Climate change stressors (e.g., warming and ocean acidification) are an imminent challenge to the physiological performance of marine organisms. Several studies spanning the last decade have reported widespread effects of warming and acidification on marine fishes, especially teleosts, but more work is needed to elucidate the responses in marine elasmobranchs, i.e., sharks and rays. Dispersal capacity, as a result of locomotor performance, is a crucial trait that will determine which group of elasmobranchs will be more or less vulnerable to changes in the environment. In fact, efficient and high locomotor performance may determine the capacity for elasmobranchs to relocate to a more favorable area. In this review we integrate findings from work on locomotion of marine sharks and rays to identify characteristics that outline potential vulnerabilities and strength of sharks and rays under climate change. Traits such as intraspecific variability in response to climatic stressors, wide geographic range, thermotaxis, fast swimming or low energetic costs of locomotion are likely to enhance the capacity to disperse. Future studies may focus on understanding the interacting effect of climatic stressors on morphology, biomechanics and energetics of steady and unsteady swimming, across ontogeny and species.
Continue reading ‘Swimming performance of sharks and rays under climate change’Archive Page 4
Swimming performance of sharks and rays under climate change
Published 21 March 2023 Science ClosedTags: biological response, fish, morphology, multiple factors, performance, physiology, review, temperature
Internship – Ocean Acidification International Coordination Centre
Published 21 March 2023 Jobs ClosedDuty Station: Monaco
Duration of Appointment/Start: 1 year, Summer 2023
Application Deadline: 24 April 2023
Main Purpose
The main purpose of this internship will be to provide support to the IAEA’s Ocean Acidification International Coordination Centre (OA-ICC) for its numerous activities and initiatives in the areas of communication, capacity building, and science. The internship will be carried out in the Radioecology Laboratory (REL) of the IAEA’s Marine Environment Laboratories in Monaco. The laboratory is engaged in applied research on the accumulation and transfer of contaminants in freshwater, coastal and marine ecosystems and associated biota.
Tasks / Key Results Expected
- Provide support to the OA-ICC in communication activities including drafting quarterly
newsletters, web stories, and updating the OA-ICC website and news stream. - Participate in OA-ICC meetings and support the team in day-to-day activities.
- Assist the OA-ICC in the organization of capacity building activities including the organization of training courses.
Knowledge, Skills and Abilities
- Knowledge, Skills and Abilities
- Strong ability to work in an international environment and as part of a team.
- Good knowledge of Marine Ecology.
- Knowledge of ocean acidification is an asset.
- Experience in drafting communication material is an asset.
- Strong analytical skills: ability to articulate, conceptualize, plan and execute ideas is an asset.
Qualifications and Experience
- University degree in Environmental Science, Marine Biology, Ecology or a related field.
- Experience working in an international organization is an asset.
- Good written and spoken English essential; fluency in any other IAEA official language (Arabic, Chinese, French, Russian, Spanish) an asset.
Applicant Eligibility
- Candidates must be a U.S. Citizen, be a minimum of 20 years of age and have completed at least three years of full-time studies at a university or equivalent institution towards the completion of a first degree.
- Candidates may apply up to one year after the completion of a bachelor’s, master’s or doctorate degree.
- Candidates must not have previously participated in the IAEA’s internship programme.
- Excellent written and spoken English essential; fluency in any other IAEA official language (Arabic, Chinese, French, Russian) an asset.
- Candidates must attach two signed letters of recommendation to their application.
How to Apply: https://anl.box.com/v/HowToApply-Intern
Continue reading ‘Internship – Ocean Acidification International Coordination Centre’Scientists seek ways to save marine life from ocean acidification
Published 21 March 2023 Media coverage , Web sites and blogs ClosedThe long-term impacts of acidification on ocean waters are causing higher mortality in sea life, but scientists at Oregon State University are searching for solutions.
Oyster farmers were the first hit in the early 2000s with $110 million in production losses.
“Seed farmers, they grow the oysters that are young, that are planted out; they were having real problems about a decade ago, but because of, basically, being able to measure the chemistry and knowing now how to augment that water that’s going into the hatchery, they’re back in business,” said Oregon State University professor Francis Chan.
In response to the death rates among oyster larvae, Oregon State University started doing research on water chemistry to identify the problem.
