page_title: Human impact on marine life
section_title: Multiple stressors
hierarchical_section_title: Human impact on marine life / Multiple stressors
caption_attribution_description: English: Multiple Stressors and Ecological Complexity Require A New Approach to Coral Reef Research (2016). Pendleton Linwood Hagan, Hoegh-Guldberg Ove, Langdon Chris, Comte Adrien. Frontiers in Marine Science 3, 00036. A conceptual framework describing ecological processes that contribute to coral reefs growth and maintenance versus the biological and anthropogenic factors that can work against these processes. The inner circle depicts important coral reef ecosystem constituent species. The next circle represents ecosystem features that are important to people. The next circle, along with the arrows showing calcification and decalcification illustrates that in pre-Anthropocene times coral reefs experienced net growth where calcification probably exceeded decalcification; the balance has been reversed at some time during the Anthropocene. The outermost circle captures key environmental stressors that affect coral reef health and determine whether coral reefs grow or decline (inspired by Cinner et al. 2015). Funding for this study was provided by the Prince Albert II Foundation. To read this study, visit (http://journal.frontiersin.org/article/10.3389/fmars.2016.00036/full). Linwood Pendleton is available for comment by contacting Erin McKenzie, erin.mckenzie@duke.edu. Español: Diagrama conceptual que describe los procesos ecológicos que contribuyen al crecimiento y mantenimiento de los arrecifes de coral y los factores antropogénicos que pueden afectar negativamente a estos procesos. Puedes leer este estudio completo en la siguiente dirección: http://journal.frontiersin.org/article/10.3389/fmars.2016.00036/full. Linwood Pendleton esta disponible para comentarios a través de Erin McKenzie, erin.mckenzie@duke.edu.
context_page_description: Human activities affect marine life and marine habitats through overfishing, habitat loss, the introduction of invasive species, ocean pollution, ocean acidification and ocean warming. These impact marine ecosystems and food webs and may result in consequences as yet unrecognised for the biodiversity and continuation of marine life forms.
  According to the IPCC, since 1950 "many marine species across various groups have undergone shifts in geographical range and seasonal activities in response to ocean warming, sea ice change and biogeochemical changes, such as oxygen loss, to their habitats."
  It has been estimated only 13% of the ocean area remains as wilderness, mostly in open ocean areas rather than along the coast.
context_section_description: If more than one stressor is present the effects can be amplified. For example, the combination of ocean acidification and an elevation of ocean temperature can have a compounded effect on marine life far exceeding the individual harmful impact of either.
  While the full implications of elevated CO₂ on marine ecosystems are still being documented, there is a substantial body of research showing that a combination of ocean acidification and elevated ocean temperature, driven mainly by CO₂ and other greenhouse gas emissions, have a compounded effect on marine life and the ocean environment. This effect far exceeds the individual harmful impact of either.  In addition, ocean warming exacerbates ocean deoxygenation, which is an additional stressor on marine organisms, by increasing ocean stratification, through density and solubility effects, thus limiting nutrients, while at the same time increasing metabolic demand.
  The direction and magnitude of the effects of ocean acidification, warming and deoxygenation on the ocean has been quantified by meta-analyses, and has been further tested by mesocosm studies. The mesocosm studies simulated the interaction of these stressors and found a catastrophic effect on the marine food web, namely, that the increases in consumption from thermal stress more than negates any primary producer to herbivore increase from more available carbon dioxide.
caption: Multiple stressors acting on coral reefs [123]
exif: {"Image ImageWidth": "3508", "Image ImageLength": "2481", "Image BitsPerSample": "[8, 8, 8]", "Image Compression": "LZW", "Image PhotometricInterpretation": "2", "Image ImageDescription": "TITLE=Multiple Stressors and Ecological Complexity Require A New Approach to Coral Reef Research\nAUTHORS=Pendleton Linwood Hagan, Hoegh-Guldberg Ove, Langdon Chris, Comte Adrien           \nJOURNAL=Frontiers in Marine Science      \t\nVOLUME=3      \nYEAR=2016      \n\nIn a new study published in the journal Frontiers in Marine Science, the Nicholas Institute for Environmental Policy Solutions\u2019 Linwood Pendleton\u2014with co-authors from the University of Miami, the University of Queensland and the University of Brest\u2014report that evidence is stacking up to suggest that impacts to coral reefs may be underestimated. In Pendleton words: The science is developing so rapidly around impacts to coral reefs that most in the public and scientific community have developed opinions based on outdated studies that focus on just one stressor or species of coral at a time. The has led to two main misconceptions\u2014the risk to coral reefs from global environmental changes may be overblown, and the complexity of coral reef ecosystem may make them more resilient to global environmental changes such as warmer seas, bleaching, and ocean acidification.Our work reviews recent scientific literature, with a focus on the last five years, in an effort to better understand what is known about coral reefs when they are exposed to more than one stressor. We also examined recent discoveries about the ways these stresses affect different aspects of ecological health and functioning in reefs.  It\u2019s not just bleaching and a loss of calcium shells, changes in temperature, and ocean acidification\u2014driven by the increased carbon dioxide in the atmosphere\u2014can cause coral reefs to grow more slowly and inhibit their reproduction. When these stresses occur simultaneously, they have effects that are far more detrimental than previously anticipated. The implications are, one, coral reef ecosystems may start to die or change much sooner than we thought, and two, coral reefs that are damaged, whether by storms, bleaching, or human-created actions, can\u2019t rebound like they once could.\nFunding for this study was provided by the Prince Albert II Foundation. To read this study, visit (http://journal.frontiersin.org/article/10.3389/fmars.2016.00036/full). Linwood Pendleton is available for comment by contacting Erin McKenzie, erin.mckenzie@duke.edu or 919.613.3652.", "Image Orientation": "Horizontal (normal)", "Image SamplesPerPixel": "3", "Image XResolution": "300", "Image YResolution": "300", "Image PlanarConfiguration": "1", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS6 (Macintosh)", "Image DateTime": "2016:03:21 10:24:20", "Image Artist": "V. Gonzalez Ortiz", "Image Copyright": "This is an open-access figure distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in the journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.", "Image ExifOffset": "3104", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "3242", "Thumbnail JPEGInterchangeFormatLength": "9444", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "3508", "EXIF ExifImageLength": "2481"}