Archive for October, 2016

Ocean acidification talk on tap at OSU-Cascades Science Pub (15 November 2016)

It has been called the “evil twin” of climate change. As the oceans absorb carbon dioxide from the atmosphere and surface waters become more acidic, changes to marine ecosystems are likely to follow. Coral reefs, shell-forming organisms and the fish and marine mammals that depend on them are at risk.

At Oregon State University – Cascades upcoming Science Pub on Tuesday, Nov. 15, OSU marine ecologist George Waldbusser will describe what scientists know about the biological effects of ocean acidification, focusing on Oregon’s coast and it’s highly impacted oyster industry.

The presentation will include demonstrations with live oysters and real-time carbon dioxide sensors, and audience participation.

Waldbusser is an assistant professor of ocean ecology and biogeochemistry in OSU’s College of Earth, Ocean, and Atmospheric Sciences. His research interests include animal sediment interactions, ocean acidification, marine invertebrate ecology, and estuarine biogeochemistry.

Continue reading ‘Ocean acidification talk on tap at OSU-Cascades Science Pub (15 November 2016)’

Effects of elevated carbon dioxide on contraction force and proteome composition of sea urchin tube feet

This study examined how contraction force and protein profiles of the tube feet of the sea urchin (Pseudocentrotus depressus) were affected when acclimated to 400 (control), 2000 and 10,000 μatm CO2 for 48 days. Acclimation to higher CO2 conditions significantly reduced contraction force of the tube feet. Two-dimensional gel electrophoresis showed that eight spots changed in protein volume: six up-regulated and two down-regulated. Using matrix-assisted laser desorption/ionization-quadrupole ion trap-time of flight mass spectrometry, three up-regulated spots (tubulin beta chain, tropomyosin fragment, and actin N-terminal fragment) and two down-regulated spots (actin C-terminal fragment and myosin light chain) were identified. One possible interpretation of the results is that elevated CO2 weakened contraction of the tube feet muscle through an alteration of proteome composition, mainly associated with post-translational processing/proteolysis of muscle-related proteins.

Continue reading ‘Effects of elevated carbon dioxide on contraction force and proteome composition of sea urchin tube feet’

Institutional misfit and environmental change: A systems approach to address ocean acidification

Emerging environmental threats often lack sufficient governance to address the full extent of the problem. An example is ocean acidification which is a growing concern in fishing and aquaculture economies worldwide, but has remained a footnote in environmental policy at all governance levels. However, existing legal jurisdictions do account for some aspects of the system relating to ocean acidification and these may be leveraged to support adapting to and mitigating ocean acidification. We refine and apply a methodological framework that helps objectively evaluate governance, from a social-ecological systems perspective. We assess how well a set of extant US institutions fits with the social-ecological interactions pertinent to ocean acidification. The assessment points to measured legal gaps, for which we evaluate the government authorities most appropriate to help fill these gaps. The analysis is conducted on United State federal statutes and regulations. Results show quantitative improvement of institutional fit over time (2006 to 2013), but a substantial number of measured legal gaps persist especially around acknowledging local sources of acidification and adaptation strategies to deal with or avoid impacts. We demonstrate the utility of this framework to evaluate the governance surrounding any emerging environmental threat as a first step to guiding the development of jurisdictionally realistic solutions.

Continue reading ‘Institutional misfit and environmental change: A systems approach to address ocean acidification’

Ocean acidification and the future of the seafood business

The CO2 emissions are changing the ocean, and quite possibly the seafood business with it.

This Thursday marks a meeting between scientists, government officials, and key actors of Norwegian aquaculture enterprises. The topic of discussion? The future of the seafood business.

According to the conference website, “Climate change is a compounding threat to the sustainability of capture fisheries and aquaculture development. Higher sea temperatures, acidification and rising sea level will affect the seafood business directly.”

Not only will our response determine the future competitiveness of out seafood business, but “the consequences of out actions or inactions will extend well beyond Norway´s borders…”. Associate professor Are Olsen will contribute to the discussion by presenting a key note talk on ocean acidification.

