Ocean Acidification

Tiffany Stephens, left, works at the Seagrove Kelp farm in Doyle Bay near Craig on April 14, 2021. (Photo by Jordan A. Hollarsmith/NOAA Fisheries, Alaska Fisheries Science Center)

To optimists, the plants that grow in the sea promise to diversify the Alaska economy, revitalize small coastal towns struggling with undependable fisheries and help communities adapt to climate change – and even mitigate it by absorbing atmospheric carbon.

Cultivation of seaweed, largely varieties of kelp, promises to buffer against ocean acidification and coastal pollution, the promoters say. Seaweed farms can produce ultra-nutritious crops to boost food security in Alaska and combat hunger everywhere, and not just for human beings.

“Kelp is good for everybody. It’s good for people. It’s good for animals,” Kirk Sparks, with Pacific Northwest Organics, a California company that sells agricultural products, said in a panel discussion at a mariculture conference held in Juneau in February by the Alaska Sea Grant program.

But before it achieves these broad benefits, Alaska’s mariculture industry must first address significant practical issues, including an American consumer market that has yet to broadly embrace seaweed.

…

There is encouraging scientific evidence that seaweed cultivation buffers acidification locally, as described in studies from various projects, including some from China, California and New York. Seaweed farming “could serve as a low-cost adaptation strategy to ocean acidification and deoxygenation and provide important refugia from ocean acidification,” said the study from China, published in 2021 in the journal Science of the Total Environment.

But does seaweed farming result in absorption of atmospheric carbon and prevention of it streaming back into the atmosphere? The answer is complicated, according to the science. It depends on what happens to the kelp. If dead and decomposing bits are on land or in shallow waters, they would likely release carbon back into the atmosphere, scientists say.

…

Scientists investigating the effects of ocean acidification, microplastic and lanthanum on marine organisms observed color changes in shellfish, immune system issues in some species, a decrease in cell counts and a fall in reproduction. Amid this trend, fish stocks have been gradually decreasing in the Black Sea and the quantity of fish stock does not meet the desired needs, an expert said while drawing attention to the importance of sustainable fishing.

Istanbul University’s Faculty of Science, Department of Biology and General Biology Department faculty members professor Murat Belivermis and professor Önder Kılıç examined the effects of ocean acidification, microplastic and lanthanum, which they refer to as the “triple stress factor,” on marine life in Turkish waters and human consumption within the scope of the project titled “Biological Effects of Stress Factors in the Marine Environment” initiated 10 years ago.

Belivermiş and Kılıç observe the effects of these factors by exposing the creatures they collect from the sea to stress factors in the marine environment they have created in their laboratory at the university, including mollusks, shrimp and sea urchins as they play a key role in the ecosystem.

Stating that they are currently working on a sea urchin species they collected from the Gulf of Saros, Belivermiş said, “These species live in the Marmara Sea and the North Aegean. It will generate important data and will serve us with many solutions for the future,” he said.

Acidification

Acidification in oceans has become a global issue and affects the seas around Türkiye. The reason behind ocean acidification is also increasing carbon dioxide emissions that cause the pH to drop in the sea, and organisms with a calcium carbonate skeleton are particularly affected by it. Living things spend their energy dealing with this acidification, reproduce less and their immune systems are affected, Belivermiş explained.

“Adopting a holistic approach, we have seen whitening in oyster species. In fact in previous studies, we saw reductions in the hemolymph cells of mussels due to acidification. This suggests a problem with the immune system, resulting in weakening or color changes in the shells.”

Kılıç noted that if ocean acidification seriously affects the lives of these species, it will lead to a decrease in the population, and this decrease will also transpire as a decrease in the human food supply.

…

The Hercules robot explores a forest of corals and sponges off the coast of British Columbia, in 2018.

Around the world, coral reefs are in decline due to anthropogenic CO2 emissions. Cold-water corals, such as those found off British Columbia, attract less public attention. Yet they are as threatened by global warming as their tropical counterparts.