The discovery was that carbon dioxide emissions in the air were being absorbed by the ocean, presenting a challenge to marine life trying to form their shells.
“It’s the other side of the carbon dioxide problem for the ocean because we know that carbon dioxide can change the climate, but carbon dioxide can just straight up be dissolved in sea water. And the more carbon dioxide we emit, the more it goes in the ocean. The problem is, carbon dioxide, when it’s in the ocean, it acidifies it,” said Chan.
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Continue reading ‘Scientists seek ways to save marine life from ocean acidification’Celebrating Women’s History Month 2023 with Libby Jewett
Published 21 March 2023 Web sites and blogs Closed
To celebrate Women’s History Month, we asked women throughout NOAA Research who make lasting impacts in scientific research, leadership, and support from the field to the office to share how their work contributes to NOAA’s mission of Climate Resilience and preparing for a Climate-Ready Nation. This article highlights an interview with Libby Jewett, the Director of the Ocean Acidification Program in Silver Spring. Libby founded the Ocean Acidification Program in 2011, has grown its budget and reach, and continues to steer it in important and innovative directions.
Our conversation follows:
What does climate resilience or climate-ready nation mean to you? What would you want people to know about NOAA’s work on climate resilience?
A climate ready nation is one that doesn’t accept the trajectory we are on, but rather works harder to solve the climate problem. In NOAA, we need to figure out how to enhance renewable energy and carbon dioxide removal options, without harming the oceans in the process. From an ocean acidification perspective, a climate ready nation is one in which people have essential information about how ocean acidification is playing out from local to global scales and the tools needed to adapt to its challenges.
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Continue reading ‘Celebrating Women’s History Month 2023 with Libby Jewett’Stability of alkalinity in ocean alkalinity enhancement (OAE) approaches – consequences for durability of CO2 storage (update)
Published 20 March 2023 Science ClosedTags: chemistry, laboratory, methods
According to modelling studies, ocean alkalinity enhancement (OAE) is one of the proposed carbon dioxide removal (CDR) approaches with large potential, with the beneficial side effect of counteracting ocean acidification. The real-world application of OAE, however, remains unclear as most basic assumptions are untested. Before large-scale deployment can be considered, safe and sustainable procedures for the addition of alkalinity to seawater must be identified and governance established. One of the concerns is the stability of alkalinity when added to seawater. The surface ocean is already supersaturated with respect to calcite and aragonite, and an increase in total alkalinity (TA) together with a corresponding shift in carbonate chemistry towards higher carbonate ion concentrations would result in a further increase in supersaturation, and potentially to solid carbonate precipitation. Precipitation of carbonate minerals consumes alkalinity and increases dissolved CO2 in seawater, thereby reducing the efficiency of OAE for CO2 removal. In order to address the application of alkaline solution as well as fine particulate alkaline solids, a set of six experiments was performed using natural seawater with alkalinity of around 2400 µmol kgsw−1. The application of CO2-equilibrated alkaline solution bears the lowest risk of losing alkalinity due to carbonate phase formation if added total alkalinity (ΔTA) is less than 2400 µmol kgsw−1. The addition of reactive alkaline solids can cause a net loss of alkalinity if added ΔTA > 600 µmol kgsw−1 (e.g. for Mg(OH)2). Commercially available (ultrafine) Ca(OH)2 causes, in general, a net loss in TA for the tested amounts of TA addition, which has consequences for suggested use of slurries with alkaline solids supplied from ships. The rapid application of excessive amounts of Ca(OH)2, exceeding a threshold for alkalinity loss, resulted in a massive increase in TA (> 20 000 µmol kgsw−1) at the cost of lower efficiency and resultant high pH values > 9.5. Analysis of precipitates indicates formation of aragonite. However, unstable carbonate phases formed can partially redissolve, indicating that net loss of a fraction of alkalinity may not be permanent, which has important implications for real-world OAE application.
Our results indicate that using an alkaline solution instead of reactive alkaline particles can avoid carbonate formation, unless alkalinity addition via solutions shifts the system beyond critical supersaturation levels. To avoid the loss of alkalinity and dissolved inorganic carbon (DIC) from seawater, the application of reactor techniques can be considered. These techniques produce an equilibrated solution from alkaline solids and CO2 prior to application. Differing behaviours of tested materials suggest that standardized engineered materials for OAE need to be developed to achieve safe and sustainable OAE with solids, if reactors technologies should be avoided.
