Ocean Action Hub

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Researchers publish rebuttal of prior study on ocean acidification effects on the behavior of coral reef fishes

24 Oct 2020 - A group of thirteen researchers from six countries has released a new scientific paper rejecting an earlier study claiming

24 Oct 2020 - 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 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 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.

"There are so many fundamental differences in what Clark et al. have done compared with the previous studies that the comparisons are invalid," Prof Munday said.

The authors of the rebuttal argue that experiments conducted by Clark et al. differed in at least 16 critical ways compared with previous research.

"Clark et al. claim to have closely repeated earlier studies, but failed to replicate key species, used different life stages and ecological histories, and altered methods in critical ways that reduce the likelihood of detecting ocean acidification effects."

Prof Munday said that contrary to their assertions, Clark et al. did not closely replicate the methods of past studies, some conducted over a decade ago. Instead, they made fundamental changes to flume design and methodology that would have affected results. In addition, their experimental treatments lacked the stability needed to meet necessary standards and were much more variable than in previous studies.

"The evidence that elevated CO2 can affect fish behavior is overwhelming," says Prof Göran Nilsson, a co-author from the University of Oslo. "Over 85 peer-reviewed papers by many different authors have demonstrated that elevated CO2 can affect the behavior of fish from coral reefs and other habitats, including at least 8 papers by the authors of Clark et al., which they fail to acknowledge in their paper. They also fail to address the striking result that fish exposed to elevated CO2 have altered behavior and reduced survival in the field."

"A in science is inevitable if no attempt is made to accurately replicate previous work and to acknowledge other vital evidence," Prof Munday said.

CONTINUE READING ONLINE HERE: https://phys.org/news/2020-10-publish-rebuttal-prior-ocean-acidification.html

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Warmer, acidifying ocean brings extinction for reef-building corals, renewal for relatives

31 Aug 2020 - Changes in ocean chemistry and temperature have had a dramatic effect on the diversity of corals and sea anemones, according to a team of scientists who have traced their evo

31 Aug 2020 - Changes in ocean chemistry and temperature have had a dramatic effect on the diversity of corals and sea anemones, according to a team of scientists who have traced their evolution through deep time. A new study, published Aug. 31 in the journal Nature Ecology and Evolution, finds that reef-building corals emerged only when ocean conditions supported the construction of these creatures' stony skeletons, whereas diverse softer corals and sea anemones flourished at other times. Without a significant change to anthropogenic carbon emissions, the new findings present stark implications for the present and future of hard-bodied corals while suggesting a silver lining for the diversity of some of their softer-bodied relatives.

New genetic analyses show that corals, which together with sea anemones make up a class of animals known as anthozoans, have been on the planet for 770 million years. That is 250 million years before the earliest undisputed fossil evidence of their existence—and long enough to experience massive shifts in climate, fluctuations in  and several mass extinctions.

CONTINUE READING ONLINE HERE: https://phys.org/news/2020-08-warmer-acidifying-ocean-extinction-reef-building.html

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Surface clean-up technology won't solve ocean plastic problem

17 Aug 2020 - "Even if we could collect all the plastic in the oceans—which we can't—it's really difficult to recycle, especially if plastic fragments have floated for a long time and been

17 Aug 2020 - "Even if we could collect all the plastic in the oceans—which we can't—it's really difficult to recycle, especially if plastic fragments have floated for a long time and been degraded or bio-fouled."

Clean-up devices that collect waste from the ocean surface won't solve the plastic pollution problem, a new study shows.

Researchers compared estimates of current and future plastic waste with the ability of floating clean-up devices to collect it—and found the impact of such devices was "very modest". However, river barriers could be more effective and—though they have no impact on plastic already in the oceans—they could reduce pollution "significantly" if used in tandem with surface clean-up technology.



The study—by the University of Exeter, the Leibniz Centre for Tropical Marine Research, the Leibniz Institute for Zoo and Wildlife Research, Jacobs University and Making Oceans Plastic Free—focusses on floating plastic, as sunk waste is difficult or impossible to remove depending on size and location.



