Archive for November, 2017

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Alaska Ocean Acidification Network Survey

Published 15 November 2017 Web sites and blogs Closed

The Alaska Ocean Acidification Network is interested in your opinion and priorities.  Researchers and resources managers are monitoring ocean acidification in Alaska, and need your input to develop a build-out plan for the monitoring network. Your help will make sure the plan addresses questions that are important to Alaskans. This survey should take less than 10 minutes. The AK Ocean Acidification Network appreciates your participation.

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Southern Ocean pteropods at risk from ocean warming and acidification

Published 15 November 2017 Science Closed
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Early life stages of marine calcifiers are particularly vulnerable to climate change. In the Southern Ocean aragonite undersaturation events and areas of rapid warming already occur and are predicted to increase in extent. Here, we present the first study to successfully hatch the polar pteropod Limacina helicina antarctica and observe the potential impact of exposure to increased temperature and aragonite undersaturation resulting from ocean acidification (OA) on the early life stage survival and shell morphology. High larval mortality (up to 39%) was observed in individuals exposed to perturbed conditions. Warming and OA induced extensive shell malformation and dissolution, respectively, increasing shell fragility. Furthermore, shell growth decreased, with variation between treatments and exposure time. Our results demonstrate that short-term exposure through passing through hotspots of OA and warming poses a serious threat to pteropod recruitment and long-term population viability.

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Competitive interactions moderate the effects of elevated temperature and atmospheric CO2 on the health and functioning of oysters

Published 15 November 2017 Science Closed
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Global increases in sea temperatures and atmospheric concentrations of CO2 may affect the health of calcifying shellfish. Little is known, however, about how competitive interactions within and between species may influence how species respond to multiple stressors. We experimentally assessed separate and combined effects of temperature (12 or 16°C) and atmospheric CO2 concentrations (400 and 1000 ppm) on the health and biological functioning of native (Ostrea edulis) and invasive (Crassostrea gigas) oysters held alone and in intraspecific or interspecific mixtures. We found evidence of reduced phagocytosis under elevated CO2 and, when combined with increased temperature, a reduction in the number of circulating haemocytes. Generally, C. gigas showed lower respiration rates relative to O. edulis when the species were in intraspecific or interspecific mixtures. In contrast, O. edulis showed a higher respiration rate relative to C. gigas when held in an interspecific mixture and exhibited lower clearance rates when held in intraspecific or interspecific mixtures. Overall, clearance rates of C. gigas were consistently greater than those of O. edulis. Collectively, our findings indicate that a species’ ability to adapt metabolic processes to environmental conditions can be modified by biotic context and may make some species (here, C. gigas) competitively superior and less vulnerable to future climatic scenarios at local scales. If these conclusions are generic, the relative role of species interactions, and other biotic parameters, in altering the outcomes of climate change will require much greater research emphasis.

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Timelapse of ocean acidification effects on coral

Published 14 November 2017 Web sites and blogs Closed

Stanford Earth’s Cassandra Brooks contributed footage to a new interactive David Attenborough project about the Great Barrier Reef. Brook’s video shows the effects of ocean acidification on the limestone skeleton of a sand dollar.

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Target gene expression studies on Platynereis dumerilii and Platynereis cfr massiliensis at the shallow CO2 vents off Ischia, Italy

Published 14 November 2017 Science Closed
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Many studies predict negative effects of ocean acidification on marine organisms, potentially leading to loss of biodiversity and ecosystem function. Research on species inhabiting naturally high pCO2 environments, such as volcanic CO2 vents, offers an opportunity to understand the molecular mechanisms involved in high pCO2 regulation. Here we investigate the relative expression of NADH dehydrogenase, sodium-hydrogen antiporter (NHE), carbonic anhydrase (CA) and paramyosin genes from two non-calcifying sibling Nereididae polychaetes species, Platynereis cfr massiliensis, collected in the shallow CO2 vents off Ischia (Italy; 40°43′52.0″N 13°57′46.2″E and 40°43′55.5″N 13°57′48.4″E), and P. dumerilii collected in an area nearby (40°43′34.51″N; 13°57′35.7″E). The origin of the worms was confirmed using restriction enzyme digest. NHE and paramyosin expressions were both significantly increased in P. dumerilii relative to the P. cfr massiliensis vent populations. Furthermore, a seven day laboratory transfer experiment to lower/higher pCO2 conditions was conducted to investigate the effects on the short term gene expression. The transfer experiment of the non-vent worms to high pCO2 conditions showed no significant effect on any of the genes analysed, however, two genes (NADH dehydrogenase and NHE) from worms of the vent population were significantly down-regulated under low pCO2. These findings will help to gain further insights into the cellular mechanisms affected by pCO2 changes in two polychaete species.

