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Scaling experimentally derived effects of CO₂ on marine fauna to population responses is critical for informing management about potential ecological ramifications of ocean acidification. We used an individual-based model of winter flounder to extrapolate laboratory-derived effects of elevated CO₂ assumed for early life stages of fish to long-term population dynamics. An offspring module with detailed hourly to daily representations of spawning, growth, and mortality that incorporates potential elevated CO₂ effects was linked to an annual time-step parent module. We calibrated the model using a 40 yr Reference simulation (1977–2016) that included gradual warming and then performed ‘Retrospective’ simulations that assumed a suite of elevated CO₂ effects by changing fertilization rate, mortality rate of embryos due to developmental malformations, larval growth rate, and size-at-settlement. ‘Recovery’ simulations that started at low population size were then used to further explore possible interactions between the effects of CO₂ and warming on population productivity. Warming had a major negative effect on the simulated winter flounder population abundance, and reduced larval growth had the largest single impact among the CO₂ effects tested. When a combination of the assumed CO₂ effects was imposed together, average annual recruitment and spawning stock biomass were reduced by half. In the Recovery simulations, inclusion of CO₂ effects amplified the progressive decrease in population productivity with warming. Our analysis is speculative and a first step towards addressing the need for extrapolating from laboratory effects of ocean acidification to broader, ecologically relevant scales.

Naval mines are an often unseen engine of war held in the inventories of over fifty countries and a growing number of non-state organizations. Since the Second World War, there have been twenty-four separate naval mining events, with the first of these (the 1946 mining of two Royal Navy warships off the coast of Albania) leading to the International Court of Justice's inaugural case. The only conventional international law currently governing the use of non-nuclear naval mines is the Hague Convention No. VIII of 1907, negotiated to regulate the use of a specific naval weapon built with early twentieth century technology, and used in the circumstances of wars as then fought. Although ratified by only twenty-seven countries, some jurists now transpose this convention to twenty-first century weaponry with global applicability. Through the two specific lenses of belligerent practice as witnessed during armed conflict and state preparations for war, this article examines this transposition of a convention that, by its own text, limits itself to a specific sub-set of naval mines used in wars in which all belligerents are party to the Convention, to the present situation whereby some practitioners of customary international law (CIL) seek to apply its provisions to all types of naval mines in all conflicts. In doing so, this article highlights a divergence of state practice from CIL desire, as well as the potential for contentious application of CIL to constrain nations from using potentially legitimate methods of offence and self-defence.

Population expansions of successful species have gained importance as a major conservation and management concern. The success of these ‘winners’ is widely attributed to their high adaptability and behavioural plasticity, which allow them to efficiently use opportunities provided by human-modified habitats. However, most of these studies consider conspecifics as ecological equivalents, without considering the individual components within populations. This is critical for a better understanding of the main ecological mechanisms related to the success of winning species. Here, we investigated the spatial ecology of the opportunistic yellow-legged gull Larus michahellis, a clear example of a winning species in southern Europe, to examine its degree of individual specialization in habitat use. To test for such individual strategies, we applied specialization metrics to spatial data obtained from 18 yellow-legged gulls that were GPS-tracked simultaneously during the breeding season. The results revealed that population-level generalism in habitat use in the yellow-legged gull arises through varying levels of individual specialization, and individual spatial segregation within each habitat. Importantly, we found that the combination of individual specialization and individual spatial segregation may reduce intra-specific competition, with these 2 important mechanisms driving the success of this winning species.

The rise of China is one of the most consequential events in recent history, with implications for countries around the world and across policy domains. This paper examines the significance of the rise of China for E.U. and U.S. policy and its implications for E.U.-U.S. relations. By focusing on trade, climate change, defence and security, and changes to the international order, we find that the effect of China's rise on E.U.-U.S. relations is determined by the symmetrical or asymmetrical impact on E.U. and U.S. interests respectively. A symmetrical impact in a given policy domain may bring E.U. and U.S. interests to converge towards a common response, whereas an asymmetrical impact raises the difficulty of finding common ground for cooperation with more divergent E.U. and U.S. priorities. Moreover, whether the rise of China brings short-term E.U. and U.S. interests closer together or further apart in various policy domains, it also provides an opportunity for the transatlantic partners to reconcile their differences in light of the long-term systemic adjustments called for by China's rise.

