Multi-frequency observations of seawater carbonate chemistry on the central coast of the western Antarctic Peninsula

Assessments of benthic coastal seawater carbonate chemistry in Antarctica are sparse. The studies have generally been short in duration, during the austral spring/summer, under sea ice, or offshore in ice-free water. Herein we present multi-frequency measurements for seawater collected from the shallow coastal benthos on a weekly schedule over one year (May 2012–May 2013), daily schedule over three months (March–May 2013) and semidiurnal schedule over five weeks (March–April 2013). A notable pH increase (max pH = 8.62) occurred in the late austral spring/summer (November–December 2012), coinciding with sea-ice break-out and subsequent increase in primary productivity. We detected semidiurnal variation in seawater pH with a maximum variation of 0.13 pH units during the day and 0.11 pH units during the night. Daily variation in pH is likely related to biological activity, consistent with previous research. We calculated the variation in dissolved inorganic carbon (DIC) over each seawater measurement frequency, focusing on the primary DIC drivers in the Palmer Station region. From this, we estimated net biological activity and found it accounts for the greatest variations in DIC. Our seasonal data suggest that this coastal region tends to act as a carbon dioxide source during austral winter months and as a strong sink during the summer. These data characterize present-day seawater carbonate chemistry and the extent to which these measures vary over multiple time scales. This information will inform future experiments designed to evaluate the vulnerability of coastal benthic Antarctic marine organisms to ocean acidification.

Continue reading ‘Multi-frequency observations of seawater carbonate chemistry on the central coast of the western Antarctic Peninsula’

Ocean Acidification Stakeholder Workshop, 11 August 2015, Galloway, New Jersey

Date & time: 11 August 2015, 11 a.m – 4 p.m.

Location: Board of Trustees Conference Room, Campus Center, Stockton University, Galloway, New Jersey

New Jersey Sea Grant Consortium and North Atlantic Regional Team, or NART, will host an ocean and coastal acidification workshop August 11 for stakeholders in the Garden State. This event is hosted by Stockton University, and is supported by NOAA James J. Howard Marine Sciences Laboratory, Rutgers’ Haskin Shellfish Research Laboratory and Aquaculture Innovation Center, and Delaware Sea Grant.

The day will include an overview presentation on the state of the science of ocean and coastal acidification, presentations from local industry representatives, and breakout sessions to hear more about changes you are seeing on the water, and on what issues and problems scientists and officials should focus their attention in the near future.

The workshop is free, but space is limited to the first 50 people who register.

Continue reading ‘Ocean Acidification Stakeholder Workshop, 11 August 2015, Galloway, New Jersey’

Cantwell introduces bipartisan bill to establish national ocean acidification monitoring strategy

WASHINGTON, D.C. – U.S. Senator Maria Cantwell (D-WA) introduced a bipartisan bill to enhance ocean monitoring, research and forecasting. The Coordinated Ocean Monitoring and Research Act (S. 1886) would create a national ocean acidification monitoring strategy to prioritize investments in ocean acidification sensors to areas that need it most. The bipartisan bill also directs the National Oceanic and Atmospheric Administration (NOAA) and the National Science Foundation to make investments in adaptation and mitigation research so we understand how to make our coastal economies more resilient to the threat of ocean acidification.

“Ocean acidification will have a vast impact on commercial and environmental conditions across the nation – and currently threatens jobs in Washington State.  Shellfish in the Pacific Northwest have already been negatively affected, but we don’t know yet what this means for salmon populations and larger coastal ecosystems,” said Cantwell. “This bill ensures that NOAA is making the appropriate investments in research, and monitoring the ongoing impact of this threat to our coastal economies.”

Continue reading ‘Cantwell introduces bipartisan bill to establish national ocean acidification monitoring strategy’

The Clean Power Plan offers hope for the oceans

U.S. marine ecosystems and fisheries have long been an economic engine and cultural source of wealth for our country – an invaluable resource that sustains the very air we breathe. Which is why we must take action against the triple threat carbon pollution poses for our oceans: ocean warming, reduced oxygen levels, and ocean acidification. The good news is the U.S. Environmental Protection Agency’s (EPA) Clean Power Plan, sets a first ever national limit on industrial carbon pollution and provides achievable goals for every state to help us change course and slow the damaging effects of carbon pollution.

