Ocean acidification (OA) may have varied effects on fish eco-physiological responses. Most OA studies have been carried out in laboratory conditions without considering the in situ pCO2/pH variability documented for many marine coastal ecosystems. Using a standard otolith ageing technique, we assessed how in situ ocean acidification (ambient, versus end-of-century CO2 levels) can affect somatic and otolith growth, and their relationship in a coastal fish. Somatic and otolith growth rates of juveniles of the ocellated wrasse Symphodus ocellatus living off a Mediterranean CO2 seep increased at the high-pCO2 site. Also, we detected that slower-growing individuals living at ambient pCO2 levels tend to have larger otoliths at the same somatic length (i.e. higher relative size of otoliths to fish body length) than faster-growing conspecifics living under high pCO2 conditions, with this being attributable to the so-called ‘growth effect’. Our findings suggest the possibility of contrasting OA effects on fish fitness, with higher somatic growth rate and possibly higher survival associated with smaller relative size of otoliths that could impair fish auditory and vestibular sensitivity.
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Ocean acidification affects somatic and otolith growth relationship in fish: evidence from an in situ study
Published 21 February 2019 Science ClosedTags: biological response, fish, growth, laboratory, Mediterranean, morphology, physiology
For more than a century, the world’s oceans have been becoming steadily more acidic as they soak up ever-increasing amounts of carbon dioxide from the atmosphere, and the impacts can be fatal for invertebrates such as shellfish, plankton, and corals that rely on dissolved minerals to build their shells and exoskeletons.
For at least some fish, though, the story may be more complicated.
Using precise CT scans of skate skeletons, Valentina Di Santo, a postdoctoral fellow in the lab of Evolutionary Biology Professor George Lauder, was able to show that, while ocean acidification has had led to a drop in the mineralization of some parts of the skeletons, it has had the opposite effect in other areas. The first-of-its-kind study suggests that continued ocean warming and acidification could impact everything from how fish move to how they eat. The findings are described in a Jan. 9 paper published in the Proceedings of the Royal Society B.
Divergent gene expression in the gills of juvenile turbot (Psetta maxima) exposed to chronic severe hypercapnia indicates dose-dependent increase in intracellular oxidative stress and hypoxia
Published 21 February 2019 Science ClosedTags: biological response, fish, laboratory, molecular biology
Highlights
• We investigated the impact of chronic hypercapnia on gene expression in the gills of turbot (Psetta maxima) via RT-qPCR.
• Data indicated enhanced concentrations of reactive oxygen species (ROS) in the two highest treatment levels.
• Further, dose-dependent modulations of transcriptional adjustments implied different underlying coping mechanisms.
• These modulations seemed to comprise hypoxia-mediated suppressed protein synthesis in the highest tested treatment level.
• We discuss our results within a model of capacity limitation and draw conclusions regarding the condition of the gills.
Abstract
Elevated concentrations of carbon dioxide are a common stressor for fish and other aquatic animals. In particular, intensive aquaculture can impose prolonged periods of severe environmental hypercapnia, manifold exceeding CO2 concentrations of natural habitats. In order to cope with this stressor, gills are essential and constitute the primary organ in the acclimatization process. Yet, despite a general understanding of changes in ion regulation, not much is known with regard to other cellular mechanisms. In this study, we apply RT-qPCR to investigate changes in the expression of several genes associated with metabolism, stress and immunity within gills of juvenile turbot (Psetta maxima) after an eight-week exposure to different concentrations of CO2 (low = ∼3000 μatm, medium = ∼15,000 μatm and high = ∼25,000 μatm CO2). Histological examination of the gill tissue only found a significant increase of hypertrophied secondary lamella in the highest tested treatment level. gene expression results, on the other hand, implied both, mutual and dose-dependent transcriptional adjustments. Comparable up-regulation of IL-1ß, LMP7 and Grim19 at medium and high hypercapnia indicated an increase of reactive oxygen species (ROS) within gill cells. Simultaneous increase in Akirin and PRDX transcripts at medium CO2 indicated enhanced anti-oxidant activity and regulation of transcription, while reduced mRNA concentrations of COX, EF1α and STAT2 at high CO2 denoted suppressed protein synthesis and reduced metabolic capacity. In addition to upregulated DFAD and ApoE expression, implying compensating repair measures, gills exposed to the highest tested treatment level seemed to operate close to or even beyond their maximum capacity. Thus, fitting the model of capacity limitation, our results provide evidence for accretive intracellular hypoxia and oxidative stress in the gills of turbot, dependent on the level of environmental hypercapnia. Further, genes, such as COX, may be valuable biomarkers when attempting to discriminate between a successful and an overpowered stress response.
