n the past decade, many studies have investigated the effects of low pH/high CO2 as a proxy for ocean acidification on olfactory-mediated behaviours of marine organisms. The effects of ocean acidification on the behaviour of fish vary from very large to none at all, and most of the maladaptive behaviours observed have been attributed to changes in acid–base regulation, leading to changes in ion distribution over neural membranes, and consequently affecting the functioning of gamma-aminobutyric acid-mediated (GABAergic) neurotransmission. Here, we highlight a possible additional mechanism by which ocean acidification might directly affect olfaction in marine fish and invertebrates. We propose that a decrease in pH can directly affect the protonation, and thereby, 3D conformation and charge distribution of odorants and/or their receptors in the olfactory organs of aquatic animals. This can sometimes enhance signalling, but most of the time the affinity of odorants for their receptors is reduced in high CO2/low pH; therefore, the activity of olfactory receptor neurons decreases as measured using electrophysiology. The reduced signal reception would translate into reduced activation of the olfactory bulb neurons, which are responsible for processing olfactory information in the brain. Over longer exposures of days to weeks, changes in gene expression in the olfactory receptors and olfactory bulb neurons cause these neurons to become less active, exacerbating the problem. A change in olfactory system functioning leads to inappropriate behavioural responses to odorants. We discuss gaps in the literature and suggest some changes to experimental design in order to improve our understanding of the underlying mechanisms and their effects on the associated behaviours to resolve some current controversy in the field regarding the extent of the effects of ocean acidification on marine fish.
Ocean acidification, a reduction in the pH of the oceans caused by increasing CO2, can have negative physiological effects on marine species. In this study, we examined how CO2-driven acidification affected the growth and survival of juvenile golden king crab (Lithodes aequispinus), an important fishery species in Alaska. Juveniles were reared from larvae in surface ambient pH seawater at the Kodiak Laboratory. Newly molted early benthic instar crabs were randomly assigned to one of three pH treatments: (1) surface ambient pH ~ 8.2, (2) likely in situ ambient pH 7.8, and (3) pH 7.5. Thirty crabs were held in individual cells in each treatment for 127 days and checked daily for molting or death. Molts and dead crabs were photographed under a microscope and measured using image analysis to assess growth and morphology. Mortality was primarily associated with molting in all treatments, differed among all treatments, and was highest at pH 7.5 and lowest at ambient pH. Crabs at pH 7.5 were smaller than crabs at ambient pH at the end of the experiment, both in terms of carapace length and wet mass; had a smaller growth increment after molting; had a longer intermolt period. Carapace morphology was not affected by pH treatment. Decreased growth and increased mortality in laboratory experiments suggest that lower pH could affect golden king crab stocks and fisheries. Future work should examine if larval rearing conditions affect the juvenile response to low pH.
Over the last 250 years, the intensive burning of fossil fuels along with industrial processes and land uses (e.g. clearing forests and agriculture) has contributed to an increase in atmospheric CO2 from approximately 280 to 410 ppm, with a further increase (from 730 to 1020 ppm) projected by the end of this century. About 30% of the anthropogenic CO2 has been absorbed by the ocean, with a consequent decrease of the ocean’s surface pH causing a phenomenon better known as Ocean Acidification (OA). The average pH of the surface ocean has declined from 8.2 by 0.1 units since pre-industrial times as a result of CO2 emissions and a further reduction of 0.3–0.5 pH units is expected to occur by the 2100.
This increased concentration of atmospheric CO2 has driven an increase in atmospheric and oceanic temperatures enhanced at a rate of ~ 0.2˚C per decade in the past 30 years. These rapid changing ocean conditions in pCO2 and temperature are considered two of the major threats to marine biodiversity, leading to changes in the distribution, physiology and behaviour of marine organisms, with potential consequences in community and ecosystem functioning and structure. Despite the increasing interest and amount of literature on this topic, the effects of OA and ocean warming (OW) on marine fauna is difficult to predict, especially because a wide range of impacts have been found across different life stages-and species suggesting that tolerance thresholds to such stressors can vary among life stages experienced by an organism or even between species. In this regard, an increased number of studies has been conducted to better understand the mechanisms by which species can cope with these rapid environmental changes.
