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Does ocean acidification alter fish behavior? Fraud allegations create a sea of doubt

Published 7 May 2021 Web sites and blogs Closed
Orange clownfish are among the tropical species studied in 22 papers now facing scrutiny. FREDRIK JUTFELT

A group of whistleblowers has asked three funding agencies for a misconduct investigation into a series of 22 research papers, many of them on the effects of ocean acidification on fish behavior and ecology. The request, which they shared with a Science reporter, rests on what they say is evidence of manipulation in publicly available raw data files for two papers, one published in Science, the other in Nature Climate Change, combined with remarkably large and “statistically impossible” behavioral effects from carbon dioxide reported in many of the other papers. The papers’ two main authors emphatically deny making up data, and James Cook University, Townsville, in Australia has dismissed the fabrication allegations against one of them after a preliminary investigation. But multiple independent scientists and data experts who reviewed the case flagged what they said were serious problems in the two data sets, as well as in two additional ones co-authored by one of the accused scientists. The case isn’t just about data and the future of the oceans. It highlights issues in the sociology, psychology, and politics of science, including pressure on researchers to publish in top-tier journals, the journals’ thirst for eye-catching and alarming findings, and the risks involved in whistleblowing.

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This story was supported by the Science Fund for Investigative Reporting.

Enserink M., 2021. Sea of doubts. Science 372(6542): 560-565. doi: 10.1126/science.372.6542.560

Martin Enserink, AAAS, 6 May 2021. Full article.

Exploring coastal acidification and oyster restoration activities on the United States Atlantic coast

Published 7 May 2021 Science Closed
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Executive Summary

The global ocean mediates the effect of climate change and anthropogenic carbon emissions by absorbing atmospheric carbon dioxide (Ellis et al., 2017). The ocean’s absorption of carbon dioxide results in a change in ocean chemistry and decline in seawater pH known as ocean acidification (Kapsenberg and Cyronak, 2018). Changes in ocean chemistry and pH may also be driven by primary production activity, upwelling, and river runoff into marine environments (Richards et al., 2014). Ocean acidification has the potential to adversely affect numerous marine organisms (Kapsenberg and Cyronak, 2018), however, it can be especially problematic for calcifying shellfish species (Swezey et al., 2020) like the Eastern Oyster and larval or juvenile stage organisms (Mangi et al., 2018). Temperature, salinity, dissolved oxygen levels, and acidification impact the health and longevity of oysters and oyster reefs. Oyster reefs offer numerous ecosystem services. These reefs provide habitat for benthic invertebrates, seabirds and fish that rely on reefs for feeding, nursery, and breeding grounds (Burrows et al., 2005). The Eastern Oyster (Crassostrea virginica) is a native oyster species of the U.S. Atlantic Coast. Although oysters reefs support coastal livelihoods and offer numerous ecosystem services, many reefs have been degraded by anthropogenic activities (Burrows et al., 2005). Pollution, over-harvest, and an increase in loading of suspended sediments are key threats to oyster reef health (Burrows et al., 2005). Oyster reef restoration projects focus on returning reefs to their natural state. Given the role of oysters as ecosystem engineers, and the many benefits that may be derived from healthy oyster reefs, restoration projects are a priority for communities throughout the U.S. Atlantic Coast.

Cooley et al. 2016 recommends several effective community actions that may be taken to help address ocean acidification today. This project focuses on two non-legislative actions discussed by Cooley et al. 2016. These are public education related to coastal acidification and resilience management through oyster reef restoration projects. The purpose of this project is to support coastal resource-reliant communities on the U.S. Atlantic Coast in preparing for the potential future impacts of ocean acidification on C. virginica. The project examines trends in the oyster reef restoration projects presently underway at the state and local level along the U.S. Atlantic Coast, and it considers how coastal acidification may affect the longevity of the region’s oyster reefs. Finally, the project considers the future research and management considerations needed to adequately protect oyster reefs under changing climatic conditions.

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10 years in the making: an inside look at NOAA’s Ocean Acidification Program with director Libby Jewett

Published 7 May 2021 Web sites and blogs Closed

Libby Jewett, Ph.D., Director of the NOAA Ocean Acidification Program, provides insight into ocean acidification. Jewett highlights how she became involved in ocean acidification work, how NOAA’s Ocean Acidification Program (OAP) started, and how we all can personally contribute to combatting this threat to our ocean.