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Impact of surface ocean conditions and aerosol provenance on the dissolution of aerosol manganese, cobalt, nickel and lead in seawater

Published 14 November 2017 Science Closed
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Highlights

  • Simulated ocean warming, ocean acidification and anoxia had little impact on the dissolution of aerosol Co, Mn, Ni and Pb in surface seawater
  • Aerosol provenance and chemical speciation exerted the greatest control on Co and Pb dissolution, with combustion-associated processes (indicated by trace metal enrichment factors), enhancing solubility
  • Linear relationships between enrichment factors and fractional solubility were found, which are useful in estimating solubility of Fe, Co and Pb in global data sets
  • Size fractionation of seawater leaches showed that aerosol derived dissolved Pb was mostly colloidal (0.02-0.4 μm), dissolved Mn and Co were mostly soluble (< 0.02 μm), and dissolved Ni displayed a mixed size distribution

Atmospheric deposition is an important pathway by which bioactive trace metals are delivered to the surface ocean. The proportions of total aerosol trace metals that dissolve in seawater, and thus become available to biota, are not well constrained and are therefore a key uncertainty when estimating atmospheric fluxes of these elements to surface waters. The aim of this study was to elucidate the main physico-chemical controls on the dissolution of the bioactive trace metals manganese (Mn), cobalt (Co), nickel (Ni) and lead (Pb). To this end, aerosol and surface seawater samples were collected in the Sargasso Sea and subsequently used in sequential seawater leach dissolution experiments to assess the role of aerosol source, seawater temperature, pH, and concentrations of dissolved oxygen and organic ligands, on aerosol trace metal dissolution.

Results reveal that changes in key physico-chemical parameters in seawater leaches had little effect on the proportions of Mn, Co, Ni and Pb released from aerosols, although organic ligand amendments impacted the size distribution of aerosol-derived Mn in solution. Conversely, aerosol source and composition had the most significant effect on the dissolution of aerosol Co and Pb, with the most ‘anthropogenic’ aerosol samples displaying the highest fractional solubilities in seawater (up to 58% for Co and 112% for Pb).

Fractional solubilities over the range of samples and conditions tested were in the range of 50–104% for Mn, 29–58% for Co, 40–85% for Ni and 67–112% for Pb. A large proportion (36–100%, median 89%) of the total dMn, dCo, dNi and dPb was mobilised rapidly during the first leaching step (5 min), with less dTM being released in leaches 2 through 4. Furthermore, investigation of the size distribution of the aerosol-derived trace metals in seawater showed that dissolved Pb was mostly colloidal (0.02–0.4 μm), dissolved Mn and Co were mostly soluble (< 0.02 μm), and dissolved Ni displayed a mixed size distribution. Good empirical relationships were observed between enrichment factors for aerosol antimony (Sb) and the fractional solubilities of aerosol Fe, Co and Pb, suggesting total aerosol Sb can be useful in estimating and modelling the fractional solubility of these metals using total aerosol trace metal concentrations from historical data.

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Prioritizing coastal ecosystem stressors in the Northeast United States under increasing climate change

Published 14 November 2017 Science Closed
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Highlights

• Survey and workshop ranked impacts of stressors on marine and coastal ecosystems.
• Includes ranking of current impacts and future impacts under climate change.
• Describes methodology that could be applied to other geographies or scales.
• Methods allow decision-makers to address environmental impacts under climate change.