This article examines the power dynamic between central and provincial government in China in the context of the public health crisis COVID-19. Public health institutions and policies in the first four months of the COVID-19 pandemic (January to April 2020) are examined on national and provincial levels. Thirty-one provincial level units including municipalities, provinces and autonomous regions are analysed from Jan 23ʳᵈ, when the nationwide emergency mobilization was enacted, to Apr 27ᵗʰ, when the last schools outside of epicentre Hubei province were reopened. Contrary to conventional wisdom, the study found that the Party's decentralization of decision-making power is flexible and pragmatic. China adopted a strategy of centrally coordinated response in the first weeks, and decentralized decision-making later as the first wave was mitigated. The Communist Party of China was able to centralize power when deemed necessary and was willing to decentralize when deemed helpful. The effective control of power during crises is achieved through cross-ministry institutions including the Central Coronavirus Response Team and the Joint Prevention and Control Mechanism.

China's assertive foreign policy record since the arrival of Xi Jinping to the heights of China's leadership has led many to consider him responsible for distancing China from Deng Xiaoping's cautious \"24-Character Strategy,\" better known as the \"hide and bide\" strategy. This paper contends that this is not the case. Rather, China's foreign policy has been shaped by its perceptions of the international balance of power and the strength of its national capabilities. This may be observed in China's initial adoption of Deng Xiaoping's \"hide and bide\" strategy in accordance with its feeling of vulnerability in the years following the end of the Cold War and the United States' emergence as the world's sole superpower. In consequence, \"hide and bide\" was an impermanent strategy that could be discarded when China's capabilities had grown and the international order was more favourable. Such an opportunity emerged following the 2008 Global Financial Crisis when the United States' position in the world was seemingly in decline. As a result of this event, China's perception of its own position within the international order improved given the tremendous economic growth that it had experienced over the previous three decades. Considering the changes taking place in the post-2008 international order and China's new national capabilities, China felt that it could begin to distance itself from \"hide and bide\" in favour of a more assertive posture in matters it considered of importance, such as its claims in the South and East China Seas, and develop the hard power capabilities needed to support them under the administration of Hu Jintao.

The vertical separation of organic matter formation from respiration can lead to net carbon sequestration within the ocean’s interior, making the biological pump an important component of the global carbon cycle. Understanding the response of the biological pump to the changing environment is a prerequisite to predicting future atmospheric carbon dioxide concentrations. Will the biological pump weaken or strengthen? Currently the ocean science community is unable to confidently answer this question. Carbon flux at approximately 1000 m depth, the sequestration flux, determines the removal of carbon from the atmosphere on time scales ≥100 yr. The sequestration flux depends upon: (1) input rates of nutrients allochthonous to the ocean, (2) the export flux at the base of the euphotic zone, (3) the deviation of carbon fixation and remineralization from Redfield stoichiometry, and (4) the flux attenuation in the upper 1000 m. The biological response to increasing temperature, ocean stratification, nutrient availability and ocean acidification is frequently taxa- and ecosystem-specific and the results of synergistic effects are challenging to predict. Consequently, the use of global averages and steady state assumptions (e.g. Redfield stoichiometry, mesopelagic nutrient inventory) for predictive models is often insufficient. Our ability to predict sequestration flux additionally suffers from a lack of understanding of mesopelagic food web functioning and flux attenuation. However, regional specific investigations show great promise, suggesting that in the near future predictions of changes to the biological pump will have to be regionally and ecosystem specific, with the ultimate goal of integrating to global scales.

Climate change effects on marine ecosystems involve various stressors, predominantly temperature, hypoxia and CO₂, all of which may combine with further anthropogenic stressors such as pollutants. All life forms respond to these drivers, following potentially common principles, which are insufficiently understood. Specific understanding may be most advanced in animals where the concept of ‘oxygen and capacity dependent thermal tolerance’ (OCLTT) is an integrator of various effects, linking molecular to ecosystem levels of biological organisation. Recent studies confirm OCLTT involvement in the field, causing changes in species abundance, biogeographical ranges, phenology and species predominance. At the whole-animal level, performance capacity set by aerobic scope and energy budget, building on baseline energy turnover, links fitness (within a thermal window) and functioning at the ecosystem level. In variable environments like the intertidal zone, animals also exploit their capacity for passive tolerance. While presently the temperature signal appears predominant in the field, effects may well involve other stressors, acting synergistically by narrowing the aerobic OCLTT window. Recent findings support the OCLTT concept as a common physiological basis linking apparently disjunct effects of ocean warming, acidification and hypoxia in a so-called climate syndrome. In brief, warming-induced CO₂ accumulation in body fluids links to the effects of ocean acidification mediated by the weak acid distribution of CO₂. Temperature-induced hypoxemia links to the hypoxia sensitivity of thermal tolerance. Future work will need to develop proxies for the temperature-dependent effects of climate-related stressors and also identify the principles operative in organisms other than animals and their underlying mechanisms. Mechanism-based modelling efforts are then needed to develop reliable organism to ecosystem projections of future change.