The first response of animals to a changing environment is predominantly through modification of their behaviour. To date, only a few climate change biology studies have considered behavioural plasticity as a way that animals can adjust their performance under rapid climate change, especially for marine ectotherms.
The general objective of this thesis was to evaluate the effects of ocean warming and acidification on different aspects of behaviour in marine ectotherms. To achieve this aim I investigated the behavioural responses of two marine fish and one invertebrate, through field-based and laboratory experiments.
O aumento das emissões de gás carbônico atmosférico proveniente de atividades antrópicas desde a Revolução Industrial teve como consequência uma maior participação de águas superficiais no processo de sequestro de dióxido de carbono, a fim de amenizar o efeito estufa. A principal consequência do aumento de captura de gás carbônico pelos oceanos é um fenômeno denominado acidificação oceânica. Alguns poluentes presentes na água, como por exemplo fármacos e produtos de cuidados pessoais (FPCPs) podem sofrer alterações na sua mobilidade e biodisponibilidade por conta da diminuição do pH do meio. Atualmente a quantidade de dados sobre os efeitos e o risco ambiental de FPCPs em organismos marinhos ainda é escassa. Diante deste cenário o presente estudo teve como objetivo analisar a ocorrência, o comportamento e a biodisponibilidade do fármaco orfenadrina frente a diferentes cenários de acidificação oceânica. O fármaco orfenadrina, empregado como relaxante muscular e amplamente consumido foi observado em todos os pontos de amostragem das áreas de influência dos emissários submarinos de Santos e Guarujá – SP, com concentrações que variaram LOQ a 0,5 ng/g em sedimentos. Os resultados do ensaio de toxicidade com água empregando ouriços do mar (Echinometra lucunter) nos diferentes pHs 8,0; 7,6; 7,3 apresentaram valores de CEO de 0,05mg/L e o EpH50 foi estabelecido em 7,30. Quanto aos ensaios com mexilhões Perna perna foram observados efeitos em concentrações ambientalmente relevantes, com CEO de 200 ng/g. Os resultados dos ensaios feitos para a avaliação do desenvolvimento embriolarval em água indicaram que tanto o processo de acidificação quanto o aumento da concentração afetam o desenvolvimento dos embriões de ouriço do mar. Já nos ensaios com P. perna foi possível verificar ainda que a presença do fármaco de caráter básico reduziu os efeitos da acidificação oceânica. Os resultados da análise de bioacumulação detectaram a presença da orfenadrina em todos os tecidos analisados. A análise dos ensaios de citotoxicidade nesta ocasião refutou a hipótese inicial do estudo, visto que a presença do fármaco de caráter básico reduziu os efeitos da acidificação oceânica. Neste sentido, fica evidente necessidade de se aprofundar os estudos sobre toxicologia relacionada a fármacos sob cenários de acidificação em ambiente marinho.
- Organisation/Company: University of Bergen
- Research field: Chemistry › Biochemistry Environmental science › Earth science
- Researcher profile: Established Researcher (R3)Recognised Researcher (R2)
- Application deadline: 31/10/2021 23:00 – Europe/Brussels
- Location: Norway
- Type of contract: Temporary
- Job status: Full-time
- Hours per week: 37.5
- Offer starting date: 01/04/2022
- EU Research Framework Programme: H2020 / Marie Skłodowska-Curie Actions COFUND
- Marie Curie Grant agreement number: 101034309
Call opens August 1st and closes October 31st 2021
Thematic area and supervisor
This SEAS postdoctoral research fellow position is connected to the thematic area of marine biogeochemical hazards under warming, ocean acidification, and deoxygenation.
The position is open to an incoming candidate, see mobility rules. The successful candidate will be employed at the Geophysical Institute and included in the research group on biogeochemistry as well as the Research theme ‘Carbon System’ at the Bjerknes Center for Climate research.
- Multiple oceanographic processes functioning together and increased anthropogenic CO2 make Northern Indian Ocean more susceptible to ocean acidification than other major oceans of the world.
- ACD and CCD have been defined chemically and biologically, in the NIO.
- Palaeo-records suggest shoaling of ACD and CCD during warmer (interglacial) periods leading to dissolution of pteropod and foraminiferal shells.
- The ACD lies within the OMZ and thus the strength of the latter directly affects the ACD.