Off Vancouver Island, underwater mountain ranges rise in the depths of the ocean peaceful. These remains of volcanoes are home to ecosystems of phenomenal diversity, says Robert Rangeley, scientific director of the ocean protection organization, Oceana Canada.

There are huge forests, of different types of corals, such as red tree corals or bamboo. They can be several meters high. There are also glass sponges, false starfish, octopuses, tons and tons of fish, describes the researcher, who participated in an expedition to explore 13 of these seamounts in 2018.

…

CO2 is also naturally captured by the oceans, where it dissolves in water to form carbonic acid. When CO2 concentrations are too high, however, it lowers the pH of the water and thus increases its acidity. The hotter the water, the more this cycle is accelerated, argues Gabriel Reygondeau.

Ocean acidification alters the calcification process of corals, which build their skeleton on limestone, explains Gabriel Reygondeau. Some of their vital growth and reproduction functions are also affected.

…

Shark fossils date back to the Late Ordovician Period, when a few scales date back to 450 million years ago. AFP VIA GETTY IMAGES

If you asked Valentina Di Santo what was the most surprising finding from her latest research project, she would quickly answer, “Well, first, [the fact that] there is not much known about the effect of climate change on elasmobranchs! Sharks and ray are an important group of meso- and top predators but studies to understand the effect of climate-related stressors have been scarce, especially when compared to the vast literature on the effect of climate change on physiological responses of bony fishes.” As one of the oldest and most diverse group of marine vertebrates, elasmobranchs (sharks, skates, rays and sawfishes) have survived multiple extinctions our planet has previously faced. Wipe-outs that killed off their mighty ancestors and even dinosaurs were no match for sharks… but could they finally be facing a foe even they can’t win against?

Enter climate change.

Due to climate change, our oceans are currently experiencing severe changes, including a rise in temperature, a rise in sea level, and an increase in acidity. Ocean acidification was of particular interest to the Assistant Professor of Functional Morphology at Stockholm University because, as she puts it, “understanding intraspecific variation in responses to stressors is key to identify which traits make individuals and group of elasmobranchs more or less vulnerable to the effects of environmental change.”

Because climate change has already begun, scientists have little time to test how severely it impacts different species. It’s important therefore, that researchers focus on the different characteristics (known as ‘physiotypes’) that make individuals more or less vulnerable to rapid warming and acidification. Some of these traits include body size, local adaptation to fluctuating chemical and physical conditions, age-at-maturity. “One of these [important] traits is, for example, locomotor performance,” adds Di Santo. In many animals, locomotor performance plays a fundamental role in determining their fitness. Locomotor performance is closely related to the morphology of the structures responsible for it, such as limbs and fins. In elasmobranchs, it influences vital functions such as reproduction, migration, predator avoidance, small-scale movements, and more. By delving into the literature, the Di Santon’s team was able to integrate findings from previous work on locomotion of marine sharks and rays to identify characteristics that outline potential vulnerabilities and strength of sharks and rays under climate change.

…

South of the Florida Keys lies a constellation of coral reefs—a biological and economic treasure found nowhere else in the mainland United States. Since 1990, these reefs have been protected by the Florida Keys National Marine Sanctuary, but coral health has still declined. The problems range from rising water temperatures to disease to damage caused by boaters.

Building these reefs has taken corals tens of thousands of years. Decimating them has taken humans mere decades. Since the late 1970s, healthy coral cover in the Florida Keys has fallen 90 percent.

To give these reefs a renewed chance at survival, NOAA is spearheading Mission: Iconic Reefs, one of the most ambitious reef-restoration efforts ever attempted worldwide. By 2040, the mission hopes to have restored 3 million square feet at 7 iconic reef locations—an area the size of 52 football fields—to at least 25 percent coral cover, which should be enough to allow them to repair themselves the rest of the way.

The effort involves dozens of partners: nurseries to grow millions of corals for replanting; labs and scientists to guide decisions about which corals to use and how to prepare them for conditions on the reef; technical divers to clean up dead, algae-covered reefs; and citizen-science volunteers to help plant corals and maximize their chances of survival through ongoing coral gardening—removing predators and pests, and restoring damaged corals.

