Archive for November, 2018

The Ocean Foundation launch OA Day of Action website

The Ocean Foundation has launched a new website that uses digital storytelling tools to engage users in learning about ocean acidification and encouraging them to get involved in the first OA Day of Action, on the 8th of January (8.1, for the pH of the ocean!)

The Baltimore based band Animal Collective took an interest in The Ocean Foundation’s efforts and wrote an exclusive song just for this website. The song, “Suspend the Time,” features sounds from coral reefs and is available for download exclusively through the OA Day of Action website.

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Can larvae of a marine fish adapt to ocean acidification? Evaluating the evolutionary potential of California Grunion (Leuresthes tenuis)

Ocean acidification can reduce the growth and survival of marine species during their larval stages. However, if populations have the genetic capacity to adapt and increase their tolerance of low pH and high pCO2 levels, this may offset the harmful effects of ocean acidification. By combining controlled breeding experiments with laboratory manipulations of seawater chemistry, we evaluated genetic variation in tolerance of ocean acidification conditions for a nearshore marine fish, the California Grunion (Leuresthes tenuis). Our results indicated that acidification conditions increased overall mortality rates of grunion larvae, but did not have a significant effect on growth. Groups of larvae varied widely with respect to mortality and growth rates in both ambient and acidified conditions. We demonstrate that the potential to evolve in response to ocean acidification is best described by considering additive genetic variation in fitness‐related traits under both ambient and acidified conditions, and by evaluating the genetic correlation between traits expressed in these environments. We used a multivariate animal model to estimate additive genetic (co)variance in larval growth and mortality rates under both ambient and acidified conditions (low pH/high pCO2). Our results suggest appreciable genetic variation in larval mortality rates (h2Ambient = 0.120; h2Acidified = 0.183; rG = 0.460), but less genetic variation in growth (h2Ambient = 0.092; h2Acidified = 0.101; rG = 0.135). Maternal effects on larval mortality rates accounted for 26‐36% of the variation in phenotypes, but maternal effects accounted for only 8% of the variation in growth. Collectively, our estimates of genetic variation and covariation suggest that populations of California Grunion have the capacity to adapt relatively quickly to long‐term changes in ocean chemistry.

Continue reading ‘Can larvae of a marine fish adapt to ocean acidification? Evaluating the evolutionary potential of California Grunion (Leuresthes tenuis)’

Carbon burial in deep-sea sediment and implications for oceanic inventories of carbon and alkalinity over the last glacial cycle

Although it has long been assumed that the glacial–interglacial cycles of atmospheric CO2 occurred due to increased storage of CO2 in the ocean, with no change in the size of the “active” carbon inventory, there are signs that the geological CO2 supply rate to the active pool varied significantly. The resulting changes of the carbon inventory cannot be assessed without constraining the rate of carbon removal from the system, which largely occurs in marine sediments. The oceanic supply of alkalinity is also removed by the burial of calcium carbonate in marine sediments, which plays a major role in air–sea partitioning of the active carbon inventory. Here, we present the first global reconstruction of carbon and alkalinity burial in deep-sea sediments over the last glacial cycle. Although subject to large uncertainties, the reconstruction provides a first-order constraint on the effects of changes in deep-sea burial fluxes on global carbon and alkalinity inventories over the last glacial cycle. The results suggest that reduced burial of carbonate in the Atlantic Ocean was not entirely compensated by the increased burial in the Pacific basin during the last glacial period, which would have caused a gradual build up of alkalinity in the ocean. We also consider the magnitude of possible changes in the larger but poorly constrained rates of burial on continental shelves, and show that these could have been significantly larger than the deep-sea burial changes. The burial-driven inventory variations are sufficiently large to have significantly altered the δ13C of the ocean–atmosphere carbon and changed the average dissolved inorganic carbon (DIC) and alkalinity oncentrations of the ocean by more than 100µM, confirming that carbon burial uxes were a dynamic, interactive component of the glacial cycles that significantly modified the size of the active carbon pool. Our results also suggest that geological sources and sinks were significantly unbalanced during the late Holocene, leading to a slow net removal flux on the order of 0.1PgCyr−1 prior to the rapid input of carbon during the industrial period.

Continue reading ‘Carbon burial in deep-sea sediment and implications for oceanic inventories of carbon and alkalinity over the last glacial cycle’

Robust quantification of fish early life CO2 sensitivities via serial experimentation

Despite the remarkable expansion of laboratory studies, robust estimates of single species CO2 sensitivities remain largely elusive. We conducted a meta-analysis of 20 CO2 exposure experiments conducted over 6 years on offspring of wild Atlantic silversides (Menidia menidia) to robustly constrain CO2 effects on early life survival and growth. We conclude that early stages of this species are generally tolerant to CO2 levels of approximately 2000 µatm, likely because they already experience these conditions on diel to seasonal timescales. Still, high CO2 conditions measurably reduced fitness in this species by significantly decreasing average embryo survival (−9%) and embryo+larval survival (−13%). Survival traits had much larger coefficients of variation (greater than 30%) than larval length or growth (3–11%). CO2 sensitivities varied seasonally and were highest at the beginning and end of the species’ spawning season (April–July), likely due to the combined effects of transgenerational plasticity and maternal provisioning. Our analyses suggest that serial experimentation is a powerful, yet underused tool for robustly estimating small but true CO2 effects in fish early life stages.