Abstract

Coastal and marine ecosystems around the world are under threat from a growing number of anthropogenic impacts, including climate change. Resource managers, researchers, policy makers, and coastal community planners are tasked with identifying, developing, and monitoring strategies to reduce or reverse the ecological, economic and social impact of environmental stressors. These individuals must make decisions about how to prioritize and allocate finite resources to address these issues, all under conditions of significant uncertainty about which of these stressors to address. This paper presents the results of a survey and workshop designed to rank the impact of a series of stressors on four components of the marine and coastal ecosystems of the Northeast United States. The methodology described here – expert elicitation supplemented by workshop deliberations – proved to be relatively cost-effective, time-efficient, and informative for identifying priority stressors for the ecosystem components under consideration, both now and in the future.

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Natural ocean acidification at Papagayo upwelling system (North Pacific Costa Rica): implications for reef development

Published 14 November 2017 Science Closed
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Numerous experiments have shown that ocean acidification impedes coral calcification, but knowledge about in situ reef ecosystem response to ocean acidification is still scarce. Bahía Culebra, situated at the northern Pacific coast of Costa Rica, is a location naturally exposed to acidic conditions due to the Papagayo seasonal upwelling. We measured pH and pCO2 in situ during two non-upwelling seasons (June 2012, May–June 2013), with a high temporal resolution of every 15 and 30 min, respectively, using two Submersible Autonomous Moored Instruments (SAMI-pH, SAMI-CO2). These results were compared with published data from the upwelling season 2009. Findings revealed that the carbonate system in Bahía Culebra shows a high temporal variability. Incoming offshore waters drive inter- and intra-seasonal changes. Lowest pH (7.8) and highest pCO2 (658.3 µatm) values measured during a cold-water intrusion event in the non-upwelling season were similar to those minimum values reported from upwelling season (pH = 7.8, pCO2 = 643.5 µatm), unveiling that natural acidification occurs sporadically also in non-upwelling season. This affects the interaction of photosynthesis, respiration, calcification, and carbonate dissolution and the resulting diel cycle of pH and pCO2 in the reefs of Bahía Culebra. During non-upwelling season, the aragonite saturation state (Ωa) rises to values of > 3.3 and enhances calcification. Aragonite saturation state values during upwelling season falls below 2.5, hampering calcification and coral growth. Low reef accretion in Bahía Culebra indicates high erosion rates and that these reefs grow on the verge of their ecological tolerance. The Ωa threshold values for coral growth, derived from the correlation between Ωa and coral linear extension rates, suggest that future ocean acidification will threaten reefs in Bahía Culebra. These data contribute to build a better understanding of the carbonate system dynamics and coral reefs key response (e.g. coral growth) to natural low-pH conditions, in upwelling areas in the Eastern Tropical Pacific and beyond.

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Assessing public awareness of marine environmental threats and conservation efforts

Published 14 November 2017 Science Closed
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Highlights

• Public engagement is key to conservation success.
• A well informed public can increase support in conservation efforts.
• Identified knowledge gaps within the public in marine conservation efforts.
• Value-Action Gap present within the public in Cornwall, UK.
• Improved, interdisciplinary science communication can increase public engagement.

Abstract

To successfully integrate and engage the general public into marine conservation decisions it is important that individuals are well informed. This study surveyed two sample groups, marine environmental professionals working in the UK, n = 61, and members of the public surveyed in Truro, Cornwall, UK, n = 71. Public awareness of marine environmental threats and conservation efforts was assessed through comparison with the, assumed well informed, professional sample. Findings suggest that the public are generally well informed of threats to the marine environment, but are significantly less well informed about marine conservation and management strategies. Furthermore, despite indicating concern for the marine environment, members of the public display significantly fewer pro-environmental behaviours than marine conservation professionals. Public knowledge (and action) gaps are discussed as well as how these may be minimised, including a more interdisciplinary and active approach to science communication and public engagement.