- While OMZ reduces the pH causing shoaling of ACD, denitrification in the Arabian Sea leads to increase in pH. Bay of Bengal is not conducive to denitrification.
- Impacts of ocean acidification on ecosystems are completely lacking.
- Need to collate abundant data collected since International Indian Ocean Expedition-1, laboratory and in-situ culture experiments for biological responses, and water column studies.
Characterised by one of the largest fresh water influxes in the world, the Northern Indian Ocean (NIO) is also bathymetrically, hydrodynamically and climatologically fragmented into smaller basins, making it a complex ocean basin. The monsoon system is unique to the NIO, bringing in several processes like ocean warming, dissolved oxygen depletion, evaporation, freshwater runoff induced by precipitation as well as glacial melting, nutrients derived from land runoff as well as coastal upwelling, biological productivity, oxic-degradation of organic matter and formation of oxygen minimum zones, all functional together at any given time. The seasonality and magnitude of all these processes control the pH in the NIO, as against other global oceans wherein only one or a couple of these processes are in play. The thermohaline circulation is another process that continuously affects the water chemistry in the NIO and has varied in strength over glacial-interglacial cycles. Its interaction with the NIO has the potential of affecting water masses in other ocean basins as well. While there exists limited work in the NIO directly addressing the issue of ocean acidification, substantial research has been done to understand the different hydrological and climatological processes, which influence the acidity in the basin. The present review summarises such studies which offer significant clues to the processes leading to- and impacts of- ocean acidification in the NIO. However, ocean acidification studies are in their nascent stage in the NIO. Understanding the influence of thermohaline ventilation in the Bay of Bengal, interbasinal hydrological teleconnections, impacts of ocean acidification on different trophic levels of the food chain, estimation of anthropogenic CO2 flux, estimation of pre-industrial pH and dissolution horizons by collating past chemical metrics collected, study of submarine volcanic regions as mimics of climate change and qualitative / quantitative ecosystem responses / adaptations are all promising prospects for further study in the Northern Indian Ocean.
This paper analysed several longitudinal data sets for investigating the dynamic inter-relationships between CO2 emissions and atmospheric concentrations, ambient temperatures and ocean acidification and deoxygenation. The methodological framework addressed issues such as the use of temperature ‘anomalies’, diffusion of CO2 to atmospheric stations, distributional misspecification and non-stationarity of errors affecting empirical models, and use of spline functions for modelling trends in temperatures. Longitudinal data on CO2 emissions for 163 countries and atmospheric CO2 concentrations at 10 stations, ambient temperatures from over 8,500 weather stations and seawater composition from over 380,000 oceanographic stations were analysed for 1985–2018 by estimating dynamic random effects models using maximum likelihood methods. The main findings were that CO2 emissions exhibited rapid upward trends at the country level, while minimum and maximum temperatures showed cyclical patterns; economic activity and population levels were associated with higher CO2 emissions. Second, there were gradual upward trends in annual and seasonal temperatures compiled at weather stations, and atmospheric CO2 concentrations were significantly associated with higher temperatures in the hemispheres. Third, there was a steady decline in dissolved oxygen levels, and the interactive effects of water temperatures and pH levels were significant. Overall, the results underscore the benefits of reducing CO2 emissions for ambient temperatures and for ocean deoxygenation. Synergies between CO2 emissions, ambient temperatures and ocean acidification are likely to exacerbate the melting of polar ice.
Dissolved organic carbon (DOC) release by seaweeds (marine macroalgae) is a critical component of the coastal oceans biogeochemical carbon cycle but is an aspect of seaweed carbon physiology that we know relatively little about. Seaweed-derived DOC is found throughout coastal ecosystems and supports multiple food web linkages. Here we discuss the mechanisms of DOC release by seaweeds and group them into passive (leakage, requires no energy) and active release (exudation, requires energy) with particular focus on the photosynthetic ‘overflow’ hypothesis. The release of DOC from seaweeds was first studied in the 1960’s but subsequent studies use a range of units hindering evaluation: we convert published values to a common unit (μmol C · g DW-1 · h-1) allowing comparisons between seaweed phyla, functional groups, biogeographic region, and an assessment of the environmental regulation of DOC production. The range of DOC release rates by seaweeds from each phylum under ambient environmental conditions was: 0 – 266.44 μmol C · g DW-1 · h-1 (Chlorophyta), 0 – 89.92 μmol C · g DW-1 · h-1 (Ochrophyta) and 0 – 41.28 μmol C · g DW-1· h-1 (Rhodophyta). DOC release rates increased under environmental factors such as desiccation, high irradiance, non-optimal temperatures, altered salinity and elevated dissolved carbon dioxide (CO2) concentrations. Importantly DOC release was highest by seaweeds which were desiccated (<90 times greater DOC release compared to ambient). We discuss the impact of future ocean scenarios (ocean acidification, seawater warming, altered irradiance) on DOC release rates by seaweeds, the role of seaweed-derived DOC in carbon sequestration models, and how they inform future research directions.
