• Energy Research

The unprecedented global heatwave of 2014–2017 was a defining event for many ecosystems. Widespread degradation caused by coral bleaching, for example, highlighted the vulnerability of hundreds of millions of people dependent on reefs for their livelihoods, well-being, and food security. Scientists and policy makers are now reassessing long-held assumptions about coping with anthropogenic climate change, particularly the assumption that strong local institutions can maintain ecological and social resilience through ecosystem-based management, adaptation, and restoration. Governance is struggling to address the new normal as ecosystem assemblages transform to novel configurations. A central challenge for policy makers in the Anthropocene is navigating environmental crises and coping with societal insecurity and change. Ecosystem governance needs a new paradigm to embrace rapid change and shape future trajectories. In this Perspective, we focus on coral reefs as vanguards for governance transformation. We explain the spatial, temporal, and political dynamics of reefs as they respond to climate change and outline a new governance paradigm applicable to all ecosystems.

Resumen El calentamiento del océano está aumentando la incidencia, la escala y la gravedad del blanqueamiento y la mortalidad de los corales a escala mundial, que culminó en el tercer evento mundial de blanqueamiento de corales que ocurrió durante las olas de calor marinas récord de 2014-2017. Si bien los efectos locales de estos eventos han sido ampliamente reportados, las implicaciones globales siguen siendo desconocidas. El análisis de 15.066 estudios de arrecifes durante 2014-2017 reveló que el 80% de los arrecifes estudiados experimentaron un blanqueamiento significativo de los corales y el 35% experimentó una mortalidad significativa de los corales. El alcance global del blanqueamiento y la mortalidad significativos de los corales se evaluó extrapolando los resultados de los estudios de arrecifes utilizando datos completos de teledetección del estrés por calor regional. Este modelo predijo que el 51% de los arrecifes de coral del mundo sufrieron un blanqueamiento significativo y una mortalidad significativa del 15%, superando el daño de cualquier evento de blanqueamiento global anterior. Estas observaciones demuestran que el daño generalizado del calentamiento global a los arrecifes de coral se está acelerando y subraya la amenaza que el cambio climático antropogénico representa para la transformación irreversible de estos ecosistemas esenciales. Résumé Le réchauffement des océans augmente l'incidence, l'ampleur et la gravité du blanchiment et de la mortalité des coraux à l'échelle mondiale, culminant avec le troisième événement mondial de blanchiment des coraux survenu lors de vagues de chaleur marines record de 2014-2017. Bien que les effets locaux de ces événements aient été largement rapportés, les implications mondiales restent inconnues. L'analyse de 15 066 enquêtes sur les récifs au cours de la période 2014-2017 a révélé que 80 % des récifs étudiés ont connu un blanchissement important des coraux et 35 % ont connu une mortalité importante des coraux. L'étendue mondiale du blanchiment et de la mortalité importants des coraux a été évaluée en extrapolant les résultats des enquêtes sur les récifs à l'aide de données complètes de télédétection du stress thermique régional. Ce modèle prévoyait que 51 % des récifs coralliens du monde souffraient d'un blanchissement important et 15 % d'une mortalité importante, dépassant les dommages causés par tout événement de blanchissement mondial antérieur. Ces observations démontrent que les dommages généralisés causés par le réchauffement climatique aux récifs coralliens s'accélèrent et soulignent la menace que le changement climatique anthropique fait peser sur la transformation irréversible de ces écosystèmes essentiels. Abstract Ocean warming is increasing the incidence, scale, and severity of global-scale coral bleaching and mortality, culminating in the third global coral bleaching event that occurred during record marine heatwaves of 2014-2017. While local effects of these events have been widely reported, the global implications remain unknown. Analysis of 15,066 reef surveys during 2014-2017 revealed that 80% of surveyed reefs experienced significant coral bleaching and 35% experienced significant coral mortality. The global extent of significant coral bleaching and mortality was assessed by extrapolating results from reef surveys using comprehensive remote-sensing data of regional heat stress. This model predicted that 51% of the world's coral reefs suffered significant bleaching and 15% significant mortality, surpassing damage from any prior global bleaching event. These observations demonstrate that global warming's widespread damage to coral reefs is accelerating and underscores the threat anthropogenic climate change poses for the irreversible transformation of these essential ecosystems. يؤدي ارتفاع درجة حرارة المحيطات إلى زيادة حدوث وحجم وشدة تبييض الشعاب المرجانية ونفوقها على نطاق عالمي، وبلغت ذروتها في الحدث العالمي الثالث لتبييض الشعاب المرجانية الذي حدث خلال موجات الحر البحرية القياسية في الفترة 2014-2017. في حين تم الإبلاغ عن الآثار المحلية لهذه الأحداث على نطاق واسع، إلا أن الآثار العالمية لا تزال غير معروفة. كشف تحليل 15,066 مسحًا للشعاب المرجانية خلال الفترة 2014-2017 أن 80 ٪ من الشعاب المرجانية التي تم مسحها عانت من ابيضاض مرجاني كبير و 35 ٪ عانت من وفيات مرجانية كبيرة. تم تقييم المدى العالمي للتبييض والوفيات المرجانية الكبيرة من خلال استقراء النتائج من المسوحات المرجانية باستخدام بيانات شاملة للاستشعار عن بعد للإجهاد الحراري الإقليمي. وتوقع هذا النموذج أن 51 ٪ من الشعاب المرجانية في العالم عانت من تبييض كبير و 15 ٪ من الوفيات الكبيرة، متجاوزة الأضرار الناجمة عن أي حدث تبييض عالمي سابق. تُظهر هذه الملاحظات أن الأضرار الواسعة النطاق للاحترار العالمي التي لحقت بالشعاب المرجانية تتسارع وتؤكد التهديد الذي يشكله تغير المناخ البشري المنشأ على التحول الذي لا رجعة فيه لهذه النظم الإيكولوجية الأساسية.