Continue reading ‘Robust quantification of fish early life CO2 sensitivities via serial experimentation’

Getting to know the oyster ninja

At Ocean Conservancy, we share our thoughts in news articles, videos, social media, and our website, but in podcasts? Not too often. So, I was excited to partner with the Oyster Ninja Podcast, whose host, Gardner Douglas, recently interviewed me about ocean and coastal acidification. We discussed how it harms not only oysters, crabs and other shellfish but also the small businesses and communities that depend on seafood for their jobs.

Continue reading ‘Getting to know the oyster ninja’

Climate change poses significant threat to nutritional benefits of oysters

Credit: University of Plymouth

The nutritional qualities of shellfish could be significantly reduced by future ocean acidification and warming, a new study suggests.

Research has previously shown that climate change could threaten future production, safety and quality by negatively impacting the fitness of marine species.

Now scientists from the University of Plymouth, in a study published in Marine Environmental Research, have demonstrated the potential for negative nutritional effects within economically and commercially valuable species.

The research focussed on the Pacific oyster (Magallana gigas) and the native flat oyster (Ostrea edulis), with results showing that increased temperatures and CO2 levels could significantly reduce the former’s levels of proteins, lipids and carbohydrates.

Continue reading ‘Climate change poses significant threat to nutritional benefits of oysters’

Approaches to reconsider literature on physiological effects of environmental change: examples from ocean acidification research

Understanding links between the abiotic environment and organism fitness and function is a central challenge of biology, and an issue of growing relevance due to anthropogenic environmental changes. To date, our understanding of these links has largely been based on the findings of isolated experimental studies. This command may, however, be enhanced where currently disparate data are synthesized. By outlining a range of approaches appropriate in bringing together the findings of studies considering ocean acidification effects, we hope to provide insight as to how they may be used in the future. Specifically, approaches discussed in this narrative literature review include established literature review methods, as well as emerging schemes structured around biological theories (i.e., dynamic energy budget, DEB; oxygen- and capacity-limited thermal tolerance, OCLTT; multiple performance-multiple optima, MPMO), and strategies developed in other disciplines (i.e., adverse outcome pathways, AOP). In the future approaches to use such frameworks in creative combinations may be developed. Here we discuss some of these potential combinations, specifically the use of: AOPs to identify key steps that can be explored in more detail through literature review frameworks; OCLTT and DEB frameworks to consider effects on both energy supply and allocation; MPMO frameworks to identify the performance curves of organisms whose interactions are considered in an ecosystem model. Regardless of the approach taken, synthesizing scientific literature represents a potentially powerful method to enhance understanding of the influence of the abiotic environment on whole organism fitness.

Continue reading ‘Approaches to reconsider literature on physiological effects of environmental change: examples from ocean acidification research’

Ocean acidification and Sustainable Development Goal 14: a goal but no target?

This paper explores the theme of climate change and the oceans with a focus on the “other” side of climate change: ocean acidification. It is estimated that the acidity of the oceans has increased by about 30 percent since the beginning of the Industrial era and the rate of change is particularly significant in colder Polar waters. Until recently, ocean acidification has received little attention at the international level and the particular threat posed by carbon dioxide (as opposed to other greenhouse gases) to the oceans is not specifically acknowledged within the climate change regime. By contrast, the United Nations General Assembly and other fora, such as the 1992 Convention on Biological Diversity, are increasingly acknowledging the threat posed by ocean acidification to the health of our oceans. Sustainable Development Goal 14, among other objectives, calls upon states to “minimize and address the impacts of ocean acidification, including through enhanced scientific cooperation at all levels” (14.3). Nevertheless, specific action, including targets to limit ocean acidification, have yet to be established by any institution. This chapter examines the interaction between law of the sea institutions and the climate regime in order to assess progress to date and potential for future action on ocean acidification and conclude with a number of proposals for reform.

Continue reading ‘Ocean acidification and Sustainable Development Goal 14: a goal but no target?’

Acid threatens almighty cod

For towns such as Vardo in Norway, cod fishing is a fundamental industry.

Credit: WHAMMER121736 / GETTY IMAGES

For cod facing the effects of climate change, it’s not the heat but the acid that threatens.

Ocean acidification – caused by atmospheric carbon dioxide entering the water and lowering its pH value – means there’s a narrower thermal window for the success of two species of northern cod, meaning that one of the world’s largest fisheries will be threatened if global temperature increases are not limited to 1.5 degrees Celsius, a new study finds.

The researchers, led by Flemming Dahlke of the Alfred Wegener Institute in Germany, find that embryos of cod are able to survive only within a limited temperature range, and that the range lessens in more acidic conditions.

Continue reading ‘Acid threatens almighty cod’

Ocean acidification research hub opens at PML

PML has opened the first European hub as part of a global network to observe and assess ocean acidification and its impact upon the world ocean.

The North East Atlantic Ocean Acidification Hub has been established, with support from the Department for Environment, Food and Rural Affairs (DEFRA), and will act as the European regional centre for monitoring and research into ocean acidification, primarily within the NE Atlantic region. This is part of a wider research community initiative, the Global Ocean Acidification Observing Network (GOA-ON), which has driven the formation of regional hubs in North America, Latin America, Africa and the Western Pacific to collaborate on all aspects of Ocean Acidification (OA) monitoring research. This new hub for the NE Atlantic will complement these existing hubs.

Ocean acidification is the change in ocean pH caused by elevated CO2 levels entering the water, and the chemical processes this triggers. This change in chemistry has already been shown to have wide-ranging effects on myriad marine life, having detrimental impacts on behaviours and biology, and there are likely many more consequences so far not fully understood.

Continue reading ‘Ocean acidification research hub opens at PML’


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Ocean acidification in the IPCC AR5 WG II

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