But with continued climate warming and ocean acidification expected in the foreseeable future, finding and breeding corals tough enough to withstand heat stress and rising acidity must be part of the process. So, the project will take a phased approach, allowing some restoration work to begin immediately, while simultaneously supporting ongoing research.

…

Bleached coral. Photo: Vardhan Patankar, Wikimedia

The world’s oceans form a primary component of the climate system. They contribute to climate regulation by absorbing carbon dioxide (CO₂) emissions and heat. They have absorbed over a quarter of human-caused CO₂ and around 90% of the excess heat produced in recent decades. The oceans are by far the largest active carbon reservoir on the planet, storing about 38,000 billion tonnes of carbon. They are also a crucial source of food supply and livelihoods for billions of people.

However, climate change is causing the oceans to warm and become more acidic, which in turn is may affect how the oceans absorb and store carbon. This includes the possibility that, as anthropogenic CO₂ emissions continue, some of the ocean carbon sequestration routes could change from a being sink to a source in the future.

Ocean warming, melting ice and sea-level rise

The excess heat taken up by the oceans has increased their mean temperature at an average rate of 0.11°C per decade since 1970. Because the oceans redistribute heat towards the poles, this warming is contributing to the melting of ice sheets and glaciers and leading to a rise in the mean sea level – currently estimated at 0.19m between 1901 and 2010. The greatest threat of future sea level rise comes from the possibility that the massive ice sheets in the Antarctic and Greenland could melt. Sea level rise is also caused by thermal expansion, whereby seawater becomes less dense and expands as it warms, and in recent decades this has been one of the major drivers in this change – responsible for over one-third of all sea level rise observed.

Since the industrial revolution began a little over 200 years ago, the concentration of carbon dioxide (CO₂) in the atmosphere has increased due to the burning of fossil fuels, cement production, and land use change. The ocean acts as a “carbon sink” and absorbs between 20% and 30% of the CO₂ emissions released into the atmosphere. When CO₂ is absorbed by seawater, the chemistry of the ocean is changed. This phenomenon is commonly referred to as ocean acidification (OA). 

Ocean acidification is a global threat to the world’s oceans, estuaries, and waterways. OA can harm sea life, particularly commercially valuable species. It is best known for its osteoporosis-like effects on shellfish, which makes building and maintaining shells difficult for oysters, clams, sea urchins, shallow water corals, and deep sea corals. Ocean acidification is expected to have negative overall effects on many marine species which could alter marine food web, change the community composition and structure, and food supply to humans.

The growing concern about acidity has led to an increase in research, monitoring, and the development of management measures. Long-term monitoring and scientific analysis of ocean carbon data are critical to anticipate, mitigate, and adapt to potential future changes. Effective stewardship of important OA data is also essential. A new set of OA climatologies has been developed that provides valuable OA information for the coastal ocean where 90% of fisheries yields are located. 

…

The UN Decade of Ocean Science for Sustainable Development programme “Ocean Acidification Research for Sustainability” (OARS), spearheaded by the Global Ocean Acidification Observing Network (GOA-ON), invites you to participate in the community review of its white papers. 

The OARS programme provides a vision for ocean acidification research for the next decade by setting out a roadmap that, when implemented in collaboration with multiple partners, will deliver against seven outcomes by 2030. These outcomes are: 

1. Enable the scientific community to provide ocean acidification data and evidence of known quality.
2. Identify data and evidence needs for mitigation and adaptation strategies, from local to global, by 2022.
3. Co-design and implementation of observation strategies in collaboration with data/information producers and end-users by 2025.
4. Increase understanding of ocean acidification impacts to protect marine life by 2030.
5. Provide appropriate data and information necessary to the development of societally relevant predictions and projections.
6. Increase public awareness of ocean acidification, its sources and impacts.
7. Develop strategies and solutions to enable countries and regions to include measures to reduce ocean acidification in their respective policy and legislation.

