Ocean Action Hub

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Acidifying Oceans Could Get Help from Kelp

7 Dec 2020 - Forests of fast-growing kelp influence the chemistry of the water in which they live.

7 Dec 2020 - Forests of fast-growing kelp influence the chemistry of the water in which they live. A new study evaluates their potential to ameliorate ocean acidification in sensitive coastal ecosystems.

Carbon dioxide is well known as a greenhouse gas, but its effects on climate and environments aren’t limited to the atmosphere. As more carbon dioxide fills the air, more of the gas dissolves into seawater, making the ocean more acidic and threatening marine organisms. Giant kelp may offer a local solution. As kelp grows, it captures carbon from the water and produces oxygen, possibly removing enough carbon dioxide to relieve acidification.

Hirsh et al. investigate conditions inside and outside a kelp forest in Monterey Bay, Calif., to evaluate kelp’s ability to mitigate ocean acidification in sensitive areas. Their study area experiences localized injections of deep water via upwelling events, in which equatorward winds push away surface water and draw up cold, low-pH (more acidic), low-oxygen water from offshore depths.

Upwelling also delivers nutrients, so upwelling events spark surges in kelp and phytoplankton growth and productivity. If the kelp-driven carbon fixing spurred by the nutrient inflow outpaces the amount of carbon brought up from deep water, kelp could start consuming anthropogenic carbon in the water, locally alleviating acidification stress.

CONTINUE READING ONLINE HERE: https://eos.org/research-spotlights/acidifying-oceans-could-get-help-from-kelp

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Reaching Consensus on Assessments of Ocean Acidification Trends

2 Nov 2020 - Scientists are working to establish a common methodology for evaluating rates of change in—and the various mechanisms that affect—

2 Nov 2020 - Scientists are working to establish a common methodology for evaluating rates of change in—and the various mechanisms that affect—acidification across ocean environments.

Media coverage concerning carbon dioxide (CO2) emissions into Earth’s atmosphere most often focuses on how these emissions affect climate and weather patterns. However, atmospheric CO2 is also the primary driver for ocean acidification, because the products of atmospheric CO2 dissolving into seawater reduce seawater’s pH and its concentration of carbonate ions. Since the beginning of the Industrial Revolution, the acidity of the ocean has increased by over 30%.

Some organisms in the ocean may struggle to adapt to increasingly acidified conditions, and even resilient life-forms may have a harder time finding food. Higher CO2 levels in ocean water also make it difficult for shellfish to build their shells and corals to form their reefs, both of which are made of carbonate compounds.

Ocean acidification affects the overall health of marine ecosystems as well as societal concerns about food security.
Ocean acidification, which affects the overall health of marine ecosystems as well as societal concerns about food security, has emerged as a major concern for decision-makers on local, regional, and global scales. Indeed, ocean acidification is now a headline climate indicator for the World Meteorological Organization.

Even though the world’s oceans are all connected, the effects of ocean acidification can unfold differently in various regions. The expression of ocean acidification can vary especially in coastal waters, where additional drivers, including both human-caused and natural processes such as nutrient runoff and biological productivity, vary greatly over time and space. 

CONTINUE READING ONLINE HERE: https://eos.org/science-updates/reaching-consensus-on-assessments-of-ocean-acidification-trends

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Scientists Examine Novel Options to Save Coral Reefs

18 Apr 2018 - Warming events prompt scientists to look at ecological, genetic, and engineering interventions.

18 Apr 2018 - A global bleaching event that devastated many coral reefs around the world from 2014 to 2017 has further raised the sense of urgency among coral experts to protect the reefs from damage from future elevated temperature conditions. The National Oceanic and Atmospheric Administration (NOAA) says the event is the third such global episode and the most widespread, longest, and most damaging bleaching event on record. This latest round of devastation is prompting scientists to examine potentially radical interventions.

study by an ad hoc committee of the National Academies of Sciences, Engineering, and Medicine, which kicked off in February, is looking into the science, risks, and benefits of a range of possible interventions—some involving engineering, others mainly ecological or genetic—to help reefs recover and survive.