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Ocean commitments under the Paris Agreement

Published 14 November 2017 Science Closed
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Under the Paris Agreement nations made pledges known as nationally determined contributions (NDCs), which indicate how national governments are evaluating climate risks and policy opportunities. We find that NDCs reveal important systematic patterns reflecting national interests and capabilities. Because the ocean plays critical roles in climate mitigation and adaptation, we created a quantitative marine focus factor (MFF) to evaluate how governments address marine issues. In contrast to the past, when oceans received minimal attention in climate negotiations, 70% of 161 NDCs we analysed include marine issues. The percentage of the population living in low-lying areas—vulnerable to rising seas—positively influences the MFF, but negotiating group (Annex 1 or small island developing states) is equally important, suggesting political motivations are crucial to NDC development. The analysis reveals gaps between scientific and government attention, including on ocean deoxygenation, which is barely mentioned. Governments display a keen interest in expanding marine research on climate priorities.

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International Alliance to Combat Ocean Acidification announces new members, including Fiji, and new plans for action at climate talks in Bonn

Published 14 November 2017 Press releases Closed

BONN, Germany (13. November, 2017) – As part of the UN Climate Change Conference, COP23, the International Alliance to Combat Ocean Acidification (OA Alliance) today announced new members, including the Republic of Fiji, and new commitments from world leaders to take action to protect oceans from the impacts of climate change. High-level government officials from around the world gathered to engage in meaningful conversations about ocean acidification (OA) and steps OA Alliance members can take to mitigate impacts through the United Nations Framework Convention on Climate Change.

The OA Alliance, founded by the West Coast states of California, Washington, Oregon and the Canadian Province of British Columbia, welcomed five new members to a rapidly growing worldwide coalition of governments and supporting affiliates committed to creating regional ocean acidification action plans and sharing climate action best practices with each other. The newest official members of the OA Alliance are Fiji, Sweden, the Secretariat of the Pacific Regional Environment Programme (SPREP) and the scientific and technical organization Pacific Community (SPC). Tokelau also announced their intention to join the OA Alliance at today’s event.

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Study of Bermuda corals finds temperature is most influential factor on coral growth

Published 13 November 2017 Press releases Closed

Scientists have long been concerned that decreasing ocean pH (increasing acidity) caused by increasing carbon dioxide emissions in the atmosphere could negatively impact coral reefs. Many laboratory experiments have demonstrated that increased ocean acidity slows down coral calcification, the process by which corals grow and build their hard structure. But far fewer studies have tested how increasing ocean acidity affects coral growth in the natural environment, where a multitude of additional factors such as light, temperature, and nutrients are also important.

A new paper based on research led by scientists at Scripps Institution of Oceanography at the University of California San Diego that was published this week in Science Advances found a surprising answer to this question. Scripps chemical oceanographer Andreas Andersson, his graduate student Travis Courtney, and an international team of collaborators from the Bermuda Institute for Ocean Sciences and Christian-Albrecht University in Germany, among others, were involved in the study funded by the National Science Foundation.

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Environmental controls on modern scleractinian coral and reef-scale calcification

Published 13 November 2017 Science Closed
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Modern reef-building corals sustain a wide range of ecosystem services because of their ability to build calcium carbonate reef systems. The influence of environmental variables on coral calcification rates has been extensively studied, but our understanding of their relative importance is limited by the absence of in situ observations and the ability to decouple the interactions between different properties. We show that temperature is the primary driver of coral colony (Porites astreoides and Diploria labyrinthiformis) and reef-scale calcification rates over a 2-year monitoring period from the Bermuda coral reef. On the basis of multimodel climate simulations (Coupled Model Intercomparison Project Phase 5) and assuming sufficient coral nutrition, our results suggest that P. astreoides and D. labyrinthiformis coral calcification rates in Bermuda could increase throughout the 21st century as a result of gradual warming predicted under a minimum CO2 emissions pathway [representative concentration pathway (RCP) 2.6] with positive 21st-century calcification rates potentially maintained under a reduced CO2 emissions pathway (RCP 4.5). These results highlight the potential benefits of rapid reductions in global anthropogenic CO2 emissions for 21st-century Bermuda coral reefs and the ecosystem services they provide.

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Ocean acidification on the agenda in Bonn

Published 13 November 2017 Press releases Closed
A picture of a sea urchin

Photo credit: Natural England Flickr

Tomorrow the Environment Minister Thérèse Coffey will head to the UN Climate Change Conference in Germany to discuss our world-class marine science and leading research into ocean acidification.

