Archive for September, 2019



Selectively bred oysters can alter their biomineralization pathways, promoting resilience to environmental acidification

Commercial shellfish aquaculture is vulnerable to the impacts of ocean acidification driven by increasing carbon dioxide (CO2) absorption by the ocean as well as to coastal acidification driven by land run off and rising sea level. These drivers of environmental acidification have deleterious effects on biomineralization. We investigated shell biomineralization of selectively bred and wild‐type families of the Sydney rock oyster Saccostrea glomerata in a study of oysters being farmed in estuaries at aquaculture leases differing in environmental acidification. The contrasting estuarine pH regimes enabled us to determine the mechanisms of shell growth and the vulnerability of this species to contemporary environmental acidification. Determination of the source of carbon, the mechanism of carbon uptake and use of carbon in biomineral formation are key to understanding the vulnerability of shellfish aquaculture to contemporary and future environmental acidification. We, therefore, characterized the crystallography and carbon uptake in the shells of S. glomerata, resident in habitats subjected to coastal acidification, using high‐resolution electron backscatter diffraction and carbon isotope analyses (as δ13C). We show that oyster families selectively bred for fast growth and families selected for disease resistance can alter their mechanisms of calcite crystal biomineralization, promoting resilience to acidification. The responses of S. glomerata to acidification in their estuarine habitat provide key insights into mechanisms of mollusc shell growth under future climate change conditions. Importantly, we show that selective breeding in oysters is likely to be an important global mitigation strategy for sustainable shellfish aquaculture to withstand future climate‐driven change to habitat acidification.

Continue reading ‘Selectively bred oysters can alter their biomineralization pathways, promoting resilience to environmental acidification’

Expert backs international call for action to safeguard our oceans

A report by the Intergovernmental Panel on Climate Change (IPCC) cites several research papers authored by University of Plymouth academics

A world-leading expert on ocean acidification has backed international calls for immediate action to protect our seas against the threat of global environmental change.A report published by the Intergovernmental Panel on Climate Change (IPCC), which cites several research papers authored by University of Plymouth researchers, has revealed the extent of the crisis facing humanity as the ocean and its services begin to show signs of collapse.

It also calls for urgent measures to be put in place, asking that between now and the end of 2020, the High Seas should be protected under international law.

Professor Jason Hall-Spencer, from the University of Plymouth, recently co-authored a report by the International Programme on the State of the Ocean (IPSO) which warned that failure to take action in the next 10 years could result in catastrophic changes in the functioning of the global ocean.

Continue reading ‘Expert backs international call for action to safeguard our oceans’

In response to the IPCC Special Report on Ocean and Cryosphere in a Changing Climate, the OA Alliance brings together Governments and outlines policy frameworks for taking action

New York, NY– As part of a series of events supporting the UN Climate Action Summit and Climate Week in New York, the International Alliance to Combat Ocean Acidification (Ocean Acidification Alliance) is calling for national and subnational action to protect oceans from the impacts of rising carbon emissions.

Today’s release of the IPCC Special Report on the Ocean and Cryosphere in Changing Climate emphasized that climate change is already having major impacts on our ocean, making our ocean warmer, more acidified, more stratified and oxygen depleted.  From oyster die-offs to coral reef bleaching to marine heat waves and harmful algal blooms, coastal communities around the world are feeling the effects on fisheries, aquaculture, tourism and marine ecosystems.

Continue reading ‘In response to the IPCC Special Report on Ocean and Cryosphere in a Changing Climate, the OA Alliance brings together Governments and outlines policy frameworks for taking action’

Fish are in trouble with the climate crisis, IPCC report finds

Since the 1970s, the climate crisis has made our oceans warmer and more acidic, reducing the number of fish we rely on for our food and putting the future of fish in peril, according to a major UN report out Wednesday.

Rising temperatures mean oceans will have less oxygen, and this, along with more heatwaves and increased acidification, will make fish move further away from the coast and create larger deadzones, where life cannot survive.

Ultimately, the report said, this will lead to the extinction of some species of fish, which Americans have been eating an increasing amount of recent years.