Phase-shifts from one persistent assemblage of species to another have become increasingly commonplace on coral reefs and in many other ecosystems due to escalating human impacts. Coral reef science, monitoring and global assessments have focused mainly on producing detailed descriptions of reef decline, and continue to pay insufficient attention to the underlying processes causing degradation. A more productive way forward is to harness new theoretical insights and empirical information on why some reefs degrade and others do not. Learning how to avoid undesirable phase-shifts, and how to reverse them when they occur, requires an urgent reform of scientific approaches, policies, governance structures and coral reef management.

The Great Barrier Reef (GBR) provides a globally significant demonstration of the effectiveness of large-scale networks of marine reserves in contributing to integrated, adaptive management. Comprehensive review of available evidence shows major, rapid benefits of no-take areas for targeted fish and sharks, in both reef and nonreef habitats, with potential benefits for fisheries as well as biodiversity conservation. Large, mobile species like sharks benefit less than smaller, site-attached fish. Critically, reserves also appear to benefit overall ecosystem health and resilience: outbreaks of coral-eating, crown-of-thorns starfish appear less frequent on no-take reefs, which consequently have higher abundance of coral, the very foundation of reef ecosystems. Effective marine reserves require regular review of compliance: fish abundances in no-entry zones suggest that even no-take zones may be significantly depleted due to poaching. Spatial analyses comparing zoning with seabed biodiversity or dugong distributions illustrate significant benefits from application of best-practice conservation principles in data-poor situations. Increases in the marine reserve network in 2004 affected fishers, but preliminary economic analysis suggests considerable net benefits, in terms of protecting environmental and tourism values. Relative to the revenue generated by reef tourism, current expenditure on protection is minor. Recent implementation of an Outlook Report provides regular, formal review of environmental condition and management and links to policy responses, key aspects of adaptive management. Given the major threat posed by climate change, the expanded network of marine reserves provides a critical and cost-effective contribution to enhancing the resilience of the Great Barrier Reef.