Saturday is ‘Oceans Action Day’ and the Minister will join leaders from around the world to address progress made on tackling climate change and its impacts on the marine environment.

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Rising CO2 & sea life (audio)

Published 13 November 2017 Media coverage Closed

A new analysis finds that most if not all marine species will be affected by the rising acidity in the oceans from CO2 emissions. Research scientist Ulf Riebesell of the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany spoke with host Steve Curwood about his team’s findings and what increasing ocean acidity could mean for species like corals and cod as well people who depend on the sea for food.

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Oceans are about to become giant pools of seltzer

Published 13 November 2017 Media coverage 2 Comments

Climate change’s spike up in carbon dioxide means that oceans—which cover 71 percent of Earth’s surface—are going to become cesspools.

“I have to admit, we’re just scratching the surface here,” Ulf Riebesell told The Daily Beast recently. He’s talking about how only now, decades after climate change was recognized as an impending crisis, we’re figuring out how the extreme temperatures facing Earth will affect the water covering 71 percent of the planet.

Riebesell is the lead author of a landmark study involving more than 250 scientists, 580 peer-reviewed articles, 20 German research institutions, and 350 marine species, trying to understand how climate change will affect the world’s oceans. Eight diligent years and $25.5 million later, Riebesell’s team’s research was presented at the annual United Nations Climate Change Conference in Bonn, Germany, this week.

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Ocean acidification threatens New England fishing industry

Published 13 November 2017 Media coverage Closed

Among the many environmental byproducts of global climate change, the lesser known process called ocean acidification is posing an immediate threat the New England shellfish industry, experts say.

As excess carbon dioxide is absorbed into the oceans combined with freshwater runoff into coast waters, it is starting to have profound effects on marine life, from oysters to tiny snails at the base of the food chain.

In New Hampshire, Sen. David Watters (D-Dover), oversaw the passage of a bipartisan 2016 bill that established The New Hampshire Coastal Marine Natural Resources and Environment Commission which began meeting earlier this year.

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Evaluating features of periphytic diatom communities as biomonitoring tools in fresh, brackish and marine waters

Published 13 November 2017 Science Closed
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Highlights

• Diversity of periphytic diatoms from freshwater, brackish water and marine sites from the same biogeographical region was assessed.
• Taxonomical parameters (life-forms, cell density, biovolume, Shannon index, species richness and % relative abundance) effectively differentiate impacted sites from less-impacted one.
• Lipid bodies and deformities in diatoms show tremendous potential to be used as a rapid early warning system for assessing the ecological health of fluvial ecosystem.

Abstract

The aims of this study were to assess the biodiversity of periphytic diatom assemblages in fresh, brackish and marine waterbodies of Korea, and to assess the effect of environmental and anthropogenic factors on parameters such as the quantity and biovolume of lipid bodies and deformations of diatoms as early warning measures of anthropogenic impact. Diatom samples were collected from 31 sites (14 freshwater, 10 brackish and 7 marine), which included less impacted (upstream) and impacted (downstream) sites in each water type. Our results showed higher abundance and biodiversity of periphytic diatoms at the less impacted sites in terms of species richness, Shannon index, cell count and biovolume of the communities than at the impacted sites for freshwater and estuarine sites, but not for marine sites. 84 diatom species were noted in freshwater, 80 in brackish water and 40 in marine waters. In comparison to diatoms of the impacted sites, those of less impacted freshwater, brackish and marine sites had less lipid bodies (also less biovolume) and a lower percentage of teratological frustules, and showed more mobile forms in the community. Principal component analysis (PCA) also showed clear segregation of impacted from less impacted sites by the extent of the presence of lipid bodies (higher both in number and biovolume) and deformities in diatom frustules. Pearson correlation analysis revealed that lipid body induction and deformities were positively correlated with metals (Cd, Co, Cr, Cu, Fe, Pb and Zn) and nutrients (total phosphorus and total nitrogen), whereas they showed negative correlation with salinity, dissolved oxygen, suspended solutes and pH. Life-forms, lipid bodies and deformities in diatoms may be an effective biomonitoring tool for assessing biological effects of pollutants in non-marine aquatic ecosystems in Korea.

