Ocean acidification

Today in Vienna, at a meeting of the International Atomic Energy Agency (IAEA) Board of Governors, U.S. Ambassador Jackie Wolcott announced the allocation of just over $1,013,000 in U.S. funding for the IAEA Nuclear Sciences and Applications Environment Laboratories in Monaco to study ocean acidification and degraded marine ecosystems. The funding is provided by the U.S. Department of Energy’s Office of Science through the IAEA’s Peaceful Uses Initiative.

The contribution includes approximately $665,000 for the Ocean Acidification International Coordination Center (OA-ICC) located at the IAEA’s environment laboratories. The OA-ICC works to promote, facilitate, and communicate global activities on ocean acidification. It also serves as a hub to bring together scientists, policy makers, media, schools, the general public, and other ocean acidification stakeholders. Since 2012, the United States has donated over $4 million to the OA-ICC to work with partners across the globe to advance ocean acidification science and international collaboration.

Ethereal, swaying pillars of brown kelp along California’s coasts grow up through the water column, culminating in a dense surface canopy of thick fronds that provide homes and refuge for numerous marine creatures. There’s speculation that these giant algae may protect coastal ecosystems by helping alleviate acidification caused by too much atmospheric carbon being absorbed by the seas.

A new on-site, interdisciplinary analysis of giant kelp in Monterey Bay off the coast of California sought to further investigate kelp’s acidification mitigation potential. “We talk about kelp forests protecting the coastal environment from ocean acidification, but under what circumstances is that true and to what extent?” said study team member Heidi Hirsh, a PhD student at Stanford’s School of Earth, Energy & Environmental Sciences (Stanford Earth). “These kinds of questions are important to investigate before trying to implement this as an ocean acidification mitigation strategy.”

MADISON, Wis. — Coral reefs are vibrant communities that host a quarter of all species in the ocean and are indirectly crucial to the survival of the rest. But they are slowly dying — some estimates say 30 to 50 percent of reefs have been lost — due to climate change.

In a new study, University of Wisconsin-Madison physicists observed reef-forming corals at the nanoscale and identified how they create their skeletons. The results provide an explanation for how corals are resistant to acidifying oceans caused by rising carbon dioxide levels and suggest that controlling water temperature, not acidity, is crucial to mitigating loss and restoring reefs.

Invasive long-spined sea urchins have boomed along Tasmania’s East Coast in recent decades, taking advantage of warming waters under climate change and a lack of predators due to fishing to overgraze kelp beds and create extensive urchin barrens devoid of other marine life.

However, the urchins themselves are vulnerable to another side-effect of climate change – ocean acidification caused by increased absorption of CO₂ emissions into the oceans – which can jeopardise the ability of calcifying marine organisms like urchins to form skeletons.

A new study by IMAS researchers Dr Scott Ling and Prof Catriona Hurd along with Dr Chris Cornwall (Victoria University, Wellington) and Dr Bronte Tilbrook (CSIRO) measured pH in both healthy kelp beds and overgrazed urchin barrens.

Published in the journal PLOS One, the study used the data to project how Tasmania’s urchin populations and kelp ecosystems will be shaped by the multiple stressors they face as the climate continues to change on this coast.

The combined environmental threat of plastic pollution and ocean acidification are having significant impacts on species living in our oceans, according to new research.

An international team of scientists found that after three weeks of being submerged in the ocean, the bacterial diversity on plastic bottles was twice as great as on samples collected from the surrounding seawater.

However, in areas of elevated carbon dioxide, a large number of taxonomic groups – including bacteria that play an important role in carbon cycling – were negatively impacted.

Conversely, other species – including those have previously been shown to thrive in areas of high ocean plastics and to potentially cause disease on coral reefs – were enriched by it.

The team determined that a combination of ocean pH changes and the release of immense quantities of carbon dioxide during volcanism events in what is now Siberia caused ocean acidification and global warming. The most extensive mass extinction in Earth’s history took place about 252 million years ago when 90 per cent of ocean life and 70 per cent of life on land perished.
 
