Inter- and intra-specific carbon and nitrogen assimilation by dinoflagellate and diatom species

Phytoplankton are key components in primary production and their growth is determined mainly by the availability of nitrogen-nutrients in the ocean. The paradigm that phytoplankton prefer ammonium over nitrate when both substrates are present has been tested using 15N-labelled tracers on cultured diatoms and dinoflagellates isolated from two widespread geographical areas – the Baltic Sea and the Arabian Sea. We found contrary to the paradigm that both taxa preferred nitrate over ammonium and a significant within-species variation in N assimilation. Carbon uptake rates in the same experiments were estimated using 13C-labelled tracer

Intraspecific variability in the response of bloom-forming marine microalgae to changed climate conditions

Phytoplankton populations can display high levels of genetic diversity that, when reflected by phenotypic variability, may stabilize a species response to environmental changes. We studied the effects of increased temperature and CO2 availability as predicted consequences of global change, on 16 genetically different isolates of the diatom Skeletonema marinoi from the Adriatic Sea and the Skagerrak (North Sea), and on eight strains of the PST (paralytic shellfish toxin)-producing dinoflagellate Alexandrium ostenfeldii from the Baltic Sea. Maximum growth rates were estimated in batch cultures of acclimated isolates grown for five to 10 generations in a factorial design at 20 and 24°C, and present day and next century applied atmospheric pCO2, respectively. In both species, individual strains were affected in different ways by increased temperature and pCO2. The strongest response variability, buffering overall effects, was detected among Adriatic S. marinoi strains. Skagerrak strains showed a more uniform response, particularly to increased temperature, with an overall positive effect on growth. Increased temperature also caused a general growth stimulation in A. ostenfeldii, despite notable variability in strain-specific response patterns. Our data revealed a significant relationship between strain-specific growth rates and the impact of pCO2 on growth—slow growing cultures were generally positively affected, while fast growing cultures showed no or negative responses to increased pCO2. Toxin composition of A. ostenfeldii was consistently altered by elevated temperature and increased CO2 supply in the tested strains, resulting in overall promotion of saxitoxin production by both treatments. Our findings suggest that phenotypic variability within populations plays an important role in the adaptation of phytoplankton to changing environments, potentially attenuating short-term effects and forming the basis for selection. In particular, A. ostenfeldii blooms may expand and increase in toxicity under increased water temperature and atmospheric pCO2 conditions, with potentially severe consequences for the coastal ecosystem

Tribunal Duties and the Exclusion of Evidence in International Arbitration: The Tug-of-War of Fairness and Efficiency

Arbitral procedure aims to strike the right balance between fairness and efficiency in the specific and unique circumstances of the case. However, in some difficult cases, both considerations can pull in opposite directions. The exclusion of evidence provides a particularly apt example in which the dilemma arises, aggravated by the considerable evidentiary discretion vested in tribunals and the overall lack of guidance in applicable laws and rules on approaching such circumstances. This article argues that the tug-of-war between fairness and efficiency in the context of the exclusion of evidence can be resolved with the help of relevant tribunal duties which should guide the exercise of tribunal discretion. These include the duty (1) to resolve the dispute; (2) to observe due process; (3) to conduct the procedure efficiently and effectively; (4) to act with impartiality and independence; and (5) to render an award that is enforceable/not subject to set aside

Characterisation of Rules in International Commercial Arbitration:Between procedure, substance and party autonomy

Rules in international arbitration can have various characterisations. Some are ‘substantive’ and others ‘procedural’, determined by direct party agreement or subject to tribunal discretion. Given that the proper meaning of these concepts tends to be conflated and interpreted without rigour, this paper argues that, subject to contrary mandatory provisions in the leges arbitri and in the absence of direct party agreement on procedure, tribunals should follow the procedure-substance characterisation found under the applicable substantive law selected by the parties. If substantive law deems a rule to be procedural, tribunals are under no duty to apply the rule. Instead, tribunals can rely on their discretion to determine the appropriate course of action. Conversely, if substantive law characterises a rule as substantive, tribunals must apply the rule, despite the scope for challenges to arbitral awards on grounds of errors of law is minimal. In doing so, the article distinguishes how the issue is approached in arbitration compered to general private international law and acknowledged that the true meaning of ‘procedure’ and ‘substance’ requires a principled case-by-case analysis

Internationalising Adjudication:Towards an Incremental and Polycentric Harmonisation

The paper focuses on internationalising adjudication, a fast ADR mechanism using a third-party adjudicator to make a decision, a timely issue in light of the recent UNCITRAL model clause on adjudication, and the ISAF draft model adjudication law. This authors discuss how harmonisation can be achieved, arguing that, given the discrepancies in adjudication across jurisdictions, harmonisation should be progressively incremental, and should build shared principles and standards rather than imposing a straitjacket on diverse legal systems. Harmonisation should be polycentric, working at different levels to achieve the intended purpose. The paper examines three ways to achieve it – model clauses, a model law and an international convention

Transporting ideas between marine and social sciences: experiences from interdisciplinary research programs.

