|
Ocean Warming Affecting Marine Ecosystems - Science journal articles
07/23/2010
| Marilyn Sigman, Alaska SeaGrant/MAP
Tags: Climate Change, Changes in Alaska Marine Ecosystems, Ocean Acidification
|
In its recent ocean news update, SeaWeb summarized several articles from the June 18, 2010, issue of Science related to the effects of ocean warming.
Absorption of carbon dioxide and heat - the scale and pace of change in chemical and physical conditions have set in motion a wide range of biological responses, including:
- Changes in the distribution, abundance, and productivity of phytoplankton communities
- Acidification and stratification of the ocean
- Decrease in annual productivity by at least six percent since the early 1980s with nearly 70 percent of this decline occurring in the polar and subpolar regions
- Rising temperatures in polar regions are reducing ice thickness and extent, removing habitat for species from polar bears to penguins and fundamentally altering marine ecosystems.
- Warming waters are prompting a poleward shift in the distribution of a number of species, resulting in an increase in the number of invasive or exotic species, including pathogens. (Hoegh-Guldberg and Bruno)
- Ocean pH is lower now than it has been in 20 million years. (Kerr)
- The rate of ocean pH is unprecedented, a factor of 30 to 100 times faster than changes in the recent geological past, and perturbations will last many centuries to millennia. (Doney)
- Some marine species may benefit from higher CO2 levels such as phytoplankton, seagrass, and seaweed species that increase their rate of photosynthesis. (Doney)
Sources: The free online summaries of the articles are reprinted below. Full articles are available with subscriptions to Science.
Science 18 June 2010:
Vol. 328. no. 5985, pp. 1523 - 1528
DOI: 10.1126/science.1189930
The Impact of Climate Change on the World’s Marine Ecosystems
Marine ecosystems are centrally important to the biology of the planet, yet a comprehensive understanding of how anthropogenic climate change is affecting them has been poorly developed. Recent studies indicate that rapidly rising greenhouse gas concentrations are driving ocean systems toward conditions not seen for millions of years, with an associated risk offundamental and irreversible ecological transformation. The impacts of anthropogenic climatechange so far include decreased ocean productivity, altered food web dynamics, reduced abundance of habitat-forming species, shifting species distributions, and a greater incidence ofdisease. Although there is considerable uncertainty about the spatial and temporal details,climate change is clearly and fundamentally altering ocean ecosystems. Further change will continue to create enormous challenges and costs for societies worldwide, particularly those in developing countries. Full article (Subscription required)
Science 18 June 2010:
Vol. 328. no. 5985, pp. 1500 - 1501
DOI: 10.1126/science.328.5985.1500
Ocean Acidification Unprecedented, Unsettling
By spewing carbon dioxide from smokestacks and tailpipes at a gigatons-per-year pace, humans are lowering the pH of the world ocean. The geochemical disruption will reverberate for tens of thousands of years. It's less clear how marine life will fare. With nothing in the geologic record as severe as the ongoing plunge in ocean pH, paleontologists can't say for sure how organisms that build carbonate shells or skeletons will react. In the laboratory, corals always do poorly. The lab responses of other organisms are mixed. In the field, researchers see signs that coral growth does slow, oyster larvae suffer, and plankton with calcareous skeletons lose mass. Full article (Subscription required)http://www.sciencemag.org/content/328/5985/1512.abstract
Science 18 June 2010:
Vol. 328. no. 5985, pp. 1512 - 1516
DOI: 10.1126/science.1185198
The Growing Human Footprint on Coastal and Open-Ocean Biogeochemistry
Climate change, rising atmospheric carbon dioxide, excess nutrient inputs, and pollution in its many forms are fundamentally altering the chemistry of the ocean, often on a global scale and, in some cases, at rates greatly exceeding those in the historical and recent geological record. Major observed trends include a shift in the acid-base chemistry of seawater, reduced subsurfaceoxygen both in near-shore coastal water and in the open ocean, rising coastal nitrogen levels, and widespread increase in mercury and persistent organic pollutants. Most of these perturbations, tied either directly or indirectly to human fossil fuel combustion, fertilizer use, and industrial activity, are projected to grow in coming decades, resulting in increasing negative impacts on ocean biota and marine resources.Full article (Subscription required)
|