The authors estimate that the amount of plastic reaching the ocean will peak in 2029, and surface plastic will hit more than 860,000 metric tonnes—more than double the current estimated 399,000—by 2052 (when previous research suggested the rate of plastic pollution may finally reach zero).



"The important message of this paper is that we can't keep polluting the oceans and hoping that technology will tidy up the mess," said Dr. Jesse F. Abrams, of the Global Systems Institute and the Institute for Data Science and Artificial Intelligence, both at the University of Exeter.



"The other major solutions are to bury or burn it—but burying could contaminate the ground and burning leads to extra CO2 emissions to the atmosphere."

 

CONTINE READING ONLINE HERE: https://phys.org/news/2020-08-surface-clean-up-technology-wont-ocean.html

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Ten years to save world's most threatened sea turtle population

7 Apr 2020 -The Eastern Pacific leatherback turtle will be lost forever if insufficient conservation action is taken over the next ten years, a new study by conservation scientists has war

7 Apr 2020 -The Eastern Pacific leatherback turtle will be lost forever if insufficient conservation action is taken over the next ten years, a new study by conservation scientists has warned.

The study by the Laúd OPO Network, a group of conservation scientists and organisations including Fauna & Flora International (FFI), says the current prognosis for the critically endangered Eastern Pacific leatherback population is "dire." Expanded actions to save the world's largest sea turtle must begin within five years and grow throughout the decade to ensure the stabilisation and eventual increase of the Eastern Pacific leatherback, the conservationists said.

The study, published by Nature in its open access journal Scientific Reports, follows the news that no leatherback turtle nests were recorded across the three most important nesting sites in Nicaragua in the 2019-2020 nesting season. Last year was the first time they had been recorded absent at one of these sites in Nicaragua.

CONTINUE READING ONLINE HERE: https://phys.org/news/2020-04-ten-years-world-threatened-sea.html

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Research shows mangrove conservation can pay for itself in flood protection

17 Apr 2020 - The natural coastal defenses provided by mangrove forests reduce annual flooding significantly in critical hotspots around the world.

17 Apr 2020 - The natural coastal defenses provided by mangrove forests reduce annual flooding significantly in critical hotspots around the world. Without mangroves, flood damages would increase by more than $65 billion annually, and 15 million more people would be flooded, according to a new study published March 10 in Scientific Reports.

"Mangroves provide incredibly effective natural defenses, reducing flood risk and damages," said Pelayo Menéndez, a postdoctoral fellow in the Institute of Marine Sciences at UC Santa Cruz and first author of the paper.

Climate change is increasing the risk of coastal flooding through its effects on sea level rise and the intensity of hurricanes. According to the study's authors, conservation and restoration of natural defenses such as mangroves offers cost-effective ways to mitigate and adapt to these changes.

CONTINUE READING ONLINE HERE: https://phys.org/news/2020-03-mangrove.html

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Online prototype could improve ocean migratory species governance

10 Oct 2019 - An online mapping and knowledge platform prototype could soon offer free and easily accessible information on the migratory patterns of endangered species in the ocean.

10 Oct 2019 - An online mapping and knowledge platform prototype could soon offer free and easily accessible information on the migratory patterns of endangered species in the ocean.

The Migratory Connectivity in the Ocean (MiCO) system has been launched by The University of Queensland's Dr. Daniel Dunn.

The  included Duke University, the Smithsonian Migratory Bird Centre, and a team of 71 international researchers.

"This online tool provides insights on the  and movements of marine wildlife, helping better inform conservation efforts and the sustainable use of oceans worldwide," Dr. Dunn said.

"Migratory  including , marine mammals, seabirds and fish, travel thousands of kilometres each year, often through ocean habitats at severe risk from human threats like overfishing, pollution, marine debris and .

"The cumulative impact of these threats can threaten populations of marine species and are often spread across a number of global jurisdictions."

MiCO links the large amount of data on  being gathered by researchers with environmental managers or policy-makers, who lack the capacity, time and budget to analyse the data.

The Smithsonian Migratory Bird Centre's Dr. Autumn-Lynn Harrison said they developed MiCO to analyse and interpret these global data.

"This provides a single, unified access to treasure troves of knowledge for direct use in policy and management," she said.