The oceans comprise 70% of the surface area of our planet, contain some of the world’s richest natural resources and are one of the most significant drivers of global climate patterns. As the marine environment continues to increase in importance as both an essential resource reservoir and facilitator of global change, it is apparent that to find long-term sustainable solutions for our use of the sea and its resources and thus to engage in a sustainable blue economy, an integrated interdisciplinary approach is needed. As a result, interdisciplinary working is proliferating. We report here our experiences of forming interdisciplinary teams (marine ecologists, ecophysiologists, social scientists, environmental economists and environmental law specialists) to answer questions pertaining to the effects of anthropogenic-driven global change on the sustainability of resource use from the marine environment, and thus to transport ideas outwards from disciplinary confines. We use a framework derived from the literature on interdisciplinarity to enable us to explore processes of knowledge integration in two ongoing research projects, based on analyses of the purpose, form and degree of knowledge integration within each project. These teams were initially focused around a graduate program, explicitly designed for interdisciplinary training across the natural and social sciences, at the Gothenburg Centre for Marine Research at the University of Gothenburg, thus allowing us to reflect on our own experiences within the context of other multi-national, interdisciplinary graduate training and associated research programs

Effects of adaptation, chance, and history on the evolution of the toxic dinoflagellate Alexandrium minutum under selection of increased temperature and acidification

The roles of adaptation, chance, and history on evolution of the toxic dinoflagellate Alexandrium minutum Halim, under selective conditions simulating global change, have been addressed. Two toxic strains (AL1V and AL2V), previously acclimated for two years at pH 8.0 and 20◦C, were transferred to selective conditions: pH 7.5 to simulate acidification and 25◦C. Cultures under selective conditions were propagated until growth rate and toxin cell quota achieved an invariantmean value at 720 days (ca. 250 and ca. 180 generations for strains AL1V and AL2V, respectively). Historical contingencies strongly constrained the evolution of growth rate and toxin cell quota, but the forces involved in the evolution were not the same for both traits. Growth rate was 1.5–1.6 times higher than the one measured in ancestral conditions. Genetic adaptation explained two-thirds of total adaptation while one-third was a consequence of physiological adaptation. On the other hand, the evolution of toxin cell quota showed a pattern attributable to neutralmutations because the final varianceswere significantly higher than thosemeasured at the start of the experiment. It has been hypothesized that harmful algal blooms will increase under the future scenario of global change. Although this study might be considered an oversimplification of the reality, it can be hypothesized that toxic blooms will increase but no predictions can be advanced about toxicity.Universidad de Málaga. Campus de excelencia internacional. Andalucia Tech. Financially supported by the Spanish Ministry of Science and Innovation by the grant CGL2008-00652/BOS, and Junta de Andalucía Research Group RNM-115

Time capsules in natural sediment archives—Tracking phytoplankton population genetic diversity and adaptation over multidecadal timescales in the face of environmental change

© 2017 John Wiley & Sons Ltd. Undisturbed records of resting stages produced in the past and stored in coastal sediments are very valuable to science, because they may provide unique insights into past evolutionary and ecological trajectories. Within marine phytoplankton, multidecadal time series of monoclonal strains germinated from resting stages have been established for diatoms (Skeletonema marinoi) and dinoflagellates (Pentapharsodinium dalei), spanning ca. a century. Phenotypic and genotypic analyses of these time series have revealed effects of past environmental changes on population genetic structure. Future perspectives include direct comparisons of phenotypes and genotypic data of populations, for example, by genomewide assays that can correlate phenotypic trends with genotypes and allele frequencies in temporally separated strains. Besides their usefulness as historical records, "seed" banks of phytoplankton resting stages also have the potential to provide an inoculum that influences present populations through "dispersal from the past" (the storage effect) and are important for adaptation to future environments through their standing genetic diversity

Priority effects in a planktonic bloom-forming marine diatom

Priority effects occur when a species or genotype with earlier arrival has an advantage such that its relative abundance in the community or population is increased compared with later-arriving species. Few studies have dealt with this concept in the context of within-species competition. Skeletonema marinoi is a marine diatom that shows a high degree of genetic differentiation between populations over small geographical distances. To test whether historical events such as priority effects may have been important in inducing these patterns of population differentiation, we performed microcosm experiments with successive inoculation of different S. marinoi strains. Our results show that even in the absence of a numerical advantage, significant priority effects were evident. We propose that priority effects may be an important mechanism in initiating population genetic differentiation