How forecasting ‘underwater weather’ could save WA’s shellfish
Published 21 February 2019 Media coverage Closed
(Photo by Ted S. Warren/AP)
Washington’s waters are under threat from a villain you can’t see. This computer model is giving oyster farmers a lifeline as they seek to adapt to one of the biggest marine crises of our era.
Washington is home to thousands of marine species. Salmon, crabs and bivalve shellfish like oysters and clams fuel both the aquatic food chain and human fisheries — and they thrive under stable levels of acidity, salinity and other marine growing conditions.
But over the past few decades, climate change has acidified the world’s oceans at an unprecedented rate, threatening the biodiversity that defines our region and supports these fisheries. As the concentration of carbon dioxide in our atmosphere increases, the ocean dissolves more of it at the surface — producing conditions in Puget Sound and beyond that exacerbate shell deformation, promote toxic algal blooms and create other hurdles to healthy waters. According to the Washington State Blue Ribbon Panel on Ocean Acidification, 30 percent of Washington’s marine species are in danger from it.
Continue reading ‘How forecasting ‘underwater weather’ could save WA’s shellfish’
Responses of macroalgae to CO2 enrichment cannot be inferred solely from their inorganic carbon uptake strategy
Published 21 February 2019 Science ClosedTags: algae, biogeochemistry, biological response, growth, laboratory, morphology, photosynthesis, physiology, South Pacific
Increased plant biomass is observed in terrestrial systems due to rising levels of atmospheric CO2, but responses of marine macroalgae to CO2 enrichment are unclear. The 200% increase in CO2 by 2100 is predicted to enhance the productivity of fleshy macroalgae that acquire inorganic carbon solely as CO2 (non‐carbon dioxide‐concentrating mechanism [CCM] species—i.e., species without a carbon dioxide‐concentrating mechanism), whereas those that additionally uptake bicarbonate (CCM species) are predicted to respond neutrally or positively depending on their affinity for bicarbonate. Previous studies, however, show that fleshy macroalgae exhibit a broad variety of responses to CO2 enrichment and the underlying mechanisms are largely unknown. This physiological study compared the responses of a CCM species (Lomentaria australis) with a non‐CCM species (Craspedocarpus ramentaceus) to CO2 enrichment with regards to growth, net photosynthesis, and biochemistry. Contrary to expectations, there was no enrichment effect for the non‐CCM species, whereas the CCM species had a twofold greater growth rate, likely driven by a downregulation of the energetically costly CCM(s). This saved energy was invested into new growth rather than storage lipids and fatty acids. In addition, we conducted a comprehensive literature synthesis to examine the extent to which the growth and photosynthetic responses of fleshy macroalgae to elevated CO2 are related to their carbon acquisition strategies. Findings highlight that the responses of macroalgae to CO2 enrichment cannot be inferred solely from their carbon uptake strategy, and targeted physiological experiments on a wider range of species are needed to better predict responses of macroalgae to future oceanic change.