Each of these seven outcomes is led by co-champions, experts in their fields, who, together with their expert working group, will develop the path towards achieving their outcomes. These seven white papers are an important step on that path: Each paper outlines the vision for the outcome, highlights the key outputs and products, describes the research and outreach activities and identifies the key inputs and partners necessary to successfully implement each outcome.    

With this review, we invite the community to provide their thoughts and input to the OARS programme and the implementation plans. 

To participate in the review, please download the pdf of the outcome or outcomes you would like to review as well as the review template (available here). Use the template to submit your specific comments, referencing the precise outcome and page your comment  ; one single template can be used to review more than one white paper. Once you have finished the review, please send your completed template to the GOA-ON Secretariat secretariat@goa-on.org no later than 20. March 2023. 

If you are interested in contributing to any of the seven OARS outcomes or just want to hear more, please contact us! The GOA-ON secretariat will put you in touch with the outcome champions: secretariat@goa-on.org

Open Data is a strategy for incorporating research data into the permanent scientific record by releasing it under an Open Access license. Whether data is deposited in a purpose-built repository or published as Supporting Information alongside a research article, Open Data practices ensure that data remains accessible and discoverable. A growing number of journals ask now authors to publish datasets in reliable FAIR-aligned data repositories when submitting the articles.

In order to facilitate this process, a data compilation is hosted at PANGAEA Data Publisher for Earth and Environmental Science and maintained in the framework of the International Atomic Energy Agency (IAEA) Ocean Acidification International Coordination Centre (OA-ICC) in collaboration with Xiamen University, China and the Laboratoire d’Océanographie de Villefranche, France. The goal of this data compilation is to ensure the archival and streamlining of data on the biological response to ocean acidification (and other environmental drivers), as well as to provide easy access to the data for all users. 

On PANGAEA (https://www.pangaea.de/), at the time of article submission, data will be made available to the scientific community in a coherent format and with a citable DOI. Upon acceptation of your manuscript, your datasets will be also accessible through a user-friendly portal (http://oa-icc.ipsl.fr/) that allows users to easily access relevant biological response data based on a set of filters. Please note that only datasets related to experimental or observational assessments of ocean acidification impacts and comprising at least 2 carbonate chemistry parameters will be displayed on the data portal. 

You can contribute by contacting Yan Yang, OA-ICC Data Curator, State Key Laboratory of Marine Environmental Science, China (yangyan@xmu.edu.cn)

For the first time, an international research team compiled a set of best practices to assess and report ocean acidification trends. Standardized procedures for measuring ocean carbon chemistry are already largely  established, but a common set of best practices for trend analysis are missing. These best practices will facilitate ocean acidification comparison of trends across different regions. They also allow the research community to establish enduring accurate records of change that communicate the current status of ocean acidification to the public.

Ocean acidification occurs when  the ocean absorbs carbon dioxide from the atmosphere, causing  a fundamental chemical change. The global rise in ocean acidity is fueled by human-emitted greenhouse gases. The global ocean has absorbed approximately 620 billion tons of carbon dioxide (~25%) from emissions released into the atmosphere by burning fossil fuels. Impacts from ocean acidification will vary by region. In order to implement adaptation and mitigation strategies, managers need an accurate and comparable understanding of how ocean acidification progresses globally, regionally and locally. This requires standardized procedures at all levels of data collection, dissemination, and analysis.

Read more at the link below.

Click to read the full article

Around one quarter of the CO₂ emitted from human activities annually is absorbed by the ocean. This has been shown to affect the chemistry of the seawater, causing a drop in pH which has major implications for many marine species and ecosystems.

Despite the threat that ocean acidification (OA) poses, there is currently no global framework for monitoring its biological impacts, and this is hampering efforts to fully assess the rate and scale of the issue. As such, a team of ocean acidification experts, including scientists from Plymouth Marine Laboratory (PML), have created a new methodology designed to ensure best practice in future OA monitoring and improve globally-coordinated efforts to understand and mitigate its effects.

