Declining oxygen in the global ocean and coastal waters

  • Posted on: Mon, 01/08/2018 - 11:42
  • By: kcanesi

BACKGROUND Oxygen concentrations in both the open ocean and coastal waters have been declining since at least the middle of the 20th century. This oxygen loss, or deoxygenation, is one of the most important changes occurring in an ocean increasingly modified by human activities that have raised temperatures, CO2 levels, and nutrient ...

Effects of ocean acidification, temperature and nutrient regimes on the appendicularian Oikopleura dioica: A mesocosm study

  • Posted on: Mon, 06/13/2016 - 05:56
  • By: Anonymous

Appendicularians are free-swimming tunicates that are common in most oceans, coastal waters, and estuaries. They build delicate, gelatinous houses that they use to filter food from the water. This study found that appendicularian abundance increased with ocean acidification, warmer temperatures, and higher nutrient levels. This suggests that appendicularians will play ...

Effects of low pH and raised temperature on egg production, hatching and metabolic rates of a Mediterranean copepod species (Acartia clausi) under oligotrophic conditions.

  • Posted on: Mon, 06/13/2016 - 05:56
  • By: Anonymous

The egg production rate, hatching success, and respiration of a Mediterranean copepod were not affected by ocean acidification conditions. Warming and food availability did have some effects. (Laboratory study)

Marine biodiversification in response to evolving phytoplankton stoichiometry

  • Posted on: Mon, 06/13/2016 - 05:56
  • By: Anonymous

Diversification of the marine biosphere is intimately linked to the evolution of the biogeochemical cycles of carbon, nutrients, and primary productivity. Analysis of the ratio of carbon-to-phosphorus buried in sedimentary rocks during the past 3 billion years indicates that both food quantity and, critically, food quality increased through time as ...

Energetic plasticity underlies a variable response to ocean acidification in the pteropod, Limacina helicina antarctica

  • Posted on: Mon, 06/13/2016 - 05:56
  • By: Anonymous

Ocean acidification conditions suppressed the metabolism of an Antarctic pteropod by approximately 20 percent in some instances. However, the effect on metabolism depended on abundance of phytoplankton in the region and the pteropods' baseline level of metabolism. Pteropod populations may be compromised by climate change, both directly by acidification-related suppression ...

Food availability outweighs ocean acidification effects in juvenile Mytilus edulis: Laboratory and field experiments

  • Posted on: Mon, 06/13/2016 - 05:56
  • By: Anonymous

Blue mussels grew and calcified 7 times faster in the Kiel Fjord (Baltic Sea), where low pH (ocean acidification) conditions prevailed, than at an outer fjord site where pH levels were higher In addition, the mussels were able to outcompete barnacles at the inner fjord, low pH site. Thus, blue ...

Ocean Acidification-Induced Food Quality Deterioration Constrains Trophic Transfer

  • Posted on: Wed, 03/30/2016 - 13:37
  • By: petert

Our present understanding of ocean acidification (OA) impacts on marine organisms caused by rapidly rising atmospheric carbon dioxide (CO2) concentration is almost entirely limited to single species responses. OA consequences for food web interactions are, however, still unknown. Indirect OA effects can be expected for consumers by changing the nutritional ...

Habitat traits and food availability determine the reponse of marine invertebrates to ocean acidification

  • Posted on: Wed, 03/30/2016 - 13:01
  • By: petert

Energy availability and local adaptation are major components in mediating the effects of ocean acidification (OA) on marine species. In a long-term study, we investigated the effects of food availability and elevated pCO2 (ca. 400, 1000 and 3000 μatm) on growth of newly settled Amphibalanus (Balanus) improvisus to reproduction, and on their offspring. We also ...

Effect of ocean acidification on the fatty acid composition of a natural plankton community

  • Posted on: Wed, 03/30/2016 - 12:09
  • By: petert

The effect of ocean acidification on the fatty acid composition of a natural plankton community in the Arctic was studied in a large-scale mesocosm experiment, carried out in Kongsfjorden (Svalbard, Norway) at 79° N. Nine mesocosms of ~50 m3 each were exposed to 8 different pCO2 levels (from natural background conditions to ~1420 ...

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