'Weedy' fish species to take over our future oceans

Date:  July 6, 2017

Source:  University of Adelaide

Summary:  The ocean acidification expected in the future will reduce fish diversity significantly, with small ‘weedy’ species dominating marine environments, researchers have demonstrated for the first time.

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Study examines ocean acidification effects on rockfish, a key California marine prey base

Date: January 5, 2017
Source: California State University, Monterey Bay

A new study led by researchers from Moss Landing Marine Labs of San Jose State University, California State University Monterey Bay and University of California Santa Cruz examines how ocean acidification may negatively affect some juvenile rockfish, a key marine prey base to the Calif. ecosystem. The research, which suggests potential negative affects to the structure and function of marine ecosystems that support coastal fishieries and communities, was conducted in collaboration with researchers at the National Oceanic and Atmospheric Administration's Southwest Fisheries Science Center and the Monterey Bay Aquarium Research Institute.

"Our study shows that some rockfish are more tolerant than others when exposed to future ocean chemistry conditions. Copper rockfish displayed behavioral changes, slower swimming speeds, depressed ability for aerobic activity, and increased expression of regulatory genes. Blue rockfish did not show significantly altered behavior or physiology," said Cheryl Logan, co-author and assistant professor at the School of Natural Sciences at CSU Monterey Bay who led the genomics portion of the study. "Blue rockfish showed gene expression changes indicative of greater acclimatization capacity."

 

Read on 

Acid attack: Can mussels hang on for much longer?

Date: July 5, 2016

Source: Society for Experimental Biology

Scientists from The University of Washington have found evidence that ocean acidification caused by carbon emissions can prevent mussels attaching themselves to rocks and other substrates, making them easy targets for predators and threatening the mussel farming industry.

"A strong attachment is literally a mussel's lifeline" says Professor Emily Carrington, one of the lead researchers. Mussels attach themselves to hard surfaces so that they can filter plankton from seawater for food. They generally live in tidal zones, where the strong waves and currents protect them from predators such as crabs, fish and sea stars. But if a mussel falls off its perch, it sinks down into calmer waters where it is readily eaten.

Future conditions may make it more difficult for mussels to attach themselves out of harm's way. This is because the pH level appears to be critical during the attachment process, and our oceans are becoming more acidic from absorbing CO2emissions from the atmosphere. "Our early laboratory studies showed mussels made weaker attachment threads when seawater pH dropped below 7.6" says Professor Carrington. These results could have severe implications for aquaculture. In mussel farms, the mussels attach themselves to ropes suspended in the water for 6-12 months while they grow to market size. Currently, weak attachments can cause up to 20% of the crop to fall off and be lost on the seafloor.

The researchers have shown that the change in pH specifically affects the adhesive plaque which cements the mussel to the underlying surface. "We investigated whether lowering seawater pH would affect the curing process of the attachment threads" says Professor Carrington. Threads made by mussels in seawater with a "normal" pH of 8 were then kept at either pH 8, 7 or 5 to cure for 12 days. Using a materials testing machine, the team found that threads cured at the lower pH values were 25% weaker than the controls. "We conclude that mussels rely on the high pH of seawater to cure their adhesive effectively and form strong attachments" says Professor Carrington. Furthermore, one mussel species Mytilus trossulus also made fewer and weaker threads when the temperature of the water was increased from to above 18 °C. In contrast, a closely related non-native species Mytilus galloprovincialis made more and stronger threads. This suggests warming oceans will increasingly favour the non-native species, allowing it to expand its distribution polewards and push out native species.

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Study shows rising ocean acidification likely to cause shrimp to taste bad

10 hours ago by Bob Yirka

 

Credit: National Oceanic and
Atmospheric Administration

(Phys.org)—A study conducted by a small team of researchers with members from the U.K., Sweden and Canada has revealed that in the future as the oceans become more acidic, it appears likely that the taste of shrimp will become less appealing. In their paper published in the Journal of Shellfish Research, the team describes how they raised test shrimp in higher than normal acidic water and then held taste tests with volunteers.