Effects of light and darkness on pH regulation in three coral species exposed to seawater acidification
Published 20 February 2019 Science ClosedTags: biological response, calcification, corals, laboratory, light, Mediterranean, morphology, multiple factors, photosynthesis, physiology, respiration
The resilience of corals to ocean acidification has been proposed to rely on regulation of extracellular calcifying medium pH (pHECM), but few studies have compared the capacity of coral species to control this parameter at elevated pCO2. Furthermore, exposure to light and darkness influences both pH regulation and calcification in corals, but little is known about its effect under conditions of seawater acidification. Here we investigated the effect of acidification in light and darkness on pHECM, calcifying cell intracellular pH (pHI), calcification, photosynthesis and respiration in three coral species: Stylophora pistillata, Pocillopora damicornis and Acropora hyacinthus. We show that S. pistillata was able to maintain pHECM under acidification in light and darkness, but pHECM decreased in P. damicornis and A. hyacinthus to a much greater extent in darkness than in the light. Acidification depressed calcifying cell pHI in all three species, but we identified an unexpected positive effect of light on pHI. Calcification rate and pHECM decreased together under acidification, but there are inconsistencies in their relationship indicating that other physiological parameters are likely to shape how coral calcification responds to acidification. Overall our study reveals interspecies differences in coral regulation of pHECM and pHI when exposed to acidification, influenced by exposure to light and darkness.
Ocean acidification could mean bad news for Dungeness crab
Published 20 February 2019 Media coverage ClosedAs local fishermen continue to ply their trade in Del Norte County waters, scientists are studying the effects of climate change on a myriad of species including Dungeness crab.
In an action plan published October 2018, the State of California outlines priorities for research into ocean acidification caused by global carbon dioxide emissions by the burning of fossil fuels, including prevention and adaptation.
According to Jessica Williams, project scientist for the Ocean Science Trust, which has been working with the California Ocean Protection Council, though the research into the impacts of ocean acidification is new, there will be a lot of impacts to several different species. This includes Dungeness crab as well as the algal blooms that contribute to fisheries closures due to domoic acid, Williams said.
Continue reading ‘Ocean acidification could mean bad news for Dungeness crab’
Indirect effects of ocean warming and acidification on the realized recruitment of Agaricia agaricites
Published 20 February 2019 Science ClosedTags: biological response, corals, growth, laboratory, mortality, multiple factors, North Atlantic, physiology, reproduction, temperature
Over the past few decades, coral cover has declined worldwide due to overfishing, disease, and storms, and these effects have been exacerbated by ocean warming and acidification. Corals are extremely susceptible to these changes because they are already living close to their thermal and aragonite saturation thresholds. Ocean warming and acidification (OAW) may also impact coral survival and growth by impacting their settlement cues. Coral larvae use crustose coralline algae (CCA) and their associated biofilms as cues for settlement, i.e., habitat selection. Settlement cues can also be negatively affected by increased water temperature and acidity. It was hypothesized that the impacts of OAW on settlement substrate can further threaten coral persistence by altering/inhibiting larval settlement and potentially decreasing the post-settlement survival and growth of coral recruits. In this study, we 1) assessed the effect of substrate quality (substrate conditioned in ambient or OAW conditions) on settlement of A. agaricites larvae, 2) determined the effect of substrate quality on post-settlement survival and growth of A. agaricites recruits, and 3) determined the effect of ocean warming and acidification on the post-settlement survival and growth of A. agaricites recruits. Aragonite settlement tiles were placed offshore for one month to accrue CCA and associated biofilms, and were then conditioned in either ambient (29°C, 8.2 pH) or predicted future oceanic conditions (31°C, 7.9 pH) conditions for 7 – 10 days. Agaricia agaricites larvae were then introduced to the settlement tiles, and their settlement percentage was calculated. Once a week for 12 weeks after larval settlement, the size, survival, and pigmentation of A. agaricites recruits was recorded. Larvae settled marginally more on optimally conditioned tiles than on tiles previously exposed to OAW conditions (p=0.053). The survival of coral recruits in OAW conditions was greatly reduced, their growth was very limited, and they became paler over time. When reared in ambient conditions, recruits on OAW treated substrate initially displayed higher survival rates than recruits on ambient treated substrate. After 3 weeks in ambient conditions, however, survival rates were similar for recruits on ambient and OAW treated substrate; their growth curves were very similar, and coral recruits became more pigmented over time. Ocean warming and acidification conditions not only directly impacted the growth, survival, and pigmentation of A. agaricites recruits, but it also indirectly affected larval 5 settlement by likely altering microbial composition in bacterial biofilms on the settlement tiles. These results indicate that future conditions of ocean warming and acidification can be deleterious for A. agaricites, particularly after settlement. If the early life stages of scleractinian corals are negatively affected by OAW conditions, successful recruitment throughout the Caribbean and Florida Reef Tract could decrease. As a result, recovery from disturbances could be hindered, thus compromising the sustainability of many coral species and other marine ecosystems that depend on coral reefs for protection, habitat, and food.