In a study recently published in the journal Nature Geoscience, an international team of Earth scientists, including Brock University Professor Uwe Brand, provide a conclusive roadmap of the geochemical processes that led to this massive biotic extinction.
 
“What we learned is the event occurred in pulses, with each pulse constricting the hospitable environment further and further, cascading down to the extinction event over a short geological timeline,” Brand said.

The team, including members from Canada, Germany and Italy, determined that a combination of ocean pH changes and the release of immense quantities of carbon dioxide during volcanism events in what is now Siberia caused ocean acidification and global warming.
 
Ocean acidification restricted livable parameters for marine life, while warming increased temperature and rainfall globally. These pulses caused weathering and overloaded oceans with nutrients, which depleted their dissolved oxygen.

A new study has shown ocean acidification is no longer a sombre forecast for the Great Barrier Reef but a present-day reality

Newswise — Ocean acidification is no longer a sombre forecast for the Great Barrier Reef but a present-day reality, a new study reveals.

The study, published in the international Journal Scientific Reports, shows carbon dioxide (CO₂) and ocean acidification are rapidly increasing on the Reef. Seawater CO₂ has risen 6 per cent over the past 10 years and matches the rate of CO₂ increases in the atmosphere, confirming the influence of atmospheric CO₂ on seawater CO₂ levels.

“People talk about ocean acidification in terms of 50 years’ time, but for the first time our study shows how fast ocean acidification is already happening on the Reef,” said Dr Katharina Fabricius, lead author and Senior Principal Research Scientist at the Australian Institute of Marine Science (AIMS).

Two decades of data document a dwindling of mussels, barnacles and snails

The waters of the Gulf of Maine are warming faster than oceans almost anywhere on Earth. As the level of carbon dioxide rises in the atmosphere, it’s absorbed by the sea, causing pH levels to fall. Ocean acidification makes it difficult for shellfish to thicken their shells –their primary defense against predators.

In a U.S. National Science Foundation-funded study published in Communications Biology, researchers Peter Petraitis of the University of Pennsylvania and Steve Dudgeon of California State University, Northridge, show that the changing climate is taking a toll on Maine’s sea life.

Study analyzes the reaction of plankton communities to increased carbon dioxide

26 October 2020 / Kiel. Marine food webs and biogeochemical cycles react very sensitively to the increase in carbon dioxide (CO2) – but the effects are far more complex than previously thought. This is shown in a study published by a team of researchers from the GEOMAR Helmholtz Centre for Ocean Research Kiel in the journal Nature Climate Change. Data were combined from five large-scale field experiments, which investigated how the carbon cycle within plankton communities reacts to the increase of CO2.

The ocean plays a key role in the current climate change, as it absorbs a considerable part of the atmospheric carbon dioxide emitted by mankind. On the one hand, this slows down the heating of the climate, and on the other hand, the dissolution of CO₂ in seawater leads to acidification of the oceans. This has far-reaching consequences for many marine organisms and thus also for the oceanic carbon cycle. One of the most important mechanisms in this cycle, is called the biological carbon pump. Part of the biomass that phytoplankton forms in the surface ocean through photosynthesis sinks to the depths in the form of small carbonaceous particles. As a result, the carbon is stored for a long time in the deep sea. The ocean thus acts as a carbon sink in the climate system. How strongly this biological pump acts varies greatly from region to region and depends on the composition of species in the ecosystem.

A group of thirteen researchers from six countries has released a new scientific paper rejecting an earlier study claiming ocean acidification has no effects of the behavior of coral reef fishes.

Earlier this year, a paper by Clark et al. published in Nature claimed that previous experiments on the effects of elevated CO₂ on reef fish behavior could not be repeated, and argued ocean acidification has no effects on the behaviors of coral reef fishes.

In a comprehensive rebuttal published in Nature, lead author Professor Philip Munday from the Centre of Excellence for Coral Reef Studies at James Cook University said there are fundamental methodological differences between the studies conducted in the “provocative” Clark et al. article and the earlier studies with which they made direct comparison.