Continue reading ‘Stability of alkalinity in ocean alkalinity enhancement (OAE) approaches – consequences for durability of CO2 storage (update)’Effects of ocean acidification on the early life history processes of the breadcrumb sponge Halichondria panicea
Published 20 March 2023 Science ClosedTags: biological response, laboratory, morphology, mortality, North Pacific, performance, porifera, reproduction
Ocean acidification (OA) is predicted to result in reduced survival, growth, reproduction, and overall biodiversity of marine invertebrates, and yet we lack information about the response to OA of some major groups of marine organisms. In particular, we know relatively little about how OA will impact temperate sponges, which will experience more extreme low pH conditions than tropical species. In this study, we quantified OA-induced changes in early life history patterns (larval mortality and condition, settlement rate, recruit survival, and size) in the non-calcifying breadcrumb sponge Halichondria panicea collected from a temperate intertidal site in the California Current Large Marine Ecosystem. Sponge larvae were exposed to OA conditions for 15 days, and early life history patterns were observed. Compared with baseline (“present”) conditions, larval mortality and settlement rates increased in the acidified treatment (“future”). This effect was restricted to larval stages; treatment had no effect on the growth and survival of recruits. This study is significant in that it shows that H. panicea may be particularly vulnerable to changes in ocean pH during the larval stage, which could ultimately reduce total sponge abundance by diminishing the number of larvae that survive to settlement.
Continue reading ‘Effects of ocean acidification on the early life history processes of the breadcrumb sponge Halichondria panicea’Will ocean acidification affect the digestive physiology and gut microbiota of whelk Brunneifusus ternatanus?
Published 20 March 2023 Science ClosedTags: biological response, growth, laboratory, molecular biology, mollusks, morphology, North Pacific, physiology
To understand the physiological responses of the Brunneifusus ternatanus to future ocean acidification (OA), histology, enzyme activity and gut bacterial composition at different pH levels (Control: C group, pH 8.1; Exposure period: EP group, pH 7.3) for 28 days were studied under laboratory conditions. Microbiota composition was analyzed using 16S rRNA gene amplicon sequencing. Enzyme activities of trypsin (TRY), lipase (LPS), amylase (AMS), and lysozyme (LZM) were used as biochemical indicators, as well as weight gain rate (WGR), specific growth rate (SGR) as growth indicators. The stress caused by OA resulted in alterations to the intestine, including partially swollen and degranulated enterocytes and rough endoplasmic reticulum (RER). The relative abundance of the core phylum in the acidified group changed significantly, showing an increase in Tenericutes and a decrease in Proteobacteria. Firmicutes/Bacteroides ratio declined from 4.38 in the control group to 1.25 in the EP group. We found that the enzymes TRY, LPS, and AMS activities were inhibited at reduced pH, which was positively correlated with the dominant genera Mycoplasma and Bacteroides; while LZM activities showed a significant increment, but showing a strong negative correlation. Furthermore, both WG and SRG values showed a depression at low pH lever. These results suggest that if anthropogenic CO2 emissions continue to accelerate, OA could negatively impact the whelk’s health, compromising their growth performance and even survival. These findings will benefit the future risk assessments of OA or other related emerging environmental issues.
Continue reading ‘Will ocean acidification affect the digestive physiology and gut microbiota of whelk Brunneifusus ternatanus?’Deadline extended: call for community review on OARS white papers
Published 20 March 2023 Projects , Web sites and blogs ClosedDEADLINE EXTENDED until 30 April 2023!
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.
To participate in the review, please visit the webpage linked below to download the pdf of the outcome or outcomes you would like to review as well as the review template. Use the template to submit your specific comments, referencing the precise outcome and page you are commenting on; 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 30 April 2023.
