• Energy Research

Climate change in recent decades has been identified as a significant threat to natural environments and human wellbeing. This is because some of the contemporary changes to climate are abrupt and result in persistent changes in the state of natural systems; so called regime shifts (RS). This study aimed to detect and analyse the timing and strength of RS in Estonian climate at the half-century scale (1966-2013). We demonstrate that the extensive winter warming of the Northern Hemisphere in the late 1980s was represented in atmospheric, terrestrial, freshwater and marine systems to an extent not observed before or after the event within the studied time series. In 1989, abiotic variables displayed statistically significant regime shifts in atmospheric, river and marine systems, but not in lake and bog systems. This was followed by regime shifts in the biotic time series of bogs and marine ecosystems in 1990. However, many biotic time series lacked regime shifts, or the shifts were uncoupled from large-scale atmospheric circulation. We suggest that the latter is possibly due to complex and temporally variable interactions between abiotic and biotic elements with ecosystem properties buffering biotic responses to climate change signals, as well as being affected by concurrent anthropogenic impacts on natural environments.

Abstract Studying how food web structure and function vary through time represents an opportunity to better comprehend and anticipate ecosystem changes. Yet, temporal studies of highly resolved food web structure are scarce. With few exceptions, most temporal food web studies are either too simplified, preventing a detailed assessment of structural properties or binary, missing the temporal dynamics of energy fluxes among species. Using long‐term, multi‐trophic biomass data coupled with highly resolved information on species feeding relationships, we analysed food web dynamics in the Gulf of Riga (Baltic Sea) over more than three decades (1981–2014). We combined unweighted (topology‐based) and weighted (biomass‐ and flux‐based) food web approaches, first, to unravel how distinct descriptors can highlight differences (or similarities) in food web dynamics through time, and second, to compare temporal dynamics of food web structure and function. We find that food web descriptors vary substantially and distinctively through time, likely reflecting different underlying ecosystem processes. While node‐ and link‐weighted metrics reflect changes related to alterations in species dominance and fluxes, unweighted metrics are more sensitive to changes in species and link richness. Comparing unweighted, topology‐based metrics and flux‐based functions further indicates that temporal changes in functions cannot be predicted using unweighted food web structure. Rather, information on species population dynamics and weighted, flux‐based networks should be included to better comprehend temporal food web dynamics. By integrating unweighted, node‐ and link‐weighted metrics, we here demonstrate how different approaches can be used to compare food web structure and function, and identify complementary patterns of change in temporal food web dynamics, which enables a more complete understanding of the ecological processes at play in ecosystems undergoing change.

Abstract Improving the health of coastal and open sea marine ecosystems represents a substantial challenge for sustainable marine resource management, since it requires balancing human benefits and impacts on the ocean. This challenge is often exacerbated by incomplete knowledge and lack of tools that measure ocean and coastal ecosystem health in a way that allows consistent monitoring of progress towards predefined management targets. The lack of such tools often limits capabilities to enact and enforce effective governance. We introduce the Baltic Health Index (BHI) as a transparent, collaborative and repeatable assessment tool. The Index complements existing, more ecological‐oriented, approaches by including a human dimension on the status of the Baltic Sea, an ecosystem impacted by multiple anthropogenic pressures and governed by a multitude of comprehensive national and international policies. Using a large amount of social–ecological data available, we assessed the health of the Baltic Sea for nine goals that represent the status towards set targets, for example, clean waters, biodiversity, food provision, natural products extraction and tourism. Our results indicate that the overall health of the Baltic Sea is suboptimal (a score of 76 out of 100), and a substantial effort is required to reach the management objectives and associated targets. Subregionally, the lowest BHI scores were measured for carbon storage, contaminants and lasting special places (i.e. marine protected areas), albeit with large spatial variation. Overall, the likely future status of all goals in the BHI averaged for the entire Baltic Sea is better than the present status, indicating a positive trend towards a healthier Baltic Sea. However, in some Baltic Sea basins, the trend for specific goals was decreasing, highlighting locations and issues that should be the focus of management priorities. The BHI outcomes can be used to identify both pan‐Baltic and subregional scale management priorities and to illustrate the interconnectedness between goals linked by cumulative pressures. Hence, the information provided by the BHI tool and its further development will contribute towards the fulfilment of the UN Agenda 2030 and its Sustainability Development Goals. A free Plain Language Summary can be found within the Supporting Information of this article.