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Young sea stars suffer more from ocean acidification than adults

Date:

September 26, 2014

Source:

Helmholtz Centre for Ocean Research Kiel (GEOMAR)

Summary:

Young sea stars from the Baltic Sea suffer more from the effects of ocean acidification than adults. In a laboratory experiment, scientists showed that younger animals already eat less and grow more slowly at only slightly elevated carbon dioxide concentrations.

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Ocean acidification slurps up oysters

Editor’s note: We’re publishing a series from The Story Group that shows Americans on the front lines of climate change. The videos put faces to the warnings in the latest National Climate Assessment.

“The ocean is so acidic that it is dissolving the shells of our baby oysters,” says Diani Taylor of Taylor Shellfish Farms in Shelton, Wash. She and her cousin Brittany are fifth-generation oyster farmers, and are grappling with ocean waters that are more acidic and corrosive than their fathers, grandfathers, and great-grandfathers knew.

Read more and video

Ocean Acidification robs reef fish of their fear of predators

Date:

April 13, 2014

Source:

Australian Institute of Marine Science

Summary:

Research on the behavior of coral reef fish at naturally-occurring carbon dioxide seeps in Milne Bay in eastern Papua New Guinea has shown that continuous exposure to increased levels of carbon dioxide dramatically alters the way fish respond to predators. 

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Ocean acidification may increase 170 percent this century

November 2013: Ocean acidification may increase by a staggering 170 percent by 2100 says an international report led by the International Geosphere-Biosphere Programme, and marine ecosystems and biodiversity are likely to irreversibly change as a result with far-reaching consequences. The legacy of historical fossil fuel emissions on ocean acidification will be felt for centuries.

One of the lead authors Ulf Riebesell of GEOMAR Helmholtz Centre for Ocean Research Kiel said: "What we can now say with high levels of confidence about ocean acidification sends a clear message. Globally we have to be prepared for significant economic and ecosystem service losses. But we also know that reducing the rate of carbon dioxide emissions will slow acidification. It was emphasised by the experts that if society continues on the current high emissions trajectory, cold water coral reefs may become unsustainable and tropical coral reef erosion is likely to outpace reef building this century.

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Scientists Analyze the Effects of Ocean Acidification On Marine Species

Aug. 25, 2013 — Ocean acidification could change the ecosystems of our seas even by the end of this century. Biologists at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), have therefore assessed the extent of this ominous change for the first time. In a new study they compiled and analysed all available data on the reaction of marine animals to ocean acidification. The scientists found that whilst the majority of animal species investigated are affected by ocean acidification, the respective impacts are very specific.

The AWI-researchers present their results as an Advance Online Publication on Sunday 25 August 2013 in Nature Climate Change.

The oceans absorb more than a quarter of anthropogenic carbon dioxide emitted to the atmosphere. They form a natural store without which Earth would now be a good deal warmer. But their storage capacities are limited and the absorption of carbon dioxide is not without consequence. Carbon dioxide dissolves in water, forms carbonic acid and causes the pH value of the oceans to drop -- which affects many sea dwellers. In recent years much research has therefore been conducted on how individual species react to the carbon dioxide enrichment and the acidifying water. So far the overall extent of these changes on marine animals has been largely unknown.

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Rapid Adaptation Is Purple Sea Urchins' Weapon Against Ocean Acidification

June 12, 2013 — In the race against climate change and ocean acidification, some sea urchins may still have a few tricks up their spiny sleeves, suggesting that adaptation will likely play a large role for the sea creatures as the carbon content of the ocean increases.

"What we want to know is, given that this is a process that happens over time, can marine animals adapt? Could evolution come to the rescue?" said postdoctoral researcher Morgan Kelly, from UC Santa Barbara's Department of Ecology, Evolution and Marine Biology. She is a co-author of the paper "Natural variation, and the capacity to adapt to ocean acidification in the keystone sea urchinStrongylocentrotus purpuratus." The paper was published in the latest edition of the journal Global Change Biology.