"Some migratory species spend 75 percent of their time in international waters, and knowledge from MiCO has already played a vital role in the evolution of international marine policies."

"Migratory species connect economies and ecosystems in a way that requires a shared approach to governance," Dr. Dunn said.

CONTINUE READING: https://phys.org/news/2019-10-online-prototype-ocean-migratory-species.html

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Ocean ecosystems take two million years to recover after mass extinction

30 Sept 2019 - If we carry on emitting carbon and interfering with marine ecosystems, we run the risk of losing one of its critical carbon-storing and food-providing players. 

30 Sept 2019 - Around 66m years ago, a giant asteroid struck the Earth, causing the extinction of the dinosaurs, ammonites, and many other species.

The asteroid was equally devastating at a driving ocean plankton to near-. This crippled the base of the marine food chain and shut down important ocean functions, such as the absorption and delivery of carbon dioxide from the atmosphere to the ocean floor.

Given the real threat of a sixth mass extinction event brought about by human-caused climate breakdown and habitat disruption, we wanted to find out how long the  took to reboot after the last one. What we found has grave implications for the long-term outlook of marine ecosystems should we tip the critical base of its food chain over the threshold of extinction.

The nanoplankton almost totally wiped out 66m years ago—also known as coccolithophores – are now widespread once more in the sunlit upper oceans. Although roughly 100 times smaller than a grain of sand, they are so abundant that they are visible from space as swirling blooms in the ocean surface.

When these microscopic plankton die, they leave behind exquisite armored exoskeletons known as coccospheres made from the mineral calcite, composed of bonded calcium and carbon. Along with the dead plankton cells, these skeletons slowly fall to the ocean floor, forming a muddy calcium and carbon-rich sediment. As this sediment compacts, it forms chalk and limestone, leaving us with iconic landscapes such as white chalk cliffs – the shallow sea floor of a forgotten age, since lifted up by tectonic activity.

Conserved within this compacted sediment is a continuous fossil record stretching back 220m years. It is this fossil record—the most abundant on the planet – that can tell us how ecosystems responded to the extinction of nanoplankton. Changes in the diversity and abundance of the plankton that once lived in the ocean above reflect the  that played out in the millennia after the giant asteroid hit.

We extracted a continuous core of deep-sea sediment from the Pacific Ocean. For the first 13m years after the mass extinction event, we took a sample of the fossil record at intervals of 13,000 years. We measured fossil abundance, diversity and cell sizes from over 700,000 specimens, producing probably the largest fossil dataset ever produced from a single site.

CONTINUE READING: https://phys.org/news/2019-09-ocean-ecosystems-million-years-recover.html

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'Blue finance' hopes to put oceans on a sustainable path

27 Sept 2019 - 'Blue finance' aims to help raise funding for the responsible use of oceans.

27 Sept 2019 - 'Blue finance' aims to help raise funding for the responsible use of oceans.

The world's oceans are set to become an increasingly vital resource for helping the planet cope with soaring population growth, but officials are only beginning to craft regulatory frameworks that would ensure "blue financing" goes where it's needed most.

From food production and marine biotechnology research to seabed mining and , investors are expecting a wave of initiatives in the waters that cover 70 percent of the Earth's surface.

But the ventures will also require stepped up efforts to keep oceans clean and viable—eight million tonnes of plastic are entering each year, according to the World Bank, and over-fishing has already severely depleted some stocks.

"Much of what has to be done in the blue economy is regulation," said Sean Kidney, co-founder of the Climate Bonds Initiative.

Without coordinated action among governments, he warned, "in 30 years time we may not be catching fish but jellyfish."

Kidney's nonprofit aims to steer the massive amounts of funds raised by debt issuance toward  and other climate-friendly projects.

That could mobilise millions for offshore wave or wind energy ventures as pressure mounts on governments to tackle  and smog.

The money could also finance coastal renewal projects that will become more urgent as cities grow, and as more retirees and as well as tourists flock to pristine beaches and resorts.

"Because what we have done in the last 100 years is fundamentally destroy the coastal system," Kidney said.