What brought you to this position?

After receiving my Ph.D. from the University of Maryland in biology, focusing on marine ecology in the Chesapeake Bay, I was hired by NOAA to work on harmful algal blooms and hypoxia, or low oxygen levels in seawater. Colleagues started talking about ocean acidification around 2006 as a new important topic that was not well understood and a considerable potential threat to marine ecosystems.

In 2007, I became a founding member of NOAA’s Ocean Acidification Steering Committee. I also became the point of contact for ocean acidification in the National Ocean Service, where I was at the time, and initiated, with other members of the Steering Committee, drafting NOAA’s first comprehensive ocean acidification research plan. When NOAA’s OAP was created, I applied and became the founding director, where I have been since May 2011.

What is ocean acidification? How has the field grown since its discovery?

Ocean acidification refers to the change in ocean chemistry — specifically, a reduction in the pH of our ocean over an extended period caused primarily by the uptake of carbon dioxide from the atmosphere. Ocean acidification was first discovered in the early 1900s when scientists realized that rising levels of atmospheric carbon dioxide would be taken up by the ocean, causing changes in the ocean’s chemistry. We’ve known that this had the potential to happen for a long time — however, it wasn’t until the early 2000s that NOAA, with other international scientists, detected a change in chemistry in the open ocean, documented with data.

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Dr Li-Qing Jiang – mapping the impact of carbon emissions on the oceans

Published 7 May 2021 Web sites and blogs Closed

The climate crisis and the chemistry of the oceans are inextricably connected. The oceans have absorbed close to a third of our carbon dioxide emissions since the beginning of the Industrial Revolution, leading to an increasingly acidic environment and making it more difficult for organisms such as corals, molluscs, and plankton to form their shells and skeletons. Mapping future changes in ocean chemistry is the first step in developing mitigation strategies. However, our knowledge of the future state of the oceans relies on mathematical models that are often not calibrated with modern ship-based observations. Dr Li-Qing Jiang of the University of Maryland and his collaborators are improving ocean acidification predictions by coupling millions of past and present ocean chemistry measurements with the best model projections at each location of the global ocean.

The Ocean as a Carbon Sink

The global oceans have absorbed about 30% of the carbon dioxide released by human activity over the past 200 years. As it dissolves in seawater, carbon dioxide reacts with water to form a weak acid called carbonic acid. Therefore, as atmospheric carbon dioxide increases, so does the acidity of the oceans – a process called ocean acidification.

When ocean acidity rises, calcium carbonate saturation – which describes the tendency of calcium carbonate minerals to form or dissolve – decreases. As many marine organisms need calcium carbonate minerals to build their protective shells and skeletons, they can suffer from slow growth and even dissolution when the ocean is too acidic. Ocean acidification is already having catastrophic effects on coral reefs, some of the world’s most important and biodiverse ecosystems.

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Postdoctoral research assistant in biogeochemistry of calcifying nannoplankton

Published 7 May 2021 Jobs Closed

University of Oxford – Earth Sciences

Earth Sciences, South Parks Road, Oxford

Location: Oxford

Salary: £32,817 – £36,914 p.a, Grade 7

Hours: Full Time

Contract Type: Fixed-Term/Contract

Placed On: 6th May 2021

Closes: 25th June 2021

Job Ref: 150797

Apply

Description

Calcifying phytoplankton, such as coccolithophores, are a fundamental component of the marine carbon cycle. Yet, we have little understanding how changing climate affects calcification and how it is going to evolve under the environmental pressure imposed by global warming and ocean acidification. Currently there is little mechanistic understanding of how energy and carbon flow between photosynthesis and calcification in coccolithophores, and how this dynamic coupling is affected by resource limitation and environmental stress. Our knowledge gap on the environmental sensitivity of the coupling between photosynthesis and calcification means that we still do not know whether coccolithophore calcification increases or decreases in response to ocean acidification, despite 20 years of research.