Drawing on a wealth of data from previous experiments and observations, the publication “Unifying biological field observations to detect and compare ocean acidification impacts across marine species and ecosystems: What to monitor and why” proposes five broad classes of biological indicators that, when coupled with environmental observations including carbonate chemistry, would create a far more advanced understanding of the rate and severity of the biological changes taking place due to ocean acidification globally.

…

PHOTOGRAPH: FRANCOIS GOHIER/GETTY IMAGES

Taryn Foster believes Australia’s dying coral reefs can still be rescued—if she can speed up efforts to save them. For years, biologists like her have been lending a hand to reefs struggling with rising temperatures and ocean acidity: They’ve collected coral fragments and cut them into pieces to propagate and grow them in nurseries on land; they’ve crossbred species to build in heat-resistance; they’ve experimented with probiotics as a defense against deadly diseases.

But even transplanting thousands of these healthy and upgraded corals onto damaged reefs will not be enough to save entire ecosystems, Foster says. “We need some way of deploying corals at scale.” Sounds like a job for some robots.

In a healthy ocean, individual corals called polyps build their skeleton by extracting calcium carbonate from seawater. They then fuse with corals of the same genetic makeup to form huge colonies—coral reefs. But as the ocean absorbs more carbon dioxide from the atmosphere, the water becomes more acidic, making it difficult for the polyps to build their skeletons or to keep them from dissolving. Acidification inhibits reef growth, and with global ocean temperatures rising, corals are struggling to survive.

In the Great Barrier Reef, for instance, coral growth has slowed in recent decades, partly because during heat waves the corals expel the tiny algae that live inside their tissues and provide them with nutrients, causing them to bleach. Bleached corals are not dead but are more at risk of starvation and disease, and the loss of coral reefs has a devastating impact on the thousands of fish, crabs and other marine animals that rely on them for shelter and food.

…

At an event entitled “Ocean Acidification: A Crisis in the making“, hosted by Back to Blue in Tokyo, Japan, on February 2rd, chairman of The Nippon Foundation Yohei Sasakawa, and chairman of The Economist Group Lord Deighton made opening remarks, inviting urgent action to tackle ocean acidification.

Peter Thomson, UN Special Envoy for Oceans, said, “In light of the biodiversity framework adopted at the end of last year, ocean acidification is an urgent issue. Today’s event is very significant. This year, the G7 meeting will be held in Japan, a maritime nation. I hope that Japan will show leadership in this regard.” Panellists included Steve Widdicombe, Scientific Director of Plymouth Marine Laboratory, a world authority on marine ecology, and Japanese fisheries researchers.

Back to Blue released its Ocean Acidification programme in December 2022. The publication focuses on the need to address ocean acidification and is based on insights and research provided by some of the world’s leading ocean scientists. The publication highlights how time is rapidly running out to avoid the worst effects of ocean acidification and the worst impacts of ocean acidification on marine life, livelihoods, and economies.

Ocean acidification occurs when seawater absorbs CO2 generated by human activities such as burning fossil fuels. More than a quarter of the CO2 emitted by humans into the atmosphere has been absorbed by the oceans each year, but CO2 emissions are now increasing so rapidly that the oceans are no longer able to absorb it. As a result, the chemistry of the ocean is changing, acidity is increasing, and the ability of many marine organisms to protect themselves, grow, and reproduce is weakening.

The publication highlights that if we continue on our current high-emissions trajectory, many marine organisms, including molluscs, pteropods (“sea butterflies”) and warm-water corals, will be at very high risk from acidification as early as 2050. The adverse impacts from the decline of such organisms on ocean biodiversity and marine food chains are likely to be severe.

…

On behalf of the SOLAS-IMBeR Ocean Acidification working group (SIOA), we are asking for your help in gathering information regarding the next “Ocean in a High CO₂ World Symposium.”

The International Symposium on the Ocean in a High CO₂ World was first initiated in 2004 in Paris, France and held every 4 years until its 5^th edition organized in Lima, Peru in 2022 (https://www.highco2-lima.org/). It gathers hundreds of researchers, students, and government and industry representatives with a common interest in ocean acidification and its impacts. It has been a pre-eminent forum for sharing the latest scientific findings in the field, and affords attendees opportunities to network, create new collaborations, and share knowledge with developing countries.