The integrity of coral reefs worldwide is jeopardized by ocean acidification (OA). Most studies conducted so far have focused on the vulnerability to OA of corals inhabiting shallow reefs, while nothing is currently known about the response of mesophotic scleractinian corals. In this study we assessed the susceptibility to OA of corals, together with their algal partners, inhabiting a wide depth range. We exposed fragments of the depth generalist coral Stylophora pistillata collected from either 5 or 45 meters to simulated future OA conditions, and assessed key molecular, physiological and photosynthetic processes influenced by the lowered pH. Our comparative analysis reveals that mesophotic and shallow S. pistillata corals are genetically distinct and possess different symbiont types. Under the exposure to acidification conditions, we observed a 50% drop of metabolic rate in shallow corals, whereas mesophotic corals were able to maintain unaltered metabolic rates. Overall, our gene expression and physiological analyses show that mesophotic corals possess a greater capacity to cope with the effects of OA compared to their shallow counterparts. Such capability stems from physiological characteristics (i.e. biomass and lipids energetics), a greater capacity to regulate cellular acid-base parameters, and a higher baseline expression of cell-adhesion and extracellular matrix genes. Moreover, our gene expression analysis suggests that the enhanced symbiont photochemical efficiency under high pCO₂ levels could prevent acidosis of the host cells and it could support a greater translocation of photosynthates, increasing the energy pool available to the host. With this work, we provide new insights on the response to OA of corals living at mesophotic depths. Our investigation discloses key genetic and physiological traits underlying the potential for corals to cope with future OA conditions.
Region(s) of Study: U.S. States and Territories
Primary Contact(s): email@example.com
NOAA’s National Centers for Coastal and Ocean Science Competitive Research Program, Climate Program Office, and Ocean Acidification Program, in partnership with the Office of National Marine Sanctuaries and the Integrated Ocean Observing System Office, are pleased to announce a Fiscal Year 2022 Federal Funding Opportunity (FFO) to understand multi-stressor impacts on marine ecosystems under climate change.
Climate change is exacerbating existing environmental stressors (e.g., hypoxia, harmful algal blooms, and ocean acidification) through changes to the fundamental drivers of ecosystems (e.g., temperature, precipitation, seasonal cycles, and biogeochemistry). These changes impact processes such as deoxygenation, nutrient and carbon cycling, respiration rates, stratification, ocean circulation, upwelling, and mixing, with implications for the prevalence, severity, and duration of harmful algal blooms, ocean acidification, and hypoxia events. Understanding how these multiple stressors interact and subsequently impact species, habitat assemblages, and ecosystems is critical for place-based management.
NOAA is soliciting proposals to increase our understanding of the combined impacts of multiple stressors, including harmful algal blooms, deoxygenation, ocean acidification, and increasing temperatures, on the function and health of marine ecosystems within the context of climate change. This information will be used to improve place-based management of marine protected areas and enable the proactive protection of these critical ecosystems under future climate scenarios. NOAA expects to fund 1–2 projects for up to four years in duration, with an approximate annual budget of $1 million, not to exceed $4 million in total.
A letter of intent is required. The deadline for letters of intent is October 4, 2021; and full applications are due January 18, 2022. View the full FFO here.
Fernandes and Cyr file legislation offering incentives to communities to protect aquatic ecosystems.
Cape and Islands lawmakers are looking to protect the precious water resources stewarded by coastal communities by proposing legislation that provides incentives for communities to reduce nutrient pollution that damages aquatic habitats, according to a press release.
State Rep. Dylan Fernandes, D-Falmouth, and state Sen. Julian Cyr, D-Truro, recently filed legislation to create a Blue Communities Program that highlights the importance of reducing ocean acidification through nine different initiatives.