PUCCA (Photosynthetic Underpinnings of Coccolithophore Calcification) will take advantage of advances in cutting-edge techniques that document and mechanistically interrogate the sensitivity of coccolithophore calcification rates to the environment. A new physiological model of carbon isotopic fractionation in coccolithophores allows the reconstruction of species-specific calcification rates from the sedimentary record. Additionally, methods have advanced that can extract and characterise biochemical molecules from fossils over a hundred million years old which will allow the interrogation of controlling environmental parameters.

The successful candidate will be responsible for identifying which environmental parameter(s) drive the highest coccolithophore calcification rates during the Cenozoic, and across the modern ocean. As approaches, they will use ocean sediments as a recorder of coccolithophore stable isotope vital effects, extracted polysaccharides and other organic molecules, as a measure of the physiological sensitivity of calcification to different environmental regimes. They will also document how the sensitivity of calcification rates to environmental parameters is influenced by cellular resource allocation strategies using culture experiments of a range of strains of Emiliania huxleyi subjected to environmental limitation. These experiments will provide the foundation for calibrating organic molecules for the environmental impact on their structure and composition.

The successful candidate will hold, or be close to completion of, a relevant PhD. They will also have experience in stable isotope palaeoceanography and/or nannofossil palaeontology. Familiarity/prior experience with physiology (ideally of coccolithophores), and an understanding of organic/biochemistry, and biomineralisation will be an advantage. They will have the ability to manage their own academic research and associated activities and have excellent communication skills, including the ability to write for publication and present research proposals and results.

For further details of the responsibilities/duties, please see job description. This post is fixed term for 3 years from 06 September 2021 (or as soon as possible after). Candidates should apply online by midday on Friday 25 June 2021. Interviews will be held in mid-July 2021.

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EarthLab 2021 showcase: biology and ocean acidification from Jan Newton

Published 7 May 2021 Events Closed

Curious about what we do?

Join us for our second annual showcase, featuring lightning-style presentations from our member organizations, grantees, and other partners  who are working towards an equitable, just & sustainable world where people and planet thrive.

MAY 18 | 1:00 PM | ONLINE

Presentations include:

RSVP TODAY

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Communities of Ocean Action on Ocean Acidification webinar announcement

Published 6 May 2021 Events Closed

You’re invited!

The Communities of Ocean Action on Ocean Acidification, Bronte Tilbrook (CISRO) and Peter Swarzenski (IAEA) will provide updates about progress made on the Voluntary Commitments (VC) and other developments. They will be joined by Roshan Ramessur (OA Africa Network) and Kirsten Isensee (IOC-UNESCO) who will share lessons learned from their VCs during the past year. UN-DESA will conclude the meeting by giving a brief demo on how to submit your own VC and use the COA online resources.

17 May 2021 2:00 PM – 3:00 PM CEST

Registration: https://attendee.gotowebinar.com/regi…/2393100666611507214

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Exposure time modulates the effects of climate change-related stressors on fertile sporophytes and early-life stage performance of a habitat-forming kelp species

Published 6 May 2021 Science Closed
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Highlight

  • Ocean warming (OW) reduced the sorus photosynthetic performance.
  • OW reduced meiospore germination rate.
  • OW and ocean acidification reduced meiospore release (MR).
  • MR is more sensitive to temperature changes than to pCO2 changes.
  • Longer exposure to OW increased the negative effects on germination rate.

Abstract

Understanding the impact of increases in pCO2 (OA) and extreme changes in temperature on marine organisms is critical to predicting how they will cope with climate change. We evaluated the effects of OA as well as warming and cooling trend temperature on early reproductive traits of Lessonia trabeculata, a foundation kelp species. Sori discs were maintained for an exposure time (ET) of 3 (T3) and 7 (T7) days to one of two contrasting pCO2 levels (450 and 1100 μatm). In addition, at each pCO2 level, they were subjected to three temperature treatments: 15 °C (control), 10 °C (cool) and 19 °C (warm). Subsequently, we compared sorus photosynthetic performance (Fv/Fm), the number of meiospores released (MR) and their germination rate (GR) after 48 h of settlement, with values obtained from sori discs not exposed (DNE) to the treatments. The Fv/Fm measured for DNE was lower than at T3 and T7 at 10 and 15 °C but not at 19 °C. Regardless of temperature, we found no significant differences between MR measured at T0 and T3 were found. MR at T7 was significantly lower at 19 °C than at 10 and 15 °C. We found only aA significant reduction in MR in response to elevated pCO2 was only found at T3. The GR of meiospores released by DNE and then maintained for 48 h to 19 °C decreased significantly by ∼33 % when compared with those maintained for the same time at 10 and 15 °C. A similar, but more drastic reduction (∼54 %) in the GR was found in meiospores released by sori discs exposed for T3 and maintained for 48 h to 19 °C. We suggest that OA and warming trend will threaten the early establishment of this species with further consequences for the functioning of the associated ecosystem.