The Clean Power Plan is the centerpiece of a Climate Action Plan put forward by President Obama. For the first time, it will put limits on the carbon pollution generated by power plants–the single largest source of this pollution in the United States. The proposed standards will help cut power sector carbon pollution by 30 percent below 2005 levels by 2030 by setting state-by-state targets. The beauty of the plan is that it provides every state with flexible options in how they choose to meet those targets. Tools they can choose from include making existing coal-fired power plants more efficient, increasing use of renewables such as solar and wind, and tightening energy efficiency, for example in homes and buildings. (…)

Continue reading ‘The Clean Power Plan offers hope for the oceans’

New study exposes negative effects of climate change on Antarctic fish

Scientists at University of California Davis and San Francisco State University have discovered that the combination of elevated levels of carbon dioxide and an increase in ocean water temperature has a significant impact on survival and development of the Antarctic dragonfish (Gymnodraco acuticeps).

The research article was published today in the journal Conservation Physiology.

The study, which was the first to investigate the response to warming and increased pCO2 (partial pressure of carbon dioxide) in a developing Antarctic fish, assessed the effects of near-future ocean warming and acidification on early embryos of the naked dragonfish, a shallow benthic spawner exclusive to the circumpolar Antarctic. As the formation of their embryos takes longer than many species (up to ten months), this makes them particularly vulnerable to a change in chemical and physical conditions.

Continue reading ‘New study exposes negative effects of climate change on Antarctic fish’

Ocean acidification exerts negative effects during warming conditions in a developing Antarctic fish

Anthropogenic CO2 is rapidly causing oceans to become warmer and more acidic, challenging marine ectotherms to respond to simultaneous changes in their environment. While recent work has highlighted that marine fishes, particularly during early development, can be vulnerable to ocean acidification, we lack an understanding of how life-history strategies, ecosystems and concurrent ocean warming interplay with interspecific susceptibility. To address the effects of multiple ocean changes on cold-adapted, slowly developing fishes, we investigated the interactive effects of elevated partial pressure of carbon dioxide (pCO2) and temperature on the embryonic physiology of an Antarctic dragonfish (Gymnodraco acuticeps), with protracted embryogenesis (∼10 months). Using an integrative, experimental approach, our research examined the impacts of near-future warming [−1 (ambient) and 2°C (+3°C)] and ocean acidification [420 (ambient), 650 (moderate) and 1000 μatm pCO2 (high)] on survival, development and metabolic processes over the course of 3 weeks in early development. In the presence of increased pCO2 alone, embryonic mortality did not increase, with greatest overall survival at the highest pCO2. Furthermore, embryos were significantly more likely to be at a later developmental stage at high pCO2 by 3 weeks relative to ambient pCO2. However, in combined warming and ocean acidification scenarios, dragonfish embryos experienced a dose-dependent, synergistic decrease in survival and developed more slowly. We also found significant interactions between temperature, pCO2 and time in aerobic enzyme activity (citrate synthase). Increased temperature alone increased whole-organism metabolic rate (O2 consumption) and developmental rate and slightly decreased osmolality at the cost of increased mortality. Our findings suggest that developing dragonfish are more sensitive to ocean warming and may experience negative physiological effects of ocean acidification only in the presence of an increased temperature. In addition to reduced hatching success, alterations in development and metabolism due to ocean warming and acidification could have negative ecological consequences owing to changes in phenology (i.e. early hatching) in the highly seasonal Antarctic ecosystem.

Continue reading ‘Ocean acidification exerts negative effects during warming conditions in a developing Antarctic fish’

Effect of pH and temperature on antioxidant responses of the thick shell mussel Mytilus coruscus

This study evaluated the combined effects of seawater pH decrease and temperature increase on the activity of antioxidant enzymes in the thick shell mussel Mytilus coruscus, an ecological and economic bivalve species widely distributed along the East China Sea. Mussels were exposed to three pH levels (8.1, 7.7 and 7.3) and two temperatures (25°C and 30°C) for 14 days. Activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione (GSH), acid phosphatase (ACP), alkaline phosphatase (AKP) and glutamic-pyruvic transaminase (GPT) were measured in gills and digestive glands after 1, 3, 7 and 14 days of exposure. All enzymatic activities were significantly impacted by pH, temperature. Enzymatic activities at the high temperature were significantly higher than those at the low temperature, and the mussels exposed to pH 7.3 showed significantly higher activities than those under higher pH condition for all enzymes except ACP. There was no interaction between temperature and pH in two third of the measured activities suggesting similar mode of action for both drivers. Interaction was only consistently significant for GPX. PCA revealed positive relationships between the measured biochemical indicators in both gills and digestive glands. Overall, our results suggest that decreased pH and increased temperature induce a similar anti-oxidative response in the thick shell mussel.

Continue reading ‘Effect of pH and temperature on antioxidant responses of the thick shell mussel Mytilus coruscus’

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