Ocean acidification

Microcolony of the coral Stylophora pistillata, also called Smooth Cauliflower Coral, with microsensor.
Credit: Eric Tambutté, Centre Scientifique de Monaco

Coral reefs are made up of massive calcium carbonate skeletons. The present study, published in Science Advances on January 16th 2019, reveals insights into the process of calcification, namely the process that leads to the formation of these skeletons. Elucidating coral calcification is key to a deeper understanding and better predictions of how and why coral reefs respond to environmental changes, such as ocean acidification.

“By combining microscopy and microsensor measurements, we were able to directly measure calcium, carbonate and pH at the site of calcification in coral microcolonies of Stylophora pistillata and derive important carbonate chemistry parameters from it. We show that all measured and derived parameters are higher at the coral than in the surrounding seawater. This points to the importance of calcium and carbon concentrating mechanisms that are actively regulated by the coral to form its skeleton,” says lead author Duygu Sevilgen, scientist at the CSM and former PhD-student at the Max-Planck-Institute for Marine Microbiology.

Continue reading ‘Full carbonate chemistry at the site of calcification in a tropical coral’

Photo: Getty

Thanks to carbon dioxide emissions, Earth’s seas are getting both warmer and more acidic. Until now, the consequences of ocean acidification were thought to be mostly limited to marine animals that make hard, calcium carbonate shells, but new research suggests that fish will feel the impact too. Acidic conditions can screw with how their skeletons develop, which could have ramifications for everything about their fishy lives.

As an ever-increasing concentration of carbon dioxide in our atmosphere bleeds into the oceans, the resulting chemical reaction is lowering the water’s pH. This is already hurting oysters and other shellfish, and eating away at coral reefs. Recently, scientists have also determined that acidic seas can blunt the sensitive senses of smell of some fish, making it difficult for them to sniff out prey or to avoid becoming a meal.

Continue reading ‘Add screwed-up fish skeletons to the list of possible climate change horrors’

Orono, Maine — The effect of ocean acidification on iron availability to phytoplankton in the eastern North Pacific is the focus of a three-year, more than $954,000 National Science Foundation collaborative research grant to the University of Maine, University of Washington and University of South Florida.

UMaine School of Marine Sciences professor Mark Wells will lead the project, in collaboration with Charles Trick from the Western University and Kristen Buck from the University of South Florida. Joining them will be Shigenobu Takeda of the University of Nagasaki, and graduate and undergraduate students from the four universities.

The international collaboration also will feature educational outreach for the public, with Maine K-12 students and their teachers engaged in learning opportunities during and after the research cruise.

Continue reading ‘Exploring the effects of ocean acidification on iron for phytoplankton in North Pacific’

The ability to smell is critical for salmon. They depend on scent to avoid predators, sniff out prey and find their way home at the end of their lives when they return to the streams where they hatched to spawn and die.

New research from the University of Washington and NOAA Fisheries’ Northwest Fisheries Science Center shows this powerful sense of smell might be in trouble as carbon emissions continue to be absorbed by our ocean. Ocean acidification is changing the water’s chemistry and lowering its pH. Specifically, higher levels of carbon dioxide, or CO2, in the water can affect the ways in which coho salmon process and respond to smells.

Continue reading ‘Salmon may lose the ability to smell danger as carbon emissions rise (text and video)’

New research from the University of Washington and NOAA Fisheries’ Northwest Fisheries Science Center shows this powerful sense of smell might be in trouble as carbon emissions continue to be absorbed by our ocean. Ocean acidification is changing the water’s chemistry and lowering its pH. Specifically, higher levels of carbon dioxide, or CO2, in the water can affect the ways in which coho salmon process and respond to smells.

Continue reading ‘Salmon may lose the ability to smell danger as carbon emissions rise’

Something peculiar is happening in the azure waters off the rocky cliffs of Ischia, Italy. There, streams of gas-filled volcanic bubbles rising up to the surface are radically changing life around them by making seawater acidic. Stanford researchers studying species living near these gassy vents have learned what it takes to survive in acidic waters, providing a glimpse of what future oceans might look like as they grow more acidic.

Their findings, published December 11 in Nature Communications, suggest that ocean acidification driven by human-caused carbon dioxide emissions could have a larger impact than previously thought.

“When an organism’s environment becomes more acidic, it can dramatically impact not only that species, but the overall ecosystem’s resilience, function and stability,” said Stanford marine biologist Fiorenza Micheli, lead author on the paper. “These transformations ultimately impact people, especially our food chains.”

Continue reading ‘Stanford researchers uncover startling insights into how human-generated carbon dioxide could reshape oceans’

Evidence is rapidly accumulating that ocean acidification and elevated temperatures will have catastrophic consequences for marine organisms and ecosystems. In fact, it is something we are already witnessing. Coral reefs are bleaching, while snails and other calcifying marine organisms struggle to build their shells, scales and skeletons and juvenile marine animals even struggle to navigate to suitable habitats.

Yet many primary producers, including seaweeds, are predicted to thrive in the acidic oceans of the future – as they use CO₂ from the seawater to produce energy by photosynthesis.

Humans have eaten seaweeds for tens of thousands of years and today the diets of billions of people, especially in Asia, are based on cultivated seaweeds. However, while future ocean conditions may improve the yield of farmed seaweeds, we do not know how the nutritional content of seaweeds will be affected by climate change. To investigate this, we recently looked into how the iodine content of seaweeds will be affected by future climate change scenarios.

Continue reading ‘Ocean acidification will increase the iodine content of edible seaweeds and their consumers’