Ocean acidification harms cod larvae more than previously thought
Published 20 February 2019 Press releases Closed
Decreasing pH values in the seawater harm cod larvae more than previously thought.
Credit: Catriona Clemmesen/GEOMAR (CC BY 4.0)
Acidification is, next to rising temperatures and dwindling oxygen concentrations, one of the major threats to marine life due to the changing global climate. Carbon dioxide concentrations in the atmosphere are rising and the ocean therefore takes up increasing amounts of CO2 from the atmosphere as well. The reaction of carbon dioxide with the water forms carbonic acid, the pH is lowered — the ocean becomes more acidic.
To what extent and how ocean acidification affects the marine ecosystem as a whole is incredibly hard to predict, but evidence is accumulating that some species are affected adversely. One of these species is the Atlantic cod. A new scientific study, which was just published in the scientific journal Global Change Biology by scientists from the GEOMAR Helmholtz Centre for Ocean Research Kiel with colleagues from France and Norway, as well as previously published articles show that the high carbon dioxide concentrations damage this species, particularly the early life stages, like eggs and larvae.
Continue reading ‘Ocean acidification harms cod larvae more than previously thought’
Seagrass can mitigate negative ocean acidification effects on calcifying algae
Published 20 February 2019 Science ClosedTags: algae, biological response, calcification, chemistry, field, laboratory, mesocosms, physiology, South Atlantic
The ultimate effect that ocean acidification (OA) and warming will have on the physiology of calcifying algae is still largely uncertain. Responses depend on the complex interactions between seawater chemistry, global/local stressors and species-specific physiologies. There is a significant gap regarding the effect that metabolic interactions between coexisting species may have on local seawater chemistry and the concurrent effect of OA. Here, we manipulated CO2 and temperature to evaluate the physiological responses of two common photoautotrophs from shallow tropical marine coastal ecosystems in Brazil: the calcifying alga Halimeda cuneata, and the seagrass Halodule wrightii. We tested whether or not seagrass presence can influence the calcification rate of a widespread and abundant species of Halimeda under OA and warming. Our results demonstrate that under elevated CO2, the high photosynthetic rates of H. wrightii contribute to raise H. cuneata calcification more than two-fold and thus we suggest that H. cuneata populations coexisting with H. wrightii may have a higher resilience to OA conditions. This conclusion supports the more general hypothesis that, in coastal and shallow reef environments, the metabolic interactions between calcifying and non-calcifying organisms are instrumental in providing refuge against OA effects and increasing the resilience of the more OA-susceptible species.
Continue reading ‘Seagrass can mitigate negative ocean acidification effects on calcifying algae’
Forty-five scientists and marine policy officials are meeting at the University of Otago amid moves to use the Commonwealth’s collective power to counter the threat of ocean acidification.
The Commonwealth Ocean Acidification Action Group Workshop includes more than 30 scientists and officials from many countries, including 18 in the Commonwealth.
Participants, including from the United Kingdom, Australia, the US, and the Pacific Islands, aim to better counter the impacts of ocean acidification.
The three-day workshop ends today, and is the action group’s first activity.
New Zealand last year volunteered to champion this group as part of its support for the Commonwealth Blue Charter – an agreement by all 53 Commonwealth countries to solve ocean-related problems collaboratively.