The main drivers of ocean acidification in Massachusetts are global increases in atmospheric carbon dioxide caused by anthropogenic emissions, and local nutrient pollution leading to the eutrophication of coastal waters.
Open date: 28 July 2021
Next review date: Wednesday,18 Aug 2021 at 11:59pm (Pacific Time)
Apply by this date to ensure full consideration by the committee.
Final date: Friday, Dec 31, 2021 at 11:59pm (Pacific Time)
Applications will continue to be accepted until this date, but those received after the review date will only be considered if the position has not yet been filled.
Postdoctoral Scholar in Ocean Chemistry, Ecological Change and Coastal Communities
A postdoctoral research scholar position is available at the University of California at Davis, Bodega Marine Laboratory. The position is suitable for remote or in person work at Bodega Marine Laboratory.
The successful candidate will work on a project that integrates oceanographic data with ecological data-syntheses on species-specific responses to the synergistic effects of ocean acidification, oxygenation, and temperature change. The work connects to ongoing research on the vulnerability of human communities in California and Oregon to these same threats. This is part of an interdisciplinary set of projects with PIs at UC Davis (Hill, Gaylord, Sanford), UC Santa Cruz (Kroeker), Oregon State University (Spalding, Wolters), San Diego State University (Levine) and the California Ocean Science Trust (Whiteman, Teneva).
Specifically, the postdoctoral scholar would have leadership opportunities in projects relating to:
● Integration of oceanographic data with a synthesis of ecological vulnerability thresholds: developing interpretations and products that aim to understand the impacts of oceanographic change on key US West Coast species
● Connecting these findings to research on the adaptive capacity of the aquaculture industry and other marine resource dependent coastal communities, including downscaling oceanographic and ecological data to specific communities
● Public engagement, including collaborations with community partners, workshops with managers and decision makers, and opportunities to further develop science communication and community engagement practices
● Mentoring of graduate students and undergraduate students in related projects
Successful candidates will benefit from a dynamic and highly collaborative environment and the opportunity to interact with the extended scientific community at UC Davis, which ranks among the top 10 public research universities in the US. The UC Davis Bodega Marine Lab research team would serve as the primary mentors for this postdoctoral position and aim to provide a postdoctoral experience that launches the candidate into their next career step. We seek a scholar who will enjoy working in an interdisciplinary team that considers impacts of climate change on marine ecosystems across multiple spatial and temporal scales. The postdoctoral scholar will be encouraged to present their research at scientific conferences as well as lead author and coauthor work derived from these projects.
Additional information on the Bodega Marine Laboratory research team can be found here: https://www.bodegaoceanacidification.com/ Additional information on the primary project the postdoctoral scholar would be able to work on is here: https://www.lenfestocean.org/en/research-projects/geospatial-patterns-and-species-impacts-of-changing-ocean-chemistry-on-the-west-coast
While the position will be based at Bodega Marine Laboratory, it can be completed remotely with minimal travel (1-2 weeks/year) to California for team meetings. There are no fieldwork requirements for this position.
A PhD in a relevant field (marine science, oceanography, geosciences, biological sciences, or similar) is required. Candidates must be within the first 5 years of their Ph.D. degree date, based upon UC Davis policy.
Preference will be given to candidates with demonstrated experience in:
● large oceanographic datasets and ocean biogeochemistry
● oceanographic and ecological modeling, spatial interpolation techniques, statistical tools, and/or GIS.
