce the dose to island residents. By 2004, over 70 percent of the cesium-137 deposition in soil from fallout in 1954 will have decayed to a non-radioactive substance. Over the next 10-20 years, more than one-half of the remaining cesium-137 in the soil and vegetation of the atoll islands will have disappeared by decay or washed out of the soil by rain. Removing some soil, applying crushed coral around living areas, and spreading potassium fertilizer across agricultural areas will reduce the level of radiation exposure in the resettled population to levels below those considered safe by the Nuclear Claims Tribunal and to levels well below those considered safe by the international scientific community.

BackgroundStrong variations are observed between and within taxonomic groups in the age of extant species and these differences can clarify factors that render species more vulnerable to extinction. Understanding the factors that influence the resilience of species is thus a key component of evolutionary biology, but it is also of prime importance in a context of climate change and for conservation in general. We explored the effect of extrinsic and intrinsic factors on the timing of the oldest diversification event in over 600 vertebrate species distributed worldwide. We used phylogenetic comparative methods to show that color polymorphism, latitude and reproduction (the latter through its interaction with latitude) affected the timing of the oldest diversification event within a species.ResultsSpecies from higher latitudes tended to be younger, and colour-polymorphic species were older than monomorphic species. Mode of reproduction was important also, in that the age of oviparous species decreased with latitude, whereas no pattern was apparent for viviparous species. Organisms which have already persisted for a long time may be more likely to deal with future modifications of their environment.ConclusionsSpecies that are colour polymorphic, viviparous, and/or live at low latitudes have exhibited resilience to past environmental changes, and hence may be better able to deal with current climate change.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-016-0646-8) contains supplementary material, which is available to authorized users.