We have prepared a survey to evaluate the needs for a 6^th edition as well as its format. It takes between 5 and 10 minutes to fill out. You can find the survey at: https://forms.gle/wRdtCC9GL8xi7Umv6

Deadline for submission: March 15, 2023

Many thanks for your help and contribution,

Sam Dupont & Sarah Flickinger

The UN Decade program “Ocean Acidification Research for Sustainability” (OARS) is organizing a session on “Ocean Acidification 2.0 – From Chemistry to Society” at the next ASLO meeting in Palma de Mallorca (4-9 June 2023).  Consider submitting an abstract by February 23rd!

This session aims at providing a platform for the ocean acidification community together with those who have a shared interest of protecting and conserving biodiversity in the face of global changes. It will promote actions to address the need for broader, more diverse, inclusive, and interdisciplinary collaboration and co-design of science and action. There is a need for purposeful efforts to facilitate inclusion of all interested researchers in monitoring and ocean acidification research networks. We encourage submission of poster and presentation focusing on, for instance, co-design approach, new experimental designs encompassing the chemical and biological complexity (e.g. natural variability, ecology, evolution, multiple stressors), syntheses and meta-analyses, and unification of chemical and biological observations (see below for a full description of the session).

You can submit your abstract for the session “SS066 Ocean Acidification 2.0 – From Chemistry to Society” before February 23^rd at: https://www.aslo.org/palma-2023/abstract-preparation-guide/

For any questions, contact: sam.dupont@bioenv.gu.se

SS066 Ocean Acidification 2.0 – From Chemistry to Society

Sam Dupont, University of Gothenburg (sam.dupont@bioenv.gu.se)
Iris Hendriks, IMEDEA (CSIC-UIB) (iris@imedea.uib-csic.es)
Jan Newton, University of Washington (janewton@uw.edu)

Ocean acidification has gained increasing recognition across national and international policy frameworks, such as national ocean action plans, the 2030 Agenda and the UNFCCC. To fully address and minimize its effects, scientists, governments, and end-users will benefit from co-designing science, monitoring, research, and syntheses that support informed choices about national mitigation, adaptation, and preparedness strategies. An overwhelming body of evidence documents ocean acidification, with potential significant impacts on marine species and ecosystems. The increase of atmospheric CO₂ due to fossil fuel burning is the main driver of ocean acidification in the open ocean. In the coastal zone, the variability in pCO₂ and pH is also driven by biological, near-shore and land-based processes, such as river run-off, stratification, and tides. The complexity of bridging chemical and biological changes associated with ocean acidification is often under-estimated. Today, projections rely mainly on proxy variables like pH, carbonate saturation states, dissolved oxygen, temperature, and salinity, and simplistic thresholds to speculate about the status and trends of biodiversity and ecosystem services. Ecosystem response to ocean acidification can be only assessed when considering factors such as adaptation to local chemical variability, evolutionary processes, ecological interactions, and the modulating role of other environmental drivers or stressors. Therefore, global, regional, and local impacts on biology and ecology, whether gradual or stepwise, are not fully resolved. Experimental work often over-simplifies these processes, for instance by focusing on single species and stressors, short-term responses, and static conditions that do not incorporate natural variability. Ocean observing and data are often focused on one or a handful of physical and biogeochemical parameters, but generally do not include biology and ecosystem. On the other hand, results from experimental work and from in situ observing efforts are not always well integrated into synthesis and modeling efforts. As a consequence, although data are being generated about ocean acidification changes and separately about some ecological changes, we are not able to evaluate whether a local resource or ecosystem service is changing due to ocean acidification. The UN Decade program “Ocean Acidification Research for Sustainability” (OARS) aims to provide a road map to fill these gaps. In line with the vision of OARS, this session aims at providing a platform for the ocean acidification community together with those who have a shared interest of protecting and conserving biodiversity in the face of global changes. It will promote actions to address the need for broader, more diverse, inclusive, and interdisciplinary collaboration and co-design of science and action. There is a need for purposeful efforts to facilitate inclusion of all interested researchers in monitoring and ocean acidification research networks. We will encourage submission of poster and presentation focusing on, for instance, co-design approach, new experimental designs encompassing the chemical and biological complexity (e.g. natural variability, ecology, evolution, multiple stressors), syntheses and meta-analyses, and unification of chemical and biological observations.