● programming in R and data management in GitHub
● publication of scientific results, and a publication record appropriate for career stage
How to Apply:
Applicants should submit a cover letter with a brief description of thesis research, a Curriculum Vitae, a statement of contributions to diversity, equity and inclusion and contact information for three references. For suggestions on writing a statement of Contributions to Diversity, Equity and Inclusion, please see
Application material should be submitted via the online application system at:
Marine sponges are becoming an increasing source of novel biomedical and antibacterial compounds. Many of these compounds are synthesized as secondary metabolites from symbiotic bacteria and have immense potential in the pharmaceutical industry. However, climate change may pose a threat to the viability of marine sponges and result in the loss of future medical discoveries. Therefore, this paper looks at the effect climate change may have on marine sponges by subjecting fragments of the marine sponge, Halichondria panicea, into aquaria representing different climate change scenarios to study the effect that global warming and ocean acidification may have on its symbiotic bacteria. To model climate change towards the end of the 21st century, conditions from the IPCC’s 2014 climate change report were simulated to determine specific growth conditions. The fragments were placed in the different RCP growth conditions for two weeks, then dissociated, filtered, and the extracts incubated on Hektoen enteric agar for 48 hours. The results showed that climate change has adverse effects on the marine sponge, Halichondria panicea, by decreasing their symbiotic bacterial population by around 18 %
Otopetrins comprise a family of proton channels that are required for the development of calcified structures including otoliths and statoconia in vertebrates. To date, it remains unknown how otopetrins contribute to the calcification process. Using the sea urchin larva, we could demonstrate that the otopetrin ortholog otop2l encodes a proton channel that is essential for the formation of the CaCO3 skeleton. otop2l is exclusively expressed by the calcifying primary mesenchyme cells, where it promotes the exit of protons liberated by the mineralization process. Given the deep phylogenetic origin of otopetrins in animals, our work identified a key mechanism in the mineralization process with relevance for many calcifying species and their responses to changes in environmental pH.
Otopetrins comprise a family of proton-selective channels that are critically important for the mineralization of otoliths and statoconia in vertebrates but whose underlying cellular mechanisms remain largely unknown. Here, we demonstrate that otopetrins are critically involved in the calcification process by providing an exit route for protons liberated by the formation of CaCO3. Using the sea urchin larva, we examined the otopetrin ortholog otop2l, which is exclusively expressed in the calcifying primary mesenchymal cells (PMCs) that generate the calcitic larval skeleton. otop2l expression is stimulated during skeletogenesis, and knockdown of otop2l impairs spicule formation. Intracellular pH measurements demonstrated Zn2+-sensitive H+ fluxes in PMCs that regulate intracellular pH in a Na+/HCO3−-independent manner, while Otop2l knockdown reduced membrane proton permeability. Furthermore, Otop2l displays unique features, including strong activation by high extracellular pH (>8.0) and check-valve–like outwardly rectifying H+ flux properties, making it into a cellular proton extrusion machine adapted to oceanic living conditions. Our results provide evidence that otopetrin family proton channels are a central component of the cellular pH regulatory machinery in biomineralizing cells. Their ubiquitous occurrence in calcifying systems across the animal kingdom suggest a conserved physiological function by mediating pH at the site of mineralization. This important role of otopetrin family proton channels has strong implications for our view on the cellular mechanisms of biomineralization and their response to changes in oceanic pH.
- We identified orthologous genes (ompa and ompb) in European sea bass
- Ompa and ompb genes differ in amino acid sequences and in their expression pattern
- Acidification induces intra- and intergenerational plasticity in omps expression
- Both ompa and ompb mRNA could be used as novel molecular markers of OSN in sea bass
Since sensory system allows organisms to perceive and interact with their external environment, any disruption in their functioning may have detrimental consequences on their survival. Ocean acidification has been shown to potentially impair olfactory system in fish and it is therefore essential to develop biological tools contributing to better characterize such effects. The olfactory marker protein (omp) gene is involved in the maturation and the activity of olfactory sensory neurons in vertebrates. In teleosts, two omp genes (ompa and ompb) originating from whole genome duplication have been identified. In this study, bioinformatic analysis allowed characterization of the ompa and ompb genes from the European seabass (Dicentrarchus labrax) genome. The European seabass ompa and ompb genes differ in deduced amino acid sequences and in their expression pattern throughout the tissues. While both ompa and ompb mRNA are strongly expressed in the olfactory epithelium, ompb expression was further observable in different brain areas while ompa expression was also detected in the eyes and in other peripheral tissues. Expression levels of ompa and ompb mRNA were investigated in adult seabass (4 years-old, F0) and in their offspring (F1) exposed to pH of 8 (control) or 7.6 (ocean acidification, OA). Under OA ompb mRNA was down-regulated while ompa mRNA was up-regulated in the olfactory epithelium of F0 adults, suggesting a long-term intragenerational OA-induced regulation of the olfactory sensory system. A shift in the expression profiles of both ompa and ompb mRNA was observed at early larval stages in F1 under OA, suggesting a disruption in the developmental process. Contrary to the F0, the expression of ompa and ompb mRNA was not anymore significantly regulated under OA in the olfactory epithelium of juvenile F1 fish. This work provides evidence for long-term impact of OA on sensorial system of European seabass as well as potential intergenerational acclimation of omp genes expression to OA in European seabass.
