Significant habitat loss will continue to occur due to climate change for many species and areas, including Arctic and coral reef ecosystems, while habitat in other areas and for other species will expand. These changes will consequently alter the distribution, abundance, and productivity of many marine species.

This finding is from chapter 24 of Climate Change Impacts in the United States: The Third National Climate Assessment.

Process for developing key messages: A central component of the assessment process was the Oceans and Marine Resources Climate assessment workshop that was held January 23-24, 2012, at the National Oceanographic and Atmospheric Administration (NOAA) in Silver Spring, MD, and simultaneously, via web teleconference, at NOAA in Seattle, WA. In the workshop, nearly 30 participants took part in a series of scoping presentations and breakout sessions that began the process leading to a foundational Technical Input Report (TIR) entitled “Oceans and Marine Resources in a Changing Climate: Technical Input to the 2013 National Climate Assessment.”018aba6e-7bff-4124-ae9a-f2521e683bd1 The report, consisting of nearly 220 pages of text organized into 7 sections with numerous subsections and more than 1200 references, was assembled by 122 authors representing governmental agencies, non-governmental organizations, tribes, and other entities. The chapter author team engaged in multiple technical discussions via teleconferences that permitted a careful review of the foundational TIR018aba6e-7bff-4124-ae9a-f2521e683bd1 and of approximately 25 additional technical inputs provided by the public, as well as the other published literature, and professional judgment. The chapter author team met at Conservation International in Arlington, VA on 3-4 May 2012 for expert deliberation of draft key messages by the authors, wherein each message was defended before the entire author team before the key message was selected for inclusion in the report. These discussions were supported by targeted consultation with additional experts by the lead author of each message to help define “key vulnerabilities.”

Description of evidence base: The key message is supported by extensive evidence documented in the Oceans Technical Input Report018aba6e-7bff-4124-ae9a-f2521e683bd1 and additional technical inputs received as part of the Federal Register Notice solicitation for public input, as well as stakeholder engagement leading up to drafting the chapter. Many peer-reviewed publications3d9112b9-6aa1-4614-9599-6966c9591ef9 b78bfacb-e00f-4af6-8ad7-dff157f8b8b4 b09adbe5-6a17-4d3c-ab96-b3d9e306af67 f516a114-4604-4062-a1b3-e70a4cbbba9e describe threats to coral reefs induced by global change. There are also many relevant and recent peer-reviewed publications006ce4db-d72c-400a-a409-c6a536e55664 128194f0-1295-4321-a7bf-a8dee1fc2247 d7265962-536c-4002-b3a7-1ed6e8841753 8b09bbe8-9f42-412e-a4d6-ef4889f56556 3f1b7fd7-3b1b-4b7f-8b68-802eddde7a27 c767db68-2732-424b-9dc6-e6bf94bc7a8e that discuss impacts on marine species and resources of habitat change that is induced by climate change.

New information and remaining uncertainties: Regional and local variation is, again, a major component of the remaining uncertainties. Different areas, habitats, and species are responding differently and have very different adaptive capacities. Those species that are motile will certainly respond differently, or at least at a different rate, by changing distribution and migration patterns, compared to species that do not move, such as corals. Although it is clear that some fish stocks are moving poleward and to deeper water, how far they will move and whether most species will move remains unclear. A key uncertainty is the extent to which various areas will benefit from range expansions of valuable species or increases in productivity, while other areas will suffer as species move away from previously productive areas. The loss of critically important habitat due to climate change will result in changes in species interactions that are difficult to predict.

Assessment of confidence based on evidence: There is very high confidence that habitat and ecosystems are changing due to climate change, but that change is not unidirectional by any means. Distribution, abundance, and productivity changes are species and location dependent and may be increasing or decreasing in a complex pattern.

References :

• Oceans and Marine Resources in a Changing Climate: Technical Input to the 2013 National Climate Assessment (018aba6e)
• The effects of eelgrass habitat loss on estuarine fish communities of southern New England (f516a114)
• Climate Change and Marine Fish Distributions: Forecasting from Historical Analogy (d7265962)
• Climate change and deepening of the North Sea fish assemblage: a biotic indicator of warming seas (006ce4db)
• Changing spatial distribution of fish stocks in relation to climate and population size on the Northeast United States continental shelf (8b09bbe8)
• Sea Ice Retreat Alters the Biogeography of the Bering Sea Continental Shelf (128194f0)
• Coral Reefs Under Rapid Climate Change and Ocean Acidification (b09adbe5)
• Climate Change and Distribution Shifts in Marine Fishes (3f1b7fd7)
• Phase shifts and stable states on coral reefs (b78bfacb)
• Reefs at Risk Revisited (3d9112b9)
• Integrating ecophysiology and plankton dynamics into projected maximum fisheries catch potential under climate change in the Northeast Atlantic (c767db68)