OARS White Paper Community Review
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
Continue reading ‘Deadline extended: call for community review on OARS white papers’The carbonate system and air-sea CO2 fluxes in coastal and open-ocean waters of the Macaronesia
Published 17 March 2023 Science ClosedTags: biogeochemistry, chemistry, field, North Atlantic
The CO2 system, anthropogenic carbon (Cant) inventory and air-sea CO2 fluxes (FCO2) were analysed in the archipelagic waters of the Macaronesian region. The (sub)surface data were collected during POS533 (February and March, 2019) in coastal areas leeward of Cape Verde (CV), Canary Islands (CA) and Madeira (MA) and through the vessel track. The CO2 variability was controlled by changes in temperature, biological activity and advection processes forced by spatial heterogeneities in the Canary Upwelling System, the mixed layer depth, the mesoscale activity and the circulation patterns. The surface fCO2,sw variability was driven by biological production and CO2-rich water injection in tropical waters and by temperature fluctuations in subtropical waters. The factors controlling the upper ocean changes in the total inorganic carbon normalized to a constant salinity (NCT) were assessed. The uptake and storage of anthropogenic carbon, calculated by using the TrOCA 2007 approach described, as an upper limit, > 60% (>90% above the MLD) of the NCT increase from preformed values. The organic carbon pump accounted 36.6-40.9% for tropical waters and lose importance for subtropical waters (7.5-11.6%), while the carbonate pump has a minimal contribution (<4.2%). The upper-ocean Cant inventory in coastal areas of CV (8,570 Km2), CA (7.960 Km2) and MA (1,250 Km2) was 7.57 x 103, 9.26 x 103 and 8.86 x 103 µmol kg-1, respectively (0.51, 0.58 and 0.09 Tg C, respectively). In terms of FCO2, the CV, CA and MA behaved as a winter CO2 sink (-4.74, -3.90 and -8.34 mmol m-2d-1, respectively) while a strong outgassing was detected over the Cape Blanc filament (20-25 mmol m-2d-1). The total average FCO2 for the ocean area of the three archipelagos (371,250 Km2) was -28.27 Gg CO2 d-1. The POS533 data were compared and compilated with SOCAT and GLODAP data and a new set of equations was provided to calculate the fCO2,sw, Cant and FCO2 in the Macaronesian region based on physical and biogeochemical properties.
Continue reading ‘The carbonate system and air-sea CO2 fluxes in coastal and open-ocean waters of the Macaronesia’Ocean acidification and warming modify stimulatory benthos effects on sediment functioning: an experimental study on two ecosystem engineers
Published 17 March 2023 Science ClosedTags: biological response, laboratory, mollusks, mortality, multiple factors, North Atlantic, physiology, sediment, temperature, zooplankton
Many macrofauna have a stimulatory effect on sediment functioning through their burrowing, feeding and irrigation activities. Here, we investigated the single and combined effect of ocean acidification and warming on the stimulatory effect of two key-species inhabiting sandy seabeds in the Southern Bight of the North Sea; the bivalve Abra alba and the polychaete Lanice conchilega. The species were separately incubated in natural sediment in the laboratory under ambient, low pH (pH: -0.3), warm (T: + 3°C) and mimicked climate change (pH: -0.3, T: +3°C) conditions. After six weeks of incubation, nutrient and oxygen exchange were measured at the sediment-water interface to estimate aerobic sediment metabolism and nitrogen cycling. Both species facilitate sediment community oxygen consumption, nitrification and denitrification under ambient conditions. The stimulatory effect of A. alba disappeared in a low pH environment and decreased over time in the warmer treatments along with increased mortality. In contrast, L. conchilega stimulated sediment biogeochemical cycling more when seawater becomes acidified (+ 8 to 41%, depending on the function) but warming had no effect. We explain these species-specific climate change effects by different behavioral and physiological coping strategies that cascade on to sediment biogeochemical cycling, especially through altered oxygenation the sediment matrix.