Continue reading ‘Group ready to take action on ocean acidification’
Effects of ocean warming and acidification on fertilization success and early larval development in the green sea urchin Lytechinus variegatus
Published 19 February 2019 Science ClosedTags: biological response, echinoderms, growth, laboratory, morphology, multiple factors, physiology, reproduction, respiration, temperature
Highlights
• Acidification delayed larval development, stunted growth, and increased asymmetry.
• Warming decreased fertilization success and accelerated larval development.
• Warming outweighed acidification and led to accelerated development.
• Acidification and warming had additive effects on fertilization and growth.
Abstract
Ocean acidification and warming are predicted to affect the early life of many marine organisms, but their effects can be synergistic or antagonistic. This study assessed the combined effects of near-future (2100) ocean acidification (pH 7.8) and warming (+3 °C) on the fertilization, larval development and growth of the green sea urchin, Lytechinus variegatus, common in tropical reefs of Florida and the Caribbean. Acidification had no effect on fertilization, but delayed larval development, stunted growth, and increased asymmetry. Warming decreased fertilization success when the sperm:egg ratio was higher (1847:1), accelerated larval development, but had no effect on growth. When exposed to both acidification and warming, fertilization rates decreased, larval development accelerated (due to increased respiration/metabolism), but larvae were smaller and more asymmetric, meaning acidification and warming had additive effects. Thus, climate change is expected to decrease the abundance of this important herbivore, exacerbating macroalgal growth and dominance on coral reefs.
The on-going rise of carbon dioxide (CO2) in the atmosphere is not only changing our climate—it is also changing our oceans.
Take a look at the work of the NIWA-led CARIM project into what these changes may mean for the delicate balance of marine life.
A governing framework for international ocean acidification policy
Published 19 February 2019 Science ClosedTags: policy
Highlights
• Ocean acidification (OA) poses a threat to marine systems and the goods and services they provide.
• A framework is needed to guide the international response to minimize and address OA.
• International policy should have three objectives: mitigation, adaptation and the redress of harm.
• These three objectives can be pursued by a number of multilateral agreements.
• Such an approach may fill the governance gap created by the lack of OA treaty.
Abstract
Ocean acidification (OA) is a major emergent stressor of marine ecosystems with global implications for biodiversity conservation, sustainable development and economic prosperity. International action is imperative for addressing it. This paper builds a science-based governing framework, identifying three overarching policy objectives and six areas for action that should be pursued so as to minimise this global problem. No unifying OA treaty or legal instrument with the explicit task of addressing OA currently exists and it looks highly unlikely that any will eventuate. A more pragmatic approach is to use existing multilateral agreements. However, taking on OA as a unified problem seems to be beyond the scope of existing agreements, due to structural limitations and the willingness of Parties. Given this, it is more likely that OA will be addressed by a network of agreements, each responding to discrete elements of the problem of OA within their capabilities. However, it is unclear how existing MEA capabilities extend to addressing OA. This paper therefore offers an analytical framework through existing governance structures can be explored for their capabilities to respond to OA.
Continue reading ‘A governing framework for international ocean acidification policy’
The impact of ocean acidification on the gonads of three key Antarctic benthic macroinvertebrates
Published 19 February 2019 Science ClosedTags: Antarctic, biological response, chemistry, echinoderms, laboratory, morphology, physiology, reproduction
Highlights
• Ocean Acidification may act as an endocrine disruptor on invertebrate gonads
• Different species show different response to low pH in a simultaneous exposure
• Gametogenic stage and feeding condition affect the species response to low pH
Abstract
CO2 atmospheric pressure is increasing since industrial revolution, leading to a lowering of the ocean surface water pH, a phenomenon known as ocean acidification, with several reported effects on individual species and cascading effects on marine ecosystems. Despite the great amount of literature on ocean acidification effects on calcifying organisms, the response of their reproductive system still remains poorly known. In the present study, we investigated the histopathological effects of low pH on the gonads of three key macroinvertebrates of the Terra Nova Bay (Ross Sea) littoral area: the sea urchin Sterechinus neumayeri, the sea star Odontaster validus and the scallop Adamussium colbecki. After 1 month of exposure at control (8.12) and reduced (7.8 and 7.6) pH levels, we dissected the gonads and performed histological analyses to detect potential differences among treatments. Results showed significant effects on reproductive conditions of A. colbecki and S. neumayeri, while O. validus did not show any kind of alteration. Present results reinforce the need to focus on ocean acidification effects on soft tissues, particularly the gonads, whose damage may exert large effects on the individual fitness, with cascading effects on the population dynamic of the species.