The US dietary guidelines recommend 8-12 ounces of seafood a week to keep a healthy diet. Fish plays an even bigger role internationally, providing up to half of all animal protein eaten in developing countries and it remains a leading source of vitamins and minerals.

Continue reading ‘Fish are in trouble with the climate crisis, IPCC report finds’

Oregon pushes action plan as international attention shifts to climate impacts on oceans

A new United Nations report on the impacts of climate change gives a bleak outlook for the world’s oceans and ice caps unless global warming is significantly curbed soon.

The report comes from the Intergovernmental Panel on Climate Change, a group of 100 scientists from 36 countries, including the United States. It shows that releases of carbon dioxide and other gases from the production and burning of fossil fuels and other human activity have already caused the oceans to be warmer, more acidic and less productive.

Some of these consequences are playing out in the Pacific Northwest.  The report says there’s a very high confidence “marine heatwaves have … doubled in frequency since 1982 and are increasing in intensity.”

Continue reading ‘Oregon pushes action plan as international attention shifts to climate impacts on oceans’

Present and future adaptation of marine species assemblages: DNA-based insights into climate change from studies of physiology, genomics, and evolution

Marine species live in a dynamic physical and biological environment that demands frequent physiological adjustment and can result in strong natural selection or shifts in species ranges. We illustrate the patterns and processes of adaptation to environmental change with genetic-based examples that range from a focus on single proteins to whole genomes to whole communities. This work shows how single amino acid changes adapt proteins to function at different temperatures. It shows how acidification impacts expression of proteins in energy pathways in adults and exerts natural selection on many genes in larvae. Whole genome surveys along coastlines are now possible, and they reveal unexpected patterns of genetic differentiation even in highly dispersive species. Genetic surveys of over 70 species along the North American west coast show high levels of genetic diversity and genetic structure clustered at headlands and capes known to mark species range boundaries. Finally, new surveys of DNA variation in whole communities show promise for rapid monitoring that can augment and complement traditional dive surveys. Overall, dynamics in the physical environment have a strong effect on organism physiology, which results in diverse patterns of population growth and persistence, as well as of species range and evolutionary capacity. The high level of adaptive genetic variation shown here suggests an ability for marine populations to adapt in the face of climate change, but many questions remain about how fast, complete, and effective this evolution will be.

Continue reading ‘Present and future adaptation of marine species assemblages: DNA-based insights into climate change from studies of physiology, genomics, and evolution’

Connecting science to policymakers, managers, and citizens

Twenty years ago, the creation of a new scientific program, the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO), funded by the Packard Foundation, provided the opportunity to integrate—from the outset—research, monitoring, and outreach to the public, policymakers, and managers. PISCO’s outreach efforts were initially focused primarily on sharing scientific findings with lay audiences, but over time they evolved to a more interactive, multi-directional mode of engagement. Over the next two decades, PISCO science and scientists significantly influenced local, state, federal, and international decisions about many topics, but especially marine protected areas, hypoxia, ocean acidification, fishery management, and marine diseases. PISCO scientists’ long-term data and understanding of key ecosystem processes also enabled them to detect anomalies, investigate rapidly, and inform others about novel developments such as hypoxia, acidification, warming, and disease. Especially during a time of dynamic changes in ecosystems, long-term data like PISCO’s have proven invaluable. Moreover, PISCO’s dual focus on understanding fundamental processes and finding solutions (not just identifying problems) has resulted in rich opportunities to co-create knowledge with citizens and translate that knowledge into action by citizens, managers, and policymakers. PISCO has delivered on its goal to serve society through science.