The ocean has absorbed around a quarter of our carbon emissions since the industrial revolution, by absorbing CO2 from the atmosphere. This process also leads to ocean acidification.

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Influence of acidification and eutrophication on physiological functions of Conticribra weissflogii and Prorocentrum donghaiense

Eutrophication and acidification have been the most concerned environmental problems in coastal ecosystem. However, their combined effect on coastal ecosystem function was unknown. Both diatom (Conticribra weissflogii) and dinoflagellate (Prorocentrum donghaiense) are used as coastal algal model. Seven parameters were determined for physiological function assessment, including cell density, chlorophyll a (Chl a), protein, malonaldehyde (MDA), superoxide dismutase, carbonic anhydrase (CA), and nitrate reductase (NR). The influence of nitrate (N) and phosphate (P) on MDA and CA in C. weissflogii was significant, and that on Chl a and protein in P. donghaiense were also significant. However, the influence of acidification on physiological functions was not significant. The effect of acidification could be intensified by coastal eutrophication. More importantly, the coexist influence of acidification and eutrophication on CA, NR and protein in C. weissflogii and MDA in P. donghaiense was significant. Both NR activity and Chl a content in P. donghaiense were positively correlated to N and P concentration when pH were 7.9 and 7.8, respectively. With simultaneous worsening of acidification and eutrophication, the cell growth of P. Donghaiense was accelerated more obviously than C. weissflogii, i.e., dinoflagellate was more adaptable than diatom, thus algal species distribution and abundance could be changed.

Continue reading ‘Influence of acidification and eutrophication on physiological functions of Conticribra weissflogii and Prorocentrum donghaiense’

Fish responses to ocean acidification comes with a cost

Ocean acidification is currently recognized as a major threat to marine ecosystems and has become one of the fastest growing research fields in marine sciences. The excessive amount of anthropogenic carbon dioxide is making our oceans warmer and more acidic, by changing its basic chemistry. Since the industrial revolution era, ocean water has become 30% more acidic – faster than any known change in ocean chemistry for the last 300 million years. Present predictions indicate that with the current carbon dioxide emissions, this acidity values may double until the end of this century, comparing to pre-industrial times. This profound and abrupt change in ocean chemistry can lead to a multitude of cascading effects in different ecosystems. Many of the physiological changes expected to occur may affect particular key functional groups of species such as phytoplankton (the base of marine food webs) and ecosystem engineers (responsible to create and modify habitats) like corals. These are good examples of calcifying marine groups, which are known to be particularly susceptible to ocean acidification due to their dependence on calcium carbonate (an element that is scarce under acidified conditions) to build their exoskeleton. Nonetheless, the tolerance and sensitivity of other marine organisms to changes imposed by ocean acidification is becoming increasingly evident.

Continue reading ‘Fish responses to ocean acidification comes with a cost’

CO2 leakage from carbon dioxide capture and storage (CCS) systems affects organic matter cycling in surface marine sediments

Carbon dioxide capture and storage (CCS), involving the injection of CO2 into the sub-seabed, is being promoted worldwide as a feasible option for reducing the anthropogenic CO2 emissions into the atmosphere. However, the effects on the marine ecosystems of potential CO2 leakages originating from these storage sites have only recently received scientific attention, and little information is available on the possible impacts of the resulting CO2-enriched seawater plumes on the surrounding benthic ecosystem. In the present study, we conducted a 20-weeks mesocosm experiment exposing coastal sediments to CO2-enriched seawater (at 5000 or 20,000 ppm), to test the effects on the microbial enzymatic activities responsible for the decomposition and turnover of the sedimentary organic matter in surface sediments down to 15 cm depth. Our results indicate that the exposure to high-CO2 concentrations reduced significantly the enzymatic activities in the top 5 cm of sediments, but had no effects on subsurface sediment horizons (from 5 to 15 cm depth). In the surface sediments, both 5000 and 20,000 ppm CO2 treatments determined a progressive decrease over time in the protein degradation (up to 80%). Conversely, the degradation rates of carbohydrates and organic phosphorous remained unaltered in the first 2 weeks, but decreased significantly (up to 50%) in the longer term when exposed at 20,000 ppm of CO2. Such effects were associated with a significant change in the composition of the biopolymeric carbon (due to the accumulation of proteins over time in sediments exposed to high-pCO2 treatments), and a significant decrease (∼20–50% at 5000 and 20,000 ppm respectively) in nitrogen regeneration. We conclude that in areas immediately surrounding an active and long-lasting leak of CO2 from CCS reservoirs, organic matter cycling would be significantly impacted in the surface sediment layers. The evidence of negligible impacts on the deeper sediments should be considered with caution and further investigated simulating the intrusion of CO2 from a subsurface source, as occurring during real CO2 leakages from CCS sites.