Climate in Svalbard 2100 – a knowledge base for climate adaptation
Published 18 February 2019 Science ClosedTags: Arctic, review
This report was commissioned by the Norwegian Environment Agency in order to provide basic information for climate change effect studies and climate change adaptation in Svalbard. It includes descriptions of historical, as well as projections for future climate development in the atmosphere, hydrosphere, cryosphere and ocean, and it includes effects on the physical nature, e.g. risks associated with landslides and avalanches. The projections for future climate are based on the global climate models used in the IPCCs fifth assessment report (IPCC, 2013). Dependent on availability of model data, three scenarios for emissions of greenhouse gases are used: “RCP8.5” (“business as usual”; “high emissions”), “RCP4.5” (reductions after 2040; “medium emissions”) and “RCP2.6” (drastic cuts from 2020; “low emissions”). Climate change in the atmosphere and land surface are projected up to the year 2100 and in the ocean up to the year 2070.
The report is to a large degree an assessment of existing literature and model results, e.g. the Arctic CORDEX regional climate models. In addition, a fine scale atmospheric regional climate model (COSMO-CLM) has been run, and the results were applied for estimating changes in e.g. heavy rainfall, frost days, snow, permafrost and glaciers. Further, a hydrological model has been run for Svalbard for present and projected future climate, based on input data from Arctic CORDEX. Also for the ocean, new analyses have been performed, based on the best available model data. Below follows a summary based on a combination of the assessment and results from new analyses.
Continue reading ‘Climate in Svalbard 2100 – a knowledge base for climate adaptation’
Implicações fisiológicas e ecológicas de interações interespecíficas nos bentos marinho-subsídio para o entendimento de cenários atuais e futuros (in Portuguese)
Published 18 February 2019 Science ClosedTags: algae, BRcommunity, echinoderms, laboratory, mesocosms, multiple factors, photosynthesis, physiology, South Atlantic, temperature
Biotic interactions are increasingly known to shape ecosystem community structure. Recently, there has been a renewed focus on species interactions in light of global change, especially ocean warming (OW) and ocean acidification (OA) in marine ecosystems. In coastal environments, macroalgae are among the most important taxa as they are often the most abundant primary producers and form the base of food webs. However, due to their sedentary nature, they are also vulnerable to the effects of climate change. In order to better understand how species interactions will be affected by climate change stressors, a solid understanding of how interspecies interactions operate under present-day conditions is needed. The first chapter of this thesis attempts to characterize seasonal variation in macroalgal physiology and biochemistry, and how interspecific interactions might affect algal fitness and palatability to a sea urchin herbivore (Echinometra lucunter). Specimens of Jania rubens, Sargassum cymosum, and Ulva lactuca were collected from monospecific patches or from associations , where individuals were in physical contact with another species, in both summer and winter. Net photosynthesis, nitrogen reductase activity, and pigment, phenolic and carbonate content of algae were evaluated among different associations across the two seasons. The results indicate that in addition to seasonal variation in most parameters measured, interactions between algae could change in both magnitude and sign (positive, negative or neutral) in different seasons. The no-choice herbivory assay (conducted in winter) revealed that both Jania and Ulva were consumed at higher rates when they were associated with each other, whereas Sargassum was not affected. These results suggest that macroalgae may influence the physiology and biochemical composition of neighboring species and subsequently affect their palatability, which may influence local community structure. To further evaluate effects of species interactions under climate change stressors, an experiment was performed to assess algal-herbivore interactions under OW and OA conditions. The most preferentially consumed algae from the first experiment (Jania rubens) and the sea urchin E. lucunter were evaluated in a 21-day mesocosm study with treatments of control, OW, OA, and OW+OA. Algal physiology was unaffected by increased temperature (+4°C) and pCO2 (1,000 ppm), but changes in the biochemical composition of the algal tissue were found. Metabolic rates of the sea urchin E. lucunter were higher in the ambient temperature, high pCO2 treatment, and feeding assays showed that this influenced consumption, with increased feeding rates in this treatment. The results here show that although algal biochemical composition was affected by future pCO2, at least in the short term, direct effects to sea urchin metabolism were more important for impacting this algae-herbivore interaction.