Alien species contribute to global change in all marine ecosystems. Environmental variability can affect species distribution and population sizes, and is therefore expected to influence alien species. In this study, we have investigated temporal variability of 11 alien species representing different trophic levels and ecological functions in two gulfs of the brackish Baltic Sea in relation to environmental change. Independent of the invasion time, organism group or the life-history stage, abundance and/or biomass of the investigated alien species was either stable or displayed abrupt increases over time. Timing in population shifts was species-specific and exhibited no generic patterns, indicating that the observed large shifts in environmental parameters have no uniform consequences to the alien biota. In general, the inter-annual dynamics of alien and native species was not largely different, though native species tended to exhibit more diverse variability patterns compared to the alien species. There were no key environmental factors that affected most of the alien species, instead, the effects varied among the studied gulfs and species. Non-indigenous species have caused prominent structural changes in invaded communities as a result of exponential increase in the most recent invasions, as well as increased densities of the already established alien species.

En 2004, l'Assemblée générale des Nations Unies (ONU) a approuvé un processus régulier pour faire rapport sur les aspects environnementaux, économiques et sociaux de l'océan mondial. Le Mécanisme de notification et d'évaluation systématiques à l'échelle mondiale de l'état du milieu marin, y compris les aspects socio-économiques, a produit la première évaluation mondiale intégrée du milieu marin en décembre 2016 (connue sous le nom de première évaluation mondiale des océans). La deuxième évaluation, qui sera livrée en décembre 2020, s'appuiera sur les bases de référence incluses dans la première évaluation, en mettant l'accent sur l'établissement de tendances dans l'environnement marin pertinentes pour les besoins mondiaux en matière de rapports tels que ceux associés aux objectifs de développement durable des Nations Unies. Au cœur du processus d'évaluation et de ses résultats se trouvent deux composantes. Premièrement, l'utilisation des résultats de l'observation et de la surveillance des océans et de la recherche pour évaluer temporellement les composantes physiques, chimiques, biologiques, sociales, économiques et culturelles des environnements côtiers et marins afin d'établir leur état actuel, les impacts affectant actuellement les environnements côtiers et marins, les réponses à ces impacts et les tendances actuelles associées. Deuxièmement, il y a le courtage des connaissances sur les observations océaniques et la recherche associée pour fournir des informations clés qui peuvent être utilisées et appliquées pour répondre aux besoins de gestion et de politique à l'échelle locale, régionale et mondiale. En identifiant à la fois les lacunes dans les connaissances et les besoins en capacités, le processus d'évaluation fournit également une orientation aux décideurs pour le développement et le déploiement futurs de systèmes d'observation soutenus nécessaires pour améliorer les connaissances et soutenir les aspirations nationales associées au développement durable des écosystèmes côtiers et marins. La contribution de la communauté d'observation des océans, des gestionnaires et des décideurs politiques est essentielle pour s'assurer que les informations vitales requises pour soutenir les objectifs d'interface science-politique du Mécanisme sont incluses dans l'évaluation. Ce livre blanc de la communauté traite des développements dans la liaison des observations et de la science océaniques avec la politique réalisée dans le cadre du processus d'évaluation, et ceux nécessaires pour établir des liens stratégiques à l'avenir. En 2004, la Asamblea General de las Naciones Unidas (ONU) aprobó un proceso regular para informar sobre los aspectos ambientales, económicos y sociales de los océanos del mundo. El Proceso Regular para la Presentación de Informes y la Evaluación del Estado del Medio Marino a Nivel Mundial, incluidos los Aspectos Socioeconómicos, produjo la primera evaluación global integrada del medio marino en diciembre de 2016 (conocida como la primera Evaluación Mundial de los Océanos). La segunda evaluación, que se realizará en diciembre de 2020, se basará en las líneas de base incluidas en la primera evaluación, con un enfoque en el establecimiento de tendencias en el medio marino con relevancia para las necesidades mundiales de presentación de informes, como las asociadas con los Objetivos de Desarrollo Sostenible de la ONU. El centro del proceso de evaluación y sus resultados son dos componentes. En primer lugar, es la utilización de los resultados de la observación y el monitoreo de los océanos y la investigación para evaluar temporalmente los componentes físicos, químicos, biológicos, sociales, económicos y culturales de los entornos costeros y marinos para establecer su estado actual, los impactos que afectan actualmente a los entornos costeros y marinos, las respuestas a