Most people associate hurricanes with high winds, intense rain and rapid flooding on land. But these storms can also change the chemistry of coastal waters. Such shifts are less visible than damage on land, but they can have dire consequences for marine life and coastal ocean ecosystems.

We are oceanographers who study the effects of ocean acidification, including on organisms like oysters and corals. In a recent study, we examined how stormwater runoff from Hurricane Harvey in 2017 affected the water chemistry of Galveston Bay and the health of the bay’s oyster reefs. We wanted to understand how extreme rainfall and runoff from hurricanes influenced acidification of bay waters, and how long these changes could last.

Our findings were startling. Hurricane Harvey, which generated massive rainfall in the Houston metropolitan area, delivered a huge pulse of fresh water into Galveston Bay. As a result, the bay was two to four times more acidic than normal for at least three weeks after the storm.

This made bay water corrosive enough to damage oyster shells in the estuary. Because oyster growth and recovery rely on many factors, it is hard to tie specific changes to acidification. However, increased acidification certainly would have made it harder for oyster reefs damaged by Hurricane Harvey to recover. And while our study focused on Galveston Bay, we suspect that similar processes may be occurring in other coastal areas.

Continue reading Hurricane Harvey more than doubled the acidity of Texas’ Galveston Bay, threatening oyster reefs

The research puts modern oceanic climate change in context

The research vessel JOIDES Resolution collecting samples in the Indian Ocean off the western coast of Australia in 2017. Gabriel Tagliaro

During the Cretaceous Period around 100 million years ago, Earth’s oceans were nearly unrecognizable. Below the waves swam marine reptiles: lizard-like mosasaurs, long-necked plesiosaurs and gargantuan sea turtles. These behemoths lived alongside squid-like ammonites encased in tightly-coiled shells and a slew of bizarre fish.

94 million years ago, these strange seas became nearly uninhabitable. Oxygen levels plummeted, and the ocean acidified during an episode known as the Oceanic Anoxic Event 2 (OAE2) that sent ripples through marine ecosystems worldwide. “As geologists, we’re drawn to times when things went wrong during the past,” said Matt Jones, a former research fellow at the National Museum of Natural History who now works with the United States Geological Survey. “We’re trying to understand why the oceans lost so much oxygen content in the mid Cretaceous.”

…

As they retrieved samples from the seafloor, the team noticed the pale-colored cores were punctuated by a green and black band of sediment several centimeters thick — a sign that something dramatic had happened to the oceanic environment. Based on its position in the core, they estimated that this band of dark sediment was deposited during the OAE2.

The black bands of mudstone in the cores represent periods when oxygen levels along the seafloor in the Mentelle Basin plummeted. Brian Huber, NMNH

Scientists from NOAA’s Atlantic Oceanographic and Meteorological Laboratory (AOML), and our cooperative institute partners, the University of Miami’s Cooperative Institute of Marine and Atmospheric Studies  and the Northern Gulf Institute, recently participated in Ocean Acidification Annual Community Meetings at the Scripps Institute of Oceanography in San Diego, California. Over the course of multiple days, scientists attended various meetings on ocean acidification research topics, visited laboratories, met with fellow scientists, learned about new ocean acidification technologies, and much more. 

NOAA’s Ocean Acidification Program (OAP) seeks to better prepare society to respond to changing ocean conditions by understanding the processes of ocean acidification through interdisciplinary partnerships both nationally and internationally. The goals of the OAP community meeting are to shape the future of the OAP; to inform community members of OAP updates, encourage collaborations with the ocean acidification research community, discuss research gaps and how to address them, and to make ocean acidification research more diverse and accessible.

…