Differential responses to ocean acidification between populations of Balanophyllia elegans corals from high and low upwelling environments
Published 18 February 2019 Science ClosedTags: biological response, corals, laboratory, molecular biology, North Pacific, physiology, respiration
Ocean acidification (OA), the global decrease in surface water pH from absorption of anthropogenic CO2, may put many marine taxa at risk. However, populations that experience extreme localized conditions, and are adapted to these conditions predicted in the global ocean in 2100, may be more tolerant to future OA. By identifying locally adapted populations, researchers can examine the mechanisms used to cope with decreasing pH. One oceanographic process that influences pH, is wind driven upwelling. Here we compare two Californian populations of the coral Balanophyllia elegans from distinct upwelling regimes, and test their physiological and transcriptomic responses to experimental seawater acidification. We measured respiration rates, protein and lipid content, and gene expression in corals from both populations exposed to pH levels of 7.8 and 7.4 for 29 days. Corals from the population that experiences lower pH due to high upwelling, maintained the same respiration rate throughout the exposure. In contrast, corals from the low upwelling site had reduced respiration rates, protein content, and lipid‐class content at low pH exposure, suggesting they have depleted their energy reserves. Using RNA‐Seq, we found that corals from the high upwelling site upregulated genes involved in calcium ion binding and ion transport, most likely related to pH homeostasis and calcification. In contrast, corals from the low upwelling site downregulated stress response genes at low pH exposure. Divergent population responses to low pH observed in B. elegans highlight the importance of multi‐population studies for predicting a species’ response to future OA.
Ocean acidification sensors installed in Suva Harbour observing water acidity and temperature
Published 18 February 2019 Media coverage Closed
- British High Commissioner to Fiji, Melanie Hopkins [far left/red top] adds that this will enable Fiji to conduct surveys that will make assessments on how much acidification is in Fiji waters
Ocean acidification sensors have been installed in the Suva Harbour providing real‑time observations of coastal water acidity and temperature.
This was highlighted by British High Commissioner to Fiji, Melanie Hopkins who adds that this will enable Fiji to conduct surveys that will make assessments on how much acidification is in Fiji waters and help measure temperature of the oceans to see how this affects the marine life and how Fiji can mitigate these changes.
This was made possible through the Commonwealth Marine Economies Programme that is being funded by the UK.
In-situ behavioural and physiological responses of Antarctic microphytobenthos to ocean acidification
Published 18 February 2019 Science ClosedTags: abundance, Antarctic, biological response, chemistry, community composition, field, laboratory, otherprocess, photosynthesis, physiology, primary production
Ocean acidification (OA) is predicted to alter benthic marine community structure and function, however, there is a paucity of field experiments in benthic soft sediment communities and ecosystems. Benthic diatoms are important components of Antarctic coastal ecosystems, however very little is known of how they will respond to ocean acidification. Ocean acidification conditions were maintained by incremental computer controlled addition of high fCO2 seawater representing OA conditions predicted for the year 2100. Respiration chambers and PAM fluorescence techniques were used to investigate acute behavioural, photosynthetic and net production responses of benthic microalgae communities to OA in in-situ field experiments. We demonstrate how OA can modify behavioural ecology, which changes photo-physiology and net production of benthic microalgae. Ocean acidification treatments significantly altered behavioural ecology, which in turn altered photo-physiology. The ecological trends presented here have the potential to manifest into significant ecological change over longer time periods.