Climate-enhanced stock assessment models represent potentially vital tools for managing living marine resources under climate change. We present a climate-enhanced stock assessment where environmental variables are integrated within a population dynamics model assessment of biomass, fishing mortality and recruitment that also accounts for process error in demographic parameters. Probability distributions for the impact of the associated environmental factors on recruitment and growth can either be obtained from Bayesian analyses that involve fitting the population dynamics model to the available data or from auxiliary analyses. The results of the assessment form the basis for the calculation of biological and economic target and limit reference points, and projections under alternative harvest strategies. The approach is applied to northern rock sole (Lepidopsetta polyxystra), an important component of the flatfish fisheries in the Eastern Bering Sea. The assessment involves fitting to data on catches, a survey index of abundance, fishery and survey age-compositions and survey weight-at-age, with the relationship between recruitment and cold pool extent and that between growth increment in weight and temperature integrated into the assessment. The projections also allow for an impact of ocean pH on expected recruitment based on auxiliary analyses. Several alternative models are explored to assess the consequences of different ways to model environmental impacts on population demography. The estimates of historical biomass, recruitment and fishing mortality for northern rock sole are not markedly impacted by including climate and environmental factors, but estimates of target and limit reference points are sensitive to whether and how environmental variables are included in stock assessments and projections.
Climate change is one of the biggest challenges for humans in the modern world. Specifically, global warming due to greenhouse gases emissions constitutes a big part of it. Objective of The Paris Agreement, signed in 2016, is to maintain the global average temperature rise well below 2◦C above pre-industrial levels. However, global warming is strictly linked to another problem related to climate change: ocean acidification. Although various strategies that aim at counteracting global warming have been recently proposed and discussed, few are the technological solutions that prevent simultaneously global warming and ocean acidification. Among these, Ocean Liming technique is based on the idea of sequestering atmospheric carbon dioxide adding alkalinity to seawater, obtained by dissolution of slaked lime. The aim of this thesis work is to investigate the feasibility of Ocean Liming with the assessment of the calcium hydroxide concentration and seawater pH in the wake of a ship, conducted with a three dimensional reactive CFD modelling, in order to incorporate dynamic chemical parameters. The simulations have been conducted with a parallel Finite Differences – Large Eddy Simulation solver, wrote in Fortran 90. The work is divided in two main parts. The first one is focused on the code validation process, with the analysis of a laminar Poiseuille channel flow and a turbulent round jet. The second one consists in the simulation of slaked lime discharge in the near wake of a ship. In particular, the proposed configurations differ in slaked lime mass flow rate, type of injection (single or double) and the operational regime of the ship propeller (modelled with R-BET physical model). To complete the study, a preliminary analysis of the hull ship (modelled with a bluff body) effect on slaked lime dissolution is presented. The results are proposed with a study of space and time evolution of slaked lime concentration levels and pH variation across the computational domain. The solver could be used for future developments on this field of research, with the study of different slaked lime discharge configurations.
An ocean acidification buoy in Puerto Rico helps scientists understand changing conditions in our oceans and atmosphere.
Since 2008, a NOAA Ocean Acidification Program (OAP) buoy has been positioned in La Parguera, Puerto Rico where it collects data for scientists studying the chemistry, biology, geology, and physics of the Caribbean Sea. A recent NOAA video available in English and in Spanish explains the impact of increased levels of carbon dioxide (CO2) and ocean acidification on ocean chemistry and on marine life in our oceans.
Knowledge of ocean acidification and warming conditions is critical to advance the 2030 Sustainable Development Goals of the United Nations in Puerto Rico. The information provided by NOAA is relevant for tracking progress towards achieving mitigation and adaptation actions around the island because rapid changes in ocean acidification and warming have significant impacts on the ocean’s ability to sequester CO2 from the atmosphere and ocean ecosystem services (e.g., tourism, food, coastal protection).
What is Ocean Acidification?