Graphical abstract

Under laboratory conditions were investigated the combined effect of pCO2, temperature and the exposure time on sorus photosynthetic performance (Fv/Fm) and meiospore performance (release and germination rate) of a habitat-forming kelp Lessonia trabeculata. The results suggest that important traits such as sorus photosynthetic performance, meiospores released and germination rate can be affected by those stressors and by the extent to which the sori are exposed. We concluded that ocean warming and ocean acidification might threaten the early establishment of this species with further consequences for the ecosystem functioning, goods and services in coastal environments.

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Rapid reduction of pH and CaCO3 saturation state in the Tsugaru Strait by the intensified Tsugaru warm current during 2012‐2019

Published 6 May 2021 Science Closed
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Abstract

To examine the ocean acidification of coastal water as the result of the oceanic uptake of anthropogenic atmospheric CO2, we initiated acidification monitoring in the eastern part of the Tsugaru Strait, through which the Tsugaru Warm Current flows eastward from the Sea of Japan to the North Pacific. Annual mean pH and CaCO3 saturation state during 2012–2019 decreased considerably throughout all depths at rates of 0.0030−0.0051 yr−1 and 0.017−0.036 yr−1, respectively. These rates of decrease are faster than those caused by increasing atmospheric CO2, and faster than those observed during previous research. These fast rates are attributed to an enhanced increase in dissolved inorganic carbon concurrently with increases in salinity and density caused by elevated mixing of the upper and deeper waters from the Sea of Japan at the western part of the strait. The elevated mixing is attributable to the strengthening of the Tsugaru Warm Current.

Plain Language Summary

Approximately 30% of the total amount of CO2 released to the atmosphere by human activities has accumulated in the global ocean. This oceanic uptake of CO2 has resulted in ocean acidification. In coastal waters the acidification affects marine organisms, thus coastal ecosystems may be more vulnerable to acidification than the open ocean. To examine the extent to which acidification has advanced in the eastern part of the Tsugaru Strait, through which the Tsugaru Warm Current passes from the Sea of Japan to the North Pacific, we initiated a time‐series observation of acidification. The pH reduction is found to have enhanced considerably across the whole depth during 2012‐2019 at a rate faster than that caused by increasing atmospheric CO2 and at the highest rates observed during previous research. The rapid pH reduction is found to be attributable to the enhanced rate of increase of dissolved inorganic carbon concurrently with increases in salinity and density caused by elevated mixing of the upper and deeper waters from the Sea of Japan at the western strait due to the strengthening of the Tsugaru Warm Current. In other straits that are connected to the open ocean, the strengthening of their throughflow may also accelerate acidification.

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Project on ocean acidification connects the environmental movement, researchers and authorities

Published 6 May 2021 Projects , Web sites and blogs Closed

Ocean acidification threatens our entire ecosystem. Yet, there is not much talk about it. The BALSAM project is launching a campaign to open people’s eyes to a phenomenon that can have drastic consequences for both nature and humans.

Archipelago
The BALSAM project aims to reach groups who share the environmental movement’s concerns about ocean acidification Photo: Henrik Trygg/imagebank.sweden.se

Carbon dioxide emissions cause not only climate change, but also ocean acidification. Corals, salmon, shrimp and shellfish, as well as the entire ecosystem, are at risk.

– Ocean acidification has sometimes been called the “equally evil twin of climate change”. Still, the awareness of ocean acidification is not as big as the awareness of, for example, the increase in temperature in the oceans, says Marko Reinikainen, project manager at AirClim.

The BALSAM project, which is run by organizations in five countries in the Baltic Sea region, wants to increase awareness of the consequences of ocean acidification. Therefore, the Ocean Acidification Action Week campaign is launched May 3-9.