Continue reading ‘Ocean acidification and warming modify stimulatory benthos effects on sediment functioning: an experimental study on two ecosystem engineers’Effects of ocean acidification and eutrophication on the growth and photosynthetic performances of a green tide alga Ulva prolifera
Published 17 March 2023 Science ClosedTags: algae, biological response, growth, laboratory, multiple factors, North Pacific, nutrients, photosynthesis, physiology
With the impact of fossil fuel burning and industrialization, atmospheric CO2 concentration will reach about 1000 ppmv in 2100, and more and more CO2 will be absorbed by ocean, resulting in ocean acidification. The Chinese coastal waters are showing unexpectedly high levels of acidification due to a combination of global ocean acidification and severe regional eutrophication, which is caused by natural accumulation or human activities such as aquacultural tail water input, potentially affecting macroalgal blooms. However, little is known about the combined effects of ocean acidification and entrophication on the eco-physiology of bloom-forming macroalgae. This study investigated Ulva prolifera, a dominant species causing green tide in the South Yellow Sea, and explored its growth and physiological responses under the combination conditions of ocean acidification and enriched nutrients. In this study, U. prolifera thalli were cultured under two CO2 conditions (air and 1000 μatm) and two nutrient conditions (High Nutrient, HN, 135 μmol L-1 N and 8.5 μmol L-1 P; Normal Nutrient, NN, 27 μmol L-1 N and 1.7 μmol L-1 P). The results showed that eutrophication conditions obviously enhanced the relative growth rate and photosynthetic performance of U. prolifera. Elevated pCO2 had no significant effect on U. prolifera growth and photosynthetic performance under normal nutrient conditions. However, under eutrophication conditions elevated pCO2 inhibited U. prolifera growth. Moreover, eutrophication conditions markedly improved the contents of chlorophyll a, chlorophyll b and nitrate reductase activity and inhibited the soluble carbohydrate content, but elevated pCO2 had no significant effect on them under nutrient-replete conditions. In addition, elevated pCO2 significantly reduced the carotenoid content under eutrophication conditions and had no effect on it under normal nutrient conditions. These findings indicate that seawater eutrophication would greatly accelerate U. prolifera bloom, which may also be suppressed to a certain extent by ocean acidification in the future. The study can provide valuable information for predicting the future outbreaks of U. prolifera green tide in nearshore regions.
Continue reading ‘Effects of ocean acidification and eutrophication on the growth and photosynthetic performances of a green tide alga Ulva prolifera’Deep resilience: an evolutionary perspective on calcification in an age of ocean acidification
Published 16 March 2023 Science ClosedTags: biological response, calcification, paleo, review
The success of today’s calcifying organisms in tomorrow’s oceans depends, in part, on the resilience of their skeletons to ocean acidification. To the extent this statement is true there is reason to have hope. Many marine calcifiers demonstrate resilience when exposed to environments that mimic near-term ocean acidification. The fossil record similarly suggests that resilience in skeletons has increased dramatically over geologic time. This “deep resilience” is seen in the long-term stability of skeletal chemistry, as well as a decreasing correlation between skeletal mineralogy and extinction risk over time. Such resilience over geologic timescales is often attributed to genetic canalization—the hardening of genetic pathways due to the evolution of increasingly complex regulatory systems. But paradoxically, our current knowledge on biomineralization genetics suggests an opposing trend, where genes are co-opted and shuffled at an evolutionarily rapid pace. In this paper we consider two possible mechanisms driving deep resilience in skeletons that fall outside of genetic canalization: microbial co-regulation and macroevolutionary trends in skeleton structure. The mechanisms driving deep resilience should be considered when creating risk assessments for marine organisms facing ocean acidification and provide a wealth of research avenues to explore.
Continue reading ‘Deep resilience: an evolutionary perspective on calcification in an age of ocean acidification’Evaluating environmental controls on the exoskeleton density of larval Dungeness crab via micro computed tomography
Published 16 March 2023 Science ClosedTags: biological response, crustaceans, field, individualmodeling, laboratory, modeling, morphology, North Pacific, reproduction
Dungeness crab (Metacarcinus magister) have significant socioeconomic value, but are threatened by ocean acidification (OA) and other environmental stressors that are driven by climate change. Despite evidence that adult harvests are sensitive to the abundance of larval populations, relatively little is known about how Dungeness megalopae will respond to these stressors. Here we evaluate the ability to use micro-computed tomography (μCT) to detect variations in megalope exoskeleton density and how these measurements reflect environmental variables and calcification mechanisms. We use a combination of field data, culture experiments, and model simulations to suggest resolvable differences in density are best explained by minimum pH at the time zoeae molt into megalopae. We suggest that this occurs because more energy must be expended on active ion pumping to reach a given degree of calcite supersaturation at lower pH. Energy availability may also be reduced due to its diversion to other coping mechanisms. Alternate models based on minimum temperature at the time of the zoea-megalope molt are nearly as strong and complicate the ability to conclusively disentangle pH and temperature influences. Despite this, our results suggest that carryover effects between life stages and short-lived extreme events may be particularly important controls on exoskeleton integrity. μCT-based estimates of exoskeleton density are a promising tool for evaluating the health of Dungeness crab populations that will likely provide more nuanced information than presence-absence observations, but future in situ field sampling and culture experiments are needed to refine and validate our results.