Continue reading ‘CO2 leakage from carbon dioxide capture and storage (CCS) systems affects organic matter cycling in surface marine sediments’

Ecology of coralline red algae and their fossil evidences from India

Coralline red algae are important components of numerous tropical and temperate carbonate systems throughout the world. The environmental factors such as light, water depth, temperature and ocean chemistry have been acknowledged by researchers worldwide to have an impact on the recruitment and diversity of shallow-water coralline algae in marine benthic environments. The potential of coralline red algae as marine climate archives has also been highlighted in many recent studies. A brief overview of the fossil coralline red algae from various sedimentary basins of India is presented herein as well as their palaeoecological applications. The shortcomings and future prospects of coralline algal studies in India pertinent to significant aspects such as palaeoecology, palaeoenvironmental reconstructions, climate dynamics and extinction episodes are also discussed succinctly.

Continue reading ‘Ecology of coralline red algae and their fossil evidences from India’

Climate change: Scientists seek to find the ‘tipping point’ of ocean acidification around NZ

Kiwi scientists are simulating how New Zealand’s coastal environment will respond to potentially disastrous effects of acidification caused by climate change.

The new study aims to pinpoint a possible “tipping point” at which ecosystems could collapse – potentially threatening our aquaculture industry.

Ocean acidification, often receiving less public attention than other major climate change impacts like sea level rise and violent storms, is increasingly concerning scientists because of the global threat it poses to coral communities and shellfish aquaculture.

It’s driven by increasing carbon dioxide in the atmosphere, which is absorbed by oceans and causes pH levels to drop and waters to become more acidic.

Scientists are particularly worried about the survival of organisms that have shells composed of calcium carbonate, ranging from corals to shellfish, as it becomes more difficult to grow and maintain in a more acidic ocean.

In a new study, the first of its kind in the world, New Zealand researchers will test how microbes in near-shore sediments respond to pH levels simulated to reflect those projected in 50 years’ time.

Continue reading ‘Climate change: Scientists seek to find the ‘tipping point’ of ocean acidification around NZ’

Virtual reality shines light on ocean acidification

Software released last week by Stanford researchers allows anyone with virtual reality (VR) gear to witness ocean acidification firsthand. Developed by Stanford’s Virtual Human Interaction Lab, the free simulation takes users on an educational “field trip” to discover the science behind rising acidity in our oceans — a less visible consequence of burning fossil fuels.

“Our number one goal was to try and create a virtual field trip in science and chemistry,” said Jeremy Bailenson, professor of communications and founding director of the lab. “You can have these field trips anytime and anywhere.”

The simulation first transports you to a scene of heavy traffic, where you follow carbon dioxide molecules from the street to the ocean. Sinking below the surface, you then wade through a healthy reef teeming with wildlife. The narrator instructs you to count the number of snails using your virtual hands. You count a dozen or so. Moments later, you are transported to a reef under elevated acidity, where you attempt the species count again. You find none. As the narrator explains, this is because the reef has grown too acidic to support shell-building organisms, which form an important part of the marine food chain.

Continue reading ‘Virtual reality shines light on ocean acidification’

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Ocean acidification in the IPCC AR5 WG II

OUP book