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CO2 capture by pumping surface acidity to the deep ocean

Published 5 May 2021 Science Closed
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The majority of IPCC scenarios call for active CO2 removal (CDR) to remain below 2oC of warm- ing. On geological timescales, ocean uptake regulates atmospheric CO2 concentration, with two homeostats driving CO2 uptake: dissolution of deep ocean calcite deposits and terrestrial weathering of silicate rocks, acting on 1ka to 100ka timescales, respectively. Many current ocean-based CDR proposals effectively act to accelerate the latter. Here we present a method which relies purely on the redistribution and dilution of acidity from a thin layer of the surface ocean to a thicker layer of deep ocean, with the aim of reducing surface acidification and accelerating the former carbonate homeostasis. This downward transport could be seen analogous to the action of the natural biological carbon pump. The method offers advantages over other ocean CDR methods and direct air capture approaches (DAC): the conveyance of mass is minimized (acidity is pumped in situ to depth), and expensive mining, grinding and distribution of alkaline material is eliminated. No dilute substance needs to be concentrated, avoiding the Sherwood’s Rule costs typically encountered in DAC. Finally, no terrestrial material is added to the ocean, avoiding significant alteration of seawater ion concentrations or issues with heavy metal toxicity encountered in mineral-based alkalinity schemes. The artificial transport of acidity accelerates the natural deep ocean compensation by calcium carbonate. It has been estimated that the total compensation capacity of the ocean is on the order of 1500GtC. We show through simulation that pumping of ocean acidity could remove up to 150GtC from the atmosphere by 2100 with- out excessive increase of local ocean pH. For an acidity release below 2000m, the relaxation half-life of CO2 return to the atmosphere was found to be ∼2500 years (∼1000yr without account- ing for carbonate dissolution), with ∼85% retained for at least 300 years. The uptake efficiency and residence time were found to vary with the location of acidity pumping, and optimal areas were determined. Requiring only local resources (ocean water and energy), this method could be uniquely suited to utilize otherwise-unusable open ocean energy sources at scale. We examine technological pathways that could be used to implement it and present a brief techno-economic estimate of 130-250$/tCO2 at current prices and as low as 93$/tCO2 under modest learning-curve assumptions.

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Differential responses in anti-predation traits of the native oyster Ostrea edulis and invasive Magallana gigas to ocean acidification and warming

Published 5 May 2021 Science Closed
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Ocean acidification and warming (OAW) pose a threat to marine organisms, with particular negative effects on molluscs, and can jeopardize the provision of associated ecosystem services. As predation is an important factor shaping populations in the marine environment, the ability of organisms to retain traits valuable in predation resistance under OAW may be decisive for future population maintenance. We examine how exposure to seawater temperature (control: 16.8°C and warm: 20°C) and atmospheric pCO2 (ambient [~400], ~750, and ~1000 ppm) conditions affects traits linked to predation resistance (adductor muscle strength and shell strength) in two ecologically and economically important species of oysters (Magallana gigas and Ostrea edulis) and relate them to changes in morphometry and fitness (condition index, muscle and shell metrics). We show that O. edulis remained unimpacted following exposure to OAW scenarios. In contrast, the adductor muscle of M. gigas was 52% stronger under elevated temperature and ~750 ppm pCO2, and its shell was 44% weaker under combined elevated temperature and ~1000 ppm pCO2. This suggests greater resistance to mechanical predation toward the mid-21st century, but greater susceptibility toward the end of the century. For both species, individuals with more somatic tissue held an ecological advantage against predators; consequently, smaller oysters may be favoured by predators under OAW. By affecting fitness and predation resistance, OAW may be expected to induce shifts in predator-prey interactions and reshape assemblage structure due to species and size selection, which may consequently modify oyster reef functioning. This could in turn have implications for the provision of associated ecosystem services.

