Archive for the 'Media coverage' Category



The pH problem

Dr Cliff Law is investigating how photoplankton respond to ocean acidification. Photo: Dave Allen

Dr Cliff Law is investigating how photoplankton respond to ocean acidification. Photo credit: Dave Allen

The tiny single-cell aquatic plants that produce half of all our oxygen are threatened by ocean acidification. Maureen Howard talks to researchers about the danger and what’s to be done. 

Oceans gift us more than just a bracing walk on the beach, a feed of paua or the glimpse of a humpback whale from a boat off Kaikoura. At the base of the oceans’ foodweb are a multitude of single-celled phytoplankton species that produce 50% of the world’s oxygen and remove atmospheric carbon dioxide.

Phytoplankton might drift with the ocean currents, but they arguably drive the flourishing of life on earth. And now they are under threat.

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In kelp forests, scientists seek climate change refuge for herring roe

Lauren Bell points to herring eggs growing on silicone baking sheets, which mimic the texture of kelp but don’t photosynthesize. Bell is a researcher from UC Santa Cruz working closely with UAS professor Angie Bowers to study the impact of climate change on herring roe.

Lauren Bell points to herring eggs growing on silicone baking sheets, which mimic the texture of kelp but don’t photosynthesize. Bell is a researcher from UC Santa Cruz working closely with UAS professor Angie Bowers to study the impact of climate change on herring roe. Photo credit: Katherine Rose/KCAW

Aerial surveys of Sitka Sound showed a lot of active herring spawn this week, stretching over 31 nautical miles to date. But that wasn’t the only place to find roe.

In the basement of the Sitka Sound Science Center, researchers are incubating thousands of herring eggs to determine the effects of warming ocean temperatures and ocean acidification on the species — now and in the future.

Continue reading ‘In kelp forests, scientists seek climate change refuge for herring roe’

Chilean experts assess climate change impacts on Antarctic marine systems

 A photo of one of the boats taking part in Antarctic Scientific Expedition #55, carried out between January and March of 2019. Chilean scientists involved in that expedition have installed pH meters in the waters surrounding Antarctica to assess the extent to which increased levels of CO2 in the atmosphere, the main driver of climate change, are affecting ocean acidification. EPA-EFE/Paulina Möller/Private archive

A photo of one of the boats taking part in Antarctic Scientific Expedition #55, carried out between January and March of 2019. Chilean scientists involved in that expedition have installed pH meters in the waters surrounding Antarctica to assess the extent to which increased levels of CO2 in the atmosphere, the main driver of climate change, are affecting ocean acidification. Photo Credit: EPA-EFE/Paulina Möller/Private archive

Santiago, Apr 4 (efe-epa).- Chilean scientists have installed pH meters in the waters surrounding Antarctica to assess the extent to which increased levels of CO2 in the atmosphere, the main driver of climate change, are affecting ocean acidification.

As part of Antarctic Scientific Expedition #55, carried out between January and March of this year, the specialists plunged a sensor to a depth of 30 meters (98 feet) to measure pH levels (how acidic or alkaline the water is).

The project at South Bay, just off Doumer Island, involved launching a capsule from a boat and keeping it submerged for a period of one year so it can take readings of pH levels at three-hour intervals.

Continue reading ‘Chilean experts assess climate change impacts on Antarctic marine systems’

Editorial: Acid test

North Atlantic Right Whales.Jessica Taylor/New England Aquarium photo.

Right whales in the North Atlantic.  Photo Credit: Jessica Taylor/New England Aquarium

Scientists tend to be cautious folk.

They tend to couch their words carefully when they talk about things like a recently observed 50 per cent reduction in zooplankton in parts of the North Atlantic, and the effects that could be having on the cod stocks.

But here are three remarkably clear paragraphs from Canada’s Changing Climate Report 2019.

Read them — there won’t be a test at the end, but maybe there should be.

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Crabby but crabtivating: hermit crabs and ocean acidification

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Searching through the intertidal at Tower Beach at low tide. Photo Credit: Kelly Borkowski.

Walking along Tower Beach, you might not realize how many different invertebrates are right below your feet. Giant isopods, small-but-mighty barnacles, common shore crabs, blue mussels, and periwinkle snails.

You pick up what you think is an unsuspecting periwinkle snail, but when you turn the shell over, you find a small bristly claw instead of a slimy muscular foot. You just found a hairy hermit crab!

Otherwise known as Pagurus hirsutiusculus, these hermit crabs are found in intertidal ecosystems from California to Alaska. Fluctuations in conditions, incredible competition and intense predation are just some of the challenges they see on a daily basis in the intertidal zone. It already sounds like these guys have it pretty bad, but there’s more…

Continue reading ‘Crabby but crabtivating: hermit crabs and ocean acidification’

Reduced nitrogenase efficiency dominates response of the globally important nitrogen fixer Trichodesmium to ocean acidification

The response of the prominent marine dinitrogen (N2)-fixing cyanobacteria Trichodesmium to ocean acidification (OA) is critical to understanding future oceanic biogeochemical cycles. Recent studies have reported conflicting findings on the effect of OA on growth and N2fixation of Trichodesmium. Here, we quantitatively analyzed experimental data on how Trichodesmium reallocated intracellular iron and energy among key cellular processes in response to OA, and integrated the findings to construct an optimality-based cellular model. The model results indicate that Trichodesmium growth rate decreases under OA primarily due to reduced nitrogenase efficiency. The downregulation of the carbon dioxide (CO2)-concentrating mechanism under OA has little impact on Trichodesmium, and the energy demand of anti-stress responses to OA has a moderate negative effect. We predict that if anthropogenic CO2 emissions continue to rise, OA could reduce global N2 fixation potential of Trichodesmium by 27% in this century, with the largest decrease in iron-limiting regions.

Continue reading ‘Reduced nitrogenase efficiency dominates response of the globally important nitrogen fixer Trichodesmium to ocean acidification’

Ocean acidification reduces habitat for Antarctic organisms

Unhealthy pteropod with dissolving shell ridges showing the effects of ocean acidification Photo Credit: NOAA Fisheries Collection via Wikimedia Commons

The ocean absorbs about one-third of the excess carbon dioxide (CO2) in the atmosphere from the burning of fossil fuels. After being taken up by the ocean, this CO2 causes chemical reactions that make seawater more corrosive – a process known as ocean acidification. This is bad news for the millions of tiny organisms in the ocean that make their shells from a chemical compound called aragonite, which is a form of calcium carbonate. As the ocean becomes more acidic, it becomes harder for these calcifying organisms to form and maintain their shells.

Continue reading ‘Ocean acidification reduces habitat for Antarctic organisms’


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OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

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