CONTINUE READING: https://phys.org/news/2019-09-blue-oceans-sustainable-path.html

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Ending Overfishing Is Opportunity to Combat Climate Crisis - Report

6 Sept 2019 - Ending overfishing would not only secure vital fish populations for the future, but constitutes a significant climate emergency action, according to the latest report.

6 Sept 2019 - Ending overfishing would not only secure vital fish populations for the future, but constitutes a significant climate emergency action, according to the latest report. According to Our Fish, the report's findings offer EU governments a realistic opportunity to deliver immediate and effective action on dangerous climate change, as well as meeting their legal obligations to finally quit overfishing. 

The working paper, Ending Overfishing Can Mitigate Impacts of Climate Change, by Dr. Rashid Sumaila and Dr. Travis Tai of the University of British Columbia, finds that "overfishing and climate change are not mutually exclusive problems to be addressed separately," as both are severely impacting ocean health, and putting marine ecosystems and the goods and services they provide to communities at risk. Ending overfishing would give the ocean respite from human pressure, making it more resilient to the effects of the climate crisis, while helping to restore critically valuable marine ecosystems, says the paper. 

"A healthy person is more likely to survive an epidemic than a person who is less healthy, and because of overfishing we have severely weakened the ocean's immune system" said Dr. Sumaila. "Ending overfishing now would strengthen the ocean, making it more capable of withstanding climate change and restoring marine ecosystems". Dr. Sumaila is in Brussels this week to brief EU policymakers on how ending overfishing in EU waters supports EU commitments to taking climate action.

Dr. Sumaila hosted a webinar on climate action and overfishing, on September 2nd, at 1500 CET. To view the video of the webinar, click here. 

The working paper finds that: 

  1. Overfishing and climate change are two of the biggest stressors on ocean health, including to marine ecosystems, biodiversity and fisheries;
  2. Recent estimates suggest that at least 40% of fish stocks in the North East Atlantic and 87% in the Mediterranean and Black Seas are currently subject to unsustainable fishing practices, including stocks that are overfished or exploited at an unsustainable rate [2];
  3. The onset of rapid climate-related changes in marine ecosystems will increase pressure on fish populations, with the potential of extinction for some species;
  4. Decisive action is critical to ensure the long-term sustainability of marine ecosystems and fisheries;
  5. Due to the current inefficiencies that result in catching more fish than nature can generate, improvements in fisheries management to achieve MSY would not only increase long-term catch, but actually offset some of the negative effects of climate change on catches;
  6. Implementation of strategies to increase resilience has been found to help with recovery from extreme climate impacts; overfishing and climate change are not mutually exclusive problems to be addressed separately, and holistic comprehensive solutions must be found to address these two global challenges.

CONTINUE READING: https://phys.org/wire-news/329043040/ending-overfishing-is-opportunity-to-combat-climate-crisis-rep.html

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New threat from ocean acidification emerges in the Southern Ocean

27 Aug 2019 - The oceans act as a carbon sink and have already absorbed more than 40% of anthropogenic carbon emissions.

27 Aug 2019 - The oceans act as a carbon sink and have already absorbed more than 40% of anthropogenic carbon emissions. The majority of this CO2 has been taken up by the Southern Ocean making these waters hotspots of ocean acidification (OA).

Lead author of the paper published in Nature Climate Change, Dr. Katherina Petrou from the University of Technology Sydney, said that although changes in  pH have been shown to impact marine calcifying organisms, the consequences for non-calcifying  are less clear.

"Previous studies reported a range of responses to OA [in phytoplankton] yet rarely considered how environmental pH shifts might affect silicification rates in diatoms," she says.

"Diatoms are unique phytoplankton in that they need silicic acid to produce silica cell walls. Under the microscope they look like beautiful glass jewellery boxes, but importantly, this dense, glass-like armour promotes sinking, which makes diatoms an important conduit for transport of carbon to the where it can be stored for millennia."

Diatoms are responsible for around 40% of ocean productivity which means they play a major role in supporting marine food webs, sustaining life for millions of creatures, including humans.

"The only genuine way to circumvent this outcome, is to cut our greenhouse gas emissions and limit the acidification of our oceans," the researchers say.

CONTINUE READING ONLINE HERE: https://phys.org/news/2019-08-threat-ocean-acidification-emerges-southern.html