Continue reading ‘Evaluating environmental controls on the exoskeleton density of larval Dungeness crab via micro computed tomography’Symbiont composition and coral genotype determines massive coral species performance under end-of-century climate scenarios
Published 16 March 2023 Science ClosedTags: biological response, corals, laboratory, molecular biology, multiple factors, performance, protists, temperature
The recent decline of coral health and substantial loss of coral cover along Florida’s Coral Reef (FCR) results from local stressors such as degraded water quality and disease outbreaks in addition to anthropogenically driven global stressors including ocean warming and acidification. Intervention strategies intended for the restoration of degraded reef habitats need a better understanding of the influence of ocean warming and acidification on coral health to target coral species and individual genotypes that may be more resistant or resilient to such stressors. Here, we examined a suite of physiological traits (coral host and algal symbiont) in response to experimentally elevated water temperatures and pCO2 levels, both separately and in concert, using threatened reef-building corals Pseudodiploria clivosa and Orbicella faveolata reared within a land-based coral nursery. After two months of exposure, responses differed by coral species, where P. clivosa showed declined physiology in response to combined ocean warming and acidification stress and ocean warming alone, whereas O. faveolata showed a positive response under ocean acidification. Responses to temperature could be associated with the algal symbionts harbored, as P. clivosa was dominated by the thermally sensitive Breviolum, and O. faveolata was dominated by the thermally tolerant Durusdinium. Additionally, corals were raised in well-sourced seawater that was naturally high in pCO2, which could have led to corals acclimating to acidified conditions. Of the three P. clivosa genets tested, we determined a top-performing genotype under the combined warming and acidification treatment. O. faveolata, however, displayed high genet variation by treatment and phenotypic trait, making genotype performance rankings challenging to discern. The evidence provided in this study demonstrates that high phenotypic variation in nursery-reared corals contributes to variable warming-acidification responses, suggesting that high-standing genetic variation in nursery-reared corals could support diverse coral restoration population outcomes along FCR.
Continue reading ‘Symbiont composition and coral genotype determines massive coral species performance under end-of-century climate scenarios’Seaweed farming inspires high hopes in Alaska for economic and environmental benefits
Published 16 March 2023 Web sites and blogs Closed
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.
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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.
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Continue reading ‘Seaweed farming inspires high hopes in Alaska for economic and environmental benefits’Nanoplastics induce epigenetic signatures of transgenerational impairments associated with reproduction in copepods under ocean acidification
Published 15 March 2023 Science ClosedTags: biological response, crustaceans, laboratory, molecular biology, multiple factors, North Pacific, reproduction, toxicants, zooplankton
Ocean acidification (OA) is one of many major global climate changes that pose a variety of risks to marine ecosystems in different ways. Meanwhile, there is growing concern about how nanoplastics (NPs) affect marine ecosystems. Combined exposure of marine organisms to OA and NPs is inevitable, but their interactive effects remain poorly understood. In this study, we investigated the multi- and transgenerational toxicity of NPs on copepods under OA conditions for ten generations. The findings revealed that OA and NPs have a synergistic negative effect on copepod reproduction across generations. In particular, the transgenerational groups showed reproductive impairments in the F1 and F2 generations (F1T and F2T), even though they were never exposed to NPs. Moreover, our epigenetic examinations demonstrated that the observed intergenerational reproductive impairments are associated with differential methylation patterns of specific genes, suggesting that the interaction of OA and NPs can pose a significant threat to the sustainability of copepod populations through epigenetic modifications. Overall, our findings provide valuable insight into the intergenerational toxicity and underlying molecular mechanisms of responses to NPs under OA conditions.