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Ocean acidification dampens physiological stress response to warming and contamination in a commercially-important fish (Argyrosomus regius)

Published 13 November 2017 Science Closed
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Highlights

• Atmospheric and water conditions/contaminants influence animal physiology status.
• Scarcely studied multi-stressor effects were extricated via full-factorial design.
• Warming stimulated mercury accumulation, but was offset by acidification.
• Co-occurring acidification countered oxidative stress elicited by other stressors.
• Enhanced mitigation pathways or chemical dynamics may underpin stressor antagonism.

Abstract

Increases in carbon dioxide (CO2) and other greenhouse gases emissions are changing ocean temperature and carbonate chemistry (warming and acidification, respectively). Moreover, the simultaneous occurrence of highly toxic and persistent contaminants, such as methylmercury, will play a key role in further shaping the ecophysiology of marine organisms. Despite recent studies reporting mostly additive interactions between contaminant and climate change effects, the consequences of multi-stressor exposure are still largely unknown. Here we disentangled how Argyrosomus regius physiology will be affected by future stressors, by analysing organ-dependent mercury (Hg) accumulation (gills, liver and muscle) within isolated/combined warming (ΔT = 4 °C) and acidification (ΔpCO2 = 1100 μatm) scenarios, as well as direct deleterious effects and phenotypic stress response over multi-stressor contexts. After 30 days of exposure, although no mortalities were observed in any treatments, Hg concentration was enhanced under warming conditions, especially in the liver. On the other hand, elevated CO2 decreased Hg accumulation and consistently elicited a dampening effect on warming and contamination-elicited oxidative stress (catalase, superoxide dismutase and glutathione-S-transferase activities) and heat shock responses. Thus, potentially unpinned on CO2-promoted protein removal and ionic equilibrium between hydrogen and reactive oxygen species, we found that co-occurring acidification decreased heavy metal accumulation and contributed to physiological homeostasis. Although this indicates that fish can be physiologically capable of withstanding future ocean conditions, additional experiments are needed to fully understand the biochemical repercussions of interactive stressors (additive, synergistic or antagonistic).

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How fast is the Patagonian shelf-break acidifying?

Published 13 November 2017 Science Closed
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Highlights

• Carbonate system has been driven by dilution/evaporation and sea–air CO2 exchanges.
• The Patagonian shelf is a key area of anthropogenic carbon uptake.
• SACW is acidifying faster in the Patagonian shelf-break than in the South Atlantic.
• AAIW is under risk for aragonite undersaturation near the Patagonian shelf-break.

Abstract

Anthropogenic carbon (Cant) concentration is determined according to the TrOCA method, from carbonate system data and hydrographic parameters collected during two consecutive spring cruises (2007 and 2008) in the Argentinean Patagonian shelf-break zone between 36°S and 50°S. Cant has intruded the water column until intermediate depths, with no Cant below 1000 m, in the deeper waters (i.e., North Atlantic Deep Water and Antarctic Bottom Water) of the Northern sector of the study area (i.e., North of 38°S). The higher Cant concentration is observed in Subantarctic Shelf Water in the Southern region, whereas in the Northern sector both Tropical Water and South Atlantic Central Water are equally affected by Cant intrusion. The Antarctic Intermediate Water represents the depth-limit achieved by Cant penetration, reinforcing the role that this water mass plays as an important vehicle to transport Cant to the oceans interior. The estimated Cant average (± method precision) is 46.6 ± 5.3 μmol kg− 1, considering the full depth of the water column. The ocean acidification state (ΔpH) shows an average (± standard deviation) of − 0.11 ± 0.05, thus, indicating an annual pH reduction of − 0.0010 yr− 1 since the Industrial Revolution (c.a. 1750). The degree of aragonite saturation is lowered towards undersaturation levels of calcite. The Patagonian shelf and shelf-break zones—a strong CO2 sink region in the global ocean—are likely a key area for Cant intrusion in the southwestern South Atlantic Ocean.

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