Continue reading ‘Connecting science to policymakers, managers, and citizens’

Effect of Theora lubrica on the response of coastal soft sediment nitrogen cycling to ocean acidification

Ocean acidification could influence nitrogen cycling in coastal soft sediments, which are moderated by bioturbating macrofauna. The functioning of coastal ecosystems has a strong connection with nitrogen fluxes that occur at the sediment–seawater interface; the disturbance of the sediment matrix via bioturbation can significantly alter these fluxes. To investigate how decreasing seawater pH affects the fluxes of 02, NH4+, NO2– and NO3–, I incubated sediment core samples of intact coastal subtidal silt in four seawater recirculating systems and injected CO2 to adjust their pH to 8.0, 7.8, 7.6 and 7.4. I also incorporated bioturbation via a Bivalve treatment by adding 10 Theora lubrica (introduced infaunal bivalve) to a sediment core. Furthermore, the experiment was done in full darkness to eliminate photosynthesis, and salinity and temperature were controlled variables. Initial measurements at in situ pCO2 indicated, that the Bivalve treatment significantly increased NH4+ and NO3– effluxes, and O2 influxes, but had no effect on NO2- fluxes. After a 20-day incubation, the final measurements revealed, that seawater acidification significantly increased NH4+ and NO2– effluxes, but had no effect on the fluxes of NO3- and O2. Furthermore, I detected no significant effects on nitrogen fluxes by the interaction between the pH and Bivalve treatments; however, the interaction significantly decreased O2 influxes. I hypothesise that the addition of T. lubrica stimulated ammonification and nitrification at in situ pCO2 during the initial measurements. I also suspect that seawater acidification decreased coupled nitrification-denitrification during the final measurements. Furthermore, I suggest that T. lubrica caused both direct and indirect effects on the sediment matrix, leading to the significant decrease in O2 influxes during lower seawater pH within the Bivalve treatment cores. Overall, my study was conclusive because I was able to prove that T. lubrica had no influence on coastal soft sediment nitrogen cycling during seawater acidification. Furthermore, I demonstrated that seawater acidification significantly affected sediment nitrogen cycling, which means ocean acidification could have a profound impact on coastal ecosystem functioning in the future.

Continue reading ‘Effect of Theora lubrica on the response of coastal soft sediment nitrogen cycling to ocean acidification’

Impact of ocean acidification on growth, onset of competence, and perception of cues for metamorphosis in larvae of the slippershell snail, Crepidula fornicata

Ocean pH has been declining since the start of the Industrial Revolution, and is predicted to continue declining for at least another 200 years. Although the chemical cues that induce larval metamorphosis in marine invertebrates in part determine the distribution and persistence of many coastal marine communities, few studies have examined the effects of ocean acidification on the timing of metamorphic competence or the ability of larval invertebrates to metamorphose in response to environmental cues. Working with larvae of the marine gastropod Crepidula fornicata, we examined the impacts of sudden, short-term (2 h), and prolonged (several weeks) exposure to reduced pH as low as 7.5 on larval survival and growth, the onset of metamorphic competence, and the ability of larvae to perceive inductive cues and metamorphose in their presence. Unexpectedly, although larvae reared at pH 7.5 grew more slowly and took longer to become competent to metamorphose, exposure to acidified conditions did not appreciably impair larval cue perception for metamorphosis.

Continue reading ‘Impact of ocean acidification on growth, onset of competence, and perception of cues for metamorphosis in larvae of the slippershell snail, Crepidula fornicata’

The Intergovernmental Panel on Climate Change (IPCC) releases its Special Report on the Ocean and the Cryosphere in a Changing Climate

The new IPCC Special Report, released today,  is the first IPCC Report to focus on the role of the ocean in the global climate and the effects of climate change on the ocean. Ocean acidification is extensively covered throughout the report. A few OA-relevant excerpts from the Summary for Policymakers are cited below:

OBSERVED CHANGES AND IMPACTS

Observed Physical Changes

A2.5 The ocean has taken up between 20–30% (very likely) of total anthropogenic CO2 emissions since the 1980s causing further ocean acidification. Open ocean surface pH has declined by a very likely range of 0.017–0.027 pH units per decade since the late 1980s, with the decline in surface ocean pH very likely to have already emerged from background natural variability for more than 95% of the ocean surface area. {3.2.1; 5.2.2; Box 5.1; Figures SPM.1, SPM.2}
Continue reading ‘The Intergovernmental Panel on Climate Change (IPCC) releases its Special Report on the Ocean and the Cryosphere in a Changing Climate’


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Ocean acidification in the IPCC AR5 WG II

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