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Large-scale interventions may delay decline of the Great Barrier Reef

Published 5 May 2021 Science Closed
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On the iconic Great Barrier Reef (GBR), the cumulative impacts of tropical cyclones, marine heatwaves and regular outbreaks of coral-eating crown-of-thorns starfish (CoTS) have severely depleted coral cover. Climate change will further exacerbate this situation over the coming decades unless effective interventions are implemented. Evaluating the efficacy of alternative interventions in a complex system experiencing major cumulative impacts can only be achieved through a systems modelling approach. We have evaluated combinations of interventions using a coral reef meta-community model. The model consisted of a dynamic network of 3753 reefs supporting communities of corals and CoTS connected through ocean larval dispersal, and exposed to changing regimes of tropical cyclones, flood plumes, marine heatwaves and ocean acidification. Interventions included reducing flood plume impacts, expanding control of CoTS populations, stabilizing coral rubble, managing solar radiation and introducing heat-tolerant coral strains. Without intervention, all climate scenarios resulted in precipitous declines in GBR coral cover over the next 50 years. The most effective strategies in delaying decline were combinations that protected coral from both predation (CoTS control) and thermal stress (solar radiation management) deployed at large scale. Successful implementation could expand opportunities for climate action, natural adaptation and socioeconomic adjustment by at least one to two decades.

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High-resolution carbonate system dynamics of Netarts Bay, OR from 2014 to 2019

Published 5 May 2021 Science Closed
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Netarts Bay is a shallow, temperate, tidal lagoon located on the northern coast of Oregon and the site of the Whiskey Creek Shellfish Hatchery (WCSH). Data collected with an autonomous continuous flow-through system installed at WCSH capable of high-resolution (1 Hz) partial pressure of aqueous CO2 (pCO2) and hourly total dissolved inorganic carbon (TCO2) measurements, with combined measurement uncertainties of < 2.0% and 0.5%, respectively, is analyzed over the 2014–2019 interval. Summer upwelling, wintertime downwelling, and in situ bay biogeochemistry represent significant modes of the observed variability in carbonate system dynamics. Summer upwelling is associated with large amplitude diel pCO2 variability, elevated TCO2 and alkalinity, but weak variability in salinity. Wintertime downwelling is associated with bay freshening by both local and remote sources, a strong tidal signature in salinity, TCO2, and alkalinity, with diel pCO2 variability much less amplified when compared to summer. Further, analysis of alkalinity-salinity relationships suggests multiple water masses inhabiting the bay during 1 year: mixing of end-members associated with direct precipitation, coastal rivers, southward displacement of the Columbia River plume, California Current surface and deep upwelled waters. The importance of in-bay processes such as net community metabolism during intervals of high productivity are apparent. These direct measurements of pCO2 and TCO2 have been useful to local hatchery owners who have monitored intake waters following historic seed-production failures related to high-CO2 conditions exacerbated by ocean acidification.

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Coastal pH variability and the eco-physiological and behavioural response of a coastal fish species in light of future ocean acidification

Published 5 May 2021 Science Closed
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Ocean acidification (OA) is a global phenomenon referring to a decrease in ocean pH and a perturbation of the seawater carbonate system due to ever-increasing atmospheric CO2 concentrations. In coastal environments, identifying the impacts of OA is complex due to the multiple contributors to pH variability by coastal processes, such as freshwater inflow, upwelling, hydrodynamic processes, and biological activity. The aim of this PhD study was to quantify the local processes occurring in a temperate coastal embayment, Algoa Bay in South Africa, that contribute to pH and carbonate chemistry variability over time (monthly and 24-hour) and space (~10 km) and examine how this variability impacts a local fish species, Diplodus capensis, also commonly known as ‘blacktail’. Algoa Bay, known for its complex oceanography, is an interesting location in which to quantify carbonate chemistry variability. To assess this variability, monitoring sites were selected to coincide with the Algoa Bay Sentinel Site long-term ecological research (LTER) and continuous monitoring (CMP) programmes. The average pH at offshore sites in the bay was 8.03 ± 0.07 and at inshore sites was 8.04 ± 0.15. High pH variability (~0.55–0.61 pH units) was recorded at both offshore (>10 m depth) and inshore sites (intertidal surf zones). Many sites in the bay, especially the atypical site at Cape Recife, exhibit higher than the average pH levels (>8.04), suggesting that pH variability may be biologically driven. This is further evidenced by high diurnal variability in pH (~0.55 pH units). Although the specific drivers of the high pH variability in Algoa Bay could not be identified, baseline carbonate chemistry conditions were identified, which is necessary information to design and interpret biological experiments. Long-term, continuous monitoring is required to improve understanding of the drivers of pH variability in understudied coastal regions, like Algoa Bay.