Coral reefs, one of the world's most complex and vulnerable ecosystems, face an uncertain future in coming decades as they continue to respond to anthropogenic climate change, overfishing, pollution, and other human impacts [1, 2]. Traditionally, marine macroecology is based on presence/absence data from taxonomic checklists or geographic ranges, providing a qualitative overview of spatial shifts in species richness that treats rare and common species equally [3, 4]. As a consequence, regional and long-term shifts in relative abundances of individual taxa are poorly understood. Here we apply a more rigorous quantitative approach to examine large-scale spatial variation in the species composition and abundance of corals on midshelf reefs along the length of Australia's Great Barrier Reef, a biogeographic region where species richness is high and relatively homogeneous [5]. We demonstrate that important functional components of coral assemblages "sample" space differently at 132 sites separated by up to 1740 km, leading to complex latitudinal shifts in patterns of absolute and relative abundance. The flexibility in community composition that we document along latitudinal environmental gradients indicates that climate change is likely to result in a reassortment of coral reef taxa rather than wholesale loss of entire reef ecosystems.

Distributions of numerical abundance and resource use among species are fundamental aspects of community structure. Here we characterize these patterns for tropical reef fishes and corals across a 10,000-kilometer biodiversity gradient. Numerical abundance and resource-use distributions have similar shapes, but they emerge at markedly different scales. These results are consistent with a controversial null hypothesis regarding community structure, according to which abundance distributions arise from the interplay of multiple stochastic environmental and demographic factors. Our findings underscore the importance of robust conservation strategies that are appropriately scaled to the broad suite of environmental processes that help sustain biodiversity.

AbstractWe examined the development of coral reef science and the policies, institutions, and governance frameworks for management of coral reefs in China in order to highlight the wicked problem of preserving reefs while simultaneously promoting human development and nation building. China and other sovereign states in the region are experiencing unprecedented economic expansion, rapid population growth, mass migration, widespread coastal development, and loss of habitat. We analyzed a large, fragmented literature on the condition of coral reefs in China and the disputed territories of the South China Sea. We found that coral abundance has declined by at least 80% over the past 30 years on coastal fringing reefs along the Chinese mainland and adjoining Hainan Island. On offshore atolls and archipelagos claimed by 6 countries in the South China Sea, coral cover has declined from an average of >60% to around 20% within the past 10–15 years. Climate change has affected these reefs far less than coastal development, pollution, overfishing, and destructive fishing practices. Ironically, these widespread declines in the condition of reefs are unfolding as China's research and reef‐management capacity are rapidly expanding. Before the loss of corals becomes irreversible, governance of China's coastal reefs could be improved by increasing public awareness of declining ecosystem services, by providing financial support for training of reef scientists and managers, by improving monitoring of coral reef dynamics and condition to better inform policy development, and by enforcing existing regulations that could protect coral reefs. In the South China Sea, changes in policy and legal frameworks, refinement of governance structures, and cooperation among neighboring countries are urgently needed to develop cooperative management of contested offshore reefs.El Problema Malvado de la Desaparición de los Arrecifes de Coral en China

Marine ecosystems are in decline. New transformational changes in governance are urgently required to cope with overfishing, pollution, global changes, and other drivers of degradation. Here we explore social, political, and ecological aspects of a transformation in governance of Chile's coastal marine resources, from 1980 to today. Critical elements in the initial preparatory phase of the transformation were ( i ) recognition of the depletion of resource stocks, ( ii ) scientific knowledge on the ecology and resilience of targeted species and their role in ecosystem dynamics, and ( iii ) demonstration-scale experimental trials, building on smaller-scale scientific experiments, which identified new management pathways. The trials improved cooperation among scientists and fishers, integrating knowledge and establishing trust. Political turbulence and resource stock collapse provided a window of opportunity that triggered the transformation, supported by new enabling legislation. Essential elements to navigate this transformation were the ability to network knowledge from the local level to influence the decision-making processes at the national level, and a preexisting social network of fishers that provided political leverage through a national confederation of artisanal fishing collectives. The resultant governance scheme includes a revolutionary national system of marine tenure that allocates user rights and responsibilities to fisher collectives. Although fine tuning is necessary to build resilience of this new regime, this transformation has improved the sustainability of the interconnected social–ecological system. Our analysis of how this transformation unfolded provides insights into how the Chilean system could be further developed and identifies generalized pathways for improved governance of marine resources around the world.