Continue reading ‘Nanoplastics induce epigenetic signatures of transgenerational impairments associated with reproduction in copepods under ocean acidification’Directional fabrication and dissolution of larval and juvenile oyster shells under ocean acidification
Published 15 March 2023 Science ClosedTags: biological response, dissolution, mollusks, morphology, reproduction
Biomineralization is one of the key biochemical processes in calcifying bivalve species such as oysters that is affected by ocean acidification (OA). Larval life stages of oysters are made of aragonite crystals whereas the adults are made of calcite and/or aragonite. Though both calcite and aragonite are crystal polymorphs of calcium carbonate, they have different mechanical properties and hence it is important to study the micro and nano structure of different life stages of oyster shells under OA to understand the mechanisms by which OA affects biomineralization ontogeny. Here, we have studied the larval and juvenile life stages of an economically and ecologically important estuarine oyster species, Crassostrea hongkongensis, under OA with focus over shell fabrication under OA (pHNBS 7.4). We also look at the effect of parental exposure to OA on larvae and juvenile microstructure. The micro and nanostructure characterization reveals directional fabrication of oyster shells, with more organized structure as biomineralization progresses. Under OA, both the larval and juvenile stages show directional dissolution, i.e. the earlier formed shell layers undergo dissolution at first, owing to longer exposure time. Despite dissolution, the micro and nanostructure of the shell remains unaffected under OA, irrespective of parental exposure history.
Continue reading ‘Directional fabrication and dissolution of larval and juvenile oyster shells under ocean acidification’Ocean acidification stunts molluscan growth at CO2 seeps
Published 15 March 2023 Science ClosedTags: biological response, field, mollusks, morphology, North Pacific, physiology, vents
Highlights
- Responses of molluscan growth to ocean acidification at CO2 seeps were studied.
- Mussels near CO2 seeps grew significantly slower than those outside the seeps.
- Mussels near and outside CO2 seeps exhibited differences in tissue carbon and nitrogen isotopic signatures.
- Geochemical analysis indicated chemical shifts at the calcifying front in mussels near and outside CO2 seeps.
Abstract
Ocean acidification can severely affect bivalve molluscs, especially their shell calcification. Assessing the fate of this vulnerable group in a rapidly acidifying ocean is therefore a pressing challenge. Volcanic CO2 seeps are natural analogues of future ocean conditions that offer unique insights into the scope of marine bivalves to cope with acidification. Here, we used a 2-month reciprocal transplantation of the coastal mussel Septifer bilocularis collected from reference and elevated pCO2 habitats to explore how they calcify and grow at CO2 seeps on the Pacific coast of Japan. We found significant decreases in condition index (an indication of tissue energy reserves) and shell growth of mussels living under elevated pCO2 conditions. These negative responses in their physiological performance under acidified conditions were closely associated with changes in their food sources (shown by changes to the soft tissue δ13C and δ15N ratios) and changes in their calcifying fluid carbonate chemistry (based on shell carbonate isotopic and elemental signatures). The reduced shell growth rate during the transplantation experiment was further supported by shell δ13C records along their incremental growth layers, as well as their smaller shell size despite being of comparable ontogenetic ages (5–7 years old, based on shell δ18O records). Taken together, these findings demonstrate how ocean acidification at CO2 seeps affects mussel growth and reveal that lowered shell growth helps them survive stressful conditions.
Continue reading ‘Ocean acidification stunts molluscan growth at CO2 seeps’Pier2Peer scholarship announcement!
Published 15 March 2023 Educational Materials , Program , Resources Closed
Scholarship alert! Did you know that GOA-ON’s Pier2Peer program offers scholarships to eligible mentor/mentee pairs? These awards from The Ocean Foundation — up to $5,000 USD — help support international collaborations between mentors and mentees that result in tangible gains in technical capacity, cooperation, and knowledge. For more information, including eligibility and application information, visit the Pier2Peer webpage on GOA-ON. Make sure to apply by the April 15th deadline!
Apply to Pier2Peer Scholarship
Continue reading ‘Pier2Peer scholarship announcement!’Triple stress factor affects marine life’s reproduction in Türkiye
Published 15 March 2023 Web sites and blogs Closed
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.
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Continue reading ‘Triple stress factor affects marine life’s reproduction in Türkiye’