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Integrated ocean carbon research: a summary of ocean carbon research, and vision of coordinated ocean carbon research and observations for the next decade

Published 4 May 2021 Newsletters and reports Closed

The Integrated Ocean Carbon Research (IOC-R) programme is a formal working group of the Intergovernmental Oceanographic Commission (IOC) that was formed in 2018 in response to the United Nations (UN) Decade of Ocean Science for Sustainable Development (2021-2030), “the Decade.” The IOC-R will contribute to the science elements of the overarching Implementation Plan for the Decade1. The Implementation Plan is a high-level framework to guide actions by which ocean science can more effectively deliver its contribution and co-development with other entities to achieve the societal outcomes outlined in the Decade plan and the sustainable development goals (SDGs) of the UN.

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Geographical variation in phenotypic plasticity of intertidal sister limpet’s species under ocean acidification scenarios

Published 4 May 2021 Science Closed
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Ocean Acidification (OA) can have pervasive effects in calcifying marine organisms, and a better understanding of how different populations respond at the physiological and evolutionary level could help to model the impacts of global change in marine ecosystems. Due to its natural geography and oceanographic processes, the Chilean coast provides a natural laboratory where benthic organisms are frequently exposed to diverse projected OA scenarios. The goal of this study was to assess whether a population of mollusks thriving in a more variable environment (Talcaruca) would present higher phenotypic plasticity in physiological and morphological traits in response to different pCO2 when compared to a population of the same species from a more stable environment (Los Molles). To achieve this, two benthic limpets (Scurria zebrina and Scurria viridula) inhabiting these two contrasting localities were exposed to ocean acidification experimental conditions representing the current pCO2 in the Chilean coast (500 μatm) and the levels predicted for the year 2100 in upwelling zones (1500 (μatm). Our results show that the responses to OA are species-specific, even in this related species. Interestingly, S. viridula showed better performance under OA than S. zebrina (i.e., similar sizes and carbonate content in individuals from both populations; lower effects of acidification on the growth rate combined with a reduction of metabolism at higher pCO2). Remarkably, these characteristics could explain this species’ success in overstepping the biogeographical break in the area of Talcaruca, which S. zebrina cannot achieve. Besides, the results show that the habitat factor has a strong influence on some traits. For instance, individuals from Talcaruca presented a higher growth rate plasticity index and lower shell dissolution rates in acidified conditions than those from Los Molles. These results show that limpets from the variable environment tend to display higher plasticity, buffering the physiological effects of OA compared with limpets from the more stable environment. Taken together, these findings highlight the key role of geographic variation in phenotypic plasticity to determine the vulnerability of calcifying organisms to future scenarios of OA.

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The Bouraké semi-enclosed lagoon (New Caledonia). A natural laboratory to study the life-long adaptation of a coral reef ecosystem to climate change-like conditions

Published 4 May 2021 Science Closed
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According to current experimental evidence, coral reefs could disappear within the century if CO2 emissions remain unabated. However, recent discoveries of diverse and high cover reefs that already thrive under extreme conditions seem to contradict these projections. Volcanic CO2 vents, semi-enclosed lagoons and mangrove estuaries are unique study sites where one or more ecologically relevant parameters for life in the oceans are close or even worse than currently projected for the year 2100. These natural analogues of future conditions hold new hope for the future of coral reefs and provide unique natural laboratories to explore how reef species could keep pace with climate change. To achieve this, it is essential to characterize their environment as a whole, and accurately consider all possible environmental factors that may differ from what is expected in the future and that may possibly alter the ecosystem response.