esos impactos y las tendencias en curso asociadas. En segundo lugar, es el intercambio de conocimientos de las observaciones oceánicas y la investigación asociada para proporcionar información clave que pueda utilizarse y aplicarse para abordar las necesidades de gestión y políticas a escala local, regional y global. Al identificar las lagunas de conocimiento y las necesidades de capacidad, el proceso de evaluación también proporciona orientación a los responsables políticos para el futuro desarrollo y despliegue de sistemas de observación sostenida que se requieren para mejorar el conocimiento y apoyar las aspiraciones nacionales asociadas con el desarrollo sostenible de los ecosistemas costeros y marinos. Las aportaciones de la comunidad de observadores oceánicos, los gestores y los responsables políticos son fundamentales para garantizar que se incluya en la evaluación la información vital necesaria para respaldar los objetivos de la interfaz de políticas científicas del Proceso Ordinario. Este libro blanco de la comunidad analiza los desarrollos en la vinculación de las observaciones oceánicas y la ciencia con las políticas logradas como parte del proceso de evaluación, y las necesarias para proporcionar vínculos estratégicos en el futuro. In 2004, the United Nations (UN) General Assembly approved a regular process to report on the environmental, economic and social aspects of the world's ocean. The Regular Process for Global Reporting and Assessment of the State of the Marine Environment, including Socioeconomic Aspects produced the first global integrated assessment of the marine environment in December 2016 (known as the first World Ocean Assessment). The second assessment, to be delivered in December 2020, will build on the baselines included in the first assessment, with a focus on establishing trends in the marine environment with relevance to global reporting needs such as those associated with the UN Sustainable Development Goals. Central to the assessment process and its outputs are two components. First, is the utilisation of ocean observation and monitoring outputs and research to temporally assess physical, chemical, biological, social, economic and cultural components of coastal and marine environments to establish their current state, impacts currently affecting coastal and marine environments, responses to those impacts and associated ongoing trends. Second, is the knowledge brokering of ocean observations and associated research to provide key information that can be utilised and applied to address management and policy needs at local, regional and global scales. Through identifying both knowledge gaps and capacity needs, the assessment process also provides direction to policy makers for the future development and deployment of sustained observation systems that are required for enhancing knowledge and supporting national aspirations associated with the sustainable development of coastal and marine ecosystems. Input from the ocean observation community, managers and policy makers is critical for ensuring that the vital information required for supporting the science policy interface objectives of the Regular Process is included in the assessment. This community white paper discusses developments in linking ocean observations and science with policy achieved as part of the assessment process, and those required for providing strategic linkages into the future. في عام 2004، وافقت الجمعية العامة للأمم المتحدة على عملية منتظمة لتقديم تقارير عن الجوانب البيئية والاقتصادية والاجتماعية لمحيطات العالم. أنتجت العملية المنتظمة للإبلاغ عن حالة البيئة البحرية وتقييمها على الصعيد العالمي، بما في ذلك الجوانب الاجتماعية والاقتصادية، أول تقييم عالمي متكامل للبيئة البحرية في كانون الأول/ديسمبر 2016 (المعروف باسم التقييم العالمي الأول للمحيطات). سيعتمد التقييم الثاني، الذي سيتم تسليمه في ديسمبر 2020، على خطوط الأساس المدرجة في التقييم الأول، مع التركيز على تحديد الاتجاهات في البيئة البحرية ذات الصلة باحتياجات الإبلاغ العالمية مثل تلك المرتبطة بأهداف الأمم المتحدة للتنمية المستدامة. مركزية لعملية التقييم ومخرجاتها مكونان. أولاً، استخدام مخرجات مراقبة المحيطات ورصدها والبحوث للتقييم المؤقت للمكونات الفيزيائية والكيميائية والبيولوجية والاجتماعية والاقتصادية والثقافية للبيئات الساحلية والبحرية لتحديد حالتها الحالية، والآثار التي تؤثر حاليًا على البيئات الساحلية والبحرية، والاستجابات لتلك الآثار والاتجاهات المستمرة المرتبطة بها. ثانيًا، هو الوساطة المعرفية لعمليات مراقبة المحيطات والبحوث المرتبطة بها لتوفير المعلومات الرئيسية التي يمكن استخدامها وتطبيقها لتلبية احتياجات الإدارة والسياسة على المستويات المحلية والإقليمية والعالمية. من خلال تحديد كل من الفجوات المعرفية والاحتياجات من القدرات، توفر عملية التقييم أيضًا التوجيه لصانعي السياسات من أجل التطوير المستقبلي ونشر أنظمة المراقبة المستدامة اللازمة لتعزيز المعرفة ودعم التطلعات الوطنية المرتبطة بالتنمية المستدامة للنظم الإيكولوجية الساحلية والبحرية. تعد المدخلات من مجتمع مراقبة المحيطات والمديرين وصانعي السياسات أمرًا بالغ الأهمية لضمان تضمين المعلومات الحيوية المطلوبة لدعم أهداف واجهة السياسة العلمية للعملية المنتظمة في التقييم. يناقش هذا الكتاب الأبيض للمجتمع التطورات في ربط ملاحظات المحيطات والعلوم بالسياسة التي تحققت كجزء من عملية التقييم، وتلك المطلوبة لتوفير روابط استراتيجية في المستقبل.