Ocean acidification

A sample of the peppery furrow shell (Scrobicularia plana) as used in the research. (Carl Van Colen, Ghent University)

Projected ocean warming and acidification not only impacts the behaviour of individual species but also the wider marine ecosystems which are influenced by them, a new study shows.

Research published in Nature Climate Change shows that in warmer seawater with lower pH, a common clam – the peppery furrow shell (Scrobicularia plana) – makes considerable changes to its feeding habits.

Instead of relying predominantly on food from within the water column, it changed its behaviour to use its tube-like feeding siphon to scrape more of its food from the seafloor.

Continue reading ‘Warmer and acidified oceans can lead to ‘hidden’ changes in species behavior’

A seaweed species crucial to the survival of coral reefs may be able to gain resistance to ocean changes caused by climate change, new Te Herenga Waka—Victoria University of Wellington research recently published in Nature Climate Change shows.

The research, led by Dr Christopher Cornwall from the University’s School of Biological Sciences, showed that coralline algae can build tolerance to ocean acidification, one of the major side-effects of climate change over multiple generations.

“Coralline algae go through a natural process of calcification, where they build a calcium carbonate skeleton,” Dr Cornwall says. “Skeletons like this provide structure, allow them to grow, and protect these organisms. Our research has shown that growth of these skeletons is susceptible to climate change, at least initially.”

Continue reading ‘Crucial reef species may survive ocean changes under climate change’

New high-resolution maps show limited ocean capacity to absorb excess carbon dioxide

An international team led by researchers at the University of Maryland and the National Oceanic and Atmospheric Administration has created the most high-resolution maps to date showing changes in the pH of seawater since the Industrial Revolution began. Their study, published in the December 9, 2019 issue of the journal Nature Scientific Reports, suggests that the ocean’s capacity to continue absorbing carbon dioxide (CO2) from the atmosphere is diminishing.

Continue reading ‘Are we losing a key climate change buffer? (video)’

Denticles — the modified scales — of a puffadder shyshark seen through an optical microscope (left) and a scanning electron microscope (right) of CO2 exposed sharks denticles. Credit: Lutz Auerswald (left) / Jacqueline Dziergwa (right)

While regular fish have flat scales, shark ‘scales’ look more like teeth. But their denticles also cover their body and in particular influence their ability to swim. The denticles are made up of a compounds containing calcium.

The increasing amount of carbon dioxide (CO2) in the atmosphere due to climate change has also led to a higher concentration of CO2 in the oceans. The CO2 dissolves in the seawater to create carbonic acid that acidifies the oceans.

This higher acidity has already been found to damage the calcium carbonate in corals and other animals with calcium-based structures. The research team from three South African research institutions, from the University of Duisburg-Essen and HHU has now examined whether the more acidic seawater is also affecting sharks.

Continue reading ‘Ocean acidification is damaging shark scales’

Existing genetic variation in natural populations of Mediterranean mussels allows them to adapt to declining pH levels in seawater caused by carbon emissions

Existing genetic variation in natural populations of Mediterranean mussels allows them to adapt to declining pH levels in seawater caused by carbon emissions. A new study by biologists from the University of Chicago shows that mussels raised in a low pH experimental environment grew smaller shells than those grown at normal pH levels, but the overall survival rate of mussels grown under both conditions was the same.

The surviving population in the low pH environment differed genetically from the others, suggesting that genetic variants that already exist in a subset of the natural population of mussels allowed them to adapt to the harsher new environment. This could be good news for conservationists and seafood lovers alike, as the culinary delicacy finds ways to adjust to the changing seas.

Continue reading ‘Genetic variation gives mussels a chance to adapt to climate change’

New research by NOAA, the University of Maryland, and international partners published in Nature Scientific Reports shows that the changing chemistry of seawater has implications for continued greenhouse gas absorption.

The ocean has been playing an important role in helping slow down global climate change by removing the greenhouse gas carbon dioxide (CO₂) from the atmosphere. However, decades of ocean observations show that the CO₂ absorbed by the ocean is changing the chemistry of seawater, a process known as ocean acidification. The study discusses the reduced buffering capacity of the ocean as pH levels drop and its implications for reducing the ocean’s role as a CO₂ sink in the future.

The researchers from NCEI, the NOAA Pacific Marine Environmental Laboratory (PMEL), and research institutions in Norway stress the importance of leveraging in situ observation-based global pH data products to help improve model projections. A climatology developed from this research may lead to more preventive and adaptive solutions to reduce carbon dioxide emissions and, at the same time, allow for ocean acidification adaptation strategies in regional areas.

Continue reading ‘The future of ocean acidification’

Shellfish aquaculture is thriving in New England—some estimates suggest the market value tops $50 million. But the future of the industry’s growth is only as good as the ability of shellfish to build strong shells.

And that could prove challenging in decades to come as coastal waters in the region become more acidic, according to Jennie Rheuban, a research associate at Woods Hole Oceanographic Institution (WHOI).

“Coastal acidification here in Massachusetts is a real concern, as it can prevent mollusks from growing shells and affect how long it takes for them to reach a harvestable size,” says Rheuban. “Aquaculture businesses haven’t seen the effects yet, but the industry is vulnerable and could be at risk in the future.”

Continue reading ‘Ocean acidification gets a watchful eye in New England aquaculture ‘hot spot’’