“The major problem that we are faced with is that our conventional methods of coral reef conservation that we have come to rely on are not keeping pace with the environmental change that we are seeing these days,” Ned Cyr, director of the NOAA Fisheries Office of Science and Technology, said on 8 February. He was speaking at the initial meeting of the committee, which is in fact-finding mode in its 2-year study of interventions to increase the resilience of coral reefs. NOAA, the study’s sponsor, has environmental stewardship responsibilities that involve coral science, coral assessment and management, and conservation of corals under the U.S. federal Endangered Species Act, said Cyr, one of several NOAA scientists who made presentations to the committee about the state of reefs and the agency’s goals for the study.

Coral reefs provide ecosystem goods and services such as fisheries, storm surge protection, and tourism. However, under stressful conditions such as higher than normal temperatures, bleaching can occur when corals expel symbiotic algae. This expulsion causes the corals to turn white and become more vulnerable to disease.

“We spend millions [of dollars] on coral reef marine protected areas, on implementing sustainable fishing practices, minimizing land-based sources of pollution, replanting reefs with live corals, etc., and yet these intervention methods simply don’t match the scale of what we are facing now from global warming,” Cyr remarked. Rising levels of atmospheric carbon dioxide are leading to changing pH and calcification conditions in the oceans that are having profound consequences for reefs, he added.

“We really need new solutions that match the scale of the problem,” Cyr said. “What we really need is a paradigm shift in our approach to conservation biology.”

Radical Interventions

The project scope for the committee’s study states that reefs are threatened by “rapidly deteriorating environmental conditions that are warmer, less favorable for calcification, have impaired water quality, and pose continuing disease threats.” The study calls for looking into strategies that include translocating nonnative coral stocks or species, managed selection, “stress hardening,” and engineering solutions such as shading and cooling reefs during bleaching events. “Although these interventions raise societal, policy, legal, and likely ethical implications for decision making, these considerations are beyond the scope of this review,” the project scope notes.

Some of the interventions “are not without controversy within the scientific community and the conservation community,” Cyr told the committee, mentioning, for instance, potential concerns about genetically modified organisms, or “frankenfish.” “Where you can help us is by helping to develop a consensus for the science and management community to justify the testing and the implementation of some of these novel techniques that we think ultimately are going to be helpful in our conservation mission.”

At the meeting, Jen Koss, director of NOAA’s Coral Reef Conservation Program, told the committee that although “radical solutions” are needed quickly, “we are mindful that these need to be reviewed.” She noted past examples of interventions in other ecosystems that led to significant problems, such as introducing kudzu for soil retention in the southeastern United States.

Committee Concerns

Committee members largely agreed with the scope of the problem and the need to do something quickly about it. “The conventional things that we are doing aren’t really working or certainly aren’t working well enough or fast enough,” committee member Nancy Knowlton told Eos. Knowlton is a coral reef biologist and the Sant Chair for Marine Science at the Smithsonian Institution. She is also a senior scientist emeritus at the Smithsonian Tropical Research Institute.

“We are faced with a situation here even in reefs which have been well managed with respect to, say, overfishing and pollution, which are the things that were problematic, say, a couple of decades ago,” Knowlton continued. Corals “are still being hit really, really hard by, particularly, global warming in these mass bleaching events.”

An important consideration is weighing the costs and benefits of potential interventions such as moving species around the world, committee chair Stephen Palumbi told Eos, while bearing in mind those that have sometimes gone awry. Past failures are “a huge wake-up call” about the need to be “very careful” in considering and potentially using new interventions, added Palumbi, a professor of marine biology at Stanford University’s Hopkins Marine Station, Pacific Grove, Calif.

The goal is to have coral reefs “that can persist and thrive and still benefit humans even if we’re causing the climate to change into the future,” he said.

Mark Eakin, coordinator of NOAA Coral Reef Watch, emphasized to the committee the need for quick, effective action. “We know that climate change is accelerating and accelerating bleaching,” he said. “So we need to make sure that this study isn’t something that talks about some nice areas of science but is too little and too late for the corals.”

CONTINUE READING: https://eos.org/articles/scientists-examine-novel-options-to-save-coral-...

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