Recent measurements indicate that atmospheric CO2 levels have increased by 50% due to human activities such as the burning of fossil fuels. The ocean absorbs about a third of the CO2 that is released to the atmosphere. As atmospheric CO2 has increased, so has the amount of CO2 absorbed by the ocean. More CO2in the water increases our ocean’s acidity, a phenomenon known as ocean acidification.
The passage of House Bill 3114 is another historic Oregon first in the fight against ocean acidification and hypoxia (OAH) and shows Oregon leaders’ awareness of the importance of healthy oceans. Oregon is an epicenter for OAH and was one of the first places in the world to observe direct impacts of ocean change when oyster hatchery production collapsed in 2007 from ocean acidification.
The bill provides $1.9 million to fund research and monitoring along the Oregon coast and estuaries, develop best management practices and conduct outreach and education. ODFW will directly receive $470,000 of this funding to assess shellfish and habitat in estuaries and map estuaries to document long-term OAH impacts.
“This legislative investment helps ODFW keep a finger on the pulse of our estuaries by increasing our capacity to survey shellfish and estuary habitats more frequently,” said Caren Braby, ODFW marine resources program manager and co-chair of Oregon’s OAH Council. “Estuaries provide important nursery habitat for many ocean species and support both commercial and recreational fisheries as well as oyster mariculture operations.”
Ocean acidification is caused when carbon dioxide from the atmosphere enters the ocean and chemically reacts with ocean water, making the ocean more acidic (lowering the pH). Hypoxia (low oxygen) occurs when deep ocean waters with less oxygen rise and are pushed closer to the shore by northerly winds, and then near-bottom waters are robbed of oxygen by decaying organic matter. This happens more frequently than normal due to climate changes that heat the land and ocean waters and change normal wind patterns.
House Bill 3114 is a cohesive plan that implements recommended priorities established in Oregon’s OAH Council’s 2018 Legislative Report and the Oregon OAH Action Plan (adopted by the governor for 2019-2025) that supports fisheries, industry, and coastal communities. To learn more about ocean acidification and hypoxia and the steps Oregon is taking to address OAH, go online at www.oregonocean.info/index.php/ocean-acidification
- Gene expression profiles of the sea pen Malacobelemnon daytoni revealed an important number of transcripts upregulated in response to short-term and long-term Low pH conditions.
- The biomineralization in this coral is not acclimated after two months in the Low pH condition, indicating that the pennatulid would be striving to produce its calcium carbonate structure.
- Malacobelemnon daytoni is working extra hard at the molecular level to maintain the same enzyme activity levels.
Benthic organisms of the Southern Ocean are particularly vulnerable to ocean acidification (OA), as they inhabit cold waters where calcite-aragonite saturation states are naturally low. OA most strongly affects animals with calcium carbonate skeletons or shells, such as corals and mollusks. We exposed the abundant cold-water coral Malacobelemnon daytoni from an Antarctic fjord to low pH seawater (LpH) (7.68 ± 0.17) to test its physiological responses to OA, at the level of gene expression (RT-PCR) and enzyme activity. Corals were exposed in short- (3 days) and long-term (54 days) experiments to two pCO2 conditions (ambient and elevated pCO2 equaling RCP 8.5, IPCC 2019, approximately 372.53 and 956.78 μatm, respectively).
Of the eleven genes studied through RT-PCR, six were significantly upregulated compared with control in the short-term in the LpH condition, including the antioxidant enzyme superoxide dismutase (SOD), Heat Shock Protein 70 (HSP70), Toll-like receptor (TLR), galaxin and ferritin. After long-term exposure to low pH conditions, RT-PCR analysis showed seven genes were upregulated. These include the mannose-binding C-Lectin and HSP90. Also, the expression of TLR and galaxin, among others, continued to be upregulated after long-term exposure to low pH. Expression of carbonic anhydrase (CA), a key enzyme involved in calcification, was also significantly upregulated after long-term exposure. Our results indicated that, after two months, M. daytoni is not acclimatized to this experimental LpH condition. Gene expression profiles revealed molecular impacts that were not evident at the enzyme activity level. Consequently, understanding the molecular mechanisms behind the physiological processes in the response of a coral to LpH is critical to understanding the ability of polar species to cope with future environmental changes. Approaches integrating molecular tools into Antarctic ecological and/or conservation research make an essential contribution given the current ongoing OA processes.