Easily identified by their spherical symmetry and prickly barbs, sea urchins are found on the sea floor all over the world. They are considered a keystone species, meaning their population has an important impact on the rest of the undersea ecosystem. Too many of them and their habitat becomes barren and other algae-eating species disappear; too few and their predators -- including sea mammals, seabirds, and fish -- lose an important food source.

Due to rising carbon dioxide in Earth's atmosphere, the oceans of the future are projected to absorb more carbon dioxide, leading to acidification of the water. The change in the ocean chemistry is expected to negatively affect the way urchins and other calcifying creatures create and maintain their shells and exoskeletons.

"It gives them osteoporosis," said Kelly. Increased water acidity would cause the levels of calcium carbonate -- which the sea urchins require -- to decrease. This, in turn, would result in smaller animals, thinner shells and perhaps shorter spines for the urchins.

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Antarctic marine wildlife is under threat, study finds

Marine snails in seas around Antarctica are being affected by ocean acidification, scientists have found.

An international team of researchers found that the snails' shells are being corroded.

Experts says the findings are significant for predicting the future impact of ocean acidification on marine life.

The results of the study are published in the journal Nature Geoscience.

The marine snails, called "pteropods", are an important link in the oceanic food chain as well as a good indicator of ecosystem health.

"They are a major grazer of phytoplankton and... a key prey item of a number of higher predators - larger plankton, fish, seabirds, whales," said Dr Geraint Tarling, Head of Ocean Ecosystems at the British Antarctic Survey (BAS) and co-author of the report.

The study was a combined project involving researchers from the BAS, the National Oceanic and Atmospheric Administration (NOAA), the US Woods Hole Oceanographic Institution and the University of East Anglia's school of Environmental Sciences.

Continued:  http://www.bbc.co.uk/nature/20461646

Oysters' Future Imperiled as Oceans Acidify

Monterey, Calif. — Oysters, those slimy mollusks whose juices are thought to boost sexual desire, may be losing their comfy sea homes.

The reason? Global oceans are becoming more acidic as they absorb carbon dioxide pumped into the air from burning fossil fuels, which makes it difficult for calcifying organisms like oysters to create their shells.

The ocean is now 30 percent more acidic than it was before the Industrial Revolution.

At the Ocean Acidification meeting here this month, Anneliese Hettinger of UC Davis presented new research showing that Olympia oysters are smaller after being exposed, as larvae, to a high carbon-dioxide environment. The negative impacts of early exposure to carbon dioxide stuck with the juvenile oysters for at least four months into their lives, stunting their growth.

"We have to take a holistic approach when looking at the oyster instead of only focusing on one life stage," Hettinger said at the meeting.

Read more:  http://www.livescience.com/23903-oysters-future-imperiled-oceans-acidify.html

Scientists Predict Impact of Ocean Acidification On Shellfish

ScienceDaily (Aug. 5, 2012) — An international study to understand and predict the likely impact of ocean acidification on shellfish and other marine organisms living in seas from the tropics to the poles is published this week (date) in the journal Global Change Biology.

Ocean acidification is occurring because some of the increased carbon dioxide humans are adding to the atmosphere dissolves in the ocean and reacts with water to produce an acid.

The results suggest that increased acidity is affecting the size and weight of shells and skeletons, and the trend is widespread across marine species. These animals are an important food source for marine predators such as tropical seabirds and seals as well as being a valuable ingredient in human food production. Consequently, these changes are likely to affect humans and the ocean's large animals.

UK scientists from the British Antarctic Survey (BAS) and the National Oceanography Centre (NOC), together with colleagues from Australia's James Cook and Melbourne Universities and the National University of Singapore, investigated the natural variation in shell thickness and skeletal size in four types of marine creatures living in 12 different environments from the tropics to the Polar Regions. Their aim was to get a clearer understanding of similarities and differences between species, and to make better predictions of how these animals might respond to increasing acidity in the oceans.

Continued:  http://www.sciencedaily.com/releases/2012/08/120806085240.htm