In this study, we focus on the semi-enclosed lagoon of Bouraké (New Caledonia, SW Pacific Ocean) where a healthy reef ecosystem thrives in warm, acidified and deoxygenated water. We used a multi-scale approach to characterize the main physical-chemical parameters and mapped the benthic community composition (i.e., corals, sponges, and macroalgae). The data revealed that most physical and chemical parameters are regulated by the tide, strongly fluctuate 3 to 4 times a day, and are entirely predictable. The seawater pH and dissolved oxygen decrease during falling tide and reach extreme low values at low tide (7.2 pHT and 1.9 mg O2 L−1 at Bouraké, vs 7.9 pHT and 5.5 mg O2 L−1 at reference reefs). Dissolved oxygen, temperature, and pH fluctuates according to the tide of up to 4.91 mg O2 L−1, 6.50 °C, and 0.69 pHT units on a single day. Furthermore, the concentration of most of the chemical parameters was one- to 5-times higher at the Bouraké lagoon, particularly for organic and inorganic carbon and nitrogen, but also for some nutrients, notably silicates. Surprisingly, despite extreme environmental conditions and altered seawater chemical composition, our results reveal a diverse and high cover community of macroalgae, sponges and corals accounting for 28, 11 and 66 species, respectively. Both environmental variability and nutrient imbalance might contribute to their survival under such extreme environmental conditions. We describe the natural dynamics of the Bouraké ecosystem and its relevance as a natural laboratory to investigate the benthic organism’s adaptive responses to multiple stressors like future climate change conditions.

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Impact on fertility rate and embryo-larval development due to the association acidification, ocean warming and lead contamination of a sea urchin Echinometra lucunter (echinodermata: echinoidea)

Published 4 May 2021 Science Closed
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Ocean warming and acidification can cause deleterious effects on marine biota, which may be potentialized when associated with metal pollution. Thus, the aim of this work was to evaluate the effects of pH decrease, temperature increase and lead contamination on fertility rate and embryo-larval development of Echinometra lucunter. Gametes and embryos were exposed at pH 8.2 (control) and 7.5; at 26°C (control) and 28°C; and at lead concentrations of 0 (control), 125, 250 and 500 μg/L. These conditions were tested individually and in combination. The fertilization rate of E. lucunter was only significantly reduced in the treatments where temperature was increased and in the treatment where pH decreased. However, the development rate of the pluteus larvae was significantly affected in the majority of treatments: metal contamination in the higher concentration; decreased pH in all metal concentrations; increased temperature in the highest metal concentration; decreased pH and increased temperature and all variables combined, which is decreased pH, increased temperature and metal contamination in relation to the control group (C). The development test was shown to be more sensitive than the fertilization test in all the studied scenarios. In general, the present study suggests that pH decrease, temperature increase and metal pollution may have a significant impact on E. lucunter reproductive cycle.

Caetano L. S., Pereira T. M., Envangelista J. D., Cabral D. S., Coppo G. C., Alves de Souza L., Anderson A. B., Heringer O. A. & Chippari-Gomes A. R., in press. Impact on fertility rate and embryo-larval development due to the association acidification, ocean warming and lead contamination of a sea urchin Echinometra lucunter (echinodermata: echinoidea). Bulletin of Environmental Contamination and Toxicology. Article (subscription required).

Early career (PhD) positions for research into ocean alkalization and CO2 uptake

Published 4 May 2021 Jobs 2 Comments

Join a diverse team studying how the addition of alkalinity, produced during production of clean hydrogen fuel, can enhance the ocean’s uptake of CO2.

We are recruiting a team of early career researchers (including up to 4 PhD positions) with interest in environmental chemistry (#1 and #4 in figure), aquatic biology (#2-4), and marine physics (#3) to work within a unique, multidisciplinary team. The team will investigate the efficacy and impact of adding alkalinity to coastal seawater in order to increase the ocean’s capacity for removing CO2 from the atmosphere. The research will contribute to development of Planetary Hydrogen’s innovative co-production process, which aims to produce H2 as a clean fuel while decarbonizing our economy and contributing to Canada’s greenhouse gas reduction commitments under the Paris Agreement. For more details, please visit the project website (alkalinity.oceans.dal.ca) or contact the entire project team at: oceans@planetaryhydrogen.com.

Supervisors

  • Douglas Wallace
  • Hugh MacIntyre
  • Ruth Musgrave
  • Jeff Clements
  • Ramon Filgueira

Project Description and Opportunities

Hydroxide ion, generated as a byproduct of a novel process of hydrogen generation, can be used to increase the ocean’s ability to take up and store atmospheric CO2 in the form of dissolved bicarbonate. This alkalinity addition mimics the natural geochemical weathering reactions that have created the ocean’s massive reservoir of bicarbonate and carbonate ions, and can potentially benefit organisms that are vulnerable